• Couplings
  • Jaw Type

Flexible Couplings - Jaw Type (Bushing)

MJB-BL

Safety PrecautionsGlossaryMounting/maintenance

RoHS Compliant

  • High Torque
  • Vibration absorption characteristics
  • Electrical Insulation
MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)

Dimension Drawing

MJB-BLFlexible Couplings - Jaw Type (Bushing)寸法図

Specs/CAD

Part Number ALWBCM Number of Bolts M' Screw Tightening
Torque (N・m)		Standard Bore Diameter
D1-D2		 Price
(USD)		 CAD
Download		 Add to Cart
MJB-40-BL 40 25 66 12 2 M4 6 M4 4 146.96 CAD Cart
MJB-55-BL 55 30 78 14 2 M5 4 M5 8.5 209.46 CAD Cart
MJB-65-BL 65 35 90 15 2.5 M5 8 M5 8.5 368.27 CAD Cart
MJB-80-BL 80 45 114 18 3 M6 8 M6 14 461.56 CAD Cart
MJB-95-BL 95 50 126 20 3 M8 8 M8 35 573.08 CAD Cart

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. Lateral Misalignment
(mm)		Max. Angular
Misalignment
(°)		 Max. Axial
Misalignment
(mm)		Sleeve Hardness Mass
(g) ＊2
MJB-40-BL 20 4.9 9.8 23000 8.6×10-5 380 0.15 1 0～+1.2 A80 400
MJB-55-BL 28 17 34 17000 3.7×10-4 1400 0.2 1 0～+1.4 A80 800
MJB-65-BL 38 46 92 14000 8.0×10-4 2800 0.2 1 0～+1.5 A80 1100
MJB-80-BL 45 95 190 11000 2.5×10-3 3200 0.2 1 0～+1.8 A80 2300
MJB-95-BL 50 130 260 10000 5.4×10-3 3600 0.2 1 0～+2.0 A80 4000

＊1：　Correction of rated torque and max. torque due to load fluctuation is not required. However, if ambient temperature exceeds 30°C, be sure to correct the rated torque and max. torque with temperature correction factor shown in the following table.

The allowable operating temperature of MJB is -20°C to 60℃.

※ The shaft's slip torque may be smaller than the coupling's rated torque depending on the shaft bore. MJB-BLMJB-GRMJB-RDMJB-WHMJB-EBLMJB-EGRMJB-ERD

＊2：　These are values with max. bore diameter.

Part Number Standard Bore Diameter D1･D2
8 9.525 10 11 12 14 15 16 18 19 20 22 24 25 28 30 32 35 38 40 42 45 48 50
MJB-40-BL ● ● ● ● ● ● ● ● ● ● ● - - - - - - - - - - - - -
MJB-55-BL - - ● ● ● ● ● ● ● ● ● ● ● ● ● - - - - - - - - -
MJB-65-BL - - - - - ● ● ● ● ● ● ● ● ● ● ● ● ● ● - - - - -
MJB-80-BL - - - - - - - - - - ● ● ● ● ● ● ● ● ● ● ● ● - -
MJB-95-BL - - - - - - - - - - - - - ● ● ● ● ● ● ● ● ● ● ●

● All products are provided with hex socket head cap screw.
● Recommended tolerance for shaft diameters is h6 and h7.
●For the shaft insertion amount to the coupling, see Mounting/maintenance. ⇒Mounting and Maintenance


Part Number
Amount
Price（＄）

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Additional Modification Service

Modified Part Number

Enter the desired bore diameter and then click [Check Modified Part Number].

Standard bore diameter(D1) Standard bore diameter(D2) Modified Part Number Price Add to cart

unit:mm
Applicable Bore Diameter
D1D2		 keyway Key
b t Nominal Dimension
b×h
Standard Dimension Allowance
(JS9)		 Standard Dimension Allowance
6 7       2 ±0.0125 1.0 +0.1
0 		2×2
8 9 10     3 ±0.0125 1.4 3×3
11 12       4 ±0.0150 1.8 4×4
13 14 15 16 17 5 ±0.0150 2.3 5×5
18 19 20 22   6 ±0.0150 2.8 6×6
24 25 28 30   8 ±0.0180 3.3 +0.2
0 		8×7
32 35 36 38   10 ±0.0180 3.3 10×8
40 42 44     12 ±0.0215 3.3 12×8
45 48 50     14 ±0.0215 3.8 14×9
55 16 ±0.0215 4.3 16×10

unit:inch
Standard Inch Bore Diameter
D1D2		 Keyway
Wk T
Standard Dimension Allowance Standard Dimension Allowance
1/2 1/8 +0.002
  0		 0.560 +0.01
  0
9/16 1/8 +0.002
  0		 0.623 +0.01
  0
5/8 3/16 +0.002
  0		 0.709 +0.01
  0
11/16 3/16 +0.002
  0		 0.773 +0.01
  0
3/4 3/16 +0.002
  0		 0.837 +0.01
  0
13/16 3/16 +0.002
  0		 0.900 +0.01
  0
7/8 3/16 +0.002
  0		 0.964 +0.01
  0
15/16 1/4 +0.002
  0		 1.051 +0.01
  0
1 1/4 +0.002
  0		 1.114 +0.01
  0
1-1/8 1/4 +0.002
  0		 1.241 +0.01
  0
1-1/4 1/4 +0.002
  0		 1.367 +0.01
  0
1-3/8 5/16 +0.002
  0		 1.518 +0.01
  0
1-1/2 3/8 +0.002
  0		 1.669 +0.01
  0
1-5/8 3/8 +0.002
  0		 1.796 +0.01
  0
1-3/4 3/8 +0.002
  0		 1.922 +0.01
  0

Ambient Temperature / Temperature Correction Factor

Ambient Temperature Temperature Correction Factor
-20℃ to 30℃ 1.00
30℃ to 40℃ 0.80
40℃ to 60℃ 0.70

Slip torque

As in the table below, the bushing type MJB has different slip torque according to the bore diameter. Take care during selection.

Unit : N・m

Part Number Bore Diameter (mm)
10 11 12 14 15 16 18 19 20 22 24 25 28 30 32 35 38 40 42 45 48 50
MJB-55 32 54 75 110 130
MJB-65 160 170 180 200 210 220 240 260 270 300 320 340 370
MJB-80 280 330 380 410 480 500 500 500 500 500 500 500
MJB-95 500 500 500 500 500 500 500 500 500 500 500

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 MJB 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

Bushing Type

MJB MJB-BL MJB-GR MJB-RD MJB-WH MJB-EBL MJB-EGR MJB-ERD MJB-EWH

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)

Sleeve

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)


Material/Finish

MJB
Hub S45C
Ferrosoferric Oxide Film (Black)＊1
Outer Ring S45C
Ferrosoferric Oxide Film (Black)
Sleeve Polyurethane
Hex Socket Head Cap Screw SCM435
Ferrosoferric Oxide Film (Black)

＊1：　With regard to bore surface treatment, process needs may result in a mixture of parts with and without surface treatment. This will not lead to any issues in terms of coupling performance.


Characteristics

  • Recommended Applicable Motor
Tight Fit Easy Fit
Servomotor ○ ●
Stepping Motor ○ ○
General-purpose Motor ◎ ◎

◎: Excellent ○: Very good ●: Available

  • Property
Tight Fit Easy Fit
High Torque ◎ ◎
Allowable Misalignment ○ ○
Vibration Absorption ◎ ◎
Electrical Insulation ◎ ◎
Assembling ○ ◎
Allowable Operating Temperature -20℃ to 60℃ -20℃ to 60℃

◎: Excellent ○: Very good

  • This is a jaw type flexible coupling.
  • Excellent for high torque transmission and ideal for machine tool spindles.
  • Excellent flexibility. Excellent flexibility allows eccentricity, angular misalignment and twisting vibration to be accepted.
  • It has electrical insulation. Resistance value: Not less than 2 MΩ
  • There are four types of sleeve hardness. Please select desirable units according to usage conditions including torque and misalignment.
  • Since the sleeve's vibration absorption of Tight Fit can raise the gain of a servomotor, this unit can achieve high responsive operation exceeding the Disk coupling.
  • Easy fit allows you to assemble and partition the hub and sleeve smoothly.
    This allows you to reduce the time of assembling the unit and maintenance.
  • Sleeve Type

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)


Application

Machine tool / Spindle

Selection

Selection Based on Shaft Diameter and Rated Torque

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

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_CFlexible Couplings - Jaw Type (Bushing)

Selection Example

In case of selected parameters of shaft diameter of φ 18 and load torque of 16 N•m, the selection size forMJB-＊＊-BLMJB-＊＊-EBLis MJB-55-BLMJB-55-EBL

Eccentric Reaction Force

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information


Sleeve Details

MJB-BLFlexible Couplings - Jaw Type (Bushing)


Change in static torsional stiffness due to temperature

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information

This is a value under the condition where the static torsional stiffness at 20°C is 100%.
Changes in the static torsion spring constant within the operating temperature are shown in the graph.
Before using the unit, be aware of the deterioration of responsiveness.

MJB-BL/MJB-GR/MJB-RD/MJB-WH/MJB-EBL/MJB-EGR/MJB-ERD/MJB-EWH_TTechnical Information


Product List

MJB-40-BL

MJB-55-BL

MJB-65-BL

MJB-80-BL

MJB-95-BL

Click here to see Jaw Type

MJS-CSK-ERD

Part Name

Flexible Coupling - Jaw-Type (Short) - Clamping + Key Type

Part Number

MJS-CSK-ERD

Feature

High Torque
Vibration Absorption
Electrical Insulation

MJS-CSK-EGR

Part Name

Flexible Coupling - Jaw-Type (Short) - Clamping + Key Type

Part Number

MJS-CSK-EGR

Feature

High Torque
Vibration Absorption
Electrical Insulation

MJB-WH

Part Name

Flexible Couplings - Jaw Type (Bushing)

Part Number

MJB-WH

Feature

High Torque
Vibration Absorption
Electrical Insulation

MJB-RD

Part Name

Flexible Couplings - Jaw Type (Bushing)

Part Number

MJB-RD

Feature

High Torque
Vibration Absorption
Electrical Insulation

Click here to see Couplings

Disk Type

Disk Type

Bellows Type

Bellows Type

Cross Joint Type

Cross Joint Type

Rigid Type

Rigid Type