A: The trapezoidal screw jack uses an acme threaded screw that is completely self-locking, meaning it will hold its position without a brake mechanism or locking systems. Ball screw jack use ball screws and ball nuts to convert rotary motion to linear movement, and require approx. 1/3 the horsepower compared to a acme screw jack. Due to the efficiency of the ball screw, brake mechanism must be used to stop and hold the lifting screw in position. ……
Posted Date: 2014/07/22

A: When a rubber bellows is ordered for a jack, the closed height dimensions may change. When ordering a rubber bellows for an inverted jack, need to consider the closed height of the rubber bellows and structure thickness. Usually, under fully retracted, the rubber bellows closed height =0.13* travelling strokes. For example, upright mounting, request 1000mm stroke, plus rubber bellows closed height 0.13*1000=130mm. So need to order at least 113 ……
Posted Date: 2014/08/18

A: For translating screw jacks are fitted with a steel protective tube that stores the lifting screw when the screw jack is in the closed position. Rubber bellows are available and recommended to protect the lifting screw in the extended position. Two rubber bellows many be required for rotating screw jacks with traveling nuts.
Posted Date: 2014/08/18

A: Using standard greases and oil seals, the screw jack working temperature is from -20 degree to 100 degree. At present, we have customer use the screw jack at 300 degree with special grease and seals. Any special working temperature, please tell SIJIE sales or engineer before selecting models.
Posted Date: 2014/08/18

A: Yes, self locking, it depends on pitch, larger pitch, lower self locking. Larger speed ratio, higher self-locking. To self-locking completely, extra add braking motor.
Posted Date: 2014/07/26