CN103807408B - Axial variable pressure angle gear - Google Patents

Abstract

The invention provides an axial variable pressure angle gear capable of effectively eliminating or reducing tooth side clearance and backlash. The axially variable pressure angle gear according to the present invention has an inner end face meshing with another gear and an outer end face opposite to the inner end face, wherein at least one of the two sides of the teeth of the axially variable pressure angle gear has a The pressure angle changes from the inner end surface to the outer end surface in the axial direction of the variable pressure angle gear, and the tooth surface on the same side of the at least one side of the gear tooth is respectively formed from the tooth top to the pitch circle area and from the dedendum to the pitch circle area The tooth surface tapers with opposite angles. Therefore, the axial variable pressure angle gear according to the present invention can effectively eliminate or reduce backlash and backlash, and the axial forces generated during meshing can cancel each other, thereby reducing vibration and noise, improving bearing capacity and transmission stiffness, Good effect of prolonging the service life.

Description

Axial Variable Pressure Angle Gears

technical field

The invention relates to the field of mechanical transmission, in particular to an axial variable pressure angle gear capable of adjusting backlash.

Background technique

With the demand for the development of precision transmission, higher requirements are put forward for the realization of anti-backlash transmission and adjustable backlash. In traditional precision gear transmission, in order to realize anti-backlash transmission and adjustable backlash meshing, the commonly used technical solutions have disadvantages such as complex structure and difficult assembly. For this reason, radially displaced involute bevel gears (such as US Patents US3174356, US3171212 and US5400672) are usually used to solve the above problems. However, for radially displaced involute bevel gears, since the addendum circle is conical, the sliding coefficient changes continuously along the axial direction during meshing, which will directly increase the wear of the gearbox and reduce the service life.

In order to overcome the above disadvantages, the Chinese invention patent CN100575750C discloses an adjustable backlash thickening gear transmission pair, the gears of the gear transmission pair gradually become thicker and thicker in the axial direction from the middle of the tooth length to the two end faces of the teeth through the tooth profile. Thinning to achieve thicker gears to control transmission backlash. In addition, Chinese invention patent CN101285520B discloses a cylindrical displacement gear with variable tooth thickness. The gear uses the tangential displacement coefficient to change from small to large along the axial direction of the gear disc. A certain included angle is formed, thereby eliminating or reducing the tooth side clearance and backlash.

The tooth surfaces of the gears disclosed in the above existing patent documents all form an included angle in one direction, which makes the gear inevitably generate axial force during transmission, and the axial force generated during gear transmission will cause the gear to axially Playing, increased vibration and noise, and reduced service life. In addition, the tooth thickness of the thickened gear disclosed in the above-mentioned existing patent documents is thickened at one end surface and thinned at the other end surface, so that the load-bearing capacity and transmission stiffness of the entire tooth surface change from the tooth thickness to the thickened end in the axial direction. Decreasing toward the thinning end of the tooth thickness will cause uneven load distribution on the tooth surface in the gear transmission, and it is more likely to cause fatigue damage to the gear teeth.

Contents of the invention

In order to solve the above problems, the present invention provides an axial variable pressure angle gear that can effectively eliminate or reduce backlash and backlash, and axial forces can cancel each other. According to the axial variable pressure angle gear of the present invention, vibration and noise can be reduced, so as to realize precise transmission, and simultaneously improve bearing capacity and transmission rigidity.

The axially variable pressure angle gear according to the present invention has an inner end face meshing with another gear and an outer end face opposite to the inner end face, wherein at least one of the two sides of the teeth of the axially variable pressure angle gear has a The pressure angle changes from the inner end surface to the outer end surface in the axial direction of the variable pressure angle gear, and the tooth surface on the same side of the at least one side of the gear tooth is respectively formed from the tooth top to the pitch circle area and from the dedendum to the pitch circle area The tooth surfaces are tapered at opposite angles, and the pitch thickness of the gear teeth remains constant along the axial direction.

According to an aspect of the present invention, one side of the gear tooth has a pressure angle that changes from the inner end face to the outer end face along the axial direction.

The pressure angle on said side of the gear tooth can vary from small to large.

Optionally, the pressure angle on one side of the gear teeth may also change from large to small.

According to another aspect of the present invention, both sides of the gear teeth have pressure angles that vary from the inner end surface to the outer end surface along the axial direction.

The magnitude of the pressure angle on both sides of the gear tooth changes according to the same change law.

Optionally, the magnitude of the pressure angle on both sides of the gear teeth may also vary according to different variation rules.

Further, the pressure angle of the gear teeth can be changed in any one of linear change, parabolic change and circular arc change.

Description of drawings

The above and other aspects and features of the present invention will be clearly presented from the following description of the embodiments in conjunction with the accompanying drawings, wherein:

Fig. 1 (a) is the tooth profile diagram of the axial variable pressure angle gear according to the first embodiment of the present invention;

Fig. 1 (b) is the tooth shape sectional view of the axial variable pressure angle gear according to the first embodiment of the present invention;

2 is a perspective view showing the structure of an axial variable pressure angle gear according to a first embodiment of the present invention;

Fig. 3 (a) is the tooth profile diagram of the axial variable pressure angle gear according to the second embodiment of the present invention;

Fig. 3 (b) is the tooth shape sectional view of the axial variable pressure angle gear according to the second embodiment of the present invention;

4 is a perspective view showing the structure of an axial variable pressure angle gear according to a second embodiment of the present invention;

Fig. 5 is a tooth shape cross-sectional view of an axial variable pressure angle gear according to a third embodiment of the present invention;

Fig. 6 is a tooth profile view of an axial variable pressure angle gear according to a fourth embodiment of the present invention; and

Fig. 7 is a schematic diagram of external meshing of an axial variable pressure angle gear pair according to the present invention.

detailed description

The invention relates to an axially variable pressure angle gear, which has an inner end surface meshing with another gear and an outer end surface opposite to the inner end surface. According to the present invention, the axial variable pressure angle gear adopts the form of axial variable pressure angle, so that the tooth surface of the gear tooth forms a certain conical angle along the gear axis, and the meshing can be adjusted by adjusting the axial position of the mutually meshing gears Therefore, it can effectively eliminate or reduce the backlash and backlash of the teeth, and realize precise transmission. In addition, the tooth surface on the same side where the pressure angle changes of the axial variable pressure angle gear of the present invention forms opposite angles from the tooth top to the pitch circle area and from the dedendum to the pitch circle area, which makes the meshing The generated axial forces can cancel each other, thereby reducing vibration and noise; and the pitch thickness of the gear teeth remains unchanged in the axial direction, which further improves the bearing capacity and transmission rigidity, thus prolonging the service life.

Specifically, at least one of the two sides of the teeth of the axially variable pressure angle gear according to the present invention has a pressure angle that changes from the inner end surface to the outer end surface along the axial direction of the axial variable pressure angle gear, and the gear teeth The tooth surface on the same side of the at least one side forms opposite angles of the tooth surface taper from the tooth top to the pitch circle area and from the tooth root to the pitch circle area. According to the present invention, the pressure angle of the tooth flank can change from large to small or from small to large along the axial direction from the inner end surface to the outer end surface. In the case that the pressure angles on both sides of the gear tooth change, the magnitude of the pressure angle can change according to the same or different changing rules. For example, when the pressure angle on both sides of the gear tooth changes according to different changing laws, the pressure angle on one side of the gear tooth changes from small to large, while the pressure angle on the other side changes from large to small. In addition, the pressure angle of the gear teeth may be varied in any one of linear variation, parabolic variation, and arcuate variation.

Hereinafter, illustrative and non-limiting embodiments of the present invention will be listed with reference to the accompanying drawings, so as to describe the axial variable pressure angle gear according to the present invention in detail.

Fig. 1(a), Fig. 1(b) and Fig. 2 show an axial variable pressure angle gear according to a first embodiment of the present invention. In the first embodiment, the tooth surface pressure angles on both sides of the gear teeth adopt a linear change law from small to large along the gear axial direction from the inner end surface to the outer end surface. The solid line in Figure 1 represents the tooth shape of the outer end face, and the dotted line represents the tooth shape of the inner end face. From the tooth profile on the left side, the 1A-3A segment is an involute tooth profile with a large pressure angle on the outer end face, the segment 2A-4A is an involute tooth profile with a small pressure angle on the inner end face, and 5A is a pitch circle. Section IA and section IIA are the sections of the involute gear teeth in the upper and lower sections of the pitch circle of the gear, respectively. 8A and 9A are the left and right tooth profile schematic diagrams of section IA respectively, and 6A and 7A are the left and right tooth profile schematic diagrams of section IIA respectively. It can be seen from the schematic diagram that on the tooth surfaces on both sides of the gear teeth, the angle between the pitch circle 5A and the tooth surface of the tooth top section forms a conical outward angle, and the pitch circle 5A forms a conical inward angle between the tooth surface of the tooth root section. , That is, the tooth surface on the same side forms a tapered opposite angle (for example, 6A and 8A, 7A and 9A).

Fig. 3(a), Fig. 3(b) and Fig. 4 show an axial variable pressure angle gear according to a second embodiment of the present invention. The difference between the second embodiment of the present invention and the first embodiment is that the pressure angle of the tooth surface on the left side of the gear adopts a linear change law from small to large along the gear axial direction from the inner end surface to the outer end surface, and the pressure angle of the right tooth surface The pressure angle adopts a linear change rule from large to small along the gear axis from the inner end to the outer end. It can be seen from the schematic diagram that on the tooth surface on the left side of the gear tooth, the angle between the pitch circle 5B and the tooth surface of the top section forms a conical outward angle, and the angle between the pitch circle 5B and the tooth surface of the tooth root section forms a conical inward angle. . On the tooth surface on the right side of the gear tooth, a conical inward angle is formed from the pitch circle 5B to the top tooth surface, and a conical outward angle is formed from the pitch circle 5B to the root tooth surface. That is to say, the tooth surfaces on the same side form opposite taper angles (such as 6B and 8B, 7B and 9B).

Fig. 5 is a tooth profile sectional view of an axial variable pressure angle gear according to a third embodiment of the present invention. In the third embodiment, the pressure angle of the tooth surface on the left side of the gear tooth adopts a linear change law from small to large from the inner end surface to the outer end surface along the gear axis, and the pressure angle of the tooth surface on the right side is a constant value. On the tooth surface on the left side of the gear tooth, the angle between the pitch circle 5C and the tooth surface of the tooth top section forms a conical outward angle, and the angle between the pitch circle 5C and the tooth surface of the tooth root section forms a conical inward angle, and the tooth surface on the same side forms Tapered opposite angles (such as 6C and 8C).

Fig. 6 is a tooth profile sectional view of an axial variable pressure angle gear according to a fourth embodiment of the present invention. In the fourth embodiment, the pressure angle of the tooth surface on the left side of the gear adopts a parabolic change law from small to large along the gear axis from the inner end surface to the outer end surface, and the pressure angle of the right tooth surface adopts the law of changing from the inner end surface along the gear axis. The outer end face changes linearly from small to large. On the tooth surfaces on both sides of the gear teeth, the pitch circle 5D forms a conical outward angle to the tooth surface of the tooth top section, and the pitch circle 5D forms a conical inward angle to the tooth surface of the tooth root section, that is, the tooth surface on the same side Form a tapered opposite angle (such as 6D and 8D, 7D and 9D).

The invention illustrates here by way of example that the pressure angle of at least one side of the gear teeth varies linearly or parabolicly. However, the axially variable pressure angle gear according to the present invention is not limited thereto, and the pressure angle of at least one side of the gear tooth can change in any regularity along the gear axis, for example, in an arc shape.

Fig. 7 is a schematic diagram of external meshing of an axial variable pressure angle gear pair according to the present invention. Gear 10 and gear 11 are respectively axially variable pressure angle gears with the same change rule of the pressure angle of the meshing surfaces. Because the tooth surfaces on the same side form opposite conical angles at the upper and lower pitch circle tooth surfaces, it can be adjusted by adjusting the two meshing gears. Correct axial position to adjust the engagement backlash. Therefore, the axial variable pressure angle gear according to the present invention can effectively eliminate or reduce backlash and hysteresis, and the axial forces generated during meshing can cancel each other, thereby achieving good effects of reducing vibration and noise and prolonging service life. According to the axial variable pressure angle gear of the present invention, the tooth thickness of the pitch circle remains unchanged along the axial direction, and the tooth thickness of the cross-section of any end gradually becomes thicker and thinner in the upper and lower sections of the pitch circle respectively. In gear transmission, the tooth surface load along the The axial distribution of the gears is uniform, which further improves the load-bearing capacity and transmission rigidity of the entire gear.

While exemplary embodiments of the invention have been described, it will be apparent to those skilled in the art that changes may be made without departing from the spirit and principles of the invention, the scope of which is defined in the claims and their equivalents .

Claims (8)

1. An axial variable pressure angle gear, said axial variable pressure angle gear has an inner end face meshed with another gear and an outer end face opposite to said inner end face, wherein: At least one of the two sides of the teeth of the axial variable pressure angle gear has a pressure angle that changes from the inner end surface to the outer end surface along the axial direction of the axial variable pressure angle gear; The same-side tooth surface of the at least one side of the gear tooth forms opposite angles of the tooth surface taper from the tooth top to the pitch circle area and from the dedendum to the pitch circle area; and The pitch thickness of the gear teeth remains constant along the axial direction. 2. The axially variable pressure angle gear according to claim 1, wherein one side of the gear teeth has a pressure angle that varies from the inner end surface to the outer end surface along the axial direction. 3. The axially variable pressure angle gear according to claim 2, wherein the pressure angle on the one side of the gear tooth changes from small to large. 4. The axial variable pressure angle gear according to claim 2, wherein the pressure angle on the one side of the gear tooth changes from large to small. 5 . The axial variable pressure angle gear according to claim 1 , wherein both sides of the gear tooth have pressure angles that vary from the inner end surface to the outer end surface along the axial direction. 5 . 6 . The axially variable pressure angle gear according to claim 5 , wherein the pressure angles on both sides of the gear teeth change according to the same variation rule. 7 . 7. The axially variable pressure angle gear according to claim 5, wherein the pressure angles on both sides of the gear teeth vary according to different variation laws. 8. The axial variable pressure angle gear according to any one of claims 1-7, wherein the pressure angle of the gear tooth changes in any one of linear change, parabolic change and circular arc change.