A shaft-hole mating structure for improving mating reliability

Abstract

The present invention discloses a shaft-hole mating structure for improving mating reliability, which includes a hole and a rotating shaft. The shaft-hole mating structure further includes a bush, the bush is sleeved on the rotating shaft, and the sleeved bush and rotating shaft are inserted into the hole, so as to improve the reliability of the rotating shaft-hole mating.

Description

Technical Field

[0001] The present invention relates to a shaft - hole fitting structure, specifically a shaft - hole fitting structure for improving the fitting reliability. Background Art

[0002] The basic structure of a rotating shaft - hole fit is the fit between a circular shaft and a circular hole position. The clearance, transition, and interference fit methods and fit grades are selected according to the application scenario. Since it is difficult to manufacture an absolutely circular hole or shaft, and with the friction between the shaft and the hole during use, the fit between the shaft and the hole will inevitably be inconsistent with the initial design expectation, resulting in shaft - hole loosening or deformation.

[0003] As fitting problems continuously occur during the actual production and use of products, the fit between a circular shaft and a polygonal hole, or between a circular hole and a polygonal shaft has also emerged. Hexagons or octagons are more commonly used, and the non - fitting positions of the polygon provide space for storing grease, which can play a lubricating role. This kind of fitting structure greatly reduces fitting problems to a certain extent, but there are still inconveniences in material selection or manufacturing.

[0004] To solve this problem, this application converts the traditional rotating shaft - hole fit into the fit problem of a rotating shaft, a shaft sleeve, and a hole, and proposes a new structure. Summary of the Invention

[0005] The purpose of the present invention is to provide a shaft - hole fitting structure for improving the fitting reliability, so as to improve the reliability of the rotating shaft - hole fit.

[0006] The above - mentioned purpose of the present invention is achieved through the following technical solutions: A shaft - hole fitting structure for improving the fitting reliability includes a hole and a rotating shaft. It is characterized in that: the shaft - hole fitting structure further includes a shaft sleeve, the shaft sleeve is sleeved on the rotating shaft, and the sleeved shaft sleeve and rotating shaft are inserted into the hole.

[0007] In the present invention, an interference fit is provided between the shaft sleeve and the rotating shaft; a clearance fit is provided between the shaft sleeve and the hole.

[0008] The unilateral clearance between the shaft sleeve and the hole is 0.05 mm.

[0009] As a preferred implementation, the hole is a square hole; the shaft sleeve is cylindrical, the shaft sleeve has a side wall, and the side wall is composed of alternately distributed straight walls and arc walls; the rotating shaft is cylindrical, and the rotating shaft is a stepped shaft with a larger diameter at the shaft body and a smaller diameter at the end. The end of the rotating shaft has fan - shaped petals with arc surfaces distributed at intervals, and there are gaps between adjacent fan - shaped petals; the arc surfaces of the fan - shaped petals match the arc walls of the shaft sleeve, and the gaps match the straight walls of the shaft sleeve.

[0010] In the present invention, the number of the straight walls and the arc walls is four each; the number of the notches and the fan-shaped petals is also four each.

[0011] In the present invention, the end of the bushing has a reduced spherical hoop protruding outward, which ensures that the bushing has no axial movement and can reduce the friction with the hole.

[0012] In the present invention, the spherical hoop is a revolving spherical surface with a radius R of 2.5 mm.

[0013] In the present invention, the material of the hole is PC / ABS or PA66+GF or PPS; the material of the bushing is POM; the material of the rotating shaft is PC / ABS or PA66+GF.

[0014] Compared with the prior art, the present invention has the following remarkable effects:

[0015] (1) The shaft-hole matching structure of the present invention can provide an effective shaft-hole matching method.

[0016] (2) The shaft-hole matching structure of the present invention can ensure the reliability of shaft-hole assembly and reduce the risk of shaft-hole deformation.

[0017] (3) The shaft-hole matching structure of the present invention can be used for all products with shaft-hole matching structures, and is particularly suitable for automotive wire-controlled shifters. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present invention will be further described in detail below with reference to the drawings and specific embodiments.

[0019] Figure 1 is the assembly drawing of the shaft-hole matching structure of the present invention;

[0020] Figure 2 is Figure 1 the A-A sectional view of

[0021] Figure 3 is the three-dimensional view of the hole in the shaft-hole matching structure of the present invention;

[0022] Figure 4 is Figure 3 the front view of

[0023] Figure 5 is the three-dimensional view of the bushing in the shaft-hole matching structure of the present invention;

[0024] Figure 6 is Figure 5 the front view of

[0025] Figure 7 is Figure 5 the side view of

[0026] Figure 8It is a three-dimensional view of the rotating shaft in the shaft-hole mating structure of the present invention;

[0027] Figure 9 It is Figure 8 a side view of;

[0028] Figure 10 It is Figure 8 a front view of;

[0029] Figure 11 It is the initial state diagram of the shaft-hole mating structure of the present invention;

[0030] Figure 12 It is a schematic diagram of the shaft-hole mating structure of the present invention rotating counterclockwise to the limit position;

[0031] Figure 13 It is a schematic diagram of the shaft-hole mating structure of the present invention rotating clockwise to the limit position.

[0032] In the figure:

[0033] 1. Hole, 2. Bush, 21. Straight wall, 22. Arc wall, 23. Spherical hoop,

[0034] 3. Rotating shaft, 31. Notch, 32. Sector lobe. Specific embodiments

[0035] As Figures 1 to 13 shown, a shaft-hole mating structure for improving mating reliability includes a hole 1 and a rotating shaft 3. It is characterized in that: the shaft-hole mating structure further includes a bush 2, the bush 2 is sleeved on the rotating shaft 3, and after sleeving, the bush 2 and the rotating shaft 3 are inserted into the hole 1. There is an interference fit between the bush 2 and the rotating shaft 3; there is a clearance fit between the bush 2 and the hole 1, and the unilateral clearance between the bush 2 and the hole 1 is 0.05 mm. The theoretical size of the bush 2 is The theoretical size of the hole 1 is 15.1 mm, which is convenient for assembly.

[0036] In this embodiment, as Figure 3 , Figure 4 shown, the hole 1 is a square hole, and the corners are rounded; a quadrilateral structure is adopted, and only two pairs of sides are mated, which is convenient for manufacturing and has few mating surfaces and is easy to control. This hole 1 structure can be designed on the product shell or bracket, and a material with relatively high rigidity can be selected. The material of the hole 1 is PC / ABS (polycarbonate and acrylonitrile-butadiene-styrene copolymer and mixture), or PA66+GF (nylon plus glass fiber material) or PPS (polyphenylene sulfide), etc.

[0037] As Figures 5 to 7As shown, the bushing 2 is cylindrical and designed in the form of a combination of a circle and a polygon. The problem of difficult control of the theoretical roundness of the structure circle is fully considered, and for the convenience of manufacturing, a flat-position hidden parting line is designed. At the same time, the length of the flat position is determined by the rotation angle of the product rotating shaft and can be adjusted according to design requirements.

[0038] For the bushing outer diameter proposed in this embodiment, the flat position is 3.5 mm, and the angle that can provide the rotation of the rotating shaft is in the range of 30° counterclockwise and 30° clockwise, as shown. If the rotation angle required by the product rotating shaft is greater than 60°, the length of the flat position can be reduced; if the rotation angle required by the product rotating shaft is less than 60°, the length of the flat position can be increased. The bushing 2 is a separate structure, and the wall thickness can be set according to the size of the rotating shaft. The material that can be selected is a self-lubricating material, which is POM (polyoxymethylene). The bushing 2 has a side wall, and the side wall is composed of straight walls 21 and arc walls 22 that are alternately distributed. Figures 11 to 13

[0039] In this embodiment, the end of the bushing 2 has a reduced spherical hoop 23 that protrudes outward. The spherical hoop 23 is a revolving spherical surface with a radius R of 2.5 mm, which ensures that the bushing 2 has no axial movement and can reduce the friction with the hole 1. The remaining space between the hole 1 and the bushing 2 can also store grease to provide a lubricating effect.

[0040] Figures 8 to 10 As shown, the rotating shaft 3 is cylindrical. The rotating shaft 3 is a stepped shaft with a large diameter at the shaft body and a small diameter at the end. The end of the rotating shaft 3 has fan-shaped petals 32 with arc surfaces that are distributed at intervals, and there are gaps 31 between adjacent fan-shaped petals 32; the arc surfaces of the fan-shaped petals 32 match the arc walls 22 of the bushing 2, and the gaps 31 match the straight walls 21 of the bushing 2. Among them, the number of both the straight walls 21 and the arc walls 22 is four; the number of both the gaps 31 and the fan-shaped petals 32 is also four.

[0041] In this embodiment, the shaft 3 is designed as a stepped type, and the four-petal fan-shaped petals 32 are in interference fit with the bushing 2, which is convenient for manufacturing and has sufficient strength. In addition, the flat position on the bushing 2 also plays an anti-rotation role at this time, so that the bushing 2 and the shaft 3 are always combined together. This shaft structure can be directly designed on the product rotating shaft structure. The rotating shaft can be formed by plastic injection in one step or by secondary injection molding of hardware parts according to the strength requirements of the product. Materials with stronger rigidity can be selected, such as PC / ABS, or PA66+GF, etc.

[0042] The above embodiments of the present invention do not limit the protection scope of the present invention. The implementation manners of the present invention are not limited to this. All these, according to the above content of the present invention, in accordance with the common general knowledge and customary means in the art, without departing from the above basic technical idea of the present invention, other various forms of modifications, substitutions or changes made to the above structure of the present invention shall all fall within the protection scope of the present invention.​

Claims

1. An axle-hole fitting structure for improving the mating reliability and applicable to a vehicle-by-wire shifter, comprising a hole (1) and a rotating shaft (3). Characterized in that: The axle-hole fitting structure further includes a bushing (2), the bushing (2) sleeving the rotating shaft (3), and after sleeving, the bushing (2) and the rotating shaft (3) are inserted into the hole (1); an interference fit exists between the bushing (2) and the rotating shaft (3); a clearance fit exists between the bushing (2) and the hole (1), and the hole (1) is a square hole; the bushing (2) is cylindrical, the bushing (2) has a side wall, and the side wall is composed of alternately distributed straight walls (21) and arc walls (22); the rotating shaft (3) is cylindrical, and this rotating shaft (3) is a stepped shaft with a larger diameter at the shaft body and a smaller diameter at the end, and the end of the rotating shaft (3) has fan-shaped petals (32) with arc surfaces distributed at intervals, and there are gaps (31) between adjacent fan-shaped petals (32); the arc surface of the fan-shaped petals (32) matches the arc wall (22) of the bushing (2), and the gap (31) matches the straight wall (21) of the bushing (2); the outer diameter of the bushing (2) is φ15mm, the flat position is 3.5mm, and the angle that can provide the rotation of the rotating shaft is in the range of 30° counterclockwise and 30° clockwise.

2. The axle-hole fitting structure for improving the mating reliability and applicable to a vehicle-by-wire shifter according to claim 1, Characterized in that: The unilateral clearance between the bushing (2) and the hole (1) is 0.05mm.

3. The axle-hole fitting structure for improving the mating reliability and applicable to a vehicle-by-wire shifter according to claim 1, Characterized in that: The numbers of both the straight wall (21) and the arc wall (22) are four; the numbers of both the gap (31) and the fan-shaped petals (32) are also four.

4. The axle-hole fitting structure for improving the mating reliability and applicable to a vehicle-by-wire shifter according to claim 1, Characterized in that: The end of the bushing (2) has a reduced spherical hoop (23) protruding outward, and the spherical hoop (23) is a rotating spherical surface with a radius R of 2.5mm.

5. The axle-hole fitting structure for improving the mating reliability and applicable to a vehicle-by-wire shifter according to claim 1, Characterized in that: The material of the hole (1) is PC / ABS or PA66+GF or PPS.

6. The axle-hole fitting structure for improving the mating reliability and applicable to a vehicle-by-wire shifter according to claim 1, Characterized in that: The material of the bushing (2) is POM.

7. The axle-hole fitting structure for improving the mating reliability and applicable to a vehicle-by-wire shifter according to claim 1, Characterized in that: The material of the rotating shaft (3) is PC / ABS or PA66+GF.

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