CN107035819A - A kind of face gear pair - Google Patents

Abstract

The invention provides a kind of face gear pair, including face gear and the steamboat that cooperation is engaged with the face gear；It is characterized in that：The cog shape camber section of the steamboat is cut parallel to the steamboat axial plane；The arc section thickness is gradually reduced from centre to both sides；The intersection of the arc section and the teeth flank of tooth is curve.Pass through the correction of the flank shape that pair steamboat engaged with face gear carries out axial direction so that small gear teeth length direction thick middle, both sides are thin, improve steamboat it is axially mounted during tolerance, reduce because alignment error produces the possibility on edge basis.

Description

A face gear pair

technical field

The invention relates to the technical field of gear transmission, in particular to a face gear pair.

Background technique

Face gear transmission is a form of transmission formed by the meshing of cylindrical gears and bevel gears. It has the advantages of compact structure, large transmission ratio, high coincidence, easy installation, and easy manufacture and replacement of pinions. It has great advantages in diversion and confluence. Advantage. Due to the above advantages, face gears are used more and more in transmission between intersecting shafts. Since the complete conjugate face gear pair is very sensitive to machining and installation errors, the ideal face gear transmission should be a partially conjugated face gear pair. In the prior art, the surface gear transmission is contacted by the difference in the number of teeth between the small wheel and the face gear. However, since the contact path is perpendicular to the root cone of the face gear, the problem of edge contact is likely to occur, so that the contact position of the face gear is located at the tooth root. Even if the profile direction of the face gear is modified so that the face gear pair obtains quasi-conjugate characteristics and oblique contact paths, it is also sensitive to the axial installation error of the pinion.

Contents of the invention

In order to solve the problem that the meshing of cylindrical gear and bevel gear is sensitive to the small wheel axial installation error in the existing face gear transmission, the present invention provides a new face gear pair.

The present invention provides a face gear pair, which includes a face gear and a small wheel engaged with the face gear; the feature is that the teeth of the small wheel are cut parallel to the axis of the small wheel to form an arc-shaped section; The thickness of the arc-shaped section gradually decreases from the middle to both sides; the intersection line between the arc-shaped section and the tooth surface of the tooth is a curve.

By modifying the shape of the small wheel meshed with the face gear in the axial direction, the middle of the tooth length direction of the small wheel is thicker and the two sides are thinner, which improves the tolerance during the axial installation of the small wheel and reduces the edge foundation caused by installation errors. possibility.

Optionally, the intersection line of the arc section and the teeth is a first parabola.

Since the parabola has good transition characteristics, modifying the tooth direction of the pinion according to the first parabola can improve the meshing vibration and noise of the gear transmission.

Optionally, the vertex of the first parabola is located at the midpoint of the pinion tooth axial direction.

Optionally, the intersection line between the arc section and the teeth is an arc curve.

Optionally, the number of teeth of the small wheel is the same as that of the shape wheel forming the face gear; the teeth are cut by a plane perpendicular to the axis of the small wheel to form a tooth profile section; the tooth profile section is the same as the The intersection line of the tooth surface is the second parabola.

The direction of the tooth profile of the small wheel is modified without modifying the shape of the large wheel, so that the quasi-conjugate characteristics are obtained when the small wheel and the large wheel mesh. The contact path further improves the stability of the face gear transmission and reduces the vibration and noise during transmission.

Optionally, the apex of the second parabola is located in the middle area of the tooth.

Optionally, the face gear pair is a spur gear pair, a helical gear pair or an arc gear pair.

Description of drawings

Fig. 1 is a schematic diagram of the matching structure of a face gear pair according to an embodiment of the present invention;

Fig. 2 is a schematic diagram of the tooth structure of the small gear in the face gear pair according to the embodiment of the present invention.

detailed description

In order to enable those skilled in the art to better understand the technical solutions of the present invention, the present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments.

Figure 1 is a schematic diagram of the matching structure of a face gear pair according to an embodiment of the present invention. It can be seen from Fig. 1 that the face gear pair in this embodiment includes a face gear 1 and a small wheel 2 meshing with the face gear 1 . Wherein the face gear 1 is formed by cutting the profile wheel 3 and does not carry out tooth profile modification processing, while the small wheel 2 undergoes modification processing. Fig. 2 is a schematic diagram of the structure of the small wheel 2 teeth 11 in the face gear pair of the embodiment of the present invention, wherein the broken line represents the shape of the small wheel before modification in this embodiment, and the solid line represents the cooperation with the face gear 1 after modification 2 shapes of small wheels.

The pinion in the face gear pair in the prior art is not modified, so when it is installed with the face gear 1, the position in the axial direction must be ensured so that the axis of the pinion 2 intersects the axis of the face gear 1. The closer to the axis of the face gear 1, the smaller the gap between the small wheel 2 and the face gear 1, if the fit is not accurate, it will cause the problem of edge contact between the tooth top of the pinion and the root of the large gear during operation, resulting in the small gear of the face gear 1 The tooth root produces surface contact marks, which affects the accuracy of gear transmission and increases the strength of the gear. In order to overcome this problem, the core point of the present invention is to modify the teeth 11 of the small wheel 2 in the axial direction of the small wheel 2 to obtain modified tooth surfaces in the axial direction.

In order to describe the shape of the small wheel 2 in this embodiment, a virtual outer cutting surface is introduced in this embodiment. The teeth 11 of the small wheel 2 are cut with a plane parallel to the axis of the small wheel to form an arc-shaped section, which transitions from the middle area to both sides. The intersection line of the tooth surfaces is a curve; that is, a drum shape with a thicker middle and thinner edges is formed in the axial direction of the teeth 11 . Due to the above modification of the small wheel 2, the contact problem between the tooth top of the small wheel 2 and the tooth root edge of the large wheel at the position close to the axis of the face gear 1 during the gear meshing process can be alleviated to a certain extent, so that the tooth surface contact path along The tooth length becomes longer, which suppresses meshing vibration and reduces meshing noise. In this embodiment, the axial direction modification of the small wheel 2 is actually obtained by the walking curve of the grinding wheel along the tooth length direction of the small wheel 2. The walking curve of the grinding wheel is a parabola, and the obtained arc section is consistent with the tooth surface of the tooth 11. The line of intersection is the first parabola. The parabolic shape has good transition characteristics, which can ensure the smooth transition of the meshing during the transmission of the gears and suppress the generation of vibration. In this embodiment, the modification coefficient of the first parabola is between 0.003-0.005, of course, in other embodiments, other specific modification coefficients can be selected according to the actual gear use conditions. Of course, in other embodiments, the grinding wheel can also adopt other types of walking curves to obtain the intersection line between the corresponding arc section and the tooth surface of the tooth 11, such as an arc intersection line.

In the above embodiments, in order to better ensure the installation of the gears, the vertex of the first parabola is located at the midpoint of the teeth 11 of the small wheel 2 in the axial direction.

In order to improve the quasi-conjugate characteristics of the face gear 1 in this embodiment, the modification in the tooth profile direction is also carried out in the process of modifying the face gear 1 in the axial direction in this embodiment. The number of teeth of the pinion in this embodiment is the same as the number of teeth of the shaper cutter forming the face gear 1, rather than the form of 2-3 teeth difference between the large wheel forming wheel 3 and the small wheel 2 as in the prior art. The face gears 1 are in contact, resulting in a locally conjugated face gear pair. The tooth profile section of the small wheel 2 is obtained by modifying the standard tooth profile. Similarly, a virtual outer cutting surface is introduced to cut the small wheel 2 to realize the description of the structure of the small wheel 2 . The teeth 11 of the small wheel 2 are cut with a plane perpendicular to the axial direction of the small wheel 2, and the intersection line between the obtained section and the tooth surface of the small wheel 2 is a second parabola. As mentioned above, the parabolic shape has good transition characteristics, which can make the gear transition smoothly and prevent vibration when the gears mesh and contact. In order to ensure that the contact point between the small wheel 2 and the face gear 1 is in the middle of the teeth 11 of the small wheel 2 and the face gear 1, the apex of the second parabola is set in the middle area of the height direction of the teeth 11, preferably the small wheel 2 The pitch circle position of . The modification coefficient of the second parabola can be between 0.01-0.02, which is selected according to actual application conditions. In actual processing, the tooth profile of the small wheel 2 is directly obtained by gear shaping cutter or hobbing cutter. In order to obtain the second parabolic shape of the small wheel 2 tooth profile, the shape of the gear shaping cutter or gear hobbing cutter should have Two parabolic shapes are processed accordingly. It should be noted that in actual production, the surface of the gear shaping cutter or gear hobbing cutter used is the standard second parabolic shape, and the shape of the second parabola obtained after gear shaping will change to some extent due to the processing technology, but its The slope of the curve and other conditions still conform to the general situation of the second parabola, that is, the curve of the tooth profile in this embodiment does not completely conform to the second parabola, but has some changes.

Through the above description, the shape of the teeth 11 of the small wheel 2 in this embodiment can be obtained as shown in Figure 2. Since the modification process is carried out for the spur gear pair in this embodiment, the obtained small wheel 2 is generally the same as It is a straight-toothed cylindrical gear, and the second parabola is tangent to the straight-toothed tooth profile of the standard gear 4 in the tooth profile direction at a point in the middle of the gear. Due to the above modification method, the tolerance ability of the face gear pair transmission to the installation error is improved; when the face gear 1 and the small wheel 2 are meshed for transmission, the theoretical meshing point has a certain angle between the tooth length direction and the tooth height direction. Reduce the possibility of edge contact and get a parabolic transmission error with the opening down, which improves the meshing performance of the face gear 1 transmission.

It should be noted that in the drawings of this embodiment, only spur gears are used as the small wheel 2 for modification treatment. Since helical gears or arc gears can be obtained by simply transforming spur gears, it can be understood that the above small wheel 2 modification It can also be applied to helical or arc gears.

The face gear pair in the embodiment of the present invention has been introduced in detail above. This paper uses specific examples to illustrate the principle and implementation of the present invention. The description of the above embodiments is only used to help understand the core idea of the present invention. Without departing from the principle of the present invention, some improvements can also be made to the present invention. and modifications, these improvements and modifications also fall within the protection scope of the present invention.

Claims (7)

1. a kind of face gear pair, including face gear (1) and being engaged with the face gear (1) is matched somebody with somebody The steamboat (2) of conjunction；It is characterized in that：It is described parallel to the cutting of the steamboat (2) axial plane Teeth (11) the formation arc section of steamboat；The arc section thickness from centre to both sides by It is decrescence small；The intersection of the arc section and the teeth (11) flank of tooth is curve.

2. face gear pair according to claim 1, it is characterised in that：The arc section Intersection with the teeth (11) is the first parabola.

3. face gear pair according to claim 2, it is characterised in that：First parabolic The summit of line is located at the midpoint of little gear teeth (11) axial direction.

4. face gear pair according to claim 1, it is characterised in that：The arc section Intersection with the teeth (11) is circular curve.

5. the face gear pair according to claim any one of 1-4, it is characterised in that：It is described The number of teeth of steamboat (2) is identical with production shape wheel (3) number of teeth for forming the face gear (1)；Hang down Directly teeth (11) form flank profil section described in the plane cutting in the steamboat (2) axis；Institute The intersection for stating flank profil section and the teeth (11) flank of tooth is the second parabola.

6. face gear pair according to claim 5, it is characterised in that：Second parabolic The summit of line is located at the intermediate region of the teeth (11).

7. the face gear pair according to claim any one of 1-4, it is characterised in that：It is described Face gear pair is spur gear pair, helical gear pair or curved tooth wheel set.