As the professional manufacturer and develper of linear transmission, various screw jack is NOSEN’s main product.
There are certain clearance inside the internal parts,if it not exists,tremendous and unimagenable friction would be imposed to worm and gear. Screw jack is a common device for linear transmissio-n. With the longer use consumption, the increase abrasion causes a larger clearance.
The clearance is a representative of working accuracy of parts, there are mainly two factors that related with the clearance inside the screw jack:
1. Error compensation
Compensation for axial turbulence
Firstly, the perpendicularity error of the bearing positioningand the center line on the main shaft and its direction should be measured. Then measure the error of the end circular runout of the thrust bearing and its highest position, and finally makes that shift to the highest point. All those steps boost the conjoint installation of that and the lowest point of circular end of the thrust bearing, to reduce the amount of error in axial turbulence.
2. Shif compensation
When the lead angle of the worm is smaller than the equivalent friction angle between the mesh-ing teeth, product has self-locking property, that is ,the worm gear can only be driven by the wor-m shaft, and the worm shaft can not be driven by the worm gear. For example, in the self-locking worm mechanism used in some heavy machinery, the reverse self-locking property can safely protecting the machine. Error compensation is an adjustment method to ensure the accuracy of motion track of equipment by properly fitting the parts themselves and generating a certain degree of mutual cancellation. There are two common ways to compensate the error -- shift compensation & comprehensive compensation.
The internal clearance could be manually adjusted, which means that the center line of the main shaft in the same axial plane should be on the same side, and the error value of the front bearing is smaller than the error value of the rear bearing. The worm & gear contact in line, and their carrying capacity is much higher than that of the crossed helical gears.
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