Planar double enveloping worm drive capable of maintaining precision after wear of worm gear teeth

Abstract

The invention provides a planar double enveloping worm drive capable of maintaining precision after wear of worm gear teeth. A tooth portion of a worm gear is composed of gear teeth which are formed by feed machining of a cutter along an axis direction of the worm gear or along a rectilinear direction forming a certain angle with an axis of the worm gear, and are consistent in tooth profile along a tooth length direction of the gear teeth. A tooth crest of the worm gear is a cylindrical surface, tooth surfaces on two sides of each gear tooth of the worm gear are planes, and inclination angles of the tooth surfaces, relative to the axis of the worm gear, on two sides of each gear tooth of the worm gear are equal. A worm is meshed with the worm gear and can move along the axis of the worm gear; when the worm moves along the axis of the worm gear to different positions, tooth surfaces on two sides of the worm are enveloping surfaces which are respectively formed by generating movement according to the meshing relationship of the worm gear and the worm by taking the tooth surfaces on the corresponding sides of the gear teeth of the worm gear as generatrices. According to characteristics of distribution of contact lines, after the gear teeth of the worm gear are worn, the worm is moved into an area in which the gear teeth of the worm gear are not in contact with the worm to be worn, and service life is prolonged under the condition that contact performance is unaffected.

Description

technical field [0001] The invention relates to a worm drive, in particular to a planar enveloping toroidal worm drive capable of maintaining precision after the gear teeth of the worm gear are worn. Background technique [0002] The worm drive belongs to the cross-shaft drive, which has the characteristics of compact structure, stable transmission, low noise and small motion error. Therefore, it is widely used in mechanical equipment as a reduction device and precision transmission device. With the development of precision machinery, the requirements for precision indexing and precision reducers are getting higher and higher, and the demand is also increasing. Compared with ordinary worm drives, planar enveloping toroidal worm drives have the following advantages in addition to all the advantages of ordinary worm drives: [0003] 1) The number of teeth that the ordinary worm transmission contacts at the same time is 1-2, while the number of teeth of the worm surrounded by...

AI Technical Summary

Problems solved by technology

[0008] 1) Since the worm wheel is easy to wear, and the worm hardly wears, the unworn worm cannot move to the wedge-shaped area of ​​the unworn worm wheel, which is smaller than it, and the backlash cannot be adjusted after the worm wheel is worn.

[0009] 2) Due to the influence of the load, the wear of the worm gear tooth surface cannot be guaranteed to be uniform. Therefore, after wear, the backlash-adjustable planar enveloping toroidal worm drive will lose its original accuracy.

[0011] It can be seen that the above-mentioned existing planar enveloping toroidal worm drive obviously still has inconvenience and defects in product structure, method and use, and needs to be further improved urgently.

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