Mechanical transmission spline backlash knocking abnormal sound optimization structure

Abstract

The utility model relates to a mechanical transmission spline backlash knocking abnormal sound optimization structure which comprises a driving shaft, and an inner spline is formed in a blind hole of the driving shaft; the gear shaft is provided with a male spline; the driving shaft and the gear shaft are matched with each other through internal / external splines; wherein the gear shaft comprises a hydraulic oil damper and a limiting ring, the hydraulic oil damper comprises a piston, and the limiting ring is connected to the gear shaft in a sleeving mode and fixedly connected to the piston; a notch is further formed in the tip end face of the driving shaft, the rear edge of the notch is inclined relative to the axial direction, and a protrusion extending outwards in the radial direction of the limiting ring is formed on the limiting ring, so that when the driving shaft and the gear shaft are matched in place, the protrusion is wedged into the notch. In the application, the hydraulic oil damper adopts a hydraulic working mode, and provides more powerful and stable buffering for the problem of abnormal knocking sound of the circumferential backlash matched with the spline.

Description

Technical Field

[0001] The present application relates to the technical field of electric vehicles, and in particular to a mechanical transmission spline side clearance knocking noise optimization structure. Background Art

[0002] In the transmission system of electric vehicles, the fit between the motor shaft (i.e., the drive shaft) and the gearbox shaft (i.e., the driven shaft) needs to take into account the relative axial displacement between the two. Therefore, the fit is mainly a slippable connection. Among them, spline fit is usually adopted, and in order to facilitate the relative slip of the two shafts, the inner spline and the outer spline are mostly in the form of clearance fit. Under this premise, when the output of the motor shaft is unstable or the transmission system is vibrated by external impact, the gap between the inner and outer splines will affect the spline transmission accuracy and spline service life, and at the same time cause abnormal noise and vibration (Noise, Vibration, Harshness, NVH) of the vehicle.

[0003] CN115325099A discloses a clutch system, in which a disc spring is fixed at a flywheel spline or a clutch spline, and the friction force generated by the claws of the disc spring is used to offset the energy of external impact. However, this method of using friction to offset external impact causes greater friction damage to the disc spring; CN219277231U discloses a power drive system, in which damping seals are provided at both ends of the spline. However, in practice, O-rings are arranged at both ends of the spline of the power drive system. This method has a very limited buffering effect on the abnormal sound of spline knocking.

[0004] Therefore, it is necessary to provide a better solution for the automobile, especially its transmission system, to protect the spline fit between the motor shaft and the gearbox shaft from being damaged due to impact. Summary of the invention

[0005] In order to overcome at least one of the defects of the prior art described above, the present application proposes a mechanical transmission spline side clearance knocking noise optimization structure, comprising:

[0006] A driving shaft, a tip end surface of which is formed with a blind hole extending along its axial direction, and an inner circumferential surface of the blind hole is formed with an internal spline;

[0007] The gear shaft has an outer spline formed on its outer peripheral surface;

[0008] The drive shaft and the gear shaft cooperate with each other by means of the internal spline and the external spline;

[0009] Wherein, the gear shaft comprises a hydraulic oil damper and a stop ring, the hydraulic oil damper is located away from the drive shaft relative to the stop ring, and the hydraulic oil damper comprises a piston, the stop ring is sleeved on the gear shaft and fixedly connected to the piston; and

[0010] The tip end surface of the drive shaft is also formed with a notch, the rear edge of the notch is inclined relative to the axial direction, and the limiting ring is formed with a protrusion extending radially outward, so that when the drive shaft and the gear shaft are fitted into place with each other, the protrusion is wedged into the notch.

[0011] According to an embodiment of the present application, the inclination of the trailing edge of the notch is configured such that a virtual normal line of the trailing edge has a first component following the positive rotation direction of the drive shaft and a second component pointing to the gear shaft along its axial direction.

[0012] According to one embodiment of the present application, the hydraulic oil damper is composed of the piston and the sealing chamber sleeve, wherein the sealing chamber sleeve is sleeved on the gear shaft, and the piston is accommodated between the gear shaft and the sealing chamber sleeve, whereby the piston, the gear shaft and the sealing chamber sleeve jointly define a hydraulic oil chamber with a variable volume.

[0013] According to one embodiment of the present application, the gear shaft has an input oil passage fluidically connected to the hydraulic oil chamber.

[0014] According to one embodiment of the present application, the sealing chamber sleeve has a one-way oil leakage channel from the hydraulic oil chamber to the external environment.

[0015] According to some embodiments of the present application, the optimized structure further includes a sleeve, which is sleeved on the gear shaft and located between the limiting ring and the piston, and the limiting ring, the sleeve and the piston are pressed against each other in sequence.

[0016] According to one embodiment of the present application, the number of the notches is one or more, the number of the protrusions is equivalent to the number of the notches, and the notches and the protrusions correspond one-to-one in position along the circumference of the drive shaft and / or the gear shaft.

[0017] According to one embodiment of the present application, the gear shaft is provided with an annular groove, and includes a clamp installed to the annular groove and an elastic element sleeved on the gear shaft, the first end of the elastic element is fixedly connected to the clamp, and the second end of the elastic element is fixedly connected to the limiting ring.

[0018] According to one embodiment of the present application, the elastic element is a wave spring or a coil spring.

[0019] According to one embodiment of the present application, the gear shaft is provided with a slide groove extending along its axial direction, and the limiting ring is formed with a slider extending radially inward, and the slider performs linear motion in the slide groove to prevent the limiting ring from rotating relative to the gear shaft.

[0020] The mechanical transmission spline side clearance knocking noise optimization structure of the present application arranges the damper for buffering the spline side clearance knocking at a position far away from the spline fitting (compared with the prior art), and the damper adopts a hydraulic working mode. On the one hand, it provides a stronger and more stable buffer for the circumferential side clearance knocking noise problem of the spline fitting (for example, compared with the O-ring). On the other hand, with the help of a series of components such as limiting rings and sleeves as transitions, the damper force does not have to be applied near the spline fitting, and friction loss will not occur, further protecting the drive shaft and gear shaft. In addition, the mechanical transmission spline side clearance knocking noise optimization structure of the present application includes both a hydraulic oil chamber with a variable volume and an elastic element between the clamp and the limiting ring, which represents that the entire optimization structure includes a variety of adjustable devices, providing multiple guarantees for solving the spline side clearance knocking noise problem. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A front view of a mechanical transmission spline side clearance knocking noise optimization structure according to an embodiment of the present application is shown;

[0022] Figure 2 Shows Figure 1 The radial cross-section diagram of the mechanical transmission spline side clearance knocking noise optimization structure shown;

[0023] Figure 3 A perspective view of a drive shaft according to one embodiment of the present application is shown;

[0024] Figure 4 A perspective view showing a gear shaft according to one embodiment of the present application; and

[0025] Figure 5 A perspective view of a limiting ring according to an embodiment of the present application is shown. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0027] It should be noted that the illustrations provided in this embodiment only illustrate the basic concept of the present application in a schematic manner, and therefore the drawings only show components related to the present application rather than being drawn according to the number, shape and size of components in actual implementation. In actual implementation, the type, quantity and proportion of each component may be changed arbitrarily, and the component layout may also be more complicated.

[0028] The structures, proportions, sizes, etc. illustrated in the drawings of this specification are only used to match the contents disclosed in the specification so as to facilitate understanding and reading by persons familiar with this technology. They are not used to limit the conditions under which this application can be implemented, and therefore have no substantive technical significance. Any structural modification, change in proportion or adjustment of size, without affecting the effects and purposes that can be achieved by this application, should still fall within the scope of the technical contents disclosed in this application.

[0029] The directions or positional relationships indicated by the terms "upper", "lower", "left", "right", "middle", "longitudinal", "lateral", "horizontal", "inner", "outer", "radial", "circumferential" and the like in this specification are based on the directions or positional relationships shown in the drawings and are only for the convenience of simplifying the description. They do not indicate or imply that the devices or elements referred to must have a specific direction, be constructed and operate in a specific direction, and therefore cannot be understood as limiting the present application. In addition, the terms "first" and "second" are used for descriptive purposes only and cannot be understood as indicating or implying relative importance.

[0030] like Figure 1 , 3 , 4, where Figure 1 A front view of a mechanical transmission spline side clearance knocking noise optimization structure according to an embodiment of the present application is shown, Figure 3 A perspective view of a drive shaft according to one embodiment of the present application is shown, and Figure 4 A perspective view of a gear shaft according to an embodiment of the present application is shown. As the name implies, the transmission system of an electric vehicle includes a drive shaft 1 and a gear shaft 2. The tip end surface of the drive shaft 1 is formed with a blind hole 101 extending along the axial direction of the drive shaft 1 itself, so that the drive shaft 1 and the gear shaft 2 can be assembled in the form of a shaft-hole fit. The inner shaft surface of the blind hole 101 is formed with an internal spline 102, and the outer peripheral surface of the gear shaft 2, especially the distal section thereof, is formed with an external spline 201, whereby, when the drive shaft 1 and the gear shaft 2 are assembled, the internal spline 102 and the external spline 201 are meshed with each other in the form of a clearance fit.

[0031] like Figure 2 As shown, it shows Figure 1The radial cross-section of the mechanical transmission spline side clearance knocking noise optimization structure shown. In order to alleviate the spline side clearance knocking caused by the unstable output of the drive shaft 1 or the external impact, the gear shaft 2 is provided with a limit ring 204 and a hydraulic oil damper 206, wherein the limit ring 204 is sleeved on the gear shaft 2, and both are located outside the axial hole matching of the drive shaft 1 and the gear shaft 2. Specifically, in the present embodiment, both are located away from the drive shaft 1. Furthermore, the hydraulic oil damper 206 is farther away from the drive shaft 1 than the limit ring 204, that is, the hydraulic oil damper 206 is located on the right side of the limit ring 204. The hydraulic oil damper 206 is composed of a piston 207 and a sealing chamber sleeve 208, wherein the sealing chamber sleeve 208 is also sleeved on the gear shaft 2. Preferably, the sealing chamber sleeve 208 is installed on the left side of the gear close to the gear shaft 2. The piston 207 is accommodated between the gear shaft 2 and the sealing chamber sleeve 208, whereby the piston 207, the outer peripheral surface of the gear shaft 2 and the sealing chamber sleeve 208 together define a hydraulic oil chamber with a variable volume, wherein the piston 207 is movable along the axial direction of the gear shaft 2. The stop ring 204 is fixedly connected to the piston 207.

[0032] Back to Figure 1 The tip end surface of the drive shaft 1 is also formed with a notch 103, which includes a leading edge 104 and a trailing edge 105 along the circumference of the drive shaft 1 in conjunction with the working condition of the motor running in the forward direction. It should be noted that the trailing edge 105 is inclined relative to the axial direction of the drive shaft 1. Figure 5 , which shows a perspective view of a stop ring according to an embodiment of the present application. The stop ring 204 is formed with a protrusion 2041 extending outward along its own radial direction. When the drive shaft 1 and the gear shaft 2 are in place with each other, the protrusion 2041 is wedged into the notch 103. Preferably, the inclination direction of the trailing edge 105 is designed so that the virtual normal of the trailing edge 105 that contacts the side of the protrusion 2041 has both a first component that follows the positive operation of the motor, that is, the positive rotation direction of the drive shaft 1, and a second component that points to the gear shaft 2 along the axial direction of the drive shaft 1. The trailing edge 105 designed in this way results in that, when the rotational speed of the gear shaft 2 is lower than the rotational speed of the drive shaft 1, the side clearance between the keys at the non-working surfaces of the inner spline 102 and the outer spline 201 is the largest, and the trailing edge 105 pushes the protrusion 2041 to rotate in the forward direction of the motor. At this time, the thrust exerted by the inclined trailing edge 105 on the protrusion 2041 includes both an axial component (corresponding to the second component) and a circumferential component (corresponding to the first component), wherein the circumferential component of the thrust is transmitted to the hydraulic oil damper 206 through the limit ring 204 and then offset / buffered here.

[0033] Preferably, the number of the notches 103 and the number of the protrusions 2041 can be one or more, as long as the number of the notches 103 and the number of the protrusions 2041 remain equal. Moreover, in the case where the notches 103 and the protrusions 2041 are both plural, in order to ensure that each protrusion 2041 is wedged into the corresponding notch 103, in the circumferential direction of the drive shaft 1 and / or the gear shaft 2, each notch 103 and each protrusion 2041 are aligned with each other.

[0034] In a preferred embodiment, referring to Figure 4 and 5 The gear shaft 2 is provided with a slide groove 209 extending along its axial direction, and correspondingly, the stop ring 204 is formed with a slider 2042 extending radially inwardly. During assembly, the slider 2042 is embedded in the slide groove 209, so that the stop ring 204 slides linearly under the guidance of the slide groove 209. In other words, the stop ring 204 and the gear shaft 2 will not rotate relative to each other.

[0035] Back to Figure 2 , the gear shaft 2 is further provided with an input oil circuit 210 leading to the hydraulic oil chamber, and the external hydraulic oil tank inputs the hydraulic oil into the hydraulic oil chamber via the input oil circuit 210. On the other hand, the sealing chamber sleeve 208 is provided with a one-way oil drain passage (not shown) leading to the hydraulic oil chamber, and preferably, a one-way valve (not shown) is arranged therein, so that when the pressure in the hydraulic oil chamber is overloaded, the hydraulic oil can be discharged to the surrounding environment via the one-way oil drain passage. It can be seen that the hydraulic oil chamber can obtain hydraulic oil input or discharge hydraulic oil to release pressure as needed, so that the pressure and volume in the hydraulic oil chamber can be variable.

[0036] Considering that the stop ring 204 is not convenient to be directly fixedly connected to the piston 207 in some application scenarios, for example, the gear shaft 2 has more than one journal. In this case, the mechanical transmission spline side clearance knocking noise optimization structure of the present application further includes a sleeve 205, which is also sleeved on the gear shaft 2 and arranged between the stop ring 204 and the piston 207. Figure 2 As shown, the left end face of the sleeve 205 is pressed against the right end face of the stop ring 204, and the right end face of the sleeve 205 is pressed against the left end face of the piston 207, so that, by means of the indirect connection of the sleeve 205, the force exerted on the stop ring 204 is transmitted to the piston 207. Of course, in other embodiments, for example, in the application scenario where the gear shaft 2 does not have too many journals, the sleeve 205 may not be provided, which means that the stop ring 204 and the piston 207 are directly pressed against each other.

[0037] Furthermore, considering that the limiting ring 204 can slide linearly under the guidance of the slide groove 209, it is necessary to configure an anchoring member for the limiting ring 204. The gear shaft 2 is provided with an annular groove 211, and the clamp 202 can be installed in the annular groove 211. The gear shaft 2 also includes an elastic element 203 sleeved thereon, the first end of the elastic element 203 is fixedly connected to the clamp 202, and the second end of the elastic element 203 is fixedly connected to the limiting ring 204. Thus, with the help of the elastic element 203, the clamp 202 serves as an anchor point for the limiting ring 204. Preferably, the elastic element 203 can be in the form of a wave spring or a coil spring.

[0038] According to the above configuration, when the speed of the gear shaft 2 is greater than the speed of the drive shaft 1, there is no gap between the working surfaces of the inner spline 102 and the outer spline 201, and thus there is no impact between the two, which means that there is no NVH problem at this time. Conversely, when the speed of the gear shaft 2 is less than the speed of the drive shaft 1, the side clearance between the inner spline 102 and the non-working surface of the outer spline 20 is the largest, and the trailing edge 105 pushes the protrusion 2041 to rotate together with the forward operation of the motor. At this time, the thrust applied by the inclined trailing edge 105 to the protrusion 2041, especially its circumferential component, is transmitted to the hydraulic oil damper 206, and the hydraulic oil in the hydraulic oil chamber plays a damping role, greatly alleviating the impact energy between the splines, thereby improving the NVH knocking noise problem.

[0039] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0040] The above-mentioned embodiments only express several implementation methods of the present application, and the descriptions thereof are relatively specific and detailed, but they cannot be understood as limiting the scope of the invention patent. It should be pointed out that, for a person of ordinary skill in the art, several variations and improvements can be made without departing from the concept of the present application, and these all belong to the protection scope of the present application. Therefore, the protection scope of the patent of the present application shall be subject to the attached claims.

Claims

1. A mechanical transmission spline side clearance knocking abnormal noise optimization structure, comprising: A driving shaft, a tip end surface of which is formed with a blind hole extending along its axial direction, and an inner circumferential surface of the blind hole is formed with an internal spline; The gear shaft has an outer spline formed on its outer peripheral surface; The drive shaft and the gear shaft cooperate with each other by means of the internal spline and the external spline; Characterized in that the gear shaft comprises a hydraulic oil damper and a stop ring, the hydraulic oil damper is located away from the drive shaft relative to the stop ring, and the hydraulic oil damper comprises a piston, the stop ring is sleeved on the gear shaft and fixedly connected to the piston; and The tip end surface of the drive shaft is also formed with a notch, the rear edge of the notch is inclined relative to the axial direction, and the limiting ring is formed with a protrusion extending radially outward, so that when the drive shaft and the gear shaft are fitted into place with each other, the protrusion is wedged into the notch.

2. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 1 is characterized in that: The inclination of the trailing edge of the notch is configured such that a virtual normal line of the trailing edge has a first component following the positive rotation direction of the drive shaft and a second component pointing to the gear shaft along the axial direction thereof.

3. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 1 is characterized in that: The hydraulic oil damper is composed of the piston and the sealing chamber sleeve, wherein the sealing chamber sleeve is sleeved on the gear shaft, and the piston is accommodated between the gear shaft and the sealing chamber sleeve, so that the piston, the gear shaft and the sealing chamber sleeve jointly define a hydraulic oil chamber with a variable volume.

4. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 3 is characterized in that: The gear shaft has an input oil passage fluidly connected to the hydraulic oil chamber.

5. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 3 is characterized in that: The sealing chamber sleeve has a one-way oil leakage passage from the hydraulic oil chamber to the external environment.

6. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to any one of claims 1-5, characterized in that: It also includes a shaft sleeve, which is sleeved on the gear shaft and located between the limiting ring and the piston. The limiting ring, the shaft sleeve and the piston are pressed against each other in sequence.

7. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 1 is characterized in that: The number of the notches is one or more, the number of the protrusions is equal to the number of the notches, and the notches and the protrusions correspond one to one in position along the circumference of the drive shaft and / or the gear shaft.

8. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 1 is characterized in that: The gear shaft is provided with an annular groove and includes a clamp mounted to the annular groove and an elastic element sleeved on the gear shaft, wherein a first end of the elastic element is fixedly connected to the clamp, and a second end of the elastic element is fixedly connected to the limiting ring.

9. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 8, characterized in that: The elastic element is a wave spring or a coil spring.

10. The mechanical transmission spline side clearance knocking abnormal noise optimization structure according to claim 1, characterized in that: The gear shaft is provided with a slide groove extending along its axial direction, and the limiting ring is formed with a slider extending inwardly along its radial direction. The slider performs linear motion in the slide groove to prevent the limiting ring from rotating relative to the gear shaft.

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