rapezoidal Screw Jack – JWM Series: Self-Locking, Low Speed, Heavy Load
Trapezoidal Screw Jack – JWM Series
The trapezoidal screw jack (JWM type) is a screw lift that uses a precision trapezoidal screw pair and a high-precision worm gear pair. The trapezoidal screw operates on sliding friction – the screw and nut surfaces slide against each other.
Main features of JWM trapezoidal elevator/screw jack
●Self locking - trapezoidal screw automatically locks, able to maintain load even without braking device
●Economically efficient - simple structure, easy operation, and low maintenance costs
●Compact design - saves installation space
●Heavy load capability - designed specifically for large loads
JWM series is ideal for:
●Low-speed, low-frequency operations
●Heavy loads with infrequent movement
●Load holding applications where stopping position must be maintained
Limitations
●Lower efficiency (approx. 26%-46%) – sliding friction generates heat
●Not suitable for high-speed transmission – temperature rise is significant
●Self-locking may fail under severe vibration or shock loads – external brakes may be required
Typical Applications
JWM screw jacks are widely used in mechanical equipment, water conservancy, metallurgy, and construction industries for lifting, lowering, pushing, and tilting