Skip to main content
Home / Couplings / DJM Single Diaphragm Coupling 45# Steel, SJM Double Diaphragm Stainless Steel Expansion Sleeve Type Elastic Servo Motor Coupling

Attributes

Brand -
Category Standard Parts, Components & Industrial Consumables / Couplings
Origin -
Material 45# Steel / Stainless Steel
Coupling Type Diaphragm / Expansion Sleeve
Application Servo Motor Systems
Torque Capacity High Torque Transmission
Speed Rating High Speed Operation
Misalignment Compensation Angular, Parallel, and Axial
Backlash Zero Backlash Design
Operating Temperature -20°C to +120°C
Surface Treatment Black Oxide / Polished
Installation Method Clamping Screw Fixation

6 reviews

A

Anonymous

Mar 19, 2026

Rating: 4/5

Good value for money

Compared to imported brands, these offer similar performance at a better price point. The packaging was secure, and all mounting screws were included.

A

Anonymous

Mar 17, 2026

Rating: 5/5

Excellent torque transmission

No slippage even under heavy load startups. The diaphragm design absorbs shock loads effectively, protecting our sensitive encoder equipment.

A

Anonymous

Mar 09, 2026

Rating: 5/5

Durable and reliable

Running these in a dusty industrial environment for six months now with no signs of wear. The 45# steel construction holds up well against minor impacts and debris.

A

Anonymous

Mar 09, 2026

Rating: 4/5

Great quality, slightly tight fit

The build quality of the stainless steel version is excellent. It took a bit more effort to install due to the tight tolerance on the expansion sleeve, but once seated, it is rock solid.

A

Anonymous

Mar 05, 2026

Rating: 5/5

Solved our alignment issues

We had persistent wear issues with old jaw couplings. Switching to this diaphragm type allowed us to accommodate slight misalignments without transferring stress to the motor bearings. Game changer.

A

Anonymous

Mar 01, 2026

Rating: 5/5

Perfect for high-speed servo applications

Installed these on our CNC milling machine spindles. The zero backlash is noticeable immediately, and the vibration levels have dropped significantly. Highly recommended for precision work.

5 FAQ

Q: What is the maximum allowable angular misalignment for the SJM series?

A: The SJM Double Diaphragm series typically allows for up to 1.5 degrees of angular misalignment, depending on the specific model size.

Q: Are replacement diaphragms available if they get damaged?

A: The diaphragm is an integral part of the assembly for optimal balance. In case of damage, we recommend replacing the entire coupling unit rather than individual components.

Q: How do I determine the correct bore size for my motor shaft?

A: Please refer to the detailed dimension chart in the product manual. You can also contact our support team with your motor model number for a precise recommendation.

Q: Can I use the 45# Steel version in a humid environment?

A: While the 45# Steel has a protective coating, we recommend the Stainless Steel (SJM) version for highly humid or corrosive environments to ensure long-term durability.

Q: Does this coupling require lubrication during operation?

A: No, the diaphragm design is maintenance-free and does not require any lubrication, making it ideal for clean environments.

Explore your interests

View More
All Categories
Best Seller (30)
New List (30)
Ammonia Decomposition Hydrogen Production Equipment, Ammonia Cracking Furnace, Liquid Ammonia to Hydrogen System, Air Separation Unit

Ammonia Decomposition Hydrogen Production Equipment, Ammonia Cracking Furnace, Liquid Ammonia to Hydrogen System, Air Separation Unit

$15,479.00

Strawberry Planting Trough - Soil-Free A-Frame Vertical Planter for Vegetables and Fruits

Strawberry Planting Trough - Soil-Free A-Frame Vertical Planter for Vegetables and Fruits

$14.80

Forged Steel Wheel Hub Bolts Grade 12.9 Extended Screws Fade-Resistant for VW, Audi, Mercedes-Benz, BMW

Forged Steel Wheel Hub Bolts Grade 12.9 Extended Screws Fade-Resistant for VW, Audi, Mercedes-Benz, BMW

$95.00

Retainer Storage Case Orthodontic Appliance Soaking Cleaning Box Portable Invisible Aligner Holder for Dentures

Retainer Storage Case Orthodontic Appliance Soaking Cleaning Box Portable Invisible Aligner Holder for Dentures

$2.80

Baby Sheepskin Rattle and Shaker Stick - Brass and Peach Wood, Old-Style Handmade, Chewable, Newborn Gift Box

Baby Sheepskin Rattle and Shaker Stick - Brass and Peach Wood, Old-Style Handmade, Chewable, Newborn Gift Box

$74.00

Portable Orthodontic Retainer Cleaning Case - Rotating Travel Box for Invisible Aligners

Portable Orthodontic Retainer Cleaning Case - Rotating Travel Box for Invisible Aligners

$17.60

Full Denture Soaking and Storage Box with Filter Net for Retainers and False Teeth

Full Denture Soaking and Storage Box with Filter Net for Retainers and False Teeth

$4.80

Anka Bella Face Painting Pen Facial Special Brush Embossing Pen Line Drawing Petal Professional Pigment Pen

Anka Bella Face Painting Pen Facial Special Brush Embossing Pen Line Drawing Petal Professional Pigment Pen

$4.17

Balloon Warm Star Pre-sale: Do You Have an Illness? Phase 1 - Clash of Hearts Little Chu Su Series Merchandise

Balloon Warm Star Pre-sale: Do You Have an Illness? Phase 1 - Clash of Hearts Little Chu Su Series Merchandise

$16.00

Car Tire Stone Removal Hook - Portable Multi-function Tool for Cleaning Gravel from Tire Treads

Car Tire Stone Removal Hook - Portable Multi-function Tool for Cleaning Gravel from Tire Treads

$7.00

Imported TRANS Gearbox Eccentric Bearing 614 59 7187 616 0608 11-15 11 YSX

Imported TRANS Gearbox Eccentric Bearing 614 59 7187 616 0608 11-15 11 YSX

$183.00

Sichuan Rongxian Earthware Minfeng Wine Jar, Home Pottery with Porcelain Liner, 600-Jin Unglazed Sealed Fermentation Vessel for Homemade Liquor

Sichuan Rongxian Earthware Minfeng Wine Jar, Home Pottery with Porcelain Liner, 600-Jin Unglazed Sealed Fermentation Vessel for Homemade Liquor

$901.00

Garlic Drum Sorting Machine - Single-Clove Garlic Grading Separator and Onion Sizing Sorter - Factory Direct Sales

Garlic Drum Sorting Machine - Single-Clove Garlic Grading Separator and Onion Sizing Sorter - Factory Direct Sales

$38,080.00

Aizaofang Food-Grade Soft Silicone Handmade Soap Mold Korean Rectangular 3D Tree Shadow Silicone Mold

Aizaofang Food-Grade Soft Silicone Handmade Soap Mold Korean Rectangular 3D Tree Shadow Silicone Mold

$23.00

JMC Yusheng & Yuhu Parts – Crankshaft Position Sensor, Signal Sensor, Original Equipment

JMC Yusheng & Yuhu Parts – Crankshaft Position Sensor, Signal Sensor, Original Equipment

$95.00

[10% Off for 2 Items] Calligraphy Wool Felt Mat - Double-Sided Painted Practice Pad for Students, Bulk Wholesale, Includes Arm Rest and Four Treasures of the Study Set

[10% Off for 2 Items] Calligraphy Wool Felt Mat - Double-Sided Painted Practice Pad for Students, Bulk Wholesale, Includes Arm Rest and Four Treasures of the Study Set

$6.63

Leak-Proof Retainer Case with Double-Layer Filter for Braces, Aligners, and Dentures - Portable Cleaning and Soaking Box

Leak-Proof Retainer Case with Double-Layer Filter for Braces, Aligners, and Dentures - Portable Cleaning and Soaking Box

$22.50

Car Tire Stone Removal Hook Tool, Explosive Tire Prevention Gadget, Durable Zinc Alloy Tire Cleaning Hook for Automotive Care

Car Tire Stone Removal Hook Tool, Explosive Tire Prevention Gadget, Durable Zinc Alloy Tire Cleaning Hook for Automotive Care

$10.90

[Damai Micro-Needle Hair Transplant Patent] Micro-Needle Planting (500 Units) - Suitable for Temples and Hairline

[Damai Micro-Needle Hair Transplant Patent] Micro-Needle Planting (500 Units) - Suitable for Temples and Hairline

$4,500.00

Japan Original FEC Lifting Chain - Specialized for Electric Hoist, 6.3mm Diameter Carburized Lifting Chain

Japan Original FEC Lifting Chain - Specialized for Electric Hoist, 6.3mm Diameter Carburized Lifting Chain

$223.00

X-RAY Coating Thickness Gauge - Desktop Tianrui Professional Analyzer for Metal Electroplating Layers

X-RAY Coating Thickness Gauge - Desktop Tianrui Professional Analyzer for Metal Electroplating Layers

$9,589.60

Heavy Truck Tire Cleaning Strips - Wear-Resistant Mud Flaps and Inner Tube Skirts - Decorative Tire Tassels

Heavy Truck Tire Cleaning Strips - Wear-Resistant Mud Flaps and Inner Tube Skirts - Decorative Tire Tassels

$9.05

Mixue Bingcheng Tanned Snow King Blind Box Figure Girls Gift Birthday Cute Plush Keychain Holiday Present

Mixue Bingcheng Tanned Snow King Blind Box Figure Girls Gift Birthday Cute Plush Keychain Holiday Present

$21.01

Smart Battery Tester with Full Protection - Performance Detector for EV and Car Batteries

Smart Battery Tester with Full Protection - Performance Detector for EV and Car Batteries

$269.00

Schneider Leakage Switch IC65 Vigi C120H 2/4P D80/100/125A Leakage Circuit Breaker

Schneider Leakage Switch IC65 Vigi C120H 2/4P D80/100/125A Leakage Circuit Breaker

$1,347.75

Wenxin Tang Pumpkin-Shaped Ceramic Water Pot - Small Celadon Glaze Brush Washer for Chinese Calligraphy

Wenxin Tang Pumpkin-Shaped Ceramic Water Pot - Small Celadon Glaze Brush Washer for Chinese Calligraphy

$18.50

Dehua Mutton Fat White Porcelain Brush Washer - Minimalist Modern Ceramic Water Pot and Scholar's Desk Ornament

Dehua Mutton Fat White Porcelain Brush Washer - Minimalist Modern Ceramic Water Pot and Scholar's Desk Ornament

$39.70

Lifting Chain Slings, Four-Leg Chain Rigging with Hooks and Shackles, Manganese Steel Chains for Crane Hoisting

Lifting Chain Slings, Four-Leg Chain Rigging with Hooks and Shackles, Manganese Steel Chains for Crane Hoisting

$79.20

Taikang Bybo Dental Straumann ITI Dental Implant Metal Abutment TK

Taikang Bybo Dental Straumann ITI Dental Implant Metal Abutment TK

$8,330.00

Factory Supply Adjustable Radish Strip Cutter, Multi-Function Vegetable Slicer for Green Radishes

Factory Supply Adjustable Radish Strip Cutter, Multi-Function Vegetable Slicer for Green Radishes

$5,395.00