WJ/WJS Ball Hinge Universal Joint Coupling | 6.3-1120 N·m, 45° Angle

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WJ/WJS Ball Hinge Universal Joint Coupling – Single/Double, JB/T6139-1992, 42CrMo

Model Number
Check below, custom

Outer Diameter (mm)	Length (mm)	Bore Diameter Range (mm)
14	22	3–8
20	25	3–10
20	30	3–10
25	30	4–14
25	35	4–14
30	35	5–16
30	42	5–16
35	50	5–19
40	50	6–22
40	66	6–22
45	55	8–25
45	66	8–25
55	66	12–30
55	78	12–30
65	90	14–38
80	114	14–45

Note: Non‑standard customization is also available (as indicated in the original text). All dimensions are in millimeters (mm).

Product Description

WJ/WJS Ball Hinge Universal Joint Coupling – Single/Double, JB/T6139-1992, 42CrMo, 6.3–1120 N·m

The Apexcoupling WJ/WJS series is a precision ball hinge universal joint coupling manufactured to the JB/T6139-1992 standard. Unlike traditional cross-shaft designs, this coupling uses spherical components as the hinge point, resulting in a simpler structure, smaller volume, and smoother operation. Available in single joint (WJ) and double joint (WJS) configurations, it is ideal for applications requiring reliable power transmission between non-collinear shafts with an axis angle of up to 45°. Manufactured from 42CrMo alloy steel with an optional 304 stainless steel finish, the WJ/WJS series delivers high strength, excellent wear resistance, and long service life in demanding industrial environments.

✅ Ball hinge design replaces cross shafts for smooth, reliable operation. Simple structure, compact size, and easy maintenance. Single or double joint options for angular and parallel misalignment compensation. H7 precision bore with keyway, square, or hexagon hole options.

Key Technical Specifications

Parameter	WJ Series (Single)	WJS Series (Double)
Standard	JB/T6139-1992	JB/T6139-1992
Structure	Single ball hinge universal joint	Double ball hinge universal joint
Nominal Torque Range	6.3 – 1120 N·m	100 – 1120 N·m
Allowable Speed	500 – 1000 RPM	500 – 780 RPM
Maximum Axis Angle	45° (per joint)	45° (per joint)
Outer Diameter (D)	16 – 95 mm	32 – 95 mm
Bore Size (d)	6 – 50 mm	16 – 50 mm
Total Length (L)	34 – 190 mm	100 – 290 mm
Bore Tolerance	H7	H7
Bore Options	Y (keyway), Φ (round), S (square), F (hexagon)	Y (keyway), Φ (round), S (square), F (hexagon)
Body Material	42CrMo alloy steel (standard); optional: 304/316 stainless steel	42CrMo alloy steel (standard); optional: 304/316 stainless steel
Surface Treatment	Black oxide, polished, nickel plated, zinc plated, chrome plated	Black oxide, polished, nickel plated, zinc plated, chrome plated
Customized support	OEM, ODM, OBM	OEM, ODM, OBM
Place of Origin	Guangdong, China	Guangdong, China

🔧 Custom bores, keyways, and special materials available. Contact us with your specifications.

WJ (Single) vs WJS (Double) – Which One Do You Need?

Feature	WJ (Single Joint)	WJS (Double Joint)
Angular misalignment	✅ Up to 45°	✅ Up to 45° per joint
Parallel offset	❌ No	✅ Yes
Total articulation	Up to 45°	Up to 90°
Length	Shorter	Longer
Torque capacity	Higher for size	Slightly lower
Best for	Constant-angle, uniform-load applications	Applications with varying angles and offsets
Output speed	Fluctuates with angle	Constant velocity (with proper phasing)

Rule of thumb:

Use WJ (single joint) for applications where the shaft angle is constant and torque requirements are higher.
Use WJS (double joint) for applications where the shaft angle changes during operation or where parallel offset must be accommodated.

💡 For constant velocity: Double joint (WJS) configurations can achieve constant velocity operation by maintaining equal angles on both joints and aligning the yokes correctly.

Ball Hinge Design – Advantages Over Cross Shafts

The ball hinge (spherical) design offers several distinct advantages over traditional cross-shaft universal joints:

Feature	Ball Hinge (WJ/WJS)	Cross Shaft (Traditional)
Structure	Simple, compact	Complex, bulkier
Operation	Smooth, flexible	Can be stiff at high angles
Maintenance	Easy	More complex
Torque capacity	Good for the size	Higher for the size
Angle capability	Up to 45°	Up to 45°
Synchronous rotation	Yes (single)	No (without double joint)

✅ The ball hinge design replaces the cross shaft with spherical components, creating a more compact and smoother-operating coupling that is easier to maintain.

WJ/WJS Series – Model Range & Specifications (Reference)

WJ Series (Single Joint) – JB/T6139-1992

Model	Nominal Torque (N·m)	Max Speed (RPM)	D (mm)	d Cylindrical (mm)	L1 (mm)	L (mm)	Weight (kg)
WJ1	6.3	1000	16	6	9	34	0.05
WJ2	12.5	1000	18	8	11	40	0.06
WJ3	25	980	22	10	12	45	0.1
WJ4	40	900	26	12	13	50	0.15
WJ5	63	820	29	14	16	56	0.2
WJ6	100	780	32	16	18	65	0.3
WJ7	140	720	37	18	20	72	0.45
WJ8	224	680	42	19	23	82	0.67
WJ9	280	650	47	22	25	95	1
WJ10	355	620	52	25	29	108	1.35
WJ11	450	600	58	30	34	122	1.85
WJ12	560	570	70	35	39	140	3.15
WJ13	710	550	80	40	44	160	4.6
WJ14	1120	500	95	50	46	190	–

📐 Complete dimensional data available upon request. Contact our engineering team for custom sizing.

Model Designation – WJ/WJS Series

WJ = Single ball hinge universal joint
WJS = Double ball hinge universal joint

Bore Type	Designation	Description
Round Hole	Φ	Plain cylindrical hole with taper pin
Keyway	Y	Cylindrical hole with key and set screw
Square Hole	S	Square hole with set screw
Hexagon Hole	F	Hexagon hole with set screw

Marking Example:
WJS4–YA16/S18

WJS4 = Double ball hinge coupling, size 4
Y = Active end with keyway
A16 = Keyway type A, bore 16mm
S18 = Driven end with square hole, 18mm

Product Features & Advantages

Advantage	Benefit
Ball Hinge Design	Replaces cross shafts for simpler, smoother, and more reliable operation
42CrMo Alloy Steel	High strength, toughness, and fatigue resistance – quenched and tempered for durability
304 Stainless Steel Option	Corrosion-resistant – ideal for food & beverage, chemical, and outdoor applications
45° Angle Per Joint	Large angular compensation – accommodates significant misalignment
Double Joint (WJS) Capability	Up to 90° total articulation – handles both angular and parallel offset
H7 Precision Bore	High concentricity, accurate shaft fit – reduces vibration
Multiple Bore Options	Round, keyway, square, hexagon – choose your connection type
Synchronous Rotation	Single joint achieves synchronous rotation of main and driven shafts
Constant Velocity (WJS)	Double joint achieves constant velocity with proper phasing
Compact & Lightweight	Small volume and low weight – ideal for space-constrained applications
Low Maintenance	Simple design – easy to maintain and service
Multiple Surface Finishes	Black oxide, polished, nickel plated, zinc plated, chrome plated
Wide Application Range	Packaging, woodworking, multi-spindle drills, metallurgy, conveying, and automation

Applications

Packaging Machinery – Conveyors, wrapping machines, carton sealers
Woodworking Machinery – Multi-spindle drills, routers, saws
Multi-Spindle Drills – Precision drilling operations
Conveyor Systems – Material handling and transport
Paper Machinery – Paper production and finishing
Elevators & Lifts – Vertical transport systems
Tea Processing Equipment – Tea leaf processing machinery
Metallurgical Equipment – Rolling mills, continuous casting lines
General Automation – Pick-and-place systems, indexing tables
Low-Speed, High-Angle Applications – Equipment requiring flexible shaft connections at slow speeds

Why Choose Apex Coupling for WJ/WJS Universal Joints?

Advantage	Description
Factory Direct	Competitive B2B pricing – no middlemen
JB/T6139-1992 Standard	Manufactured to established Chinese national standard
Ball Hinge Design	Simpler, smoother, and more reliable than cross-shaft designs
Premium 42CrMo Steel	High strength, toughness, and fatigue resistance
304 Stainless Steel Option	Corrosion-resistant for demanding environments
Single or Double Joint	One product family covers all angular and offset needs
H7 Precision Bore	High accuracy, low backlash, reliable operation
Multiple Bore Options	Round, keyway, square, hexagon – fully customizable
OEM Customization	Custom bores, materials, and finishes available
Large Semi-Finished Stock	Fast delivery for standard and custom orders

FAQ

Q: What is a ball hinge universal joint?
A: A ball hinge universal joint uses spherical components as the hinge point instead of a cross shaft. This results in a simpler structure, smaller volume, smoother operation, and easier maintenance compared to traditional cross-shaft designs.

Q: What is the difference between WJ and WJS?
A: WJ is a single ball hinge universal joint – for angular misalignment only. WJS is a double ball hinge universal joint – allows both angular misalignment and parallel offset, with up to 90° total articulation.

Q: What is the maximum operating angle?
A: Each joint can operate up to 45°. For single joint (WJ), total articulation is up to 45°. For double joint (WJS), total articulation is up to 90°.

Q: What is the torque and speed range?
A: WJ series covers 6.3–1120 N·m at 500–1000 RPM. WJS series covers 100–1120 N·m at 500–780 RPM.

Q: What materials are available?
A: Standard is 42CrMo alloy steel. We also offer 304 and 316 stainless steel.

Q: What bore types are available?
A: We offer round (Φ), keyway (Y), square (S), and hexagon (F) hole options.

Q: What is the bore tolerance?
A: Standard finished bore tolerance is H7.

Q: Can double joint (WJS) achieve constant velocity?
A: Yes. With proper phasing (equal angles on both joints and aligned yokes), the WJS double joint can achieve constant velocity rotation.

Q: What are the common applications?
A: Packaging machinery, woodworking equipment, multi-spindle drills, conveyors, paper machinery, elevators, tea processing equipment, and general automation.

Q: Can I get a custom coupling?
A: Yes. We offer OEM customization – custom bores, materials, and finishes available.

Request a Quote

Send us your configuration (WJ single or WJS double), bore type, bore size, torque, and application details. Our engineers will recommend the optimal model and provide a quotation within 24 hours.