Q&A  Mechanical Protectors

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

Shock Guard ・ Shock Guard coupling

Q1 What is the compliance with the RoHS directive?
Q2 What is the allowable temperature range?
Q3 Tell me about the life span of the products.
Q4 Can we use the Torque Guard in an environment where water/oil splashes on it?
Q5 We purchased the TGB30-L but the torque was insufficient when we checked it with the actual equipment. We want to change to the TGB30-H. What can we do?
Q6 We used the Shock Guard but it did not trip when the equipment overloaded. What is the probable cause?
Q7 We want to use a Shock Guard Coupling. Are there any specific directions for installing it, on the driven side or drive side?
Q8 We want to use a high precision TGX for a high speed shaft, but it cannot stop instantaneously after a trip. Is there something you can recommend?
Q9 We want to install a sprocket on the TGB series. What are the recommended sprocket machining dimensions?

Torque Limiter ・ Torque Limiter coupling

Q10 Is asbestos used in the friction plate?
Q11 What is the material of the friction plate?
Q12 How can I fasten the TL200 to a shaft?
Q13 We want to use a Torque Limiter Coupling at a speed faster than the maximum rotation speed in the catalog.
Q14 Can we use the Torque Guard in an environment where water/oil splashes on it?
Q15 What is the maximum capacity of the product you can make?
Q16 What does NA mean in TL350-2NA?
Q17 What is the difference between the TL250-1 and TL250-2?
Q18 What is the role of a bush?
Q19 Which bush can we select when attaching the sprocket RS50-30T to the TL500-1?
Q20 What are the machining dimensions of the sprocket?
Q21 Can we ask you to machine a shaft bore?
Q22 How can I determine the 0 point for the torque setting?
Q23 Please describe the procedure for changing the torque setting.
Q24 Can we ask you to set the torque?
Q25 What is the factory-adjusted torque setting of a shaft bore machined product with a sprocket?
Q26 We want to use the TL350-1 with the RS50 with the number of teeth of 20T. Is this possible?
Q27 We want to detect slips during overload electrically.
Q28 Which side of the Torque Limiter Coupling should I direct toward the motor, the Torque Limiter side or the coupling side?
Q29 When I order "TL200-1," is a bush included?
Q30 We want to order a friction plate and a disk spring for the TL250. Is this possible?
Q31 What is a center member?
Q32 Please describe the compliance with the RoHS directive.
 Answers
Q1 What is the compliance with the RoHS directive?
A1

The TGB, TGX and TGZ series are already compliant. For the TGM and TGA series, the changeover is being made progressively. If you need RoHS-compliant products from the TGM or TGA series, specify "RoHS-compliant" in your order.

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Q2 What is the allowable temperature range?
A2

The body temperature should be between -10°C and +100°C. Contact us for use outside this temperature range.

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Q3 Tell me about the life span of the products.
A3

As a guideline, the TGB, TGX, TGZ and TGA series are rated at ten thousand trips, while the TGM series is rated at one hundred thousand trips. Note that this does not include the case where the equipment cannot stop immediately after a trip. As the trip

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Q4 Can we use the Torque Guard in an environment where water/oil splashes on it?
A4

The TGM Series is a sealed type providing excellent environmental resistance against water, oil and dust. Contact us for other series as we may be able to make special arrangements.

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Q5 We purchased the TGB30-L but the torque was insufficient when we checked it with the actual equipment. We want to change to the TGB30-H. What can we do?
A5

The only difference between the TGB30-L and TGB30-H is the spring. If the spring is changed, the TGB30-L will become the TGB30-H, but the torque indicator labeled on the product can no longer be used for set torque adjustment. This is also true for the T

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Q6 We used the Shock Guard but it did not trip when the equipment overloaded. What is the probable cause?
A6

There is a possibility that the adjusting nut (bolt) has been tightened excessively. Excessive tightening eliminates the disk's deflection, preventing the Torque Guard from tripping for overload protection. Refer to the "Tightening Amount - Torque Correl

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Q7 We want to use a Shock Guard Coupling. Are there any specific directions for installing it, on the driven side or drive side?
A7

There is no specific direction. You can install the Shock Guard Coupling on either side. Note that the maximum shaft bore diameter is different between the Shock Guard side and coupling side.

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Q8 We want to use a high precision TGX for a high speed shaft, but it cannot stop instantaneously after a trip. Is there something you can recommend?
A8

The TGXZ Series allows complete release without backlash. This model combines the non-backlash of the TGX Series and the complete release of the TGZ Series. Although this is a special specification model, it has been used successfully in many application

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Q9 We want to install a sprocket on the TGB series. What are the recommended sprocket machining dimensions?
A9


[ Click to enlarge ]

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Q10 Is asbestos used in the friction plate?
A10

Asbestos is not used in the current products. Until May 1987, we used friction plates containing asbestos. From June 1987 to September 1990, we sold both products containing asbestos and non-asbestos products. Since 1990, we have used only non-asbestos p

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Q11 What is the material of the friction plate?
A11

The friction plate is made of inorganic/organic fiber and resin as a base, added with friction stabilizer and reinforcement material, and formed by die molding.

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Q12 How can I fasten the TL200 to a shaft?
A12

Use a shaft snap ring or an end plate.

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Q13 We want to use a Torque Limiter Coupling at a speed faster than the maximum rotation speed in the catalog.
A13

By changing the sprocket to one with a high-frequency hardened tooth tip, models TL200 to TL700 can be used up to 1800 r/min, and the larger models can be used up to about 800 r/min.

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Q14 Can we use the Torque Guard in an environment where water/oil splashes on it?
A14

You cannot use standard products. When water or oil splashes onto the friction plate, the friction coefficient changes, resulting in a change in the slip torque. Water and oil also cause rust. Contact us as we may be able to make special arrangements.

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Q15 What is the maximum capacity of the product you can make?
A15

Up to 15000 N・m can be supported. Contact us if you need a higher slip torque.

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Q16 What does NA mean in TL350-2NA?
A16

From 1987 to 1990, we sold both products contains asbestos and non-asbestos products. NA indicates that the friction plate is made of non-asbestos material, in order to allow differentiation from the old products containing asbestos. Since 1990, all prod

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Q17 What is the difference between the TL250-1 and TL250-2?
A17

The number at the end indicates the number of disk springs. The TL250-2 has two disk springs of the same type as the TL250-1 in succession in the same orientation. The set torque is doubled when the tightening amount is the same. All the other parts are

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Q18 What is the role of a bush?
A18

A bush receives a radial load on the hub which is applied when the Torque Limiter slips.

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Q19 Which bush can we select when attaching the sprocket RS50-30T to the TL500-1?
A19

Select the longest (thickest) bush from the bushes which are shorter than the thickness of the center member (sprocket) to be used. For example, select B6.5 (6.5 mm) for the RS50.

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Q20 What are the machining dimensions of the sprocket?
A20

You need to machine the inner diameter according to the outer diameter of the bush. Finish the friction faces (both sides) to 3S to 6S. Refer to the catalog for the dimensions and tolerance.

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Q21 Can we ask you to machine a shaft bore?
A21

We have products machined with the shaft bore diameter tolerance of H7 and a keyway conforming to new JIS in stock. Contact us to order special shaft bore machining.

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Q22 How can I determine the 0 point for the torque setting?
A22

The 0 point is the state of no looseness when the adjusting nut (bolt) is tightened manually.

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Q23 Please describe the procedure for changing the torque setting.
A23

After the 0 point is determined, tighten the adjusting nut (bolt) gradually from the loose tightening to greater tightening while checking the operation with the actual machine, and find the optimum tightening position.

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Q24 Can we ask you to set the torque?
A24

Specify the set torque in your order and we will ship the product after setting the torque. You need to order a shaft bore machined product with a center member. Indicate the set torque value in kgf・m at the end of the model No.. Example: TL250-1-04022-1

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Q25 What is the factory-adjusted torque setting of a shaft bore machined product with a sprocket?
A25

When the torque setting is not specified, the adjusting nut (bolt) is tightened at 120° for all models.

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Q26 We want to use the TL350-1 with the RS50 with the number of teeth of 20T. Is this possible?
A26

No, it isn't possible. The allowable minimum number of sprocket teeth for the TL350 is 21T when the RS50 is used. With 20T, the outer diameter is so small that the roller chain will interfere with the hub. Refer to the catalog for the list of minimum num

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Q27 We want to detect slips during overload electrically.
A27

You can use a proximity switch and digital tachometer to detect the decrease in the rotation speed when the Torque Limiter slips. Refer to the catalog for an example.

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Q28 Which side of the Torque Limiter Coupling should I direct toward the motor, the Torque Limiter side or the coupling side?
A28

There is no specific direction on the driven side or drive side. For your reference, the maximum shaft bore diameter is larger on the coupling side.

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Q29 When I order "TL200-1," is a bush included?
A29

No, a bush will not be included because the length of the bush is not specified. If you need a bush, specify the size, for example TL200-1-B6.0.

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Q30 We want to order a friction plate and a disk spring for the TL250. Is this possible?
A30

Yes, it is possible. Specify TL250A for the friction plate and TL250S for the disk spring.

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Q31 What is a center member?
A31

It is a part held between the parts of the Torque Limiter. A sprocket is most commonly used as a center member. We also offer Torque Limiters with sprockets included.

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Q32 Please describe the compliance with the RoHS directive.
A32

Most of the Torque Limiters have been changed to RoHS compliant. For some models, however, the changeover has not yet been completed because of inventory levels. If you need RoHS-compliant products, specify "RoHS-compliant" in your order.

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