Gear connecting structure, reduction gearbox and vehicle

Abstract

The invention discloses a gear connecting structure, a reduction gearbox and a vehicle, and belongs to the technical field of vehicle engineering. The gear connecting structure comprises a gear shaft, the gear shaft comprises an optical shaft section and an outer tooth section which are arranged at intervals in the axial direction, and spline teeth of the outer tooth section are configured to be helical angle spline teeth; the first gear is provided with a shaft hole, the first gear is connected to the gear shaft in a sleeving mode through the shaft hole, the hole wall of the shaft hole is provided with a smooth wall section and an inner tooth section in the axial direction, every two adjacent spline teeth of the inner tooth section abut against the two circumferential sides of the spiral angle spline teeth respectively, and the smooth wall section is in interference fit with the smooth shaft section. According to the gear connecting structure, the reduction gearbox and the vehicle, collision abnormal sound and fretting wear can be restrained.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of vehicle engineering, and particularly relates to a gear connection structure, a reduction gearbox and a vehicle. BACKGROUND

[0002] Two gears are arranged on the intermediate shaft of the electric drive reduction gearbox. Due to the limited axial size space of the reduction gearbox, the two gears need to be designed in close proximity. In order to balance the connection reliability and the small occupied space, one gear can be integrally arranged with the intermediate shaft, and the other gear needs to be installed on the intermediate shaft in the form of a spline.

[0003] The intermediate shaft of the electric drive reduction gearbox transmits torque in two rotation directions, positive and reverse, under the two working conditions of vehicle forward driving and coasting. There is a certain backlash between the straight teeth of the spline. When the gears transmit positive and reverse torque, collision noise will occur, and relative sliding between the tooth surfaces will also easily occur, resulting in fretting wear. SUMMARY

[0004] The application provides a gear connection structure, a reduction gearbox and a vehicle, and aims to solve the technical problems that the intermediate shaft of the vehicle reduction gearbox and the gears are prone to collision noise and fretting wear during positive and reverse rotation. To this end,

[0005] In one aspect of the embodiment of the application, a gear connection structure is provided, which comprises:

[0006] The gear shaft comprises an optical shaft segment and an outer tooth segment arranged at intervals along the axial direction, and the spline teeth of the outer tooth segment are configured as helix angle spline teeth;

[0007] The first gear has a shaft hole, the first gear is sleeved on the gear shaft through the shaft hole, the hole wall of the shaft hole is provided with an optical wall segment and an inner tooth segment along the axial direction, the adjacent two spline teeth of the inner tooth segment are respectively abutted on the circumferential two sides of the helix angle spline teeth, and the optical wall segment is in interference fit with the optical shaft segment.

[0008] In some embodiments, the spline teeth of the inner tooth segment are straight teeth arranged along the axial direction of the shaft hole.

[0009] In some embodiments, at least one helix angle spline tooth is arranged between the adjacent two straight teeth.

[0010] In some embodiments, the length of the optical wall segment is less than the length of the outer tooth segment.

[0011] In some embodiments, the sum of the lengths of the optical shaft segment and the outer tooth segment is less than the sum of the lengths of the optical wall segment and the inner tooth segment.

[0012] In some embodiments, the axial length of the light wall segment is greater than or equal to one third of the axial length of the external tooth portion of the first gear.

[0013] In some embodiments, the gear connection structure further comprises a second gear, which is coaxially arranged with the gear shaft.

[0014] In some embodiments, the gear connection structure further comprises a first bearing, which is sleeved on the end portion of the gear shaft, the two axial end portions of the main body of the first gear abut against the first gear and the first bearing, and the tooth portion of the first gear is provided with a clearance gap between the second gear and the first bearing.

[0015] Another aspect of the embodiments of the present application also provides a reduction gearbox comprising the gear connection structure.

[0016] Another aspect of the embodiments of the present application also provides a vehicle comprising the reduction gearbox.

[0017] The embodiments of the present application have at least the following beneficial effects:

[0018] The gear connection structure, the reduction gearbox and the vehicle provided by the embodiments of the present application comprise a gear shaft and a first gear, the gear shaft comprises a light shaft segment and an external tooth segment arranged at intervals along the axial direction, and the spline teeth of the external tooth segment are configured as helix angle spline teeth; the first gear has a shaft hole, and the hole wall of the shaft hole is provided with a light wall segment and an internal tooth segment along the axial direction; the first gear is sleeved on the gear shaft through the shaft hole, the light wall segment is in interference fit with the light shaft segment, so as to ensure coaxial fixation of the first gear and the gear shaft and ensure transmission quality; the adjacent two spline teeth of the internal tooth segment abut against the circumferential two sides of the helix angle spline teeth respectively, so as to eliminate the circumferential movement gap of the internal tooth segment and the external tooth segment, enable stable abutment and fixation of the first gear and the gear shaft as a whole, and avoid collision noise and micro-motion wear during forward and reverse rotation of the first gear and the gear shaft. BRIEF DESCRIPTION OF DRAWINGS

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed in the embodiment description will be briefly introduced. Obviously, the drawings in the following description are some embodiments of the present application, and other drawings can also be obtained by those skilled in the art without creative labor.

[0020] Figure 1 The structural schematic diagram of the gear connection structure in the embodiments of the present application is shown;

[0021] Figure 2 The structural schematic diagram of the gear connection structure in the embodiments of the present application is shown; Figure 1Structure diagram of the inner tooth section and the outer tooth section of the gear connection structure in the first gear;

[0022] Figure 3 Structure diagram of the gear shaft of the gear connection structure in the first gear is shown. Figure 1 Structure diagram of the gear shaft of the gear connection structure in the first gear is shown.

[0023] Figure 4 Structure diagram of the gear shaft of the gear connection structure in the first gear is shown. Figure 1 Structure diagram of the first gear of the gear connection structure in the first gear is shown.

[0024] Reference signs:

[0025] 1-gear shaft, 11-light shaft section, 12-outer tooth section, 121-helical angle spline tooth;

[0026] 2-first gear, 2a-shaft hole, 2b-clearance space, 21-light wall section, 22-inner tooth section, 221-straight tooth, 23-outer tooth section;

[0027] 3-stop structure, 31-first bearing, 32-second bearing;

[0028] 4-second gear. DETAILED DESCRIPTION

[0029] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work belong to the scope of protection of the present application.

[0030] In addition, the reference numbers and / or reference letters can be repeated in different examples in the present application, and such repetition is for the purpose of simplification and clarity, and does not indicate the relationship between the various embodiments and / or arrangements discussed. In addition, the present application provides examples of various specific processes and materials, but those skilled in the art can realize the application of other processes and / or the use of other materials.

[0031] The present application will be described below in conjunction with the drawings and with reference to specific embodiments:

[0032] A transmission gear is coaxially sleeved on the intermediate shaft in the reduction gearbox, and the transmission gear and the intermediate shaft are connected through spline. Usually, the spline straight teeth arranged at intervals are used to realize the circumferential transmission. Limited by the straight insertion assembly mode, assembly gaps are inevitably left between the matched spline straight teeth. During the forward and reverse rotation of the reduction gearbox, the collision noise is easily generated between the spline straight teeth, and the fretting wear is caused, which seriously affects the service life and transmission reliability.

[0033] To this end, the embodiment of the present application provides a gear connection structure, a reduction gearbox and a vehicle, aiming to solve the technical problem of collision noise and micro-motion wear between the intermediate shaft and the gear of the vehicle reduction gearbox in the process of forward and reverse rotation to some extent.

[0034] Referring to Figure 1 、 Figure 2 、 Figure 3 and Figure 4 , in some embodiments, the spline fitting mode of the gear connection structure adopts the mode of straight teeth and spline teeth with a helix angle abutting each other, so as to eliminate the backlash, thereby reducing or even eliminating the collision noise and micro-motion wear.

[0035] Specifically, the gear connection structure comprises a gear shaft 1 and a first gear 2; the first gear 2 is provided with an axial hole 2a, and is sleeved on the gear shaft 1 through the axial hole 2a; and the inner hole wall of the axial hole 2a and the outer circumferential surface of the gear shaft 1 are respectively provided with matched spline structures, so as to realize circumferential transmission.

[0036] Among them, the gear shaft 1 is provided with a light shaft section 11 and an outer tooth section 12, and the inner wall of the axial hole 2a of the first gear 2 is provided with a light wall section 21 and an inner tooth section 22; the light wall section 21 is interference-fitted with the light shaft section 11, and the inner tooth section 22 is engaged with the outer tooth section 12. Among them, the spline teeth of the outer tooth section 12 are provided as helix angle spline teeth 121 with a certain helix angle, so as to have a larger width in the circumferential direction; correspondingly, the two circumferential sides of the helix angle spline teeth 121 are respectively abutted between two adjacent spline teeth of the inner tooth section 22, so as to eliminate the backlash, thereby limiting the circumferential displacement between the helix angle spline teeth 121 and the inner tooth section 22, so that the first gear 2 and the gear shaft 1 are fixed and integrated in the circumferential direction, and the collision noise and micro-motion wear are eliminated.

[0037] It is worth noting that the interference fit of the light shaft section 11 and the light wall section 21 can ensure the coaxiality of the gear shaft 1 and the first gear 2, thereby ensuring the transmission quality.

[0038] In some embodiments, in order to simplify the machining operation and assembly operation, the spline teeth of the inner tooth section 22 can be provided as straight teeth 221 arranged in the axial direction.

[0039] In assembly, one circumferential side wall edge of one end of the helical angular spline tooth 121 abuts against the side wall of the straight tooth 221, and then the gear shaft 1 is pushed into the shaft hole 2a of the first gear 2 in the axial direction, and with the relative movement of the gear shaft 1 and the first gear 2, the other circumferential side wall edge of the other end of the helical angular spline tooth 121 gradually approaches the side wall of the opposite straight tooth 221 until complete abutment, so that the two circumferential side walls of the helical angular spline tooth 121 abut against the two straight teeth 221 on both sides respectively, thereby achieving circumferential clamping, limiting circumferential displacement, limiting collision noise and micro-motion wear.

[0040] In some embodiments, the spline teeth between the inner tooth segment 22 and the outer tooth segment 12 are one-to-one staggered engagement, so that uniform and stable engagement can be achieved, circumferential transmission can be achieved, and uniformity of force can be maintained, reducing the risk of spline tooth collapse.

[0041] Of course, two or more helical angular spline teeth 121 can be provided between adjacent two straight teeth 221 to meet the structural strength; the specific number can be flexibly set according to the actual situation.

[0042] In some embodiments, considering that the first gear 2 and the gear shaft 1 are assembled by a sleeving process, and the light wall segment 21 and the light shaft segment 11 are in interference fit, therefore, in assembly, the outer tooth segment 12 and the inner tooth segment 22 should be assembled before the light wall segment 21 and the light shaft segment 11, so as not to affect the subsequent assembly operation due to the large resistance of the interference fit state.

[0043] Therefore, the length L1' of the light wall segment 21 can be set to be less than the length L2 of the outer tooth segment 12, so that when the first gear 2 and the gear shaft 1 are sleeved, the outer tooth segment 12 and the inner tooth segment 22 will be preferentially fitted before the interference contact of the outer tooth segment 12 and the inner tooth segment 22, so that the engagement assembly of the inner tooth segment 22 and the outer tooth segment 12 can be relatively simply completed, and the influence of the interference contact resistance of the outer tooth segment 12 and the inner tooth segment 22 is reduced.

[0044] In some embodiments, considering that the helical angular spline tooth 121 is provided in the spline between the first gear 2 and the gear shaft 1, there is a certain axial force component when transmitting circumferential torque, that is, there is a force to push the first gear 2 away from the gear shaft 1, therefore, a stop structure 3 needs to be provided at the shaft end of the first gear 2.

[0045] In some embodiments, considering that the outer tooth part 23 of the first gear 2 needs to be externally connected to other gears, the hole end of the shaft hole 21 of the first gear 2 abuts against the stop structure 3.

[0046] That is, the axial length of the first gear 2 should be greater than the sum of the lengths of the optical axis section 11 and the outer tooth section 2, so as to completely cover the optical axis section 11 and the outer tooth section 2 of the gear shaft 1. Correspondingly, the sum of the lengths of the optical wall section 21 and the inner tooth section 22 (L1+L2) should be greater than the sum of the lengths of the outer tooth section 12 and the optical axis section 11 (L1'+L2').

[0047] The stop structure 3 can be correspondingly sleeved on the end of the gear shaft 1, and axially lock the first gear 2.

[0048] In some embodiments, considering that the outer tooth part 23 of the first gear 2 needs to be connected to an external gear structure, in order to avoid interference with the stop structure 3 and other functional structures on the axial both sides of the outer tooth part 23, the axial length B of the outer tooth part 23 can be set to be less than the sum of the lengths of the optical wall section 21 and the inner tooth section 22 (L1+L2), that is, a certain avoiding space 2b is left between the outer tooth part 23 and the axial end of the first gear 2.

[0049] In some embodiments, considering that the first gear 2 is in circumferential engagement with the gear shaft 1 for transmission, in order to ensure the connection stiffness, the axial length L1 of the optical wall section 21 can be set to be greater than or equal to one third of the axial length B of the outer tooth part 23.

[0050] It is worth noting that the tooth root part of the outer tooth part 23 of the first gear 2 is a key area that bears bending stress. If the inner tooth section 22 is too long, the relief groove or transition structure during spline machining may weaken the cross-sectional area of the tooth root part, reducing its bending strength.

[0051] The axial length of the optical wall section 21 is greater than or equal to one third of the axial length of the outer tooth part 23, which can ensure that the tooth root has sufficient material thickness, avoid stress concentration leading to fatigue cracks, and ensure the structural strength and reliability of the first gear 2.

[0052] In some embodiments, the gear shaft 1 is provided with a second gear 4, so as to be connected between two gear transmission structures and realize torque transmission.

[0053] In some embodiments, in order to reduce the axial installation space and take into account the assembly simplicity, the second gear 4 can be integrally arranged with the gear shaft 1.

[0054] In some embodiments, in order to realize the rotation transmission capability of the first gear 2 and the second gear 4, the gear shaft 1 can be rotatably arranged on a support base.

[0055] Correspondingly, the end of the gear shaft 1 should be provided with a rotating support structure, such as a first bearing 31, and connected to the support base through the first bearing 31.

[0056] In some embodiments, considering that the first gear 2 needs to be provided with a stop structure 3, the first bearing 31 and the second gear 2 can be arranged as the axial stop structure of the first gear 2, clamping the first gear 2 in the middle.

[0057] Among them, the outer tooth part 23 is provided with the avoidance space 2b between the first bearing 31 and the second gear 2.

[0058] In some embodiments, in order to improve the support stability, the two ends of the gear shaft 1 can be respectively provided with rotating support structures, that is, the first bearing 31 and the second bearing 32 are respectively arranged at the two ends.

[0059] In some embodiments, the first bearing 31 and the second bearing 32 can adopt tapered bearings to meet the assembly requirements in the reduction gearbox.

[0060] In some embodiments, a reduction gearbox adopting the above gear connection structure is also provided, and the first gear 2 and the second gear 4 can be respectively connected to two transmission gears to realize torque transmission.

[0061] In some embodiments, a vehicle including the above reduction gearbox is also provided.

[0062] The embodiments of the present application have at least the following beneficial effects:

[0063] The gear connection structure, the reduction gearbox and the vehicle provided by the embodiments of the present application include a gear shaft and a first gear. The gear shaft includes a light shaft segment and an outer tooth segment arranged at intervals along the axial direction. The spline teeth of the outer tooth segment are configured as helix angle spline teeth. The first gear has a shaft hole, and the hole wall of the shaft hole is provided with a light wall segment and an inner tooth segment along the axial direction. The first gear is sleeved on the gear shaft through the shaft hole, the light wall segment is in interference fit with the light shaft segment, so as to ensure coaxial fixation of the first gear and the gear shaft and ensure transmission quality. Adjacent two spline teeth of the inner tooth segment are respectively abutted on the circumferential two sides of the helix angle spline teeth, so as to eliminate the activity gap of the inner tooth segment and the outer tooth segment in the circumferential direction, enable stable abutment and fixation of the first gear and the gear shaft, and avoid collision noise and micro-motion wear in the forward and reverse rotation process of the first gear and the gear shaft.

[0064] In the present application, unless specifically defined and limited otherwise, the "on" or "under" of the first feature to the second feature can include that the first and second features are in direct contact, or that the first and second features are not in direct contact but are in contact through another feature between them. Moreover, the "on", "above" and "over" of the first feature to the second feature includes that the first feature is directly above and obliquely above the second feature, or only indicates that the first feature is higher in horizontal height than the second feature. The "under", "below" and "under" of the first feature to the second feature includes that the first feature is directly below and obliquely below the second feature, or only indicates that the first feature is lower in horizontal height than the second feature.

[0065] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, which is only for the convenience of describing the present application and simplifying the description, and does not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0066] It should be noted that all directional indications in the embodiments of the present application are only used to explain the relative positional relationship, motion condition and the like between components in a certain posture, and if the certain posture changes, the directional indications also change accordingly.

[0067] In the present application, unless specifically defined and limited otherwise, the terms "connection", "fixing" and the like should be broadly understood, for example, "fixing" can be fixed connection, or detachable connection, or integral; can be mechanical connection, or electrical connection; can be directly connected, or indirectly connected through intermediate medium; can be the internal communication of two elements or the interaction relationship of two elements, unless otherwise specifically limited. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0068] In addition, the description such as "first", "second" and the like in the present application is only for the purpose of description, and cannot be understood as indicating or implying the relative importance of the indicated technical features or implying the number of the indicated technical features. Therefore, the features limited by "first", "second" can explicitly or implicitly include one or more of the features. In the description of the present application, the meaning of "multiple" is two or more, unless otherwise specifically limited.

[0069] In the description of the specification, the description of the terms "one embodiment", "some embodiments", "an example", "a specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present application. In the specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in the specification.

[0070] In addition, the technical solutions among various embodiments can be combined with each other, but it must be based on the fact that a person skilled in the art can realize it, and when the combination of technical solutions appears contradictory or cannot be realized, it should be considered that the combination of technical solutions does not exist and is not within the protection scope required by the present application.

[0071] Although the embodiments of the present application have been shown and described, those skilled in the art can understand that various changes, modifications, replacements and deformations can be made to the embodiments without departing from the principles and purposes of the present application, and the scope of the present application is defined by the claims and their equivalents.

Claims

1. A gear coupling structure characterized by comprising: The gear shaft comprises an optical shaft section and an external gear section arranged axially at intervals, and the spline teeth of the external gear section are configured as helix angle spline teeth. The first gear is provided with a shaft hole, the first gear is sleeved on the gear shaft through the shaft hole, and the hole wall of the shaft hole is provided with an optical wall section and an internal gear section in the axial direction, the adjacent two spline teeth of the internal gear section are respectively abutted on the circumferential two sides of the helix angle spline teeth, and the optical wall section is in interference fit with the optical shaft section. The spline teeth of the internal gear section are straight teeth arranged in the axial direction of the shaft hole.

2. The gear coupling structure of claim 1, wherein At least one helix angle spline tooth is arranged between the adjacent two straight teeth.

3. The gear coupling structure of claim 2, wherein The length of the optical wall section is less than the length of the external gear section.

4. The gear coupling structure of claim 1, wherein The sum of the lengths of the optical shaft section and the external gear section is less than the sum of the lengths of the optical wall section and the internal gear section.

5. The gear coupling structure of claim 1, wherein The axial length of the optical wall section is greater than or equal to one third of the axial length of the external tooth part of the first gear.

6. The gear coupling structure of claim 1, wherein The gear connection structure further comprises a second gear, which is coaxially arranged with the gear shaft.

7. The gear coupling structure according to any one of claims 1 to 6, wherein The gear connection structure further comprises a first bearing, which is sleeved on the end of the gear shaft, the two axial ends of the main body of the first gear are abutted on the first gear and the first bearing, and the tooth part of the first gear is provided with a clearance between the second gear and the first bearing.

8. The gear coupling structure of claim 7, wherein The gear connection structure comprises the gear connection structure according to claim 8.

9. A reduction gearbox characterised in that, The reduction box comprises the reduction box according to claim 9.

10. A vehicle characterized by comprising: ​

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