Precise axial displacement transmission device

Abstract

A precise axial displacement transmission device of a box body structure comprises a box body, an input shaft, two transmission shafts and a parallelly-meshed threaded transmission pair consisting of three axis-coplaner screw shafts, namely two long threaded screw shafts and one short threaded screw shaft. One of the two long threaded screw shafts is supported in a front box body bearing hole to serve as a positioning reference for displacement transmission. The other one of the two long threaded screw shafts is supported in the front box body bearing hole to play a meshing gap eliminating role. The short threaded screw shaft is of a split structure formed by a taper pin connecting screw and a mandrel, and the mandrel is supported in the front box body bearing hole to play a displacement transmission role. The upper gear of an input shaft supported at the upper portion of a rear box body drives gears located at the rear ends of the three screw shafts respectively though gears on two middle transmission shafts so as to achieve differential rotation of the three screw shafts. Compared with a traditional screw and nut transmission pair, the minimum precision scale of axial displacement can be remarkably improved.

Description

technical field [0001] The invention relates to a precision axial displacement transmission device, which belongs to a screw transmission pair formed by a new meshing method. Background technique [0002] The traditional mechanical precision axial displacement transmission device mostly adopts the form of screw (screw) and nut. With the current processing methods and the strength requirements for the thread tooth shape, the thread pitch can only be in the order of millimeters to 1 / 10 millimeters . Therefore, the active part rotates once, and the driven part can only move axially at most a few tenths of a millimeter. In order to obtain a small axial displacement, the rotation angle of the active part must be very small. Due to the problems of inertia, static friction and rigidity in the system, the follower cannot follow the response 100%, resulting in errors. In addition, in order to obtain high axial displacement transmission accuracy for the traditional screw nut transmi...

AI Technical Summary

Problems solved by technology

Therefore, the active part rotates once, and the driven part can only move axially at most a few tenths of a millimeter. In order to obtain a small axial displacement, the rotation angle of the active part must be very small. Due to the problems of inertia, static friction and rigidity in the system, the follower cannot follow the response 100%, resulting in errors

In addition, in order to obtain high axial displacement transmission accuracy for the traditional screw nut transmission pair, the screw nut forming the transmission pair must achieve higher machining accuracy. The internal and external thread surfaces of the screw nut must be ground, but the internal thread with a small inner diameter Difficult to grind

Therefore, the improvement of axial displacement transmission accuracy is limited to a certain extent.

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