Spline type sliding pair of a steering shaft

Abstract

The utility model discloses a spline type sliding pair of steering shaft relates to steering shaft sliding pair technical field, aims at solving the existing sliding pair transmission precision, rigidity is poorer, and the problem that there is abnormal sound when transmission, adopts the technical scheme, including spline shaft and spline pipe, the outer transmission part of spline shaft is injection molded and has injection molded body spline, the transmission part of spline shaft realizes the transmission of power with the inner transmission part of injection molded body spline and spline pipe, injection molded body spline is directly injection molded on spline shaft, and the outer transmission part of spline shaft is used as the inner mode, and the manufacturing cost and mould cost are greatly reduced, injection molded body spline includes inner transmission tooth and outer transmission tooth, the outer transmission tooth includes first transmission tooth group and second transmission tooth group, first transmission tooth group and second transmission tooth group are alternately arranged, and the outer diameter size of first transmission tooth group is greater than the outer diameter size of second transmission tooth group.

Description

Technical Field

[0001] This utility model relates to the field of steering shaft sliding pair technology, specifically a spline sliding pair for a steering shaft. Background Technology

[0002] There are two common structures for the spline sliding pair of the steering intermediate shaft: nylon-coated sliding pair and three-ring injection-molded sliding pair. Although both structures can achieve steering transmission, they have the following shortcomings: the sliding pair transmits torque entirely through the nylon coating, so it is not suitable for high-torque C-EPS applications; due to the presence of the nylon coating, the torsional stiffness of the sliding pair is low, resulting in reduced vehicle steering sensitivity; the steel teeth of the spline shaft and spline tube are designed for clearance fit, while the span of the injection-molded ring teeth is larger than that of the spline shaft steel teeth, forming an interference fit with the spline inside the spline tube. When the two are assembled, the injection-molded ring teeth are compressed and deformed, thus tightly adhering to the spline surface inside the spline tube and eliminating the physical clearance between the spline shaft and spline tube.

[0003] Chinese patent CN202122077914.6 discloses a spline sliding pair structure for a steering intermediate shaft. The technical solution adopted is that the spline shaft is provided with a large tooth spline and a small tooth spline, and the large tooth spline has a larger major diameter, a smaller diameter, and a crossbar diameter than the small tooth spline. An injection-molded spline is injected onto the small tooth spline. The injection-molded spline includes an injection-molded spline body, and the crossbar diameter of the injection-molded spline body is larger than that of the large tooth spline. An internal spline adapted to the injection-molded spline body is opened inside the spline tube.

[0004] The above technical solution can ensure that the spline sliding pair has a small torsional clearance and high torsional stiffness, but there are still the following shortcomings: the injection-molded spline only covers part of the transmission spline of the spline shaft, resulting in the uncovered transmission spline being in direct contact with the spline tube. During use, since both the spline shaft and the spline tube are made of rigid materials, abnormal noise will be generated in the transmission between them, affecting the user experience. Utility Model Content

[0005] The technical problem to be solved by this utility model is to overcome the existing defects and provide a spline sliding pair for steering shaft, which can effectively solve the problems in the background art.

[0006] To achieve the above objectives, this utility model discloses a spline-type sliding pair for a steering shaft. The technical solution includes a spline shaft and a spline tube. An injection-molded spline is injected onto the outer drive part of the spline shaft. The drive part of the spline shaft transmits power through the injection-molded spline and the inner drive part of the spline tube. By directly injection-molding the injection-molded spline onto the spline shaft and using the outer drive part of the spline shaft as the inner mold, the manufacturing cost and mold cost are greatly reduced. The injection-molded spline includes internal drive teeth and external drive teeth. The external drive teeth include a first drive tooth set and a second drive tooth set, which are alternately arranged. The outer diameter of the first drive tooth set is larger than that of the second drive tooth set. When the sliding pair is unloaded, the movement is mainly achieved by the friction between the tooth A on the injection-molded spline and the internal teeth of the spline tube. Compared with traditional nylon-coated sliding pairs, this reduces the friction between the sliding pairs and improves the smoothness of sliding, thus reducing OEM customer complaints during vehicle assembly.

[0007] As a preferred embodiment of the present invention, the first transmission gear set includes a tooth A and a blind tooth A, wherein the tooth A and the blind tooth A are alternately arranged; the second transmission gear set includes a tooth B and a blind tooth B, wherein the tooth B and the blind tooth B are alternately arranged.

[0008] As a preferred embodiment of this utility model, the inner drive part of the spline tube includes internal teeth and internal blind teeth, and the inner drive part of the spline tube meshes with the external drive teeth of the injection molded spline.

[0009] As a preferred embodiment of the present invention, the external transmission part of the spline shaft includes a first external tooth and a second external tooth, the first external tooth and the second external tooth are alternately arranged, and the outer diameter of the first external tooth is larger than the outer diameter of the second external tooth.

[0010] As a preferred technical solution of this utility model, the internal transmission teeth of the injection-molded spline include teeth C and teeth D. Teeth C meshes with the first external teeth, and teeth D meshes with the second external teeth. When the portion of tooth A on the plastic spline continues to deform to a certain extent under large torque, the gap between tooth B, which is coated on the second external tooth of the spline shaft, and the internal teeth of the spline tube is eliminated, thus sharing part of the torque carried by tooth A. This can greatly improve the overall torsional stiffness of the sliding pair and the durability of the whole vehicle, and reduce aftermarket complaints.

[0011] As a preferred embodiment of this utility model, the first external tooth is further provided with staggered external blind teeth, and the tooth C is provided with blind teeth C corresponding to the external blind teeth.

[0012] Compared with the prior art, the beneficial effects of this utility model are: by directly injection molding the spline body onto the spline shaft and using the outer drive part of the spline shaft as the inner mold, this utility model greatly reduces manufacturing costs and mold costs. When the sliding pair is unloaded, the movement is mainly achieved by the friction between the tooth A on the spline of the injection molded body and the internal teeth of the spline tube. Compared with the traditional nylon coated sliding pair, this reduces the friction between the sliding pairs and also improves the smoothness of sliding, reducing OEM customer complaints during vehicle assembly. When subjected to high torque, as the portion A of the plastic spline deforms to a certain extent, the gap between the plastic-coated tooth B of the second external tooth of the spline shaft and the internal tooth of the spline tube is eliminated, thus sharing part of the torque carried by tooth A. This can greatly improve the overall torsional stiffness of the sliding pair and the durability of the entire vehicle, resulting in fewer aftermarket complaints. Attached Figure Description

[0013] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is an exploded view of the present invention; Figure 3 This is a cross-sectional view of the present invention; Figure 4 This is a schematic diagram of the spline shaft structure of this utility model; Figure 5 This is a schematic diagram of the spline structure of the injection molded body of this utility model; Figure 6 This is a schematic diagram of the spline tube structure of this utility model.

[0014] In the diagram: 1. Splined shaft; 2. Splined tube; 3. Injection-molded spline; 11. First external tooth; 12. Second external tooth; 13. External blind tooth; 21. Internal teeth; 22. Internal blind teeth; 31. Tooth A; 32. Blind tooth A; 33. Tooth B; 34. Blind tooth B; 35. Tooth C; 36. Blind tooth C; 37. Tooth D. Detailed Implementation

[0015] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model. Example 1

[0016] like Figures 1 to 6 As shown, this utility model discloses a splined sliding pair for a steering shaft. The technical solution adopted includes a splined shaft 1, a splined tube 2, and an injection-molded spline 3. The structure and mating relationship of each component are as follows: like Figure 4 As shown, the external transmission part of the spline shaft 1 is the power input end, and the first external tooth 11 and the second external tooth 12 are alternately arranged along the axial direction, and the outer diameter of the first external tooth 11 is larger than the outer diameter of the second external tooth 12; the first external tooth 11 is provided with staggered external blind teeth 13, which are used to form a positioning fit with the injection molded spline 3 to prevent circumferential displacement.

[0017] like Figure 5 As shown, the injection-molded spline 3 is integrally formed on the outer drive part of the spline shaft 1 through injection molding. Its whole structure is ring-shaped and has both internal drive teeth that cooperate with the spline shaft 1 and external drive teeth that cooperate with the spline tube 2. Internal transmission gears include gear C35 and gear D37, wherein gear C35 meshes with the first external tooth 11 of the spline shaft 1, and gear D37 meshes with the second external tooth 12 of the spline shaft 1; and gear C35 is provided with a blind tooth C36 corresponding to the position of the external blind tooth 13, and the blind tooth C36 is embedded in the tooth groove of the external blind tooth 13 to realize the circumferential positioning of the spline shaft 1 and the injection molded spline 3; External transmission gears: including a first transmission gear set and a second transmission gear set, the two sets are alternately arranged along the axial direction, and the outer diameter of the first transmission gear set is larger than the outer diameter of the second transmission gear set; the first transmission gear set includes tooth A31 and blind tooth A32, and the second transmission gear set includes tooth B33 and blind tooth B34.

[0018] like Figure 6 As shown, the spline tube 2 is the power output end, and its inner wall has an internal transmission part including an internal tooth 21 and an internal blind tooth 22. The internal tooth 21 meshes with the teeth A31 and B33 of the external transmission teeth of the injection molded spline 3 to realize power transmission. The internal blind tooth 22 corresponds to the blind teeth A32 and B34 of the external transmission teeth of the injection molded spline 3 to limit the circumferential displacement of the spline tube 2 and the injection molded spline 3.

[0019] The circuits and mechanical connections involved in this utility model are common practices used by those skilled in the art, and technical inspiration can be obtained through a limited number of experiments. They are common knowledge.

[0020] Components not described in detail in this article are existing technologies.

[0021] Although embodiments of the present invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A splined sliding pair for a steering shaft, characterized in that: It includes a spline shaft (1) and a spline tube (2). The outer drive part of the spline shaft (1) is injection molded with an injection-molded spline (3). The drive part of the spline shaft (1) transmits power through the injection-molded spline (3) and the inner drive part of the spline tube (2). The injection-molded spline (3) includes an inner drive tooth and an outer drive tooth. The outer drive tooth includes a first drive tooth group and a second drive tooth group. The first drive tooth group and the second drive tooth group are alternately arranged, and the outer diameter of the first drive tooth group is larger than the outer diameter of the second drive tooth group.

2. The spline sliding pair of a steering shaft according to claim 1, characterized in that: The first transmission gear set includes a tooth A (31) and a blind tooth A (32), which are staggered; the second transmission gear set includes a tooth B (33) and a blind tooth B (34), which are staggered.

3. The spline sliding pair of a steering shaft according to claim 1, characterized in that: The inner drive part of the spline tube (2) includes an inner tooth (21) and an inner blind tooth (22), and the inner drive part of the spline tube (2) meshes with the outer drive tooth of the injection molded spline (3).

4. The spline sliding pair of a steering shaft according to claim 1, characterized in that: The external transmission part of the spline shaft (1) includes a first external tooth (11) and a second external tooth (12), the first external tooth (11) and the second external tooth (12) are alternately arranged, and the outer diameter of the first external tooth (11) is larger than the outer diameter of the second external tooth (12).

5. A splined sliding pair for a steering shaft according to claim 4, characterized in that: The internal transmission teeth of the injection molded body spline (3) include teeth C (35) and teeth D (37), teeth C (35) meshing with the first external teeth (11), and teeth D (37) meshing with the second external teeth (12).

6. The spline sliding pair of a steering shaft according to claim 5, characterized in that: The first external tooth (11) is also provided with external blind teeth (13) interlaced, and the tooth C (35) is provided with blind teeth C (36) corresponding to the external blind teeth (13).

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