Anti-sticking structure of internal spline of output shaft

Abstract

The utility model discloses an inner spline anti -stuck structure of output shaft, including output shaft body, the inner hole of output shaft body is equipped with inner spline, the inner hole of output shaft body is equipped with guiding import section, non -load transition section, main load spline section and bottom buffer cavity along the axial sequence, guiding import section is located the entry end in the inner hole of output shaft body, non -load transition section is by first load reduction tooth group and second isolation convex ring along the axial arrangement alternately, bottom buffer cavity is annular groove located main load spline section end. The inner spline anti -stuck structure of output shaft can effectively reduce initial meshing interference and full tooth length rigid contact, significantly reduce the risk of jamming caused by impurities, thermal expansion or fretting wear, improve the assembly smoothness and operation reliability.

Description

Technical Field

[0001] This utility model relates to the field of mechanical transmission technology, specifically to an anti-jamming structure for the internal spline of an output shaft. Background Technology

[0002] In mechanical transmission systems, the output shaft is often connected to external transmission components (such as gears, couplings, etc.) via internal splines to achieve torque transmission. Internal spline structures are widely used in automobiles, construction machinery, industrial speed reducers, and other equipment due to their advantages such as high load-bearing capacity, good centering, and easy assembly and disassembly.

[0003] Existing output shaft internal spline structures typically employ a tight fit between the full tooth length and the external spline, with minimal tooth flank clearance to ensure transmission accuracy and load-bearing capacity. However, in actual operating conditions, especially in environments with poor lubrication, significant temperature variations, or the presence of microparticles, the tooth surfaces of the internal and external splines are prone to fretting wear during long-term, repeated meshing, and impurities may also become embedded in the tooth flank clearance. Simultaneously, due to the difference in thermal expansion of metallic materials under temperature changes, the originally designed clearance may be compressed or even disappear during operation, leading to localized tooth surface compression, increased friction, and ultimately, jamming. Current common solutions mainly rely on improving machining accuracy or strengthening lubrication maintenance. While these methods have some effect, they do not address the structural design itself and cannot fundamentally eliminate the risk of jamming. Utility Model Content

[0004] The purpose of this utility model is to provide an anti-jamming structure for the internal spline of the output shaft, so as to solve the problem mentioned in the background art that the internal spline of the current output shaft is prone to jamming due to excessive tooth surface meshing caused by wear, impurities or thermal expansion under complex working conditions because of full tooth length contact and small tooth side clearance.

[0005] To achieve the above objectives, this utility model provides the following technical solution: an anti-jamming structure for an internal spline of an output shaft, comprising an output shaft body, wherein an internal spline is provided in the inner hole of the output shaft body, and the inner hole of the output shaft body is provided axially in sequence with a guide inlet section, a non-load-bearing transition section, a main load-bearing spline section and a bottom buffer cavity, wherein the guide inlet section is located at the inlet end of the inner hole of the output shaft body, the non-load-bearing transition section is composed of a first load-reducing tooth group and a second isolation convex ring arranged alternately along the axial direction, and the bottom buffer cavity is an annular groove located at the end of the main load-bearing spline section.

[0006] Preferably, the cone angle of the guide section is 2°–6°, and its axial length is 8%–15% of the length of the main load-bearing spline section.

[0007] Preferably, the tooth tip diameter of the first load-reducing tooth group is smaller than the major diameter of the internal spline, and its tooth root is located on the same cylindrical surface as the tooth root of the main load-bearing spline segment.

[0008] Preferably, there are two second isolation protrusions, with an axial width of 1.0–2.5 mm, and the surface of the second isolation protrusion is provided with an axially penetrating micro-groove.

[0009] Preferably, the tooth side of the main bearing spline segment is provided with an axial oil guide groove, and the bottom of the oil guide groove is located at the middle radial position between the tooth tip and the tooth root, with a depth of 0.02–0.05 mm.

[0010] Preferably, the bottom buffer cavity is an annular recessed groove structure with a depth of 0.5–1.5 mm and an inner diameter that is 0.3–0.8 mm larger than the major diameter of the inner spline, and the bottom of the bottom buffer cavity is chamfered.

[0011] Compared with existing technologies, the beneficial effects of this invention are: the internal spline anti-jamming structure of the output shaft can effectively reduce initial meshing interference and rigid contact along the entire tooth length, significantly reducing the risk of jamming caused by impurities, thermal expansion, or fretting wear, and improving assembly smoothness and operational reliability. This internal spline anti-jamming structure of the output shaft achieves a multi-level anti-jamming collaborative mechanism from the inlet to the end through the conical guidance of the guide section, the composite isolation design of the first unloading tooth group and the second isolation convex ring in the non-load-bearing transition section, the local load-bearing layout of the main load-bearing spline section, and the end clearance space of the bottom buffer cavity, fundamentally optimizing the reliability of the internal spline fit. Attached Figure Description

[0012] Figure 1 This is a schematic diagram of the internal spline anti-jamming structure of the output shaft according to the present invention;

[0013] Figure 2 This is a schematic diagram of the inlet end structure of the output shaft body of the present invention, which is an internal spline anti-jamming structure for an output shaft.

[0014] Figure 3 This is a side view of the main load-bearing spline section of the internal spline anti-jamming structure of the output shaft according to this utility model.

[0015] In the figure: 1. Output shaft body; 2. Internal spline; 3. Guide entry section; 4. Non-load-bearing transition section; 41. First unloading gear group; 42. Second isolation convex ring; 421. Micro-gap groove; 5. Main load-bearing spline section; 6. Bottom buffer cavity; 8. Oil guide groove; 9. Chamfer. Detailed Implementation

[0016] 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.

[0017] Please see Figure 1-3This utility model provides a technical solution: an anti-jamming structure for an internal spline of an output shaft, comprising an output shaft body 1, an internal spline 2 provided in the inner hole of the output shaft body 1, and a guide section 3, a non-load-bearing transition section 4, a main load-bearing spline section 5, and a bottom buffer cavity 6 arranged sequentially along the axial direction in the inner hole of the output shaft body 1. The guide section 3 is a toothless smooth conical surface structure located at the inlet end of the inner hole, and the non-load-bearing transition section 4 is composed of a first load-reducing tooth group 41 and a second isolation convex ring 42 arranged alternately along the axial direction. The first load-reducing tooth group 41 is a partial spline tooth with a tooth height lower than that of a normal spline tooth, and the second isolation convex ring 42 is an annular protrusion arranged around the inner hole wall, the outer diameter of which is smaller than that of the inner hole wall. The spline 2 has a small diameter, and the main load-bearing spline segment 5 is a complete standard internal spline structure used to transmit torque. The bottom buffer cavity 6 is an annular groove located at the end of the main load-bearing spline segment 5. In this structure, the external spline is first guided to center by the toothless smooth conical surface of the guide section 3 to avoid tooth surface scraping caused by angular deviation during the initial insertion. Then it enters the non-load-bearing transition section 4. The first unloading tooth group 41 cannot effectively mesh with the external spline because its tooth height is lower than that of the normal spline teeth, and only plays a preliminary positioning role. At the same time, the second isolation convex ring 42, with its annular convex structure smaller than the small diameter of the internal spline 2, forms a physical barrier on the inner wall of the hole to prevent impurities from migrating to the main load-bearing area and generating heat. The expansion allows for radial clearance. When the external spline continues to advance to the main load-bearing spline segment 5, only this segment participates in torque transmission, avoiding the cumulative deformation and stress concentration caused by traditional full-length tooth contact. During assembly or operation, the bottom buffer cavity 6 provides end clearance space for axial thermal expansion or fretting displacement, preventing the spline end from jamming. The overall structure effectively avoids the problem of excessive tooth surface meshing caused by poor lubrication, impurity embedding, or thermal expansion differences, fundamentally solving the jamming risk caused by rigid full-length tooth fit in existing technologies. The cone angle of the guide section 3 is 2°-6°, and its axial length is 8%-15% of the length of the main load-bearing spline segment 5. This structure... The guide section 3 ensures the guiding effect while preventing the guide section 3 from being too long and affecting the arrangement of the main load-bearing spline section 5. This allows the external spline to enter the inner hole of the output shaft body 1 smoothly and accurately, effectively reducing the risk of skewing and tooth surface scraping during initial insertion. The tooth tip diameter of the first load-reducing tooth group 41 is smaller than the major diameter of the inner spline 2, and its tooth root is located on the same cylindrical surface as the tooth root of the main load-bearing spline section 5. This structure ensures that the first load-reducing tooth group 41 does not form effective meshing with the external spline, but only plays a positioning and guiding role. At the same time, it maintains the continuity of the tooth root to maintain the structural strength of the inner hole and avoids stress concentration. There are two second isolation convex rings 42, and their axial width is 1.0-2.The second isolation ring 42 has a 5mm diameter and an axially penetrating micro-groove 421 on its surface. This structure enhances the barrier effect against impurities through double isolation, while the axial width ensures sealing and guiding stability. The micro-groove 421 provides a temporary storage channel for small particles or excess grease, preventing them from squeezing into the main bearing spline segment 5, thereby reducing meshing interference. The tooth side of the main bearing spline segment 5 has a micron-level axial oil guide groove 8, and the bottom of the oil guide groove 8 is located in the middle radial position between the tooth tip and the tooth root, with a depth of 0.02-0.05mm. This structure helps... A stable lubricating oil film is formed during the operation of the main load-bearing spline section 5, improving the lubrication conditions of the tooth surface, reducing fretting wear and frictional heat accumulation, thereby reducing the tendency to jam. The bottom buffer cavity 6 is an annular groove structure with a depth of 0.5-1.5mm and an inner diameter larger than the major diameter of the inner spline 2 by 0.3-0.8mm. The bottom of the bottom buffer cavity 6 has a chamfer 9. This structure provides buffer space for axial displacement caused by thermal expansion during the assembly or operation of the external spline, preventing end face jamming. Simultaneously, the chamfer 9 facilitates impurity deposition and stress release, further reducing the risk of jamming.

[0018] Working principle: When using the internal spline anti-jamming structure of this output shaft, the external spline first enters the guide section 3 from the inner hole inlet end of the output shaft body 1, slides in along its toothless smooth conical surface, and then passes through the non-load-bearing transition section 4, which is alternately arranged with the first unloading tooth group 41 and the second isolation convex ring 42. The external spline passes over the first unloading tooth group 41, whose tooth tip diameter is smaller than the major diameter of the internal spline 2, and passes through the second isolation convex ring 42, whose outer diameter is smaller than the minor diameter of the internal spline 2, and continues to advance inward until it is fully engaged with the main load-bearing spline section 5. At this time, the end of the external spline is close to or in contact with the bottom buffer cavity 6. After assembly, the external spline transmits torque on the main load-bearing spline section 5. The axial displacement that may occur during operation is accommodated by the bottom buffer cavity 6, thereby completing a series of operations.

[0019] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An anti-jamming structure for an internal spline of an output shaft, comprising an output shaft body (1), wherein an internal spline (2) is provided in the inner hole of the output shaft body (1), characterized in that: The inner hole of the output shaft body (1) is provided with a guide section (3), a non-load-bearing transition section (4), a main load-bearing spline section (5) and a bottom buffer cavity (6) in sequence along the axial direction. The guide section (3) is located at the inlet end of the inner hole of the output shaft body (1), and the non-load-bearing transition section (4) is composed of a first load-reducing tooth group (41) and a second isolation convex ring (42) arranged alternately along the axial direction. The bottom buffer cavity (6) is an annular groove located at the end of the main load-bearing spline section (5).

2. The anti-jamming structure for the internal spline of an output shaft according to claim 1, characterized in that: The cone angle of the guide section (3) is 2°-6°, and its axial length is 8%-15% of the length of the main bearing spline section (5).

3. The anti-jamming structure for the internal spline of an output shaft according to claim 1, characterized in that: The tooth tip diameter of the first unloading tooth group (41) is smaller than the major diameter of the inner spline (2), and its tooth root is located on the same cylindrical surface as the tooth root of the main load-bearing spline segment (5).

4. The anti-jamming structure for the internal spline of an output shaft according to claim 1, characterized in that: There are two second isolation protrusions (42), with an axial width of 1.0-2.5 mm, and the surface of the second isolation protrusions (42) is provided with an axially penetrating micro-groove (421).

5. The anti-jamming structure for the internal spline of an output shaft according to claim 1, characterized in that: The tooth side of the main bearing spline segment (5) is provided with a micron-level axial oil guide groove (8), and the bottom of the oil guide groove (8) is located in the middle radial position between the tooth tip and the tooth root, with a depth of 0.02-0.05mm.

6. The anti-jamming structure for the internal spline of an output shaft according to claim 1, characterized in that: The bottom buffer cavity (6) is an annular sink structure with a depth of 0.5-1.5 mm and an inner diameter that is 0.3-0.8 mm larger than the major diameter of the inner spline (2). The bottom of the bottom buffer cavity (6) is provided with a chamfer (9).

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