Spiral bevel gear pair

Abstract

The utility model discloses a spiral bevel gear pair which comprises a transmission shaft and a driven bevel gear, a driving bevel gear is arranged at one end of the transmission shaft, the driving bevel gear and the driven bevel gear are meshed with each other, the crossed axis angle of the driving bevel gear and the driven bevel gear is 90 degrees, and the vertex OAa of the pitch cone angle delta Aa of the driving bevel gear coincides with the vertex OBa of the pitch cone angle delta Ba of the driven bevel gear. The tip cone generatrix of the driving bevel gear is parallel to the root cone generatrix of the driven bevel gear at the meshing position, and the root cone generatrix of the driving bevel gear is parallel to the tip cone generatrix of the driven bevel gear at the meshing position. According to the spiral bevel gear pair, the tip cone generatrix of the driving bevel gear is parallel to the root cone generatrix of the driven bevel gear at the meshing position, the root cone generatrix of the driving bevel gear is parallel to the tip cone generatrix of the driven bevel gear at the meshing position, and the distances between the tip cone generatrix and the root cone generatrix are equal, namely, the tip clearance is constant, so that the tooth clearance at the small end is larger than that at the small end of the spiral bevel gear pair in the prior art; the phenomenon of'seizure 'caused by dislocation is not easy to occur, the service life is prolonged, and the failure rate is reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of gear transmission, in particular to a spiral bevel gear pair. Background Art

[0002] At present, the spiral bevel gear pair structure is generally used in the main reducer of domestic forklifts, which is a very important transmission component in the forklift drive axle. In actual use, the spiral bevel gear pair in the existing forklift drive axle has the following defects:

[0003] 1. Since the tooth height of the existing spiral bevel gear gradually decreases from the large end to the small end, and the vertices of the top cone angle, root cone angle and pitch cone angle coincide, the top clearance of the spiral bevel gear pair also gradually decreases from the large end to the small end of the tooth, which makes it easy for the spiral bevel gear to "bite" due to misalignment at the small end, which in turn causes damage to the spiral bevel gear pair and a relatively high failure rate;

[0004] 2. Because the root fillet radius of the small end of the spiral bevel gear is small, its stress concentration is large, the root strength is weak, and the small end tooth top is thin, so the gear strength is low;

[0005] 3. Since the tooth height and top clearance of spiral bevel gears gradually decrease from the large end to the small end, the processing is more difficult. Conventionally produced gears generally have poor meshing accuracy, unstable transmission, and loud noise. In order to improve the meshing accuracy, higher-level technology and equipment must be introduced.

[0006] Therefore, it is necessary to optimize and improve the existing spiral bevel gear pair to at least solve one of the above technical problems. Utility Model Content

[0007] The purpose of the utility model is to provide a spiral bevel gear pair to at least solve one of the problems raised in the above background technology.

[0008] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0009] A spiral bevel gear pair comprises a transmission shaft and a driven bevel gear, wherein a driving bevel gear is arranged at one end of the transmission shaft, the driving bevel gear and the driven bevel gear mesh with each other and the axis intersection angle is 90 degrees, the vertex OAa of the driving bevel gear pitch cone angle δAa coincides with the vertex OBa of the driven bevel gear pitch cone angle δBa, the top cone generatrix of the driving bevel gear is parallel to the root cone generatrix of the driven bevel gear at the meshing position, the root cone generatrix of the driving bevel gear is parallel to the top cone generatrix of the driven bevel gear at the meshing position, and the distance LA between the top cone generatrix of the driving bevel gear and the root cone generatrix of the driven bevel gear at the meshing position is equal to the distance LB between the root cone generatrix of the driving bevel gear and the top cone generatrix of the driven bevel gear at the meshing position.

[0010] Furthermore, the vertex OAa of the driving bevel gear pitch angle δAa coincides with the vertex of the driving bevel gear root angle δAc, and the vertex OAb of the driving bevel gear top cone angle δAb is located on the side of the vertex OAa of the driving bevel gear pitch angle δAa close to the driving bevel gear.

[0011] Furthermore, the vertex OBa of the driven bevel gear pitch cone angle δBa coincides with the vertex of the driven bevel gear root cone angle δBc, and the vertex OBb of the driven bevel gear top cone angle δBb is located on the side of the vertex OBa of the driven bevel gear pitch cone angle δBa close to the driven bevel gear.

[0012] Furthermore, the driving bevel gear pitch cone angle δAa is in the range of 24-26 degrees, the driving bevel gear top cone angle δAb is 6-8 degrees larger than the driving bevel gear pitch cone angle δAa, the driving bevel gear root cone angle δAc is 2-5 degrees smaller than the driving bevel gear pitch cone angle δAa, the sum of the driving bevel gear pitch cone angle δAa and the driven bevel gear pitch cone angle δBa is equal to 90 degrees, the sum of the driving bevel gear top cone angle δAb and the driven bevel gear root cone angle δBc is equal to 90 degrees, and the sum of the driving bevel gear root cone angle δAc and the driven bevel gear top cone angle δBb is equal to 90 degrees.

[0013] Further, the value of the distance LA between the top cone generatrix of the driving bevel gear and the root cone generatrix of the driven bevel gear at the meshing position is in the range of 1.1-1.5 mm.

[0014] Furthermore, the end face module of the driving bevel gear and the driven bevel gear is 7, the pressure angle is 20 degrees, and the midpoint helix angle is 35 degrees.

[0015] Compared with the prior art, the beneficial effects of the utility model are:

[0016] The utility model makes the top cone generatrix of the active bevel gear parallel to the root cone generatrix of the driven bevel gear at the meshing position, and the root cone generatrix of the active bevel gear is parallel to the top cone generatrix of the driven bevel gear at the meshing position, and makes the distance between them equal, that is, the top gap is constant, so that the tooth gap at the small end is larger than the tooth gap at the small end of the spiral bevel gear pair in the prior art, and it is not easy to cause the "seizure" phenomenon due to misalignment, thereby improving the service life and reducing the failure rate. Moreover, since the tooth gap at the small end of the spiral bevel gear pair is larger, the small end tooth root fillet radius and the small end tooth top width of the active bevel gear and the driven bevel gear can also be increased accordingly, effectively reducing the small end tooth root stress concentration of the active bevel gear and the driven bevel gear, increasing the small end tooth root strength and tooth top strength, and also can increase the tool tip fillet, thereby improving the tool life. At the same time, this top gap constant structure makes the assembly and manufacturing process of the spiral bevel gear simpler, reduces the manufacturing cost and improves the production efficiency, and the meshing accuracy can be better guaranteed, thereby ensuring the stability and low noise during meshing transmission. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the utility model;

[0018] Figure 2 It is a schematic diagram of the structure of the transmission shaft and the active bevel gear;

[0019] Figure 3 It is the structural schematic diagram of the driven bevel gear;

[0020] Figure 4 for Figure 1 A partial enlarged view of point E in the middle;

[0021] In the figure:

[0022] 1-transmission shaft, 2-driving bevel gear, 201-driving bevel gear top cone generatrix, 202-driving bevel gear root cone generatrix, 3-driven bevel gear, 301-driven bevel gear top cone generatrix, 302-driven bevel gear root cone generatrix. DETAILED DESCRIPTION

[0023] The utility model is described in detail below with reference to the accompanying drawings and specific embodiments.

[0024] See also Figure 1 to Figure 4 , an embodiment provided by the utility model:

[0025] A spiral bevel gear pair, comprising a transmission shaft 1 and a driven bevel gear 3, wherein a driving bevel gear 2 is arranged at one end of the transmission shaft 1, the driving bevel gear 2 and the driven bevel gear 3 are meshed with each other and the axis intersection angle is 90 degrees, the vertex OAa of the driving bevel gear pitch cone angle δAa coincides with the vertex OBa of the driven bevel gear pitch cone angle δBa, and the top cone generatrix 201 of the driving bevel gear is parallel to the root cone generatrix 302 of the driven bevel gear at the meshing position, which means that for the driving bevel gear 2, its top clearance is from the driving bevel gear 2 is equal from the large end to the small end, and the root cone generatrix 202 of the active bevel gear is parallel to the top cone generatrix 301 of the driven bevel gear at the meshing position, which means that for the driven bevel gear 3, its top clearance is equal from the large end to the small end of the driven bevel gear 3, and the distance LA between the top cone generatrix 201 of the active bevel gear and the root cone generatrix 302 of the driven bevel gear at the meshing position (i.e. the top clearance of the active bevel gear 2) is equal to the distance LA between the root cone generatrix 202 of the active bevel gear and the top cone generatrix 301 of the driven bevel gear at the meshing position The distance LB between them (i.e., the top clearance of the driven bevel gear 3) makes the top clearance constant, that is, when the active bevel gear 2 and the driven bevel gear 3 are meshed, the tooth clearance at the tooth top and the tooth root are equal in size, and the tooth clearance at the small end is larger than the tooth clearance at the small end of the spiral bevel gear pair in the prior art, so it is not easy to cause the "seizure" phenomenon due to misalignment, thereby improving the service life and reducing the failure rate. Moreover, since the tooth clearance at the small end of the spiral bevel gear pair is larger, the small end tooth root fillet radius and the small end tooth top width of the active bevel gear 2 and the driven bevel gear 3 can also be increased accordingly, effectively reducing the stress concentration at the small end tooth root of the active bevel gear 2 and the driven bevel gear 3, increasing the small end tooth root strength and tooth top strength, and also increasing the tool tip fillet, thereby improving the tool life. At the same time, this constant top clearance structure makes the assembly and manufacturing process of the spiral bevel gear simpler, reduces the manufacturing cost and improves the production efficiency, and the meshing accuracy can be better guaranteed, thereby ensuring the stability and low noise during meshing transmission.

[0026] Among them, the vertex OAa of the driving bevel gear pitch cone angle δAa coincides with the vertex OAa of the driving bevel gear root cone angle δAc, the vertex OAb of the driving bevel gear top cone angle δAb is located on the side of the vertex OAa of the driving bevel gear pitch cone angle δAa close to the driving bevel gear 2, the vertex OBa of the driven bevel gear pitch cone angle δBa coincides with the vertex δBc of the driven bevel gear root cone angle δBc, the vertex OBb of the driven bevel gear top cone angle δBb is located on the side of the vertex OBa of the driven bevel gear pitch cone angle δBa close to the driven bevel gear 3, the driving bevel gear pitch cone angle δAa=25°27′48″, the driving bevel gear top cone angle δAb=32°28′24″, the driving bevel gear root cone angle δAc=22°24′42″, the driving bevel gear pitch cone angle The sum of δAa and the driven bevel gear pitch cone angle δBa is equal to 90 degrees, the sum of the driving bevel gear top cone angle δAb and the driven bevel gear root cone angle δBc is equal to 90 degrees, and the sum of the driving bevel gear root cone angle δAc and the driven bevel gear top cone angle δBb is equal to 90 degrees, so as to ensure that the driving bevel gear top cone generatrix 201 is parallel to the driven bevel gear root cone generatrix 302 at the meshing position, and the driving bevel gear root cone generatrix 202 is parallel to the driven bevel gear top cone generatrix 301 at the meshing position, and at the same time ensure that the distance LA between the driving bevel gear top cone generatrix 201 and the driven bevel gear root cone generatrix 302 at the meshing position is equal to the distance LB between the driving bevel gear root cone generatrix 202 and the driven bevel gear top cone generatrix 301 at the meshing position, that is, to ensure the constant top clearance.

[0027] Among them, the value of the distance LA (top clearance) between the top cone generatrix 201 of the driving bevel gear and the root cone generatrix 302 of the driven bevel gear at the meshing point is equal to 1.3 mm. On the basis of the increase in the top clearance of the spiral bevel gear pair in the prior art, the meshing height is not less than 65% along the tooth height direction and not less than 60% along the tooth length direction, ensuring the tooth surface contact area and contact strength, thereby ensuring the working life and transmission stability of the driving bevel gear 2 and the driven bevel gear 3.

[0028] Among them, the end face module of the driving bevel gear 2 and the driven bevel gear 3 is 7, the pressure angle is 20 degrees, the midpoint helix angle is 35 degrees, the number of teeth of the driving bevel gear 2 is 10, the tooth top height is 8.715mm, and the tooth root height is 4.34mm, the number of teeth of the driven bevel gear 3 is 21, the tooth top height is 3.045mm, and the tooth root height is 10.01mm, the surface hardness of the driving bevel gear 2 and the driven bevel gear 3 is 58HRC-63HRC, the core hardness is 30HRC-40HRC, the driving bevel gear 2 and the driven bevel gear 3 are provided with a hardened layer, and the hardened layer has a carburizing depth of 0.8mm-1.2mm.

[0029] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A spiral bevel gear pair, comprising a transmission shaft (1) and a driven bevel gear (3), wherein a driving bevel gear (2) is disposed at one end of the transmission shaft (1), the driving bevel gear (2) and the driven bevel gear (3) meshing with each other and having an axis intersection angle of 90 degrees, characterized in that: The vertex OAa of the pitch cone angle δAa of the driving bevel gear coincides with the vertex OBa of the pitch cone angle δBa of the driven bevel gear, the top cone generatrix (201) of the driving bevel gear is parallel to the root cone generatrix (302) of the driven bevel gear at the meshing position, the root cone generatrix (202) of the driving bevel gear is parallel to the top cone generatrix (301) of the driven bevel gear at the meshing position, and the distance LA between the top cone generatrix (201) of the driving bevel gear and the root cone generatrix (302) of the driven bevel gear at the meshing position is equal to the distance LB between the root cone generatrix (202) of the driving bevel gear and the top cone generatrix (301) of the driven bevel gear at the meshing position.

2. A spiral bevel gear pair according to claim 1, characterized in that: The vertex OAa of the driving bevel gear pitch cone angle δAa coincides with the vertex of the driving bevel gear root cone angle δAc, and the vertex OAb of the driving bevel gear top cone angle δAb is located on the side of the vertex OAa of the driving bevel gear pitch cone angle δAa close to the driving bevel gear (2).

3. A spiral bevel gear pair according to claim 1, characterized in that: The vertex OBa of the driven bevel gear pitch cone angle δBa coincides with the vertex of the driven bevel gear root cone angle δBc, and the vertex OBb of the driven bevel gear top cone angle δBb is located on the side of the vertex OBa of the driven bevel gear pitch cone angle δBa close to the driven bevel gear (3).

4. A spiral bevel gear pair according to claim 3, characterized in that: The pitch cone angle δAa of the driving bevel gear is in the range of 24-26 degrees, the top cone angle δAb of the driving bevel gear is 6-8 degrees larger than the pitch cone angle δAa of the driving bevel gear, the root cone angle δAc of the driving bevel gear is 2-5 degrees smaller than the pitch cone angle δAa of the driving bevel gear, the sum of the pitch cone angle δAa of the driving bevel gear and the pitch cone angle δBa of the driven bevel gear is equal to 90 degrees, the sum of the top cone angle δAb of the driving bevel gear and the root cone angle δBc of the driven bevel gear is equal to 90 degrees, and the sum of the root cone angle δAc of the driving bevel gear and the top cone angle δBb of the driven bevel gear is equal to 90 degrees.

5. The spiral bevel gear pair according to claim 1, characterized in that: The value of the distance LA between the top cone generatrix (201) of the driving bevel gear and the root cone generatrix (302) of the driven bevel gear at the meshing position is within the range of 1.1-1.5 mm.

6. A spiral bevel gear pair according to claim 1, characterized in that: The end face module of the driving bevel gear (2) and the driven bevel gear (3) is 7, the pressure angle is 20 degrees, and the midpoint helix angle is 35 degrees.

Images