CN2397311Y

CN2397311Y - Backlash adjustable worm-gear and worm

Info

Publication number: CN2397311Y
Application number: CN 99241668
Authority: CN
Inventors: 张光辉
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-11-24
Filing date: 1999-11-24
Publication date: 2000-09-20
Anticipated expiration: 2009-11-24

Abstract

The utility model relates to a backlash adjustable type worm gear and worm which is characterized in that a tooth face of a worm gear 1 is a plane face, teeth of the worm wheel form a wedge shape along an axial direction, tooth planes at the corresponding sides of the wheel tooth of the plane worm wheel are respectively taken as female faces by the tooth faces on both sides of a worm 2, and a coated face which is formed by unfolding motion according to the engagement relation between the worm wheel and the worm. The utility model has the advantages of wide transmission ratio range, large loading capability, good engagement performance and reliable transmission and can be adjusted through the axial position of the worm wheel, when the transmission is changed, the tooth gap on the adjacent tooth surfaces or can compensate the thin reducing quantity of the tooth thickness of the abrased wheel teeth, and the utility model is suitable for the device such as an artillery, a machine tool, an elevator, etc.

Description

The side gap adjustable worm and gear

The utility model relates to a kind of worm and gear, especially the side gap adjustable worm and gear.

Worm drive belongs to the alternating axis transmission, has compact structure, stable drive, characteristics such as noise is low, and kinematic error is little.Thereby be widely used in the mechanized equipment as speed reducer and accurate transmission mechanism.Public worm drive at present mainly contains the transmission of straight-tooth wildhaber-wormaheel toroid helicoids worm, the toroid helicoids worm transmission of helical teeth wildhaber-wormaheel and dual lead cylindrical worm transmission.Wherein:

It is the spur gear of flank profil with the straight line that the worm gear of straight-tooth wildhaber-wormaheel toroid helicoids worm transmission is one, and the flank of tooth is the plane with the worm-wheel shaft line parallel; Worm screw is one to surround the toroid helicoids worm of worm gear, its flank of tooth be with above-mentioned worm-gear tooth plane as generatrix, make the envelope surface that generating motion forms by the meshing relation of worm gear and worm screw, belong to planar double enveloping worm.The deficiency of this transmission is: (1). by the worm screw that the horizontal frontal plane envelope forms, i is slightly little when velocity ratio, and i≤30 o'clock for example, the flank of tooth of worm screw entrance will produce undercut, when i≤60, the worm screw topping.Thereby be applicable to that velocity ratio greater than 30 motion transmission occasion, should not be used as power transmission.(2). the two halves worm gear of split type is because structural restriction generally can only lean on curve bath and bolt to compress, and reliability is not as the integrated type worm gear.(3) if worm gear is by the key connecting transmission on the keyway on the wheel hub and the axle, for guarantee wherein half worm gear relatively in addition half worm gear dislocation rotate, the keyway of worm gear don't fail to be widened, this backlash adjustment to transmission is made troubles.

The velocity ratio i of helical teeth wildhaber-wormaheel toroid helicoids worm can be less than 30.Its worm-gear tooth is the tapered plane tooth, tooth plane, both sides all with the inclination angle oblique of worm gear axis to equate, the inverted cone surfaces of symmetry are tangent fully with the worm gear axis being two of axis respectively; Its worm screw also belongs to planar double enveloping worm, this flank of tooth be tooth plane with the helical teeth wildhaber-wormaheel as generatrix, make the envelope surface that generating motion forms by the meshing relation of worm gear and worm screw.The instantaneous contact line of worm-gear tooth both sides is the antisymmetry distribution when worm gear and worm screw forward, reversing drive, and distribution with the increase at inclination angle from the engaging-in end of being partial to of worm gear gradually transition for relatively nibbling out end, Line of contact distributes and to be partial to engaging-in end when being small inclination, when the inclination angle during greater than certain angle its Line of contact will relatively nibble out end.The backlash that the worm gear of this transmission and worm screw are adjacent can not be adjusted, and also can't compensate the attenuate amount of wheel odontotripsis.

The dual lead cylindrical worm transmission claims " compound mode number worm drive " again, its worm screw is the cylindrical worm that two lateral tooth flank moduluses differ in size, the helical pitch of corresponding both sides helicoid does not wait yet, because the accumulation of helical pitch difference makes the transverse tooth thickness of worm screw gradually change along its axis; Worm gear is processed by corresponding compound mode number worm gear hob.Adjust its worm screw axial position, can adjust the attenuate amount of the backlash or the compensation wheel odontotripsis of transmission.This transmission by domestic and international application in the precision indexing mechanism of gear hobbing machine etc.Its deficiency is: (1). the compound mode number hobbing cutter spade milling difficulty of machining worm wheel, worm gear can not grindings, accurate manufacture cost height.(2). the backlash that adjacent teeth is right during the worm and gear engagement driving is unequal, can not guarantee that the backlash of every pair of tooth all meets required precision.(3). worm gear is few with the tooth logarithm that worm screw contacts simultaneously, and bearing capacity is low, and lack easy to wear, accuracy life, is difficult to the requirement of competent high speed and precision transmission (as high speed gear hobber) or heavy-loaded precision transmission (as cannon, lift machine).

The purpose of this utility model provides a kind of side gap adjustable worm and gear, the attenuate amount that backlash adjacent one another are can be adjusted or the gear teeth are worn when the worm gear of this transmission and worm meshing can compensate, to guarantee the orthodont side clearance of transmission, satisfy the requirement that engineering is heavy to the worm drive load, precision is high, the backlash amount is little.

Concrete scheme of the present utility model is: comprise worm gear, worm screw, it is characterized in that: the flank of tooth of worm gear is the plane, and worm-gear tooth axially is wedge shape along it; Worm screw two lateral tooth flanks be respectively with the respective side tooth plane of these wildhaber-wormaheel gear teeth as generatrix, make the envelope surface that generating motion forms by the meshing relation of worm gear and worm screw.

The utility model compared with prior art has following advantage:

1. this device has kept the advantage of prior art planar double enveloping worm transmission, but all grindings of worm gear, worm screw are easy to accurate the manufacturing, and the tooth logarithm ratio cylindrical worm gearing transmission that worm and gear contacts simultaneously is many; Its bearing capacity and meshing characteristic are all good than dual lead cylindrical worm transmission.

2. the worm-gear tooth plane of this device is not limited to horizontal frontal plane, and suitable gear range is bigger than the transmission of straight-tooth wildhaber-wormaheel toroid helicoids worm.

3. this device can be adjusted backlash or compensate the attenuate amount that the gear teeth are worn by the axial position that changes worm gear.It also can be used as precision drive except having the big characteristics of helical teeth wildhaber-wormaheel toroid helicoids worm Transmission bearing, applicable situation is wider than the transmission of helical teeth wildhaber-wormaheel toroid helicoids worm.

4. the worm gear of this device is the integrated type worm gear, does not have the existing defective of split type worm gear.The reliability height, and backlash is easy to adjust.

Below in conjunction with accompanying drawing the utility model is further specified:

Fig. 1 is that the worm gear flank of tooth forms schematic diagram in the utility model;

Fig. 2 is that worm tooth-surface forms schematic diagram;

Fig. 3 is the plan view of Fig. 1;

Fig. 4 is the A-A sectional view of Fig. 3;

Fig. 5 is the utility model overall structure figure, i.e. worm and gear engagement figure;

Fig. 6 is the left view of Fig. 5, also is that the utility model is by adjusting the axial position of worm gear, a kind of situation of the reduction in tooth thickness of the backlash of adjacent teeth side or compensation wheel odontotripsis when changing transmission.

By above-mentioned accompanying drawing as can be known: the utility model is made up of worm gear 1 and worm screw 2, and structure characteristic of the present utility model is: the flank of tooth of worm gear 1 is the plane, and worm-gear tooth axially is wedge shape along it; 2 liang of lateral tooth flanks of worm screw be respectively with the respective side tooth plane of these wildhaber-wormaheel 1 gear teeth as generatrix, make the envelope surface that generating motion forms by the worm gear 1 and the meshing relation of worm screw 2 transmissions.The tooth plane, both sides of worm gear 1 gear teeth is the unequal (β in inclination angle of its axis relatively ₁≠ β ₂).

The gear teeth both sides tooth of worm gear all is the plane in the utility model, but the inclination angle of their relative worm gear axis is unequal, and is tangent with two inverted cone surfaces that with the worm gear axis are center line respectively, and the end circular diameter of two back tapers on the worm gear central plane also can be unequal.As shown in Figure 1: worm screw two lateral tooth flanks be respectively with the tooth plane, both sides of these wildhaber-wormaheel gear teeth as generatrix, make the envelope surface that generating motion forms by worm gear and worm geared meshing relation.As shown in Figure 2.With regard to unidirectional transmission, it is the same that this transmission and the transmission of helical teeth wildhaber-wormaheel toroid helicoids worm are finished, and the inclination angle size on gear teeth plane is also consistent with the rule of the instantaneous contact line of worm screw to worm gear.When but forward and reverse transmission is arranged, according to the theory of engagement analysis of this transmission, after transmission parameter is determined, the inclination angle, tooth plane, both sides of worm-gear tooth respectively less than with greater than angle beta ₁, β ₂The time, the instantaneous contact line of forward, reversing drive worm gear and worm screw will lay respectively at the end that the gear teeth are partial in worm gear gear teeth both sides.Because the worm gear flank of tooth of this transmission is the plane, and worm-gear tooth axially is wedge shape along it, therefore can be by the axial position adjustment of worm gear, and the reduction in tooth thickness of the backlash of adjacent teeth side or compensation wheel odontotripsis when changing transmission.

Claims

1. a side gap adjustable worm and gear comprises worm gear (1), worm screw (2), and it is characterized in that: the flank of tooth of worm gear (1) is the plane, and worm-gear tooth axially is wedge shape along it; Worm screw (2) two lateral tooth flanks be respectively with the respective side tooth plane of this wildhaber-wormaheel (1) gear teeth as generatrix, make the envelope surface that generating motion forms by the worm gear (1) and the meshing relation of worm screw (2) transmission.

2. side gap adjustable worm and gear according to claim 1 is characterized in that: the tooth plane, both sides of the gear teeth of worm gear (1) is the unequal (β in inclination angle of its axis relatively ₁≠ β ₂).