Hollow transmission shaft

Abstract

The utility model relates to the field of transmission shafts, and discloses a hollow transmission shaft which comprises a tubular shaft body, machining sections are arranged at the two ends of the shaft body, the length of each machining section is 25%-30% of the whole length of the shaft body, the wall thickness of each machining section is 1.01-1.1 times of the wall thickness of the middle of the shaft body, and a strengthening layer is formed on the surface of each machining section through shot blasting. The hollow transmission shaft can solve the problem that when a machining section at the end of an existing hollow transmission shaft bears torque loads, the machining section is prone to structural damage and breakage is caused.

Description

Technical Field

[0001] The utility model relates to the field of transmission shafts, in particular to a hollow transmission shaft. Background Art

[0002] The drive shaft is a key component in the automobile transmission system. It is responsible for transmitting the power generated by the engine to the drive wheels through the gearbox so that the car can drive. With the development of new energy vehicles, the lightweight of vehicles has received more and more attention. In addition to the lightweight of the body, the lightweight of the parts used in the vehicle transmission system is also an important part. As a key component of the automobile transmission system, the drive shaft is now gradually developing from a solid shaft to a hollow shaft to meet the needs of new energy vehicles. The drive shaft usually includes a shaft body, a telescopic sleeve and a universal joint. The telescopic sleeve usually contains a sliding spline structure at the end of the shaft body, which can automatically adjust the length to adapt to the length change caused by the movement of the vehicle in the transmission system, such as the displacement when the suspension bounces, to ensure the correct centering of the universal joint and the smooth transmission, and at the same time to bear the role of torque transmission, axial positioning, etc. In the prior art, the spline part at the end of the drive shaft is formed by machining. In the process of developing the hollow drive shaft, it is found that the machined section at the root of the spline forms a structural weak part. When subjected to torque load, it is very easy to cause structural damage and fracture at this part, which cannot meet the use needs. Utility Model Content

[0003] The utility model aims to provide a hollow transmission shaft to solve the problem that the existing hollow transmission shaft end machined section is very likely to be structurally damaged and fractured when subjected to torque load.

[0004] To achieve the above-mentioned purpose, the utility model adopts the following technical scheme: a hollow transmission shaft, including a tubular shaft body, both ends of the shaft body are provided with machined sections, the length of the machined section is 25%-30% of the overall length of the shaft body, the wall thickness of the machined section is 1.01-1.1 times the wall thickness of the middle part of the shaft body, and the surface of the machined section is shot peened to form a strengthening layer.

[0005] Preferably, as an improvement, the length of the machined section is 28% of the overall length of the shaft body.

[0006] Preferably, as an improvement, the wall thickness of the machined section is 1.05 times the wall thickness of the middle portion of the shaft body.

[0007] Preferably, as an improvement, the thickness of the strengthening layer is less than 1 mm.

[0008] Preferably, as an improvement, the machined section is machined with splines.

[0009] Preferably, as an improvement, there is a smooth transition between the inner hole of the machined section and the inner hole in the middle of the shaft body.

[0010] Preferably, as an improvement, a groove is formed on the circumferential surface of the machined section.

[0011] Preferably, as an improvement, both ends of the shaft body are processed with inner hole chamfers and outer circle chamfers.

[0012] The principle and advantages of this scheme are: the hollow shaft structure is adopted. Compared with the traditional solid transmission shaft, the overall mass and weight of the hollow transmission shaft of this scheme are reduced. The telescopic sleeve is connected by the spline sliding of the machined sections at both ends. The inner diameter of the machined section is reduced by shrinking processing, and the wall thickness is increased, so that the structural strength of the machined section is improved. Then, a dense strengthening layer is formed on the surface of the machined section by shot peening through the strong spraying process, and the structural strength of the machined section is further improved. Such a hollow transmission shaft is used as a drive shaft for new energy vehicles. It has the characteristics of light weight and high structural strength. After bearing the torque load during use, the service life of the machined section is increased from 200,000 times to more than 600,000 times. During long-term use, there is no damage to the machined section and fracture, which effectively meets the use needs of new energy vehicles. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a front view of embodiment 1 of the utility model.

[0014] Figure 2 This is an axonometric view of Example 1 of the utility model.

[0015] Figure 3 It is a longitudinal sectional view of Example 1 of the utility model.

[0016] Figure 4 It is a longitudinal sectional view of the machined section in Example 1 of the utility model. DETAILED DESCRIPTION

[0017] The following is further described in detail through specific implementation methods:

[0018] The reference numerals in the drawings of the specification include: shaft body 1, machined section 2, spline 3, circumferential groove 4.

[0019] Embodiment 1, basically as attached Figure 1 , Figure 2 , Figure 3 As shown: A hollow transmission shaft includes a straight tube-shaped shaft body 1, with inner hole chamfers and outer circle chamfers processed at both ends of the shaft body 1. Both ends of the shaft body 1 are provided with a machined section 2, which is processed with a spline 3 and a circumferential groove 4. The length of the machined section 2 is 28% of the overall length of the shaft body 1. Figure 4As shown, the wall thickness of the machined section 2 is 0.35 mm thicker than the wall thickness of the middle part of the shaft body 1. The wall thickness of the middle part of the shaft body 1 is 7 mm, and the wall thickness of the machined section 2 is 7.35 mm. There is a smooth transition between the inner hole of the machined section 2 and the inner hole of the middle part of the shaft body 1. The surface of the machined section 2 is shot blasted and then shot peened to form a strengthening layer, and the thickness of the strengthening layer is less than 1 mm.

[0020] Embodiment 2: The difference between this embodiment and embodiment 1 is that the length of the machined section 2 is 25% of the overall length of the shaft body 1 .

[0021] Embodiment 3: The difference between this embodiment and embodiment 1 is that the length of the machined section 2 is 30% of the overall length of the shaft body 1 .

[0022] Embodiment 4: The difference between this embodiment and embodiment 1 is that the wall thickness of the machined section 2 is 1.01 times the wall thickness of the middle portion of the shaft body 1.

[0023] Embodiment 5: The difference between this embodiment and embodiment 1 is that the wall thickness of the machined section 2 is 1.1 times the wall thickness of the middle portion of the shaft body 1.

[0024] The specific implementation process is as follows: Use 34MnB5 cold-drawn tube or 34MnB5 high-frequency welded tube, cut the straight tube and perform shrinkage processing on both ends, so that the inner hole in the 28% length range of the rear end of the shrinkage is reduced, the wall thickness is increased, and the transition part of the inner hole is a smooth transition. Then turn the two end faces to obtain the preset length, and then chamfer the two ends, then turn the outer circle of the shrinkage range at both ends, and then roll the spline 3 on the part after the outer circle is turned, and then turn the circumferential groove at the spline 3 part according to the design of the transmission shaft. After the turning process is completed, the turned part is deburred, and the shaft tube is further carburized. After carburization is completed, the overall surface of the shaft tube is derusted and descaled by shot blasting, and then the XX length range of the two ends of the shaft tube is strengthened by shot peening, forming a structural strengthening section with a strengthening layer with a thickness of less than 1mm at both ends of the shaft tube. The hollow drive shaft obtained through such processing is smaller and lighter than the traditional solid drive shaft. At the same time, the structural strength of the part at the end that bears the torque load is significantly enhanced. This can effectively solve the problem that the machined section 2 at the end of the hollow drive shaft is very likely to suffer structural damage and fracture when it is subjected to torque load, thereby meeting the use needs of new energy vehicles.

[0025] The above is only an embodiment of the utility model, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the utility model, several deformations and improvements can be made, which should also be regarded as the protection scope of the utility model, and these will not affect the effect of the implementation of the utility model and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A hollow transmission shaft, characterized in that: It includes a tubular shaft body, both ends of which are provided with machined sections, the length of the machined sections is 25%-30% of the overall length of the shaft body, the wall thickness of the machined sections is 1.01-1.1 times the wall thickness of the middle part of the shaft body, and the surface of the machined sections is shot blasted and then shot peened to form a strengthening layer.

2. A hollow transmission shaft according to claim 1, characterized in that: The length of the machined section is 28% of the overall length of the shaft body.

3. A hollow transmission shaft according to claim 2, characterized in that: The wall thickness of the machined section is 1.05 times the wall thickness of the middle portion of the shaft body.

4. A hollow transmission shaft according to claim 3, characterized in that: The thickness of the strengthening layer is less than 1 mm.

5. A hollow transmission shaft according to claim 4, characterized in that: The machined section is machined with splines.

6. A hollow transmission shaft according to claim 5, characterized in that: There is a smooth transition between the inner hole of the machined section and the inner hole in the middle of the shaft body.

7. A hollow transmission shaft according to claim 6, characterized in that: The machined section is provided with a groove in the circumferential direction.

8. A hollow transmission shaft according to claim 7, characterized in that: The two ends of the shaft body are processed with inner hole chamfers and outer circle chamfers.

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