Q&A Coupling

We have posted frequently asked questions from customers in Q&A format. Please click on the question to proceed to the answer.

Words in Q&Aof

ECHT-FLEX Coupling - Basics and Handling *Not applicable to the NES series.

Q1 Why can it be used Lube-free or backlash?
Q2 What happens if a torque greater than the allowable torque is applied?
Q3 What is the maximum ambient temperature that ECHT-FLEX couplings can be used in?
Q4 Can you manufacture stainless steel or electroless nickel plated products as anti-rust measures?
Q5 Can ECHT-FLEX couplings be painted?
Q6 What happens if you tighten a U-nut without using a torque wrench?
Q7 When assembling, is there a specific direction in which the reamer bolt should be inserted?
Q8 After assembling the coupling, the disc moves up and down in the axial direction. Is this ok?
Q9 Are reamer bolts compatible with commercially available products?
Q10 Are the parts compatible?

ECHT-FLEX Coupling - Design and Specifications *Not applicable to the NES series.

Q11 What is the allowable parallel eccentricity for the single type?
Q12 Is dynamic balance adjustment necessary when using at high speeds?
Q13 What should I pay attention to when selecting a long spacer type?
Q14 What is the maximum length that can be manufactured for the long spacer type?
Q15 Can it be used in a vertical mounting layout?
Q16 What is the G type gear coupling compatible?
Q17 The standard Power-Lock specification is the EL type, but can it be installed with Power-Lock from other series?
Q18 Can the "Power-Lock" specification be used on a hollow shaft?
Q19 Is it possible to align the phase of the left and right keyways?
Q20 Can you process a tapered shaft hole?

Roller chain coupling

Q21 What does the "J" stamping on Roller chain coupling such as CR5016-J, mean?
Q22 Can I purchase Roller chain coupling parts?
Q23 Can I use standard RS roller chain for Roller chain coupling?
Q24 Is it spring clip or a split pin that holds the coupling pin in place?
Q25 Please tell me which oil seals for cases are commercially available.
Q26 Can I attach cases made by other companies to Tsubaki chain coupling bodies?
And is the reverse possible?
Q27 Do you sell special grease?
Q28 Is it okay to use only one oil seal?
回答へ
Q1 Why can it be used Lube-free or backlash?
A1

ECHT-FLEX couplings transmit power through the frictional force of the disc when the reamer bolt and U-nut are fastened together. Therefore, there is no play or sliding, and no need for oiling.

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

The allowable torque is determined by the frictional force between the reamer bolt and the disc when the U-nut is tightened. If a load greater than the allowable torque is applied, slippage will occur, which may result in damage to the coupling. Note that the allowable torque may decrease depending on the fastening method, so please refer to the catalog for details.

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Q3 What is the maximum ambient temperature that ECHT-FLEX couplings can be used in?
A3

Heat resistant temperature: 200℃
Cold resistance temperature: up to -30°C.
(Note) All types other than Square hub type with clamp fastening system use Nylock bolts, so the heat resistance temperature is up to 170°C.

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Q4 Can you manufacture stainless steel or electroless nickel plated products as anti-rust measures?
A4

Electroless nickel plating is standardized as a simple rust prevention method, mainly for clean room use. Stainless steel specifications are also available, so please feel free to contact us for more information.

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Q5 Can ECHT-FLEX couplings be painted?
A5

Painting ECHT-FLEX coupling is not recommended as the outer diameter dimensions will change depending on the film thickness, which will interfere with centering. If painting is absolutely necessary, please contact us.

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Q6 What happens if you tighten a U-nut without using a torque wrench?
A6

The allowable torque is the value when the U-nut is tightened to the specified tightening torque, so tightening without a torque wrench can cause accidents such as slippage due to insufficient tightening or deformation of parts due to excessive tightening. Always use a torque wrench when tightening and tighten to the specified tightening torque.

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Q7 When assembling, is there a specific direction in which the reamer bolt should be inserted?
A7

The reamer bolt can be inserted from either side. However, the directions of washers A and B are fixed, so please assemble according to the instructions in Instruction Manuals or catalog.


Please refer to the 3D video on our website that explains how to assemble the product.

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Q8 After assembling the coupling, the disc moves up and down in the axial direction. Is this ok?
A8

When tightening the U-nut, if a thrust load is applied to the coupling, the disc will move in an axial direction with a rattling sound. We call this phenomenon "wobbling phenomenon" (snapping), and since extra stress is being applied to the disc, we do not recommend using it in this state. If wobbling phenomenon occurs, loosen the U-nut and reassemble it with no thrust load applied to the coupling to resolve the problem.

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Q9 Are reamer bolts compatible with commercially available products?
A9

Reamer bolts for ECHT-FLEX couplings are specially designed products and are not compatible with commercially available products. If you need reamer bolts, please order them from your dealer.

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Q10 Are the parts compatible?
A10

The hubs, discs, 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 only absorbs angular misalignment, not parallel misalignment. It is recommended only for installations that allow precise centering with NC machine tools and servo motors. Generally, use the spacer type.

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Q12 Is dynamic balance adjustment necessary when using at high speeds?
A12

If vibration or noise is a problem, balance adjustment may be required after the device is assembled. If you specify the balance class and rotation speed, we will consider whether or not adjustment is possible.

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Q13 What should I pay attention to when selecting a long spacer type?
A13

When using a long spacer type at high speeds, it is necessary to check the rotational speed to avoid dangerous speeds. When selecting a product, please check the catalog to ensure that the hub end face distance (J dimension) and rotational speed for each model number are within the limits. Please contact us for details.

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Q14 What is the maximum length that can be manufactured for the long spacer type?
A14

ECHT-FLEX coupling long spacer type can be manufactured with a maximum distance between hub ends of 6,000 mm (sizes below NEH41W).
However, there may be cases where consideration is required for use, so please contact us for further details.

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Q15 Can it be used in a vertical mounting layout?
A15

There is no problem with standard spacer types and single types. For long spacer types, if the distance between hub end faces (J dimension) exceeds the table below, a special structure is required to support the bearing's own weight, so please contact us.

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Q16 What is the G type gear coupling compatible?
A16

By making the overall length and hub length the same as the gear coupling, it can be replaced as is. By replacing it with ECHT-FLEX coupling, lubrication is no longer necessary, reducing maintenance man-hours. (Made to order)
(Note) Please check the catalog for allowable misalignment values.

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Q17 The standard Power-Lock specification is the EL type, but can it be installed with Power-Lock from other series?
A17

Yes, it is. However, you must check the boss diameter of the hub to see if it can withstand the surface pressure generated by Power-Lock. Generally, we recommend the KE series, which can accommodate a wide range of shaft tolerances, or the TF series, which is designed for small hub diameter.

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Q18 Can the "Power-Lock" specification be used on a hollow shaft?
A18

Whether or not Power-Lock with a hollow shaft.

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Q19 Is it possible to align the phase of the left and right keyways?
A19

If precise alignment of the keyway phase is required, please specify "keyway phase alignment specifications" when placing your order. In this case, the maximum phase difference will be ±2 degrees. If even higher precision phase alignment is required, we recommend the Power-Lock specification.

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Q20 Can you process a tapered shaft hole?
A20

We can manufacture Φ16 (1/10 taper) or Φ11 (1/10 taper) for servo motor shafts. For other dimensions, we can manufacture if you provide a taper gauge.

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Q21 What does the "J" stamping on Roller chain coupling such as CR5016-J, mean?
A21

Roller chain coupling consist of a main body and a case. To allow them to be sold separately, the product name is suffixed with "H" for the main body and "K" for the case, but the letter "J" is stamping on both the main body and case to indicate that they comply with JIS standards.

Product name display example
・Main unit: CR5016H
Case: CR5016K

Example of product stamping
・Main unit and case: CR5016-J

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Q22 Can I purchase Roller chain coupling parts?
A22

The following parts are sold individually.

Body parts Model number example remarks
Dedicated sprocket CR5016HS Sold individually (main unit consists of two units)
Dedicated roller chain CR5016C Joint pin and spring clip (or cotter pin) included
Joint pin CR5016JP spring clip (or cotter pin) included

Case parts Model number example remarks
Oil seal CR5016OR It is also called an "oil ring."
rubber seal CR5016OS Cork sheets (2 sheets required per unit)
*Hexagon bolts are not sold as parts. (Please refer to the catalog for sizes.)


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Q23 Can I use standard RS roller chain for Roller chain coupling?
A23

The coupling-specific chain is based on a two-strand RS roller chain, so it can be used. However, the dedicated roller chain can be attached and detached by inserting and removing one coupling pin. If a two-strand standard roller chain is used, it will be connected with a coupling link, which makes assembly slightly less easy, so we recommend using the dedicated roller chain. The model numbers have the following meanings:

CR 50   16 C
    Number of sprocket teeth = Number of chain links: 16 links
    Chain number: RS50-2
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Q24 Is it spring clip or a split pin that holds the coupling pin in place?
A24

Since it is based on the Tsubaki RS roller chain, it is the same as the connecting links of RS roller chain.

・CR3012H to CR6022H: spring clip
・CR8018H to CR20022H: Cotter pin

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Q25 Please tell me which oil seals for cases are commercially available.
A25

Oil seals are special parts and are not available commercially.

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Q26 Can I attach cases made by other companies to Tsubaki chain coupling bodies?
And is the reverse possible?
A26

Each company has its own unique design, and the dimensions are slightly different, so installation is not possible.

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Q27 Do you sell special grease?
A27

We do not sell dedicated grease, so please use commercially available products. The recommended products are as follows:


Manufacturer Grease name
Idemitsu Kosan Daphne Grease MP No. 0, No. 1, No. 2
Daphne Eponex SR
Exxon Mobil Mobilux EP0, EP1, EP2
Mobil SHC Polyrex 005, 221, 222, 462
Nippon Grease Nigtite LE-0, LE-1, LE-2
Sumiko Lubricants Sumiplex MP No.0, No.1, No.2
Sumiplex L-MO No.0, No.1, No.2

*The product names listed in the table above are trademarks or registered trademarks of each company.


The recommended grease for special applications of the stainless steel series is as follows.

■Food grease
Balbis Co., Ltd.: Power Food Grease
NOK Kluber Co., Ltd.: Kluber Foods NH1 94-301
■Water-resistant food grease
NOK Kluber Co., Ltd.: Kluber Foods NH1 64-422
Sumiko Lubricant Co., Ltd.: White Alcom Grease No. 2
■Water-resistant grease
Sumiko Lubricant Co., Ltd.: Mori FM-HD Grease No.1
■ Cold-resistant grease
ENEOS Corporation: Epinoc Grease LT -40 to 120°C
■Heat-resistant grease
Idemitsu.: Daphne Eponex SR2 -20 to 160°C
ENEOS Corporation: Pyronoc Universal -20 to 175°C
■Fluorine-based grease for clean rooms
Sumiko Lubricant Co., Ltd.: Sumitec F936

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Q28 Is it okay to use only one oil seal?
A28

One side is press fit, and the oil seal side is designed to absorb misalignment while preventing grease leakage.

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