Causes of Vibration, Jerking, and Unusual Wear

• 1)Overload, glass fragments or bottle caps caught between components
• 2)Warping of the chain on the return-way
• 3)Insufficient lubrication or no lubrication
• 4)Interference between top plates
• 5)Wear of the sprocket
• 6)Unusual wear or breakage of the chain

Lubrication may drastically decrease elongation of the chain due to wear, wear of the sprockets and wear of the top plates and the wearstrips.

Utilization of a lubricant also reduces noise and power loss in operation.

Though plastic chains have self lubricating characteristics, lubrication exerts the same effect.

The most desirable lubricant is high-quality lubricating oil, however a lubricant prepared exclusively for this purpose or soap are often used when lubricating oil is not available.

Enough attention should be paid so that such a lubricant may be sufficiently applied to parts liable to wear such as those described above.

Chain wear dust, grease, general dust, spilled beverage syrup, etc., tend to accumulate during ordinary use, and may result in the following undesirable conditions that will require cleaning of the chain and the conveyor.

• 1)Contamination, damage, tip-over, or slippage of conveyed products
• 2)Increased load on the chain and/or the motor
• 3)Accelerated wear of sprocket teeth
• 4)Vibration and/or jerking of the conveyor
• 5)Accelerated wear in the curves and the top plates of the chain
• 6)Accelerated wear of the wearstrip
• 7)Growth of bacteria or other microorganisms

When the top chain is in operation, wear debris is normally generated.
Cleaning especially during initial operational periods should be performed because wear debris is prone to be generated more.

Method of fixing sprockets for plastic top chains

Place set collars tightly on both sides of a sprocket without leaving any clearances between them and use bolts to fix each set collar using the specified bolt tightening torque.

Method of fixing idlers

Place set collars on both sides of an idler and fix each set collars using the specified bolt tightening torque.

Ensure that there is clearance between the idler and set collar and that the idler rotates.

Refer to set collar for details.

5-1. Chain

Item	Inspection method	Judgment Criteria (※)
Chain elongation due to wear	Measure the length of 10 top plates by means of a measure with the chain slightly stretched to eliminate backlash through the chain links.	Show selection Chain elongation X A 0 ≦ X < +1.2% B +1.2% ≦ X < +2.6% C +2.6% ≦ X Percentage of elongation X = (Measured length – Reference length) ÷ Reference length × 100 Reference length = chain pitch ×10 Example: TTP chain: Result of measuring 10 links (reference length: 381 mm) Percentage of elongation and judgment when measured length was 387 mm: Percentage of elongation X = (387 - 381)÷381×100≒1.6% From table above, judgment is B.
Wear of top plate (Plastic Top Chain and Stainless Steel Top Chain only )	Use a vernier caliper to measure the thickness of the part of the top plate that slides on the wearstrip. Also, verify that there are no bumps, depressions, or other irregularities measuring more than 1 mm in height or depth on the conveyor surface.	Show selection Thickness t mm Made of engineering plastic (Plate thickness 4mm) steel (Plate thickness 3.2mm) A 4.0 ≧ t > 3.4 3.2 ≧ t > 2.7 B 3.4 ≧ t > 2.4 2.7 ≧ t > 1.9 C 2.4 ≧ t 1.9 ≧ t
Link height wear (Plastic modular chain )	Use a vernier caliper to measure the height of a link sliding on a wearstrip or with conveyed products.	Show selection Amount lost to wear Y mm WT0405 WT0700 Series BTC4-M WT1500/1900/2510 2250/2520/2700/3005 BT5/BT6/BT8 Series A 0 ≦ Y < 0.2 0 ≦ Y < 0.4 0 ≦ Y < 0.6 B 0.2 ≦ Y < 0.5 0.4 ≦ Y < 0.7 0.6 ≦ Y < 1.0 C 0.5 ≦ Y 0.7 ≦ Y 1.0 ≦ Y Show selection Amount lost to wear Y mm WT2500 Series WTU3015・WT3827 WT3835・BTM8H・BTC8H WT3109 WT3816 WT5707 BTH16 A 0 ≦ Y < 0.9 0 ≦ Y < 1.4 0 ≦ Y < 1.8 B 0.9 ≦ Y < 1.6 1.4 ≦ Y < 2.4 1.8 ≦ Y < 3.0 C 1.6 ≦ Y 2.4 ≦ Y 3.0 ≦ Y Amount lost to wear Y = reference link height (value from catalog) – measured height: t
Link height wear (Plastic block chain )	Use a vernier caliper to measure the height of a link sliding on a wearstrip or with conveyed products.	Show selection Amount lost to wear Y mm RSP35 RSP40・50 RSP-P08 RSP60 RSP-P012 RSP80 A 0 ≦ Y < 0.7 0 ≦ Y < 1.2 0 ≦ Y < 1.6 0 ≦ Y < 2.3 B 0.7 ≦ Y < 1.2 1.2 ≦ Y < 2.0 1.6 ≦ Y < 2.7 2.3 ≦ Y < 3.9 C 1.2 ≦ Y 2.0 ≦ Y 2.7 ≦ Y 3.9 ≦ Y Amount lost to wear Y = reference link height (value from catalog) – measured height: t
Corrosion	Check whether or not there is any place where the chain articulation is not proper due to corrosion. If corrosion should worsen, remove rust and measure the thickness of the link plate by means of a vernier caliper.	Show selection Criteria A Corrosion penetration is shallow and dispersed. B The entire surface is affected by corrosion. C Corrosion has worsened to such an extent that the thickness of the plate has been reduced.
Deformation of top plate	Inspect whether or not any of the following problems have happened: deformation of the top plate caused by things such as a broken bottle or bottle cap caught in the components; lifting of curled sections; looseness of a rivet in the top plate; or scratches on the upper surface of the top plate due to abnormal contact.	Replace the part if deemed that it may affect operation. For scratches on the upper surface of the top plate due to abnormal contact, investigate the wearstrip on the return-way to find the causes and repair it as necessary.
Chipping or unsmooth rotation of the roller	Check whether or not there is any chipping of the roller and rotation is smooth.	Replace the chain and the rollers as appropriate when there is any roller that is chipped, does not rotate smoothly or is partially worn.

A: Can be still used B: Still has margin of chain life but necessary to consider replacemen  C: Chain life already expired, needs to be replaced

Note) Contact a Tsubaki representative regarding standards for link height wear for TPUN chain.

5-2. Sprocket

When the sprocket is worn as illustrated right (to the left), the chain is prone to being caught by the tips of the teeth (A), making the departure of the chain from the sprocket difficult, hence resulting in vibration of the chain.

Though wear allowance depends on the type of conveyor and the size of the chain to a certain extent, if the sprocket is replaced when the wear reaches 1.5 to 2 mm, damage to the chain can be avoided.

When the sprocket is worn in the direction of the face width as illustrated right (to the right), the shaft may not be properly aligned, therefore correct it.

5-3. Rail

Replace the wearstrip when the thickness has been reduced to half of the original thickness.