• Couplings
  • Oldham Type

MOM-CK

Flexible Couplings - Oldham Type - Clamping + Key Type

  • High torsional rigidity
  • High Torque

Dimension Drawing

MOM-CKFlexible Couplings - Oldham Type - Clamping + Key Type寸法図

MOM-CKFlexible Couplings - Oldham Type - Clamping + Key Type寸法図

Specs/CAD

Unit : mm

Part Number A L W E F G M Screw Tightening
Torque (N・m)
Standard Bore Diameter
D1-D2
CAD RFQ
MOM-15CK 15 6.6 19 6.9 2.15 5.2 M1.6 0.25 - CAD RFQ
MOM-17CK 17 9 25 7.3 2.65 5.5 M2 0.5 - CAD RFQ
MOM-20CK 20 10 28 11.1 3.25 7.25 M2.5 1 - CAD RFQ
MOM-26CK 26 11.5 31.6 13.3 4 9 M3 1.5 - CAD RFQ
MOM-30CK 30 12 34 15.5 4 11 M3 1.5 - CAD RFQ
MOM-34CK 34 13 35 17.5 4.5 12 M4 3.5 - CAD RFQ
MOM-38CK 38 15 40.5 21.5 4.75 14 M4 3.5 - CAD RFQ
MOM-45CK 45 16.2 47.6 24.3 6.2 16 M5 8 - CAD RFQ
MOM-55CK 55 20.8 58.6 27.7 7.9 20 M6 13 - CAD RFQ
MOM-70CK 70 25 68.6 38.5 8.9 26 M6 13 - CAD RFQ

Part Number Max. Bore Diameter
(mm)
Rated
Torque*1
(N・m)
Max. Torque
(N・m) *1
Max. Rotational Frequency
(min-1)
Moment of
Inertia
(kg・m2)*2
Static
Torsional
Stiffness
(N・m/rad)
Max. Angular
Misalignment
(°)
Max. Lateral Misalignment
(mm) *3
Mass
(g) *2
MOM-15CK 6 3.3 6.6 2000 6.1×10-7 870 2 0.3 18
MOM-17CK 6.35 5.5 11 2000 1.4×10-6 1300 2 0.3 33
MOM-20CK 10 7.7 15.4 2000 2.9×10-6 1700 2 0.4 45
MOM-26CK 12 11 22 2000 9.5×10-6 3200 2 0.5 90
MOM-30CK 14 26 52 2000 1.8×10-5 4600 2 0.6 128
MOM-34CK 16 35 70 2000 3.0×10-5 6000 2 0.7 170
MOM-38CK 20 55 110 2000 5.4×10-5 7400 2 0.8 231
MOM-45CK 22 66 132 2000 1.2×10-4 16000 2 1 383
MOM-55CK 25 99 198 2000 3.4×10-4 30000 2 1.2 743
MOM-70CK 35 176 352 2000 1.0×10-3 46000 2 1.4 1350

*1: Correction of rated torque and max. torque due to load fluctuation is not required.
*2: These are values with max. bore diameter.
*3: The max. lateral misalignment varies depending on the load torque and revolution.

Part Number Standard Bore Diameter D1・D2
6 6.35 8 10 12 14 15 16 18 20 22 24 25 28 30 35
MOM-15CK - - - - - - - - - - - - - - -
MOM-17CK - - - - - - - - - - - - - - -
MOM-20CK - - - - - - - - - - - -
MOM-26CK - - - - - - - - - - -
MOM-30CK - - - - - - - - - - - -
MOM-34CK - - - - - - - - - - -
MOM-38CK - - - - - - - - -
MOM-45CK - - - - - - - - -
MOM-55CK - - - - - - - - -
MOM-70CK - - - - - - - -

● All products are provided with hex socket head cap screw.
● Recommended tolerance for shaft diameters is h6 and h7.
● A set of hubs with set screw type for one side and clamping type for the other side is available upon request.
● Bore and keyway modifications are available on request. Please contact our customer service.


Slip torque

As in the table below, the clamping type MOM-C has different slip torque according to the bore diameter. Take care during selection.

Unit : N・m

Part Number Bore Diameter
3 4 5 6 6.35 8 10 12 14 15 16 18 20 22 24 25 28 30 35
MOM-15C 0.3 0.5 0.8 1
MOM-17C 2.1 3.5 3.7
MOM-20C 3.8 6 6 6.8 7.5
MOM-26C 5.4 5.4 5.8 6.6 8.7
MOM-30C 7.4 12 14 15
MOM-34C 13 13 15 16 16
MOM-38C 16 18 20 23 25 28 31
MOM-45C 47 48 56 56 57 62
MOM-55C 42 54 55 56 89 93 97
MOM-70C 62 92 95 97 100 110 120 130

These are test values based on the conditions of shaft dimensional allowance: h7, hardness: 34-40 HRC, and screw tightening torque of the values described in MOM-C dimension tables. They are not guaranteed values.
Slip torque changes with usage conditions. Carry out tests under conditions similar to actual conditions in advance.


Structure

Set Screw Type

MOM MOM

MOM/MOM-C/MOM-K/MOM-CK_CFlexible Couplings - Oldham Type

Clamping Type

MOM-C MOM-C

MOM/MOM-C/MOM-K/MOM-CK_CFlexible Couplings - Oldham Type

Set Screws + Key Type

MOM-K MOM-K

MOM/MOM-C/MOM-K/MOM-CK_CFlexible Couplings - Oldham Type

Clamping + Key Type

MOM-CK MOM-CK

MOM/MOM-C/MOM-K/MOM-CK_CFlexible Couplings - Oldham Type


Material/Finish

MOM-CK
Hub S45C
Ferrosoferric Oxide Film (Black)
Spacer FCD400
Ferrosoferric Oxide Film (Black)
Pin Polyacetal
Hex Socket Set Screw SCM435
Ferrosoferric Oxide Film (Black)
Hex Socket Head Cap Screw SCM435
Ferrosoferric Oxide Film (Black)
Grease Lithium Soap Grease
Nippeco DXL-No.1 Made by Nippeco

Characteristics

  • Recommended Applicable Motor
MOM
Servomotor
Stepping Motor
General-purpose Motor

◎: Excellent ○: Very good ●: Available

  • Property
MOM
High Torque
High Torsional Stiffness
Allowable Misalignment

◎: Excellent ○: Very good

  • This is an oldham type flexible coupling.
  • FCD400 is adopted in the spacer. Suitable for low-speed and high-torque specification.
  • High performance grease is applied in the gap between hubs and the spacer in order to prevent sticking.
  • Slippage of hubs and a spacer allows large eccentricity and angular misalignment to be accepted.
  • A projection placed in the spacer (resin pin) allows angular misalignment to be effortlessly accepted.
  • The grease accumulated in a grease hole will gradually seep out during operation, thereby maintaining the lubrication property over a long period.

MOM/MOM-C/MOM-K/MOM-CK_CFlexible Couplings - Oldham Type


Application

Mixer / Pump / Small power press / Grinder

Precautions for Use

In case of mounting on D-cut shaft, be careful about the position of the D-cut surface of the shaft. ⇒Mounting and Maintenance
There are sizes where the hex socket head bolt exceeds the outer diameter of the coupling and the rotating diameter is larger than the outer diameter. Please be careful of the interference of coupling. 


Selection

Selection Based on Shaft Diameter and Rated Torque

The area bounded by the shaft diameter and rated torque indicates the selection size.

MOM/MOM-C/MOM-K/MOM-CK_CFlexible Couplings - Oldham Type

MOM/MOM-C/MOM-K/MOM-CK_CFlexible Couplings - Oldham Type

Selection Example

In case of selected parameters of shaft diameter of φ6 and load torque of 4N•m, the selected size is MOM-17.

Details of Shaft Hole

MOM-CKFlexible Couplings - Oldham Type - Clamping + Key Type

Unit : mm

Standard Bore Diameter
D
Keyway Key
b t Nominal Dimension
b x h
Standard Dimension Allowance
(JS9)
Standard Dimension Allowance
6・6.35 2 ±0.0125 1.0 0 - +0.1 2 × 2
8 3 ±0.0125 1.4 0 - +0.1 3 × 3
10・12 4 ±0.0150 1.8 0 - +0.1 4 × 4
14・15・16 5 ±0.0150 2.3 0 - +0.1 5 × 5
18・20・22 6 ±0.0150 2.8 0 - +0.1 6 × 6
24・25・28・30 8 ±0.0180 3.3 0 - +0.2 8 × 7
35 10 ±0.0180 3.3 0 - +0.2 10 × 8

Excerpt from JIS B 1301


Comparison of Rated Torque

MOM-CKFlexible Couplings - Oldham Type - Clamping + Key Type

Comparison of Static Torsional Stiffness

MOM-CKFlexible Couplings - Oldham Type - Clamping + Key Type


Change in static torsional stiffness due to temperature

This is a value under the condition where the static torsional stiffness at 20°C is 100%. The change of MOM in torsional stiffness due to temperature is small and the change in responsiveness is extremely small.
If the unit is used under higher temperature, be careful about misalignment due to elongation or deflection of the shaft associated with thermal expansion.

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information


Max. Lateral Misalignment

MOM's max. lateral misalignment varies depending on the load torque and revolution.

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information

  • Example

When load torque is 25 N•m and revolution is 1000 min-1, the max. lateral misalignment of MOM-55 is 0.5 mm.

MOM/MOM-C/MOM-K/MOM-CK_TTechnical Information


Product List

Customer Service

  • Usage Method
  • Technical Question
  • Customization Products
USA and Canada

NBK America LLC

9:00 to 17:00 on weekdays, Eastern Standard Time

Asia and Europe

Nabeya Bi-tech Kaisha

9:00 to 17:15 on weekdays, Japan Standard Time