Q&A  Sprocket

The following is a list of answers for frequently asked questions from our customers. Select questions to view the answers.

Words 

Sprocket in general

Q1 How should I consider sprocket's selection?
Q2 What are the main materials used for sprockets?
Q3 What kind of stainless steel is used for sprockets? Also, is there anything that can be teeth hardened (quenched)?
Q4 Is there a problem when using a combination of stainless steel and steel for sprockets and chains?
Q5 Catalog says "tooth hardening" treatment. What kind of treatment is done on the sprocket?
Q6 What is the name of each part of sprocket?
Q7 What is the "set screw" that comes standard with sprocket?
Q8 What is the shape of sprocket?
Q9 I would like to buy only A-shaped sprockets and weld the hub. Is there a problem?
Q10 After ordering, it was found that the sprocket hub diameter interfered with the layout. Is it okay to machining the hub?
Q11 What does "pilot bore" in the catalog mean?
Does it mean that the shaft bore dimensions can be manufactured within the range of "pilot bore diameter to maximum bore diameter" in the catalog?
Q12 How large is sprocket shaft bore capable of machining at most?
Q13 What happens when using a bore diameter that exceeds the maximum shaft bore diameter? Is there any problem with a small hub thickness?
Q14 What is position relation between sprocket teeth and keyway machining? Can I specify it?
Q15 Is it possible to perform a machining that specifies position relation between sprocket teeth and keyway?
Q16 When using multiple sprockets on the same axis, what is the relative position relation of keyways?
Q17 What is "Fit Bore" product?
Q18 Can sprocket be delivered with bearings incorporated into it?
Q19 What is a Lock Sprocket?
Q20 Is it possible to manufacture a shaft diameter inch size with a Lock Sprocket?
Q21 Can Lock Sprockets be used on shafts with keyway processing?
Q22 Is it OK to mount sprocket with Power Lock on a shaft with keyway processing?
Q23 I'm considering a Lock Sprocket. Can surface treatment be applied to Lock Sprocket?
Q24 Is stainless steel Lock Sprocket available?
Q25 What kind of surface treatment is possible?
Q26 I would like to have plating treatment on sprocket. What points should be caution?
Q27 What kind of sprocket should be chosen for Tsubaki Lube-Free chain "Lambda Chain"?
Q28 Can you manufacture sprockets with shear pins?
Q29 Does sprocket comply with RoHS Directive?
Q30 I will send a picture of sprocket, so could you identify specification?
Q31 There is an actual sprocket. Is it possible to send it and make the same one?
Q32 Please tell me what to be careful about when storing sprockets.
Q33 Is grease effective as a sprocket drive lubricant?
Q34 The chain has worn out and is scheduled to be replaced. The appearance of sprocket is beautiful, so I'm wondering if it can be used as it is.
Q35 I feel wear on sprocket tooth surface is too fast. What may be the cause?
Q36 The sides of sprocket teeth are worn. What could be the cause?
Q37 Sometimes the chain is riding up on the sprocket. What are the causes?
Q38 What is Indicator pins?
Q39 Do you have a sprocket that is easy to inspect?
Q40 Where can I place an order to buy sprockets? How long does it take to deliver?

RS sprocket for drive chain

Q41 What standard is tooth profile of sprocket for drive chain?
Q42 Is it necessary to calculate the strength of teeth when selecting a sprocket?
Q43 When does sprocket for drive chain require "tooth hardening treatment"? What is the reason for "with tooth hardening treatment" and "without tooth hardening treatment" in the catalogue?
Q44 Is life of sprocket same for all manufacturers?
Q45 What is the operating temperature range for sprocket?
Q46 Can standard RS sprockets be used in an environment where Cold Resistant drive chain is used (-10°C or less)?
Q47 Can standard RS sprockets be used for Heavy Duty drive chains?
Q48 Can standard RS sprockets be used for BS standard chains?
Q49 Can standard RS sprockets be used for Pin Gears?
Q50 Can chain tensioners be manufactured?
Q51 What causes sprocket uneven rotation, and how can I stop it?
Q52 The drive chain is vibrating. Can sprockets be the cause? Also, are there any countermeasures?
Q53 How much is the proper speed ratio and chain wrap angle of RS sprocket for drive chain?
Q54 How much is the appropriate shaft center distance of RS-sprockets for drive chain?
Q55 Is layout arrangement of RS sprocket for drive chain determined?
Q56 Are there any layouts / arrangements that require special attention for RS sprockets for drive chains?
Q57 Please tell me installation precision and installation procedure of RS sprocket for drive chain.
Q58 How long does RS sprocket for drive chains last? What are the points of inspection?
Q59 Please tell me symptoms of improper installation of RS sprocket for drive chain and points of inspection.

Sprocket for Small size conveyor chain

Q60 Can RS sprocket for drive chain be used for Double Pitch S roller Chain?
Q61 Can RS sprocket for drive chain be used for small size conveyor chains?
Q62 Why are odd-numbered teeth recommended for Double pitch sprockets dedicated to Double pitch (S rollers)?
Q63 Use hollow pin double pitch. What kind of sprockets can be used?
Q64 Please tell me installation precision and installation procedure of small size conveyor chains.
Q65 How long does Double pitch sprocket for small size conveyor chains last? What are the points of inspection?

Sprocket for large size conveyor chains

Q66 What is minimum number of teeth for large size conveyor chain sprocket?
Q67 Is it possible to manufacture A type sprocket without hubs for large size conveyor chain?
Q68 Does sprocket for large size conveyor chain have hanging holes?
Q69 Please tell me installation precision and installation procedure of large size conveyor chains.
Q70 How long does sprocket for large size conveyor chain last? What are the points of inspection?
Answers
Q1 How should I consider sprocket's selection?
A1

It is necessary to select a sprocket that takes into consideration the model number and specifications of the chain to be used.

The basic procedure is as follows.

  1. ①Chain size / model number selection
  2. ②Confirmation of chain roller type
  3. ③Confirmation of number of teeth (speed ratio / space)
  4. ④Necessity of teeth hardened (quenching)
  5. ⑤Confirmation of required shaft bores based on shaft design
  6. ⑥Hub Type
  7. ⑦Confirmation of hub diameter, maximum bore diameter, hub length, key surface pressure, etc. (strength, space)
  8. ⑧Determine sprocket model number
Standard sprocket is designed in consideration of strength balance and economy, however made-to-order product with dimension required for customers are also available .
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Q2 What are the main materials used for sprockets?
A2

Main materials for our sprocket are shown in the table below.

Products listed in the catalog that do not have the lineup shown in the table below will be manufactured by quotation and made-to-order manufacturing. Contact us for details.

Material Applications / features
Roller steel for general structural use When strength or hardness is not required, it is used for some sprocket without teeth hardened or hub material for weld. Teeth hardening treatment is not possible.
Carbon steel for machine structural use Widely used for standard sprockets. Wear resistance and strength can be increased by quenching the teeth.
Stainless Steel Used for corrosion resistant sprockets. Although it has high corrosion resistance, its metal strength is inferior to that of carbon steel.
Plastic Used for corrosion resistant sprockets. Although it has high corrosion resistance and is lightweight, it has the disadvantage of low in strength and weak in heat.
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Q3 What kind of stainless steel is used for sprockets? Also, is there anything that can be teeth hardened (quenched)?
A3

Materials used for stainless steel sprockets are shown in the table below. Please refer.

Stainless steel sprockets listed in the catalogue are made of austenitic stainless steel (18-8SUS) and can not be hardened teeth (quenching) due to the characteristics of material.

If teeth hardened (quenching) sprocket with stainless steel is required, martensitic stainless steel (SUS420 equivalent) make can be manufactured. (Quotation / Made-to-order product )

Also, sprockets with surface treated to increase hardness which is recommended for high strength stainless steel chain can be proposed. (Quotation / Made-to-order product )

Please contact us if you have any requests.

【Reference 】Examples of stainless steel material
SUS304 Teeth hardened (quenching) is not possible, however it has excellent corrosion resistance and can be used in corrosive atmosphere and high/low-temperature atmosphere.
It is widely used as a general standard stainless steel material for mechanical elements.
SUS316 Teeth hardened (quenching) is not possible, however it has good corrosion/acid resistance and high-temperature strength due to addition of Mo.
Suitable for applications where better corrosion resistance than SUS304 is required. Pitting corrosion resistant material.
SUS420J2 Contains the amount of carbon that enables teeth hardened (quenching). Corrosion resistance is inferior to SUS304.
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Q4 Is there a problem when using a combination of stainless steel and steel for sprockets and chains?
A4

We recommend using the same material. Lineup of stainless steel sprockets is premised on the combination with stainless steel chains.

For example, when stainless steel chains are used in combination with steel sprocket with plating, potentiometric corrosion (electrolytic corrosion) may occur, resulting in premature wear.

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Q5 Catalog says "tooth hardening" treatment. What kind of treatment is done on the sprocket?
A5

"Teeth hardened" treatment described in the catalog is a treatment that hardens the surface by induction hardening.

Teeth hardened is to improve wear resistance and strength. Generally, teeth hardened is performed when rpm is high (number of chain engagements per unit time is large), or when number of teeth is small and wrapping angle is small, or when wear inclusions are present.

Generally, carbon steel for machine structure is used as the material for teeth hardened treatment, however structural alloy steel is also available upon request.

Since it is a type of quenching treatment, it is also called "with teeth hardened treatment = quenching specifications" and "without teeth hardened treatment = unhardened specifications".

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Q6 What is the name of each part of sprocket?
A6

The names of each part of sprocket are as follows.

Name of each part of sprocket
Name of each part of sprocket
  • DH:Hub diameter
  • Dp:Pitch Diameter
  • DO:Outer Diameter
  • DB:Root Diameter
  • DC:Tooth root distance
Name of each part of sprocket
  • L:Total length
  • d:Shaft Bore Diameter
  • t:Tooth Width
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Q7 What is the "set screw" that comes standard with sprocket?
A7

The standard set screw specification for our sprocket is "hexagonal hole set screw (cup point)".

Basically, it is not attached to standard sprockets and special sprockets (quotation / made-to-order) other than Fit bores.

If main unit is stainless steel type or plating type specification, a stainless steel set screw is attached.

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Q8 What is the shape of sprocket?
A8
  1. ①Shapes of RS sprocket for drive chain and Double pitch sprocket for small size conveyor chain are classified into A type (flat plate), B type (single hub), C type (dual hub), and SD type (single dual= two single-strand chains) according to the hub shape. (Fig. 1 )
  2. ②Sprockets for large size conveyor chains are classified into 4 types by welding specifications. (Fig. 2 )

    Welding symbol W is attached to B type (single hub) and C type (double hub). Symbols marked with 1 shows welding by throughing hub to tooth profile part.

Fig. 1  Sprocket shape
A Type B type C type SD Type
A Type B type C type SD Type
Flat plate shape without hub Shape with a hub on one side of flat plate Shape with hubs on both sides of flat plate Shape that can hang two single-strand chains at same time (Different from two strands specifications )
Fig. 2  Large size conveyor sprocket shape
BW Type CW Type BW1 Type CW1 Type
BW Type CW Type BW1 Type CW1 Type
Shape with a hub welded on one side Shape with hubs welded on both sides Shape that throughs a hub and is welded from both sides as a single hub type Shape that throughs a hub and is welded from both sides as a dual hub type
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Q9 I would like to buy only A-shaped sprockets and weld the hub. Is there a problem?
A9

Hub welding to A type sprockets may not be able to maintain quality due to the heat of weld.

Avoid welding by yourself and contact us.

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Q10 After ordering, it was found that the sprocket hub diameter interfered with the layout. Is it okay to machining the hub?
A10

We do not recommend it because there is a risk of accidents such as damage due to additional machining by the customer.

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Q11 What does "pilot bore" in the catalog mean?
Does it mean that the shaft bore dimensions can be manufactured within the range of "pilot bore diameter to maximum bore diameter" in the catalog?
A11

Pilot bore is a hole required in the process of manufacturing sprocket, and is basically not made with a tolerance suitable for shaft assembly.

Shaft bore dimensions can be manufactured at appropriate tolerance within the range of pilot bore diameter +1mm to maximum bore diameter.

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Q12 How large is sprocket shaft bore capable of machining at most?
A12

With bore processing of standard pilot bore type, it is less than or equal to "maximum bore diameter" in the dimension table listed for each model number of teeth in the catalog.

For A type sprocket with no indication of maximum bore diameter, please contact us as we will consider manufacturing.

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Q13 What happens when using a bore diameter that exceeds the maximum shaft bore diameter? Is there any problem with a small hub thickness?
A13

Hub thickness affects sprocket strength. Insufficient hub thickness may result in cracks or damage.

Design the hub diameter and shaft bore diameter in consideration of sufficient strength based on the chain usage conditions so that the sprocket will not be damaged.

We also offer TOUGH TOOTH sprocket recommended for Heavy Duty chain with increased hub strength without changing the size.

Consider it when the hub strength is insufficient or the hub size cannot be changed due to space limitations.

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Q14 What is position relation between sprocket teeth and keyway machining? Can I specify it?
A14
Unless otherwise specified, keyway is machined in the following positions.
  • For Drive chain
  • For Double pitch
  • For Large size conveyor chains
  • Keyway processing near the center of tooth root
  • Keyway processing near the center of tooth root
  • Keyway processing near the center of tooth tip

※Instructions are required if accuracy is required for keyway machining position, or if it is aligned with a specific tooth position.

When requesting, instructions such as "phase alignment" and "parallel use" are required.

※『Phase alignment 』 : 「Q15.Is it possible to perform a machining that specifies position relation between sprocket teeth and keyway? 」Reference

※『Parallel use 』 : 「Q16.When using multiple sprockets on the same axis, what is the relative position relation of keyways? 」Reference

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Q15 Is it possible to perform a machining that specifies position relation between sprocket teeth and keyway?
A15

Available as made-to-order.

Please specify whether to align the keyway processing position at the center of "tooth tip" or "tooth root" as "phase alignment".

Normally, Tsubaki aligns a phase at the center of tooth root for drive chain and Double pitch, and at the center of tooth tip for large size conveyor chains.

Alignment accuracy is only visual. Please contact us If there are specific standards.

※If multiple sprockets are used on the same axis accurately, "parallel use" instruction is required.

※『Parallel use 』 : 「Q16.When using multiple sprockets on the same axis, what is the relative position relation of keyways? 」Reference

Tooth tip alignment

Tooth tip alignment

Tooth root alignment

Tooth root alignment
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Q16 When using multiple sprockets on the same axis, what is the relative position relation of keyways?
A16

Basically it is not considered. If the relative keyway positional relation to be considered, please specify "parallel use".

In such a case, please check the following two points and specify. Alignment accuracy is only visual.

  1. ①Number of sprockets used on the same axis

    In "Parallel use", when two or more sprockets are used coaxially, keyway position is aligned and processed in the specified mounting direction.
    Combined sprockets will be marked with a match mark, so the customer must manage them.

  2. ②Hub direction indication (combination direction)

    For example, in case of 2 sprockets, specify hub direction of installation, such as "hub inside-inside", "hub outside-outside", or "hub in same direction".
    (If more than 2 sprockets, please specify in drawing. )

※It is different from "phase alignment" that matches position relation between keyway and teeth. When phase alignment is required, specify it separately.

※『Phase alignment 』 : 「Q15.Is it possible to perform a machining that specifies position relation between sprocket teeth and keyway? 」Reference

2 pcs. 1 set (Hub in same direction )

Hub in same direction

2 pcs. 1 set (Hub outside-outside )

Hub outside-outside

2 pcs. 1 set (Hub inside-inside )

Hub inside-inside

4 pcs 1 set (3 pcs. in the same direction )

3 pcs. in the same direction
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Q17 What is "Fit Bore" product?
A17

"Fit bore" is a "sprocket with a finished shaft bore".

In the sense of "Fit = fit, bore = make a hole", please select specifications from service range listed in the catalog. We will perform shaft bore processing of "shaft bore processing, keyway machining, tap hole machining" and deliver it to the customer in a state where it can be used immediately.

There are "stock products with a finished shaft bore specified by us" and "made-to-order products with shaft hole processing selected by the customer".

Shaft bore machining specifications can be selected from more than 100 million options from the TT-net drawing library.

In addition to sprockets, Fit Bore is also available for belt sprockets.
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Q18 Can sprocket be delivered with bearings incorporated into it?
A18
We will consider whether it can be manufactured or not. However, depending on the specifications and conditions, we may refuse it. Contact us for details.
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Q19 What is a Lock Sprocket?
A19
Lock Sprocket is a friction-locking sprocket that locks shaft and sprocket without using a key, and has the following features.
  1. ①No play after locking (locking without backlash)
  2. ②Easy phase matching
  3. ③Easy mount and remove
  4. ④No movement in an axial direction is making retainers unnecessary.

Be sure to use a torque wrench when tightening bolts.

Sprocket will slip and rotate if it is not properly installed with the correct torque.

Use a shaft diameter tolerance of h8 and a surface roughness of Ra3.2 as your standards.

For other precautions, check the catalog and instruction manual, and use the product correctly.

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Q20 Is it possible to manufacture a shaft diameter inch size with a Lock Sprocket?
A20

Lock Sprocket does not have an inch series.

Tsubaki Power Lock has an inch series, so please use Power Lock.

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Q21 Can Lock Sprockets be used on shafts with keyway processing?
A21

Any shaft with a general keyway shape can be used.

However, noted that an allowable transmission torque will be reduced by approx. 10%.

This is because the contact area between a lock sleeve and a shaft is reduced by keyways.

Also, even when using Tsubaki Power Lock, an allowable transmission torque will be reduced as well.
(However, EL series cannot be used for shafts with keyway processing. )

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Q22 Is it OK to mount sprocket with Power Lock on a shaft with keyway processing?
A22

Any shaft with a general keyway shape can be used except EL series.

However, noted that an allowable transmission torque will be reduced by approx. 10%.

This is because the contact area between Power Lock and a shaft is reduced by keyways.

Also, even when using a lock sprocket, an allowable transmission torque will be reduced as well.

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Q23 I'm considering a Lock Sprocket. Can surface treatment be applied to Lock Sprocket?
A23
Depends on the content of surface treatment, quotation will be available as made-to-order products.
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Q24 Is stainless steel Lock Sprocket available?
A24

Lock sprockets made by stainless steel are not available.

When stainless steel type with friction locking are requested, the combination of Tsubaki Power Lock (stainless steel specification) and Tsubaki RS sprocket (stainless steel specification) is recommended.

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Q25 What kind of surface treatment is possible?
A25

Surface treatment is performed to improve corrosion and wear resistance as well as appearance qualities by applying heat treatment and chemical reactions to metallic surfaces.

Typical surface treatments we are implementing are following three. (※Please contact us as there are restrictions depending on the size. )

  1. ①Electroless nickel phosphorus plating
  2. ②Electrogalvanizing Trivalent chromate treatment
  3. ③Black oxide (Iron oxide film )

In addition, "TOUGH TOOTH" sprocket recommended for Heavy Duty chain has a surface hardness of HV800 or higher.
Surface treatments other than the above are also possible, so please contact us.

Basically, plating is not processed on shaft bore inner diameter.
Black oxide is processed on shaft bore inner diameter too.

【Reference 】Types and features of surface treatment
Electroless nickel phosphorus plating Small unevenness in film thickness even in complex shapes (Uniform film thickness )
High corrosion resistance and wear resistance, hard to peel off, resistant to bending and vibration
Electrogalvanization
Trivalent chromate treatment
Film thickness tends to be uneven depending on the shape. (Non-uniform film thickness )
Good appearance finish, high corrosion resistance and wear resistance
Black oxide (Iron oxide film ) Treatment that is inexpensive, has low corrosion resistance, and achieves rust prevention
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Q26 I would like to have plating treatment on sprocket. What points should be caution?
A26
We do not recommend that the customer surface-treat the product after purchase, as it may cause a decrease in strength.
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Q27 What kind of sprocket should be chosen for Tsubaki Lube-Free chain "Lambda Chain"?
A27
  1. ①RS sprockets for drive chains are applicable for single strand Lambda drive chains.

    Be careful when using two strands.

    Standard-type RS sprocket in the catalogue cannot be used with RS-Lambda Chain except for some models. Our standard double strand RS sprocket can be used with new RS Double Strand Compatible Lambda Chain. Select sprocket after checking Lambda Chain series/model.

  2. ②For single strand Lambda double pitch of small size conveyor chains, dedicated double pitch sprockets are available.

When selecting two or more strands, pay attention to the transverse pitch of chain.

Double Strand RS Roller Chain
RS80-2-RP
RS Double Strand Compatible Lambda Chain
RS80-LMD-S-2
RS Double Strand Conventional Lambda Chain
RS80-LMD-2
Double Strand RS Roller Chain RS Double Strand Compatible Lambda Chain RS Double Strand Conventional Lambda Chain
Can use standard RS sprockets Can use standard RS sprockets Uses special sprockets
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Q28 Can you manufacture sprockets with shear pins?
A28

We can not decide specification for dimension and tensile strength. If you do not provide detailed conditions, we apologize for the inconvenience, but we will refuse it due to quality assurance issues.

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Q29 Does sprocket comply with RoHS Directive?
A29

All of our sprockets comply with RoHS Directive. If you need a certificate, please request issuance via dealer/retailer where you purchased the product.

※RoHS Directive is subject to revision.
Please confirm the "RoHS Directive" as of the current month for hazardous materials and content standards that are prohibited for use.

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Q30 I will send a picture of sprocket, so could you identify specification?
A30

We cannot identify specification in the picture because its hard to identify it only by the appearance.

We apologize for the inconvenience, but we have declined your request.

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Q31 There is an actual sprocket. Is it possible to send it and make the same one?
A31

It is possible to help you specify the specifications by requesting a quote.

However, even after checking the actual product, it may not be possible to identify specification.

Also, please note that we are not responsible for specification even if we reply to quotation.

If it is a used product, it is difficult to identify the specifications with detailed dimensions because the original shape is not retained. If it is severely damaged, even rough specification identification may not be possible.

It may not be possible to identify the material.

We ask the customer to make the final decision for the specifications with reference to our views.

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Q32 Please tell me what to be careful about when storing sprockets.
A32

Do not store the product in an environment where it is exposed to dust, direct rain, high temperature, freezing, or corrosive atmosphere.

Please apply oil with a brush to prevent rusting.

Particularly, please pay attention to the no painted products, or no painted part of the painted products, such as shaft bores.

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Q33 Is grease effective as a sprocket drive lubricant?
A33

Greasing may be effective at the engagement part of sprocket and chain at low speeds and high loads.

However, in places with a lot of dust, wear may be accelerated by absorbing and sticking dust.

In addition, lubrication between pin and bush is crucial to reduce chain wear elongation.

Grease may be applied to prevent the oil supplied to chain from flowing out due to external factors (wind and rain, etc.). Conversely, if the grease interferes with the oil supply between pin and bush of chain, lube effect may be decreased. So please consider it carefully.

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Q34 The chain has worn out and is scheduled to be replaced. The appearance of sprocket is beautiful, so I'm wondering if it can be used as it is.
A34

Wear of sprocket cannot be judged from the beautiful appearance.

Since sprocket is worn as well as chain, please check and judge if there is no abnormality such as wear by the inspection method described in the catalog or instruction manual.

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Q35 I feel wear on sprocket tooth surface is too fast. What may be the cause?
A35

The table below summarizes possible causes and remedies for wear on a sprocket tooth (root, tooth pressing surface).

Sympton Possible causes Solution
Wear on a sprocket tooth root and tooth pressing surface Chain wear Replace the chain and sprocket at the same time.
Insufficient number of engaging teeth Increase the number of sprocket teeth.
BF chain (no rollers) used Change to RF chain (with rollers).
Insufficient hardness of tooth against wear inclusion or excessive load Use teeth hardened treatment or replaceable teeth.
Incompatibility between sprocket and chain Replace the chain or sprocket to the correct size.
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Q36 The sides of sprocket teeth are worn. What could be the cause?
A36

The table below summarizes the possible causes and remedies.

Wear on the inside of chain link plate may be also considered. Check a chain as well.

Sympton Possible causes Solution

The inside of chain plates or the sides of sprocket teeth are worn.

The inside of chain plates or the sides of sprocket teeth are worn.
Poor centering of sprocket Remove the chain and correct a centering of drive and driven sprockets.
Chain is being pushed laterally. Remove the cause of pressed, use guide rollers.
Inclined sprocket caused by poor shaft bore processing accuracy After checking the defective part, correct it and replace it with a new sprocket.

Photo 1) Example of wear due to improper installation


[Click to enlarge ]

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Q37 Sometimes the chain is riding up on the sprocket. What are the causes?
A37

The table below summarizes the possible causes and remedies.

If left unattended, it may lead to sudden breakage of the plate (Fig. 2), so be sure to inspect and take measures.

Sympton Possible causes Solution
Chain is riding up on the sprocket Chain and sprocket do not match Replace the chain or sprocket to the correct size.
Insufficient wrapping angle Wrapping angle should be 3 or more teeth. Install a tensioner.
Excessive load Reduce the load. (Attach a shock absorber, etc. )
Insufficient back tension Adjust catenary / take-up, install tensioners.
Chain is worn and elongated Replace with a new chain.
The distance of chains and sprockets are not suitable. S≠S'(See Fig. 1 ) Inspect and adjust.

S≠S' means unsuitable of center distance


[Click to enlarge ]

Fig. 1 Center distance


[Click to enlarge ]

Fig. 2 Sudden link plate fracture

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Q38 What is Indicator pins?
A38

Indicators pin is a replacement notice mark.

The sprocket has a wear limit mark, and when the tooth wear reaches the mark, the service life is judged to be the limit of use.

There are following advantages.

  1. ①Reduction of inspection labor (quicker inspection)
  2. ②Uniform judgment
  3. ③Improved safety

Replacement time can be confirmed at a glance, and inspection time and labor can be greatly reduced.

Anyone without skill can make an accurate life judgment.

Change from hand inspection to visual inspection. Minimal contacts increase safety of inspection.

Large Size Conveyor Chain Sprockets Smart Replaceable Series and RS large size sprocket for drive chain have this function, however its can be equipped on other sprockets upon request.

Previous inspections

Previous inspections

Measures the gap between the worn tooth and the tooth profile gauge

Inspection using Indicator Pins

Sprocket replacement timing can be judged at a glance.

Inspection using Indicator Pins
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Q39 Do you have a sprocket that is easy to inspect?
A39

Sprocket equipped with Indicator Pins (replacement notice mark) to confirm replacement timing at a glance is available.

Equipped as standard on Smart Replaceable Series of sprockets (Split Type, Ring Replaceable Tooth Type, Block Replaceable Tooth Type) that are frequently replaced.

Standard sprocket with Indicator Pins is identified as "Tsubaki Blue Collar Paint".

In addition to large size sprockets for drive chain, other conveyor chain sprockets are also available upon request.

※『Indicator pins 』 : 「Q38.What is Indicator pins? 」Reference

Inspection using Indicator Pins

Sprocket replacement timing can be judged at a glance.

Inspection using Indicator Pins

Equipped in 2 places every 180 °

Inspection using Indicator Pins
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Q40 Where can I place an order to buy sprockets? How long does it take to deliver?
A40

We do not sell directly, so please contact your retailer or retailer.

Please contact them for for delivery too.

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Q41 What standard is tooth profile of sprocket for drive chain?
A41

JIS standard S-tooth profile is used for Tsubaki RS sprocket's tooth profile. (JIS standard U-tooth profile is also used for some sprockets. )

Other special tooth profile are available, such as for BS tooth profile, heavy duty chain or pin gearing.


[Click to enlarge ]


[Click to enlarge ]

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Q42 Is it necessary to calculate the strength of teeth when selecting a sprocket?
A42

Generally, if working load is less than maximum allowable load of the chain, sprocket tooth will not bend or break, so select it listed in the catalog.

However, dedicated sprocket also might be consider for heavy duty type chains.

Load distribution of each tooth in wrapping transmission is complicated, so it is calculated with one tooth. However, actual chain load is shared by several teeth due to wrapping transmission, its not shared with one tooth.

Load distribution of each tooth

Load distribution of each tooth
※『Selection of sprocket 』 : 「Q1.How should I consider sprocket's selection? 」Reference Back to questions
Q43 When does sprocket for drive chain require "tooth hardening treatment"? What is the reason for "with tooth hardening treatment" and "without tooth hardening treatment" in the catalogue?
A43
For drive chains, sprocket that meets the following usage conditions is teeth hardened.
  1. ①When the number of teeth is 24 or less and the rpm is 1/8 or more of the maximum rpm listed in the kW ratings table of catalog.
  2. ②Small sprockets when speed ratio is greater than 4:1.
  3. ③For low speed and heavy load. (When using Tsubaki Heavy Duty Chain)
  4. ④When used in an atmosphere that wears teeth.
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Q44 Is life of sprocket same for all manufacturers?
A44

Depends on manufacturer. Life is reached mainly due to the wear of tooth part. So, we have implemented wear resistance focused "teeth hardening treatment."

This is a common Induction hardening, however even when compared to other companies, wear of the teeth is different in long-term use due to deep and uniform heat treatment.

"Hardening" is one of Tsubaki's strengths. Consider Tsubaki sprocket which has an advantage in wear resistance.

Cross-section comparison of teeth hardening treatment (Discolored part of teeth is hardened layer )

  • Tsubaki
  • Company A
  • Company B
  • Company C
  • Company D

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Q45 What is the operating temperature range for sprocket?
A45

Appropriate operating temperature range for RS sprocket is -10 ° C to 150 ° C, and for RS sprocket stainless steel series is -20 ° C to 400 ° C.

Not only strength changes due to temperature but also constraints due to chain lubricant must be considered.
Please check drive chain product list in the drive chain & sprocket catalog.

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Q46 Can standard RS sprockets be used in an environment where Cold Resistant drive chain is used (-10°C or less)?
A46

Standard sprockets listed in the catalog are not recommended to use at low temperatures of -10 ° C or lower, because they are made of carbon steel or rolled steel for machine structure and will reduce strength.

In some cases, custom sprockets made of special materials can be offered as a countermeasure.

Please contact us for products in an operating temperature range not listed in the catalog.

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Q47 Can standard RS sprockets be used for Heavy Duty drive chains?
A47

Standard sprocket with tooth hardening treatment can be used, however there are many cases where key surface pressure is insufficient.

"TOUGH TOOTH" is available as a recommended sprocket for Heavy Duty Drive Chains, so please consider it.

The stronger the chain, the more important it is to check the key surface pressure, etc.

Double keys or lengthened hubs can decrease surface pressure. However, from the viewpoint of space saving and pricing, we recommend "TOUGH TOOTH" with higher hub strength.

Also, when using H-class chains such as HT Heavy Duty chains and Super-H chains in multiple strands, standard RS sprockets cannot be used because the transverse pitch of the teeth is different.

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Q48 Can standard RS sprockets be used for BS standard chains?
A48

JIS standard RS sprocket cannot be used because the basic 3 dimensions (pitch, roller diameter, inner width of inner link) are different.

BS/DIN standard dedicated sprocket for BS standard chains are available.

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Q49 Can standard RS sprockets be used for Pin Gears?
A49

Dedicated sprocket with a special tooth profile is required.

It is different from JIS standard RS sprocket, and has a tooth profile suitable for wrapping transmission.

For linear and rotary motions of objects, roller chain or gear is generally used from a drive source (motor, etc.) via a reducer.

Wrapping transmission using roller chains require more space, and gears require precision machining, and both are costly.

Pin gear drive is optimal in such cases.

For pin gear drive, as shown in Fig. 1, attachment chain for chain type pin gear instead of a wheel is wrapped around the outer circumference of a drum or table. And a special tooth profile sprocket (pin gear sprocket) instead of the pinion gear is used.

Also as shown in Fig. 2, for linear motion, instead of the rack, attachment chain for chain type pin gear is installed in a straight line.

"Pin Gear Drive Unit" that includes a pin gear and a wheel or rack is also on sale.

Pin gear attachment chain

[Fig. 1]

Pin gear sprocket

[Fig. 2]

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Q50 Can chain tensioners be manufactured?
A50

We have standardized tensioner and idlers. Please consider from our specifications.

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Q51 What causes sprocket uneven rotation, and how can I stop it?
A51

One of causes of uneven rotation is speed variation of chain. Chain engages polygonally with sprocket.

Therefore, as shown in the figure below, the height of engagement (radius from the center of sprocket) differs between when engaging at the tangential position of the circle and when engaging at the chord position.

As a result, even if the drive sprocket is rotating at a constant speed, the traveling speed of chain will vary by the radius ratio. Speed variation rate is calculated by the following formula.

Speed variation rate =(V2-V1)/V2=1-cos(180°/Z) (Z is the number of teeth )

As the number of teeth increases, rotation becomes smoother and enables smooth transmission, so it is generally recommended to have 15 or more teeth.

V2 chain speed maximum

V1 chain speed minimum

Uneven rotation

Due to the speed fluctuation of chain and the nature of sprocket, the driven sprocket will have uneven rotation.

In addition, the effects of sprocket eccentric mounting errors and chain and sprocket manufacturing errors are also added.

Increasing the number of teeth on drive sprocket (larger diameter) will result in smoother transmission and less uneven rotation.

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Q52 The drive chain is vibrating. Can sprockets be the cause? Also, are there any countermeasures?
A52

Sprockets can also be the cause. The causes and countermeasures are as follows.

Polygonal motion

When chordal action (vertical motion due to sprocket and chain polygonal motion) is involved, it is possible to suppress the polygonal motion by selecting the largest number of teeth possible. Generally, 15 or more teeth are recommended.

※『Cordal action 』 : 「Q51.What causes sprocket uneven rotation, and how can I stop it? 」Reference
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Q53 How much is the proper speed ratio and chain wrap angle of RS sprocket for drive chain?
A53

Speed ratio of roller chain transmission is usually up to 7: 1. Up to about 10: 1 is possible only at very low speeds.
Wrapping angle between small sprocket and chain must be 120 ° or more. However, 90 ° or more is required for lifting.

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Q54 How much is the appropriate shaft center distance of RS-sprockets for drive chain?
A54

The minimum distance is fine as long as the teeth of the two sprockets are not in contact. The optimum center distance between the shafts is about 30 to 50 times the pitch of roller chain used. However, if the load is flactuating, a distance of 20 times or less is suitable.

About 30 to 50 times the pitch of roller chain
(20 times or less if the load is flactuating. )

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Q55 Is layout arrangement of RS sprocket for drive chain determined?
A55

General layout of roller chain transmission is as follows.

  • Ideally, the line connecting the sprocket centers should be close to horizontal.
  • In a layout that is close to vertical, the roller chain may stretch and fall off the sprocket even if it stretches a little. Thus, an idler or tensioner should be used.
  • If possible keep the angle of inclination within 60°.


[Click to enlarge ]

Fig. 1) General layout

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Q56 Are there any layouts / arrangements that require special attention for RS sprockets for drive chains?
A56

Caution is required for layout in the following cases. Please use an idler/tensioner.

  • When the slack is on the upper side

    When the center distance between the shafts is short, move the shafts to adjust distance and slightly increase the tension. (Fig. 1 )

    When the center distance is long, insert an intermediate idler under the slack part to support the roller chain. (Fig. 2 )

  • When the centerline is vertical

    Install a tensioner that can automatically adjust the amount of excess slack. (Fig. 3 )

    This is particularly necessary when the drive shaft is on the bottom.

    When pushing a tensioner outward, pay attention to the wrapping angle (120 ° or more) of sprocket and chain on drive side.

Layout when the center distance is short

Fig. 1) Layout when the center distance is short

Layout when the center distance is short

Fig. 2) Layout when the center distance is long

Layout when the center distance is short

Fig. 3) Vertical transmission

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Q57 Please tell me installation precision and installation procedure of RS sprocket for drive chain.
A57

Install correctly as described below, paying attention to the horizontal precision and parallelism of the shafts.

  1. ①Horizontal precision :Adjust within ± 1/300 with a level gauge. (Fig. 1 )
  2. ②Parallelism :Adjust within ± 1/300 = (AB) / L with a scale. (Fig. 2 )
  3. ③Using a straightedge or scale, adjust the two sprockets so that they are parallel. (Fig. 3 )
  4. ④Secure each sprocket to the shaft with keys or friction type locking device. (Be careful not to forget to assemble the collar and set screw)
Horizontal precision of the shafts

Fig. 1) Horizontal precision of the shafts

Parallelism of the shafts

Fig. 2) Parallelism of the shafts

Sprocket alignment

Fig. 3) Sprocket alignment

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Q58 How long does RS sprocket for drive chains last? What are the points of inspection?
A58

As a guideline for life and replacement, check wear of the teeth. The strength of sprocket is reduced by wear of the teeth, which adversely affects chain transmission.

Replace with a new sprocket before it becomes defective through regular inspections. The check points are as follows.

  1. ①Check wear of the tooth thickness

    Refer to the "Usage limit of tooth thickness" below, and wear of the tooth part is the value in the table. Place a caliper at right angles to the tooth root.

    Sprocket teeth are larger near a pitch circle diameter (PCD), as you can see with your finger-traces. Consider this location as the B dimension measuring location.

  2. ②Check wear of tooth surface.

    For a sprocket with teeth hardened (quenched), guide line of replacement is when the hardned layer has been removed. Teeth hardened layer is inspected visually.

  3. ③Check wear on side of teeth

    Poor installation (incorrect shaft alignment) is suspected as causes. Correct the installation of sprockets and shafts according to the instruction manual.

    If the sides of teeth are severely shaved, replace sprocket as soon as possible. There is a risk of damaging the chain.

    (In this case, wear on the inside of chain link plate may be considered, so check the chain as well. )

To reduce inspection labors and improve safety, sprockets with Indicator Pins to confirm replacement timing at a glance is available.

Usage limit of tooth thickness / Dimension B table

RS roller chain
Size
B dimensions
Normal Pin gear
RS11-SS-1 0.6 -
RS15-1 1.1 -
RS25-1 1.5 -
RS35-1 2.5 -
RS41-1 2.6 -
RS40-1 2.5 3.1
RS50-1 2.9 3.6
RS60-1 3.7 4.6
RS80-1 5.0 6.3
RS100-1 6.9 8.6
RS120-1 8.7 10.9
RS140-1 10.6 13.3
RS160-1 12.4 15.5
RS180-1 11.3 14.1
RS200-1 12.6 15.8
RS240-1 15.1 18.9
RF320-T-1 19.9 24.9
RF400-T-1 24.9 31.2
BS Roller Chain
Size
B dimensions
Normal
RF06B-1 1.6
RS08B-1 2.1
RS10B-1 2.9
RS12B-1 3.6
RS16B-1 5.0
RS20B-1 6.8
RS24B-1 7.2
RS28B-1 8.9
RS32B-1 11.9
RS40B-1 12.7


[Click to enlarge ]

Forward and reverse

One direction

Usage limit of tooth thickness / Dimension B (Fig. )

The sides of teeth are shaved.

Fig. 2) The sides of teeth are shaved.

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Q59 Please tell me symptoms of improper installation of RS sprocket for drive chain and points of inspection.
A59

【Symptoms 】

If any of the following symptoms occur, check sprocket and its installation again.

  • Roller chain is riding up on a sprocket
  • There is an unusual noises
  • Heavy vibration
  • Chain winds onto a sprocket

【Inspection points 】

Cause can be determined from the inspection of sprocket engagement.

If it is not normal, check and correct it again.

  1. ①Judgment based on a condition of contact between roller and tooth surface
    • Normal: It is normal if the engagement is uniform as shown in position A in Fig. 1).
    • Improper installation: It is abnormal if the engagement is biased as shown in position B in Fig. 1) or if the sides of teeth are shaved as shown in Fig. 2).
  2. ②Judgment based on a position of contact between roller and tooth surface
    • Normal: The normal point of impact is slightly up from the tooth root (valley).
      The strongest impact is at position A in Fig. 1). However, when initial tension is applied to the chain and tension remains on the slack side, the roller will slightly touch the tooth root. (※It is normal for idlers and tensioners to contact the center of teeth root. )
    • Abnormal: Position other than A in Fig. 1)

The cause of abnormality is that the sprocket is not installed properly or the roller chain is twisted.

If any abnormality is found, the sprocket as it is will adversely affect roller chain transmission, so replace it with new sprockets.

Contact area of the sprocket teeth

Fig. 1) Contact area of the sprocket teeth

The sides of teeth are shaved.

Fig. 2) The sides of teeth are shaved.


[Click to enlarge ]

Fig. 3) Example of wear due to improper installation

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Q60 Can RS sprocket for drive chain be used for Double Pitch S roller Chain?
A60

RS sprockets with the number of teeth is 29 or less teeth cannot be used with Double Pitch S-roller, and Double Pitch Sprocket is required.

If the number of teeth is 30 or more, a standard RS sprocket for drive chains can be used. (※This is because the pitch circle diameter = PCD is an approximate value when the number of teeth is 30 or more. )

In addition, standard RS sprocket cannot be used in multiple strands of RF2060 or larger because transverse pitch is different. Since these chains are considered special, special sprockets can also be manufactured based on the chain drawings.

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Q61 Can RS sprocket for drive chain be used for small size conveyor chains?
A61

RS sprocket for drive chain can be used for RS attachment chain for small size conveyors.

However, noted if sprocket diameter is small or attachment is special, it is necessary to consider interference with the sprocket.

Use double pitch sprocket for double pitch chain.

However, RS sprocket can be used if the number of teeth is 30 or more with Double Pitch S-roller.

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Q62 Why are odd-numbered teeth recommended for Double pitch sprockets dedicated to Double pitch (S rollers)?
A62

It is recommended because the wear life will be longer if actual number of teeth is odd with S roller.

For Double Pitch sprocket, the number of teeth that actually engage is called the effective number of teeth, and the number of apparent teeth is called the actual number of teeth.

If the base chain rollers are S rollers, the chain engages with every other tooth. (Fig. 1 )

When actual number of teeth is odd for S roller (Fig. 3), the rollers in the first rotation engage every second tooth in the order of numbers 1 to 10. However, from the second rotation, it starts engaging with tooth number 11 that is different from the previous rotation. The rollers engage with different teeth for each rotation of the sprocket, resulting in less wear and longer life.

For R roller, it engages with each tooth. (Fig. 2 )
For R rollers, the teeth that engage at each rotation are always the same, so there is no difference in wear or life by the difference in actual number of teeth.



[Click to enlarge ]

Fig. 1 . RF chain (for S rollers )
(multi-engagement sprocket )


[Click to enlarge ]

Fig. 3 . Engagement of RF chain S roller type and odd number teeth sprocket.


[Click to enlarge ]

Fig. 2 . RF chain (for R rollers )

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Q63 Use hollow pin double pitch. What kind of sprockets can be used?
A63

RS sprocket for drive chain can be used when the number of teeth is 30 or more as with standard RF Double pitch.

Double Pitch sprocket is required as they cannot be used with 29 teeth or less.
(※This is because the pitch circle diameter = PCD is an approximate value when the number of teeth is 30 or more. )

Standard RS sprocket cannot be used in multiple strands of RF2060 or larger because transverse pitch is different. Since these chains are considered special, special sprockets can also be manufactured based on the chain drawings.

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Q64 Please tell me installation precision and installation procedure of small size conveyor chains.
A64

Install correctly as described below, paying attention to the horizontal precision and parallelism of the shafts.

  1. ①Horizontal precision: Adjust within ± 1/300 with a level level. (Fig. 1 )
  2. ②Parallelism: Adjust within ± 1/100 = (AB) / L with a scale. (Fig. 2 )
  3. ③Using a straightedge or scale, adjust the two sprockets so that they are parallel. (Fig. 3 )
  4. ④Secure each sprocket to the shaft with keys or friction type locking device.

    When using sprockets in parallel, make sure that the teeth of sprockets on the same axis are in the same phase.
    (If phase alignment is required with high accuracy, specify parallel use. )。 If there are rails, adjust the alignment as well.

Fig. 1  Measurement of horizontal precision


[Click to enlarge ]

Fig. 2  Measurement of parallelism of the shafts


[Click to enlarge ]

Fig. 3  Measurement of sprocket alignment


[Click to enlarge ]

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Q65 How long does Double pitch sprocket for small size conveyor chains last? What are the points of inspection?
A65
  1. ①As a guideline for sprocket life and replacement, check wear of the teeth.
  2. ②If the sprocket wears as shown in (Fig. 2), the chain will get caught in the C part of tooth, the tooth separation will be poor, and the chain will be damaged.

    Allowable wear varies slightly depending on the type of conveyor and the size of the chain. Replace the sprocket when the wear is approximately 0.3-1.0 mm.

  3. ③If the sprocket is worn in the tooth width direction as shown in (Fig. 3), it is presumed that the cause is improper installation (inaccurate centering of the shaft).

    Be sure to improve by re-inspecting the centering of the sprocket, shaft, and rail and correcting the installation according to the instruction manual and inspection procedure.

  4. ④Wear on the inside of chain link plate may be considered, so check the chain as well.

    (If the sides of the teeth are heavily worn, replace them. )

  5. ⑤To reduce inspection labors and improve safety, sprockets with Indicator Pins to confirm replacement timing at a glance is available.
Fig. 2

Fig. 2  Sprocket tooth wear

Fig. 3

Fig. 3  Sprocket tooth wear (side )

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Q66 What is minimum number of teeth for large size conveyor chain sprocket?
A66

The number of teeth must be 6 or more in consideration of chain engagement.

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Q67 Is it possible to manufacture A type sprocket without hubs for large size conveyor chain?
A67

It is possible as a made-to-order product, so please give us an inquiry.

If it is supposed to be welded, it may lead to defects depending on the material.

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Q68 Does sprocket for large size conveyor chain have hanging holes?
A68

Sprockets with hanging holes can be checked in the catalog.

For those with hanging holes, in addition to the sprocket dimension table, the hanging hole dimensions and the number of hanging holes are specified in the hanging hole dimension list.

Hanging holes are not available on sprockets with numbers of teeth or chain numbers not listed.

If you wish, we will make an estimate after considering manufacturing, so please specify the specific position, size, and quantity.

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Q69 Please tell me installation precision and installation procedure of large size conveyor chains.
A69

Install correctly as described below, paying attention to the horizontal precision and parallelism of the shafts.

  1. ①Horizontal precision: Adjust within ± 1/300 with a level level. (Fig. 1 )
  2. ②Parallelism: Adjust within ± 1 mm with a scale. (Fig. 2 )
  3. ③Align the pair of sprockets according to the center distance. (Fig. 3 )
  4. ④Secure it to the shaft with keys or friction type locking device.

    Also, when using multiple sprockets in parallel, make sure that the teeth aligned on the axis are in the same phase. If phase alignment is required with high accuracy, specify parallel use. (Fig. 4 )

※Installation accuracy is a general value viewed from the conveyor chain itself. Follow accuracy constraints of the conveyor main unit, if any.

Fig. 1  Measurement of horizontal precision


[Click to enlarge ]

Fig. 2  Measurement of parallelism of the shafts


[Click to enlarge ]

Fig. 3  Measurement of sprocket alignment


[Click to enlarge ]

Fig. 4  Keyway alignment mark example


[Click to enlarge ]

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Q70 How long does sprocket for large size conveyor chain last? What are the points of inspection?
A70

Use Fig. 1 as a guide for wear limit of sprocket tooth surface. The life is 3 to 6 mm depending on the size.

If the chain engages with the worn sprocket teeth, it will have adverse effects such as faster chain wear. If the teeth are worn, replace them.
(※Avoid flipping the sprocket over and continuing to use sprockets with worn teeth bottoms. )

If the sides of sprocket teeth are worn, refer to Table 1 and take corrective action.
(Use Fig. 2 as a guide for wear limit of tooth side surface. )

To reduce inspection labors and improve safety, sprockets with Indicator Pins to confirm replacement timing at a glance is available.

Sympton Possible causes Solution

The inside of chain plates or the sides of sprocket teeth are worn.

The inside of chain plates or the sides of sprocket teeth are worn.
Poor centering of sprocket Remove the chain and correct a centering of drive and driven sprockets.
Chain is being pushed laterally. Remove the cause of pressed, use guide rollers.
Inclined sprocket caused by poor shaft bore processing accuracy After checking the defective part, correct it and replace it with a new sprocket.

Fig. 1  Tooth surface wear


[Click to enlarge ]

Fig. 2  Tooth side surface wear


[Click to enlarge ]

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