Bevel gear transmission device capable of eliminating clearance

Abstract

The bevel gear transmission device comprises a first transmission shaft, a second transmission shaft, a first bevel gear, a second bevel gear and a third bevel gear, and further comprises an axial displacement mechanism arranged on the second transmission shaft, and the axial displacement mechanism comprises an inertia outward-expanding sliding block and an axial pushing and abutting piece; the axial end face of the inertia outward-expanding sliding block is tightly attached to the first axial end face of the axial pushing and abutting piece, the second axial end face of the axial pushing and abutting piece is tightly attached to the end face of the third bevel gear, and the axial end face of the inertia outward-expanding sliding block and the first axial end face of the axial pushing and abutting piece are inclined faces. When the second transmission shaft rotates, through the axial end face of the inertia outward-expanding sliding block and the first axial end face of the axial pushing and abutting piece, the axial pushing and abutting piece generates axial pushing force towards the third bevel gear, and the axial pushing and abutting piece is prevented from moving in the direction away from the third bevel gear. According to the invention, the gear backlash of helical gear transmission can be eliminated, and the generation of a rotation dead zone is avoided.

Description

Technical Field

[0001] The present invention relates to a helical gear transmission device, belonging to the technical field of clearance adjustment of transmission components. Background Art

[0002] Helical gear transmission is a commonly used method in mechanical transmission. Compared with spur gear transmission, its meshing performance is good. When helical gears are meshing, the teeth gradually enter and exit the meshing state, and the contact ratio is larger than that of spur gears. This enables the load to be evenly distributed on multiple teeth, thereby improving the load-bearing capacity of the gears and reducing the load borne by a single tooth. The impact and vibration generated during the helical gear transmission process are relatively small, and the noise is also relatively low. This enables the helical gear transmission to maintain good stability under high-speed and heavy-load working conditions and operate more smoothly.

[0003] In order to obtain better forward and reverse performance and reduce the dead zone during forward and reverse switching caused by the tooth side clearance, in the prior art, a wide gear and two narrow gears are respectively arranged on two transmission shafts. The narrow gears are both meshed with the wide gear. By controlling the axial distance between the two narrow gears, the teeth of the narrow gears are respectively pressed against the two tooth sides of the teeth of the wide gear. In the prior art, sleeves or gaskets are commonly used to control the axial distance between the two narrow gears. Since the sleeves or gaskets are rigid parts, the axial distance between the two narrow gears cannot be changed. When the teeth of the gears are worn due to work, the tooth side clearance will gradually occur, and then a transmission dead zone will be generated. In the prior art, elastic parts are also used to connect the two narrow gears to control the axial distance between the narrow gears. However, when the axial force received by the narrow gears due to the load of the transmission mechanism exceeds the elastic force of the elastic parts, the elastic parts can no longer play the role of eliminating the clearance. Summary of the Invention

[0004] Aiming at the defects of the above-mentioned prior art, the present invention provides a helical gear transmission device for eliminating clearance, aiming to solve the problem of the generation of a transmission dead zone during forward and reverse switching due to gear wear.

[0005] The technical solution of the present invention is as follows: A helical gear transmission device for clearance elimination, including a first transmission shaft, a second transmission shaft, a first helical gear, a second helical gear, and a third helical gear. The first helical gear is arranged on the first transmission shaft. The second helical gear and the third helical gear are axially spaced and arranged on the second transmission shaft. The first helical gear meshes with both the second helical gear and the third helical gear. It further includes an axial displacement mechanism arranged on the second transmission shaft. The axial displacement mechanism includes an inertial outward-expanding slider and an axial pushing member. The axial end face of the inertial outward-expanding slider is in close contact with the first axial end face of the axial pushing member. The second axial end face of the axial pushing member is in close contact with the end face of the third helical gear. The axial end face of the inertial outward-expanding slider and the first axial end face of the axial pushing member are inclined surfaces. When the second transmission shaft rotates, the inertial outward-expanding slider makes the axial pushing member generate an axial thrust towards the third helical gear through the axial end face of the inertial outward-expanding slider and the first axial end face of the axial pushing member. The inertial outward-expanding slider prevents the axial pushing member from moving away from the third helical gear.

[0006] Further, the included angle between the inclined surface and the rotation plane of the axial pushing member is 5° to 30°. A smaller included angle enables the inertial outward-expanding slider to push the axial pushing member to move axially when the inertial outward-expanding slider moves radially, while the axial movement of the axial pushing member is difficult to cause the inertial outward-expanding slider to move radially.

[0007] Further, a pre-compressed radial spring is provided between the inertial outward-expanding slider and the second transmission shaft.

[0008] Further, the axial displacement mechanism includes a base connected to the second transmission shaft. The base is provided with an outer ring wall, and a pre-stretched radial spring is provided between the inertial outward-expanding slider and the outer ring wall.

[0009] By providing a pre-compressed or pre-stretched radial spring, the inertial outward-expanding slider is always kept in a state of making the axial pushing member have a tendency to move towards the third helical gear, avoiding the inertial outward-expanding slider from moving towards the second transmission shaft due to accidental vibrations or the like.

[0010] Further, the axial displacement mechanism includes a base connected to the second transmission shaft. The base is provided with a plurality of radial chutes, and the inertial outward-expanding slider is arranged in the radial chutes.

[0011] Further, a plurality of inertial outward-expanding sliders are circumferentially equally distributed on the second transmission shaft.

[0012] Further, the axial pushing member is axially slidably matched with the base.

[0013] Further, the axial pushing member is of a disc structure, the base is provided with an outer ring wall, and the axial pushing member is arranged inside the outer ring wall.

[0014] Further, a radial slideway is arranged inside the inertial outward-expanding slider, an embedded block is slidably arranged in the radial slideway, and the mass of the embedded block is greater than that of the inertial outward-expanding slider.

[0015] Further, a gasket is arranged between the inertial outward-expanding slider and the radial chute. One surface of the gasket facing the inertial outward-expanding slider is a serrated surface, and the teeth of the serrated surface incline towards the outer periphery of the base.

[0016] Compared with the prior art, the advantages of the technical solution provided by the present invention are as follows: In the present invention, the inertial outward-expanding slider radially moves outwards during the rotation of the second transmission shaft, so that the axial pushing member generates an axial thrust towards the third helical gear. When the meshing first helical gear, second helical gear, and third helical gear are worn, the axial movement of the third helical gear can eliminate the backlash generated by the wear, thereby ensuring that there is no transmission dead zone during both forward and reverse rotations. Through the reverse self-locking effect of the inclined surface, it is possible to avoid the reverse axial force generated on the third helical gear due to the load, which causes the clearance elimination effect to fail, and it is more reliable than the existing structure that only relies on elastic members to eliminate the clearance. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 Structural schematic diagram of the helical gear transmission device for clearance elimination of the embodiment.

[0018] Figure 2 Structural schematic diagram of the axial displacement mechanism of the embodiment.

[0019] Figure 3 Side view structural schematic diagram of the axial displacement mechanism of the embodiment with the axial pushing member removed.

[0020] Figure 4 Cross-sectional view schematic diagram of the axial pushing member.

[0021] Figure 5 Side view schematic diagram of the axial pushing member.

[0022] Figure 6 Partial structural schematic diagram of the axial displacement mechanism. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0023] The present invention will be further described below in conjunction with embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading this description, various equivalent modifications made by those skilled in the art to this description all fall within the scope defined by the appended claims of this application.

[0024] Please refer to Figures 1 to 5 As shown, the helical gear transmission device for clearance elimination in this embodiment includes a first transmission shaft 1, a second transmission shaft 2, a first helical gear 3, a second helical gear 4, a third helical gear 5, and an axial displacement mechanism 6. The first transmission shaft 1 and the second transmission shaft 2 are arranged in parallel. Among them, the first helical gear 3 is fixedly installed on the first transmission shaft 1, and the second helical gear 4 and the third helical gear 5 are coaxially arranged on the second transmission shaft 2 at an axial interval, and both are meshed with the first helical gear 3 at the same time. The second helical gear 4 and the third helical gear 5 have the same gear parameters, including but not limited to modulus, number of teeth, pressure angle, helix angle, etc. When processing the two, the gear blanks can be axially stacked together and then hobbed, and two helical gears with the same parameters are obtained after processing.

[0025] The axial displacement mechanism 6 is arranged on one side of the third helical gear 5 and is also located on the second transmission shaft. Since the third helical gear 5 and the second helical gear 4 are equivalent, it is easy to understand that the axial displacement mechanism 6 can also be arranged on one side of the second helical gear 4.

[0026] Specifically, the axial displacement mechanism 6 includes a base 601, an inertial outward expansion slider 602, an axial pushing member 603, and a radial spring 604. The base 601 is of a disc structure. A central shaft column 601a is provided in the middle of the bottom surface of the base 601. The central shaft column 601a is fixed to the second transmission shaft 2 by key connection or interference fit. An outer ring wall 601b is provided on the outer periphery of the bottom surface of the base 601.

[0027] A plurality of radially distributed sliding grooves 601c are provided on the bottom surface of the base 601 at equal circumferential intervals. The inertial outward expansion slider 602 is slidably arranged in the radially distributed sliding grooves 601c and can slide radially in the radially distributed sliding grooves 601c. A gasket 605 can be arranged between the inertial outward expansion slider 602 and the bottom surface of the radially distributed sliding grooves 601c to adjust the axial position of the inertial outward expansion slider 602.

[0028] A relatively heavy embedded block 602a can be arranged inside the inertial outward expansion slider 602 to enhance the centrifugal effect. One axial end surface of the inertial outward expansion slider 602 on the second transmission shaft 2 is an inclined surface 602b, and the inclined surface 602b is in close contact with the first axial end surface 603a of the axial pushing member 603. That is to say, the inertial outward expansion slider 602 is thicker on the side close to the second transmission shaft 2 and thinner on the side far from the second transmission shaft 2.

[0029] The axial pushing member 603 has a disc-shaped structure. The axial pushing member 603 is axially slidably engaged with the central shaft column 601a through a key, and the outer circumferential surface of the axial pushing member 603 is in clearance fit with the inner wall of the outer ring wall 601b to ensure smooth axial sliding. On the side of the axial pushing member 603 facing the base, there is a convex block corresponding to the position of the inertial outward-expanding slider 602. The top surface of the convex block is the first axial end face 603a, which is in close fit with the inclined surface of the inertial outward-expanding slider 602. The side of the axial pushing member 603 facing away from the base 601 is the second axial end face 603b, which is in close contact with the end face of the third helical gear 5.

[0030] When there is a backlash between the first helical gear 3 and the third helical gear 5, or when there is a backlash between the first helical gear 3 and the second helical gear 4 (in this case, the slight rotation of the first transmission shaft 1 will also result in a backlash between the first helical gear 3 and the third helical gear 5). When the second transmission shaft 2 rotates at a high speed, the inertial outward-expanding slider 602 moves radially outward under the action of centrifugal force, and the inclined surface 602b and the first axial end face 603a of the axial pushing member 603 slide relative to each other, pushing the axial pushing member 603 to move axially in the direction of the third helical gear 5, thereby eliminating the backlash. The inertial outward-expanding slider 602 similar to a wedge block will prevent the axial pushing member 603 from moving axially in the opposite direction of the third helical gear 5, ensuring that when bearing a load, even if the third helical gear 5 receives an axial force, it will still not produce a reverse axial movement, and the effective elimination of the backlash is maintained to prevent failure.

[0031] As a preferred embodiment, the angle θ between the inclined surface 602b of the inertial outward-expanding slider 602 and the rotation plane of the axial pushing member 603 (i.e., the plane perpendicular to the axis of the second transmission shaft 2) is 5° to 30°, ensuring a more reliable locking effect. In addition, it further prevents the inertial outward-expanding slider 602 from moving towards the second transmission shaft 2.

[0032] A pre-compressed radial spring 604 is provided between the inertial outward-expanding slider 602 and the central shaft column 601a of the base 601 (or a pre-stretched radial spring between the inertial outward-expanding slider 602 and the outer ring wall 601b of the base 601). The radial spring 604 forces the inertial outward-expanding slider 602 to maintain an outward movement state in the static state, avoiding the accidental inward movement of the inertial outward-expanding slider 602 due to vibration or impact, and ensuring the continuous effectiveness of the clearance elimination.

[0033] Please further combine Figure 6As shown, in a preferred embodiment, a radial slideway 602c is provided inside the inertial outward-expanding slider 602. The embedded block 602a is spherical and has a mass greater than that of the inertial outward-expanding slider 602. It is arranged inside the slideway 602c, in clearance fit with the slideway 602c and can move inside the slideway 602c. A cover is provided at the end of the slideway 602c to prevent the embedded block 602a from falling out. When the second transmission shaft 2 rotates at a high speed, the inertial outward-expanding slider 602 moves radially outward under the action of centrifugal force. At the same time, the embedded block 602a also moves radially outward inside the slideway 602c under the action of centrifugal force, and the embedded block 602a forms a radially outward impact on the inertial outward-expanding slider 602, so that the inertial outward-expanding slider 602 is clamped between the axial pushing member 603 and the base 601. In addition, the surface of the gasket 605 in contact with the inertial outward-expanding slider 602 is set as a serrated surface, and the teeth of the serrated surface incline towards the outer periphery of the base 601. In this way, the inertial outward-expanding slider 602 can easily move radially outward, while it is easily blocked when moving radially inward, which can prevent the inertial outward-expanding slider 602 from moving radially inward, prevent the axial pushing member 603 from moving axially in the opposite direction of the third helical gear 5, and prevent failure.

Claims

1. A helical gear transmission device with clearance elimination, comprising a first transmission shaft, a second transmission shaft, a first helical gear, a second helical gear, and a third helical gear, wherein the first helical gear is arranged on the first transmission shaft, the second helical gear and the third helical gear are axially spaced and arranged on the second transmission shaft, and the first helical gear is meshed with the second helical gear and the third helical gear, characterized in that: It also includes an axial displacement mechanism arranged on the second transmission shaft, the axial displacement mechanism includes an inertial outward expansion slider and an axial push member, the axial end face of the inertial outward expansion slider is in close contact with the first axial end face of the axial push member, the second axial end face of the axial push member is in close contact with the end face of the third bevel gear, the axial end face of the inertial outward expansion slider and the first axial end face of the axial push member are inclined surfaces, when the second transmission shaft rotates, the inertial outward expansion slider causes the axial push member to generate an axial thrust toward the third bevel gear through the axial end face of the inertial outward expansion slider and the first axial end face of the axial push member, and the inertial outward expansion slider prevents the axial push member from moving in a direction away from the third bevel gear.

2. The backlash-eliminating helical gear transmission device according to claim 1, characterized in that: The angle between the inclined surface and the rotation plane of the axial push-against member is 5° to 30°.

3. The backlash-eliminating helical gear transmission device according to claim 1, characterized in that: A pre-compressed radial spring is provided between the inertial outward expansion slider and the second transmission shaft.

4. The backlash-eliminating helical gear transmission device according to claim 1, characterized in that: The axial displacement mechanism comprises a base connected to the second transmission shaft, the base is provided with an outer annular wall, and a pre-stretched radial spring is provided between the inertial outward expansion sliding block and the outer annular wall.

5. The backlash-eliminating helical gear transmission device according to claim 1, characterized in that: The axial displacement mechanism comprises a base connected to the second transmission shaft, the base is provided with a plurality of radial sliding grooves, and the inertial outward sliding block is arranged in the radial sliding grooves.

6. The backlash-eliminating helical gear transmission device according to claim 1 or 5, characterized in that: A plurality of inertial expansion sliding blocks are evenly distributed in the circumferential direction of the second transmission shaft.

7. The backlash-eliminating helical gear transmission device according to claim 5, characterized in that: The axial push member is axially slidably matched with the base.

8. The backlash-eliminating helical gear transmission device according to claim 5, characterized in that: The axial push member is a disc structure, the base is provided with an outer ring wall, and the axial push member is arranged inside the outer ring wall.

9. The backlash-eliminating helical gear transmission device according to claim 1, characterized in that: A radial slideway is arranged inside the inertial outward-stretching slider, and an embedded block is slidably arranged inside the radial slideway. The mass of the embedded block is greater than the mass of the inertial outward-stretching slider.

10. The backlash-eliminating helical gear transmission device according to claim 5, characterized in that: A gasket is provided between the inertial outward sliding block and the radial sliding groove, and a surface of the gasket facing the inertial outward sliding block is a serrated surface, and the teeth of the serrated surface are inclined toward the outer periphery of the base.

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