Q&A   Shaft Coupling

The following is the list of answers for frequently asked questions from our customers. Click the question and see the answer.

ECHT-FLEX Coupling - Basic Instructions  *NES Series is not affected.

Q1 Why do the ECHT-FLEX couplings allow lube-free, non-backlash operation?
Q2 What happens when a torque greater than the allowable torque is applied?
Q3 What is the allowable ambient temperature range of the ECHT-FLEX Coupling?
Q4 Can you make a stainless steel type or electroless nickel-plated type to prevent rust?
Q5 Is it possible to paint the ECHT-FLEX Coupling?
Q6 What happens when the U nut is tightened without using a torque wrench?
Q7 Is there a specific direction in which to insert the reamer bolt during assembly?
Q8 After the coupling is assembled, the disk wobbles along the shaft. Is something wrong?
Q9 Is the reamer bolt compatible with commercially available products?
Q10 Are the parts compatible?

ECHT-FLEX Coupling - Design Specifications  *NES Series is not affected.

Q11 What is the allowable parallel eccentricity for the single type?
Q12 Is the dynamic balance adjustment necessary for high-speed applications?
Q13 What are the points we should be careful about when selecting the long spacer type?
Q14 What is the maximum length of the long spacer type you make?
Q15 Can we use the coupling in a vertical mounting layout?
Q16 What is the gear coupling-compatible G type?
Q17 The Power-Lock type uses the EL series as standard. Can we use the other series of Power-Lock for mounting?
Q18 Can we use the Power-Lock type for a hollow shaft?
Q19 Is it possible to match the keyway angles on the right and left sides?
Q20 Do you accept orders for taper shaft bore machining?

Roller chain coupling

Q21 What is the meaning of "J" such as CR5016-J marked on the roller chain coupling?
Q22 Can we purchase the parts for the roller chain coupling?
Q23 Is it possible to use the standard Tsubaki RS roller chain as the chain for the roller chain coupling?
Q24 Which is used to fasten the joint pin, a clip or a cotter pin?
Q25 Please provide the name of a commercially available oil seal for the housing.
Q26 Is it possible to mount the housing provided by another company to Tsubaki's chain coupling body, or vice versa?
Q27 Do you sell dedicated grease?
 Answers
Q1 Why do the ECHT-FLEX couplings allow lube-free, non-backlash operation?
A1

The ECHT-FLEX Coupling transmits power using the friction force of the disk tightened with the reamer bolt and U nut. Consequently, it is free from wobbling or sliding and does not require lubrication.

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Q2 What happens when a torque greater than the allowable torque is applied?
A2

The allowable torque is determined from the friction force of the disk tightened with the reamer bolt and U nut. A load greater than the allowable torque may cause a slip, resulting in damage to the coupling. Note that the allowable torque may decrease d

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Q3 What is the allowable ambient temperature range of the ECHT-FLEX Coupling?
A3

It can resist temperatures from -30°C to +200°C.
Note: Uses a Nylock bolt except for square hub type clamp fastening. Maximum heat resistance is 170°C.

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Q4 Can you make a stainless steel type or electroless nickel-plated type to prevent rust?
A4

We have the electroless nickel-plated type as standard to provide a simple form of rust-proofing intended mainly for clean room applications. A stainless steel type is also available. Contact us for details.

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Q5 Is it possible to paint the ECHT-FLEX Coupling?
A5

Painting the ECHT-FLEX Coupling is not recommended because the outer diameter changes according to the thickness of the paint coating, which prevents proper centering. Contact us if painting is absolutely necessary.

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Q6 What happens when the U nut is tightened without using a torque wrench?
A6

The allowable torque shows a value when the U nut is tightened with the specified tightening torque. Consequently, tightening without using a torque wrench may cause an accident such as a slip due to insufficient tightening or a deformation of parts due

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Q7 Is there a specific direction in which to insert the reamer bolt during assembly?
A7

The reamer bolt can be inserted in either direction. Note that washers A and B have a specific direction. Refer to the instruction manual or catalog for assembly.


Visit our website for a 3D video on assembly methods.

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Q8 After the coupling is assembled, the disk wobbles along the shaft. Is something wrong?
A8

If any thrust load is being applied to the coupling while the U nut is tightened, the disk will wobble along the shaft. We call this the "wobbling phenomenon." We do not recommend its use in this state because excessive stress is being applied to the dis

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Q9 Is the reamer bolt compatible with commercially available products?
A9

No, the reamer bolts for the ECHT-FLEX Coupling are dedicated, special design products and are not compatible with commercially available products. If you need the reamer bolts, order them via your dealer.

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Q10 Are the parts compatible?
A10

The hubs, disks, and bolts used in the single type, spacer type, and long spacer type are common and compatible.

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Q11 What is the allowable parallel eccentricity for the single type?
A11

The single type absorbs angular eccentricity only and does not absorb parallel eccentricity. As a result, this type is recommended only for the application where precise centering for NC machine tools or servomotors can be made. For general applications,

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Q12 Is the dynamic balance adjustment necessary for high-speed applications?
A12

If vibration or noise presents a problem, a balance adjustment may be required after the equipment is assembled. If you specify the balance quality grade and rotation speed, we can check the adequacy of the adjustment.

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Q13 What are the points we should be careful about when selecting the long spacer type?
A13

When using the long spacer type at high speed, you need to check the rotation speed to avoid a critical speed. For the selection, see the catalog and confirm that the distance between the hub faces (distance J) and the rotation speed of the model No. are

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Q14 What is the maximum length of the long spacer type you make?
A14

Long spacer type Echt-Flex Coupling can be manufactured with a hub face distance up to 6,000mm (for NEH41W sizes and smaller).
However, further of the usage application will be needed. Please contact a Tsubaki representative.

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Q15 Can we use the coupling in a vertical mounting layout?
A15

Yes, you can use the standard spacer type and single type. For the long spacer type, if the distance between the hub faces (Distance J) exceeds the values in the following table, special construction is required to support the weight of the coupling. Con

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Q16 What is the gear coupling-compatible G type?
A16

Having the same overall length and hub length as gear couplings, the G type coupling replaces the current gear coupling without any extra work. The replacement with the ECHT-FLEX Coupling eliminates the need for lubrication and reduces maintenance work.
Note: See the catalog for allowable misalignment values.

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Q17 The Power-Lock type uses the EL series as standard. Can we use the other series of Power-Lock for mounting?
A17

Yes, you can. Note that you should check the diameter of the hub to determine whether it can withstand the surface pressure generated by the Power-Lock. For general use, we recommend the KE series which supports a wide range of shaft tolerances and the T

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Q18 Can we use the Power-Lock type for a hollow shaft?
A18

Contact us if you want to use the hollow shaft with a Power-Lock. Design considerations need to be made regarding the material strength of the hollow shaft and its internal diameter.

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Q19 Is it possible to match the keyway angles on the right and left sides?
A19

When accurate matching of the keyway angles is required, please specify the "matching keyway angle type" when placing your order. In this case, we make the coupling with a maximum angle difference of ±2 degrees. When higher accuracy is required in matchi

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Q20 Do you accept orders for taper shaft bore machining?
A20

Yes, we can make bores of φ16 (1/10 taper) and φ11 (1/10 taper) for servomotor shafts. For other dimensions, we can make them if you provide the taper gauge.

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Q21 What is the meaning of "J" such as CR5016-J marked on the roller chain coupling?
A21

The roller chain coupling consists of a body and a housing. We add a suffix "H" for the body and "K" for the housing to their model numbers to sell them separately. The marking of "J" on both body and housing is not the model No. but indicates compliance

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Q22 Can we purchase the parts for the roller chain coupling?
A22

The following parts are sold individually.

Parts of the body unit Model No. example Note
Dedicated sprocket CR5016HS Sold as a single piece (Two pieces are used in the body.)
Dedicated roller chain CR5016C Joint pins and clips (or cotter pins) included.
Joint pin CR5016JP Clips (or cotter pins) included

Housing parts Model No. example Note
Oil seal CR5016OR Also referred to as the "oil ring"
Packing CR5016OS Cork sheet (Two sheets required for one housing)
※ Hex bolts are not sold as parts. (Refer to the catalog for the size.)


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Q23 Is it possible to use the standard Tsubaki RS roller chain as the chain for the roller chain coupling?
A23

Yes, it is possible because the dedicated chain of the coupling is designed based on the two-row RS roller chain. Note, however, that the dedicated roller chain can be attached/removed with the insertion/extraction of a single joint pin. The two-row stan

CR 50   16 C
    No. of sprocket teeth = No. of chain links: 16 links
    Chain No.: RS50-2
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Q24 Which is used to fasten the joint pin, a clip or a cotter pin?
A24

Since the chain is based on the Tsubaki RS roller chain, the method is the same as the joint link of the RS roller chain. ・CR3012H to CR6022H: Clip ・CR8018H to CR20022H: Cotter pin

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Q25 Please provide the name of a commercially available oil seal for the housing.
A25

The oil seal is a dedicated part and is not commercially available.

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Q26 Is it possible to mount the housing provided by another company to Tsubaki's chain coupling body, or vice versa?
A26

Each company has its own original design. Since the dimensions are always different, mounting is impossible.

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Q27 Do you sell dedicated grease?
A27

We don't sell dedicated grease. Use commercially available products. The following products are recommended:


Maker Grease name
Idemitsu Daphne Eponex EP.1 or 2
EMG Marketing Godo Kaisha Mobilux EP.1 or 2
Nippon Grease NIGTIGHT LY.1 or 2
JX Nippon Oil & Energy Corporation EPNOC Grease AP.1 or 2
Showa Shell Shell Alvania EP.1 or 2
Kyodo Yushi Unilube DL.1 or 2
Cosmo Oil Lubricants Cosmo Grease Dynamax EP.1 or 2

Recommended lubricating grease for stainless series specific application
    ■Food grade grease
        BALBIS co., ltd : Power Food Grease
        NOK KLUBER co., ltd : Kluberfood NH1 94-301
    ■Waterproof food grade grease
        NOK KLUBER co., ltd : Kluberfood NH1 64-422
        Sumico Lubricant co., ltd : White Alcom Grease No.2
    ■Waterproof grease
        Sumico Lubricant co., ltd : Moly FM-HD Grease No.1
    ■Heat resistant grease
        Idemitsu : Daphne Eponex SR2 -20~200℃
        JX Nippon Oil & Energy Corporation : PYRONOC UNIVERSAL -10~200℃
    ■Fluorine grease for clean room
        Sumico Lubricant co., ltd : Sumitec F936

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