A starter drive shaft assembly

Abstract

The utility model relates to the technical field of starter drive shaft, especially relates to a starter drive shaft assembly, its technical scheme includes: axle body and flange plate, the axle body is integrally formed with flange plate, the axle body includes integrally formed's pivot section, spiral spline section and ladder axle, the ladder axle is located pivot section top, the flange plate center is provided with the mounting groove, and the flange plate evenly distributes a plurality of mounting holes along the circumference, the mounting groove is inlayed and is embedded with the wear -resisting bearing of groove body adaptation, the mounting hole is worn and is installed weak shear section, the weak shear section is equipped with positioning structure, with mounting hole adaptation to realize pre -tightening fixed, and have the connecting fixed and overload protection function simultaneously. The utility model has the advantages of overload protection, convenient maintenance, solves the problem that the safety protection of existing drive shaft is insufficient, maintenance is complicated, meets the stable and reliable operation demand of starter.

Description

Technical Field

[0001] This utility model relates to the field of starter drive shaft technology, specifically a starter drive shaft assembly. Background Technology

[0002] As a key component of the engine starting system, the starter motor's performance directly determines the engine's starting success rate. The drive shaft assembly, the core torque transmission link connecting the starter motor and the engine, bears the important responsibility of stably transmitting starter motor power to the engine flywheel. This component needs to operate for extended periods under conditions of high-speed rotation and periodic torque impacts. Its structural rationality, connection stability, and safety protection capabilities not only affect the starter motor's starting smoothness but also directly relate to the service life and operational safety of both the starter motor and the engine. Therefore, it is an indispensable and crucial aspect in the design of starter motor components.

[0003] Traditional starter drive shafts typically employ a single shaft with a conventional mounting structure, using standard connection methods to assemble with the starter housing. They lack specialized protection and maintenance optimizations for unexpected malfunctions. Since starter motors may face sudden overload conditions such as mechanical jamming or engine over-revving during operation, conventional mounting structures cannot promptly cut off power transmission in case of abnormal torque. Furthermore, repairs require complete disassembly of the drive shaft assembly. This results in insufficient safety protection and poor maintenance convenience, failing to meet the requirements for long-term stable, reliable, and low-cost starter motor maintenance.

[0004] Therefore, there is an urgent need for a starter drive shaft assembly to solve the above problems. Utility Model Content

[0005] The purpose of this utility model is to provide a starter drive shaft assembly that has the advantages of overload protection and convenient maintenance, solves the problems of insufficient safety protection and cumbersome maintenance of existing drive shafts, and meets the requirements for stable and reliable operation of starters.

[0006] To achieve the above objectives, this utility model provides the following technical solution: a starter drive shaft assembly, comprising a shaft body and a flange, wherein the shaft body and the flange are integrally formed, and the shaft body includes an integrally formed rotating shaft section, a helical spline section, and a stepped shaft, wherein the stepped shaft is disposed at the top of the rotating shaft section; the flange has a mounting groove in its center, and multiple mounting holes are evenly distributed around the flange; a wear-resistant bearing adapted to the groove body is embedded in the mounting groove; a weak shear section is inserted into the mounting hole, and the weak shear section has a positioning structure that adapts to the mounting hole to achieve pre-tightening fixation, and also has the functions of connection fixation and overload protection.

[0007] Preferably, the positioning structure of the weak shear segment is a conical positioning head, which is adapted to fit the conical surface of the inner wall of the mounting hole.

[0008] In the design, the tapered positioning head of the weak shear section is fitted and conforms to the tapered surface of the inner wall of the mounting hole, which realizes the precise alignment and reliable pre-tightening of the weak shear section in the mounting hole, and has the advantages of efficient assembly and anti-loosening connection.

[0009] Preferably, the wear-resistant bearing is made of a self-lubricating material, and its inner wall is provided with an oil storage structure for storing lubricating medium.

[0010] In the design, the wear-resistant bearing made of self-lubricating material and the oil storage structure on its inner wall achieve continuous lubrication supply when the shaft rotates, which has the advantages of reducing friction loss and ensuring smooth operation.

[0011] Preferably, the helical spline segment is located at the lower part of the shaft segment, and its tooth profile is a standard tooth profile adapted to the starter one-way valve.

[0012] In the design, the spiral spline section located at the lower part of the shaft section and using a standard tooth profile achieves precise meshing and matching with the starter one-way valve, and has the advantages of stable power transmission and smooth separation.

[0013] Preferably, the shaft is made of high-strength alloy material and heat-treated, and the shaft section has anti-torsional properties.

[0014] The design utilizes a high-strength alloy material and heat-treated shaft body, along with a rotating shaft section with anti-torsion properties, to achieve stable bearing of the starter's working torque. It also features reliable structural strength and strong fatigue resistance.

[0015] Preferably, the mounting groove and the wear-resistant bearing are fixed by an interference fit.

[0016] In the design, the mounting groove and the wear-resistant bearing are fixed with an interference fit, which realizes the stable assembly of the wear-resistant bearing in the mounting groove and has the advantages of high rotational coaxiality and suppression of axial movement.

[0017] Preferably, the number of mounting holes is three, the diameter of the stepped shaft is smaller than the diameter of the main body of the rotating shaft section, and it is adapted to be connected to the starter motor transmission components.

[0018] The design incorporates three mounting holes and a stepped shaft with a diameter smaller than that of the main shaft section, achieving balanced force fixation of the flange and precise transmission connection of the shaft, resulting in advantages such as good assembly stability and strong adaptability.

[0019] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention utilizes a weak shear segment with a positioning structure inserted into the mounting hole of the flange. This weak shear segment combines connection and overload protection functions. When the starter motor encounters an overload condition, the weak shear segment can break in time based on its own structural strength, cutting off the transmission path of abnormal torque. This effectively solves the problem of insufficient safety protection in existing drive shafts and achieves reliable overload protection. Simultaneously, the weak shear segment is pre-tightened and fixed by the positioning structure and the mounting hole. After a failure, there is no need to disassemble the entire transmission structure of the shaft; only the broken weak shear segment needs to be removed and replaced to complete the repair. This solves the problem of cumbersome maintenance of existing drive shafts and achieves convenient maintenance. Furthermore, the flange and shaft are integrally formed, with a suitable wear-resistant bearing embedded in the central mounting groove. Combined with the integrally formed rotating shaft section, helical spline section, and stepped shaft on the shaft, this further ensures the coaxiality of the shaft rotation and the smoothness of power transmission, effectively meeting the requirements for stable and reliable starter motor operation. Attached Figure Description

[0020] Figure 1 This is a schematic diagram of the structure from one perspective of the present invention; Figure 2 This is a schematic diagram of the structure of this utility model from another perspective; Figure 3 This is a frontal cross-sectional view of the present invention. Figure 4 For the present utility model Figure 3 A magnified view of the structure at point A in the middle; Figure 5 This is a schematic diagram of the connection structure between the shaft and the flange of this utility model.

[0021] In the diagram: 1. Shaft body; 11. Rotating shaft section; 111. Stepped shaft; 12. Spiral spline section; 2. Flange; 21. Mounting groove; 22. Mounting hole; 3. Weak shear section; 4. Wear-resistant bearing. Detailed Implementation

[0022] 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.

[0023] Example: Figures 1 to 5 As shown, one embodiment of the present invention is a starter drive shaft assembly, comprising a shaft body 1 and a flange 2 integrally formed with the shaft body 1.

[0024] The shaft 1 includes an integrally formed rotating shaft section 11, a helical spline section 12, and a stepped shaft 111. The stepped shaft 111 is located at the top of the rotating shaft section 11. All three are integrally forged and then precision machined. The rotating shaft section 11 is the main power transmission part of the shaft 1. It is made of high-strength alloy material and heat-treated to have good anti-torsion performance, which is used to stably bear the torque output of the starter. The diameter of the stepped shaft 111 is smaller than the main diameter of the rotating shaft section 11. It adopts a matching fit with the starter transmission components. Its end face is provided with a positioning chamfer to achieve precise shaft connection while avoiding jamming during operation. The helical spline section 12 is located at the lower part of the rotating shaft section 11. Its tooth profile is a standard tooth profile that is compatible with the starter one-way valve. The tooth surface is precision machined to form a smooth bearing surface, reducing the meshing friction with the spline inside the starter one-way valve and ensuring the smoothness of power transmission and disengagement.

[0025] Flange 2 and shaft 1 are coaxially integrally formed. A mounting groove 21 is provided at the center of flange 2. The inner side of the mounting groove 21 is fitted and fixed to wear-resistant bearing 4 using an interference fit. Wear-resistant bearing 4 is made of self-lubricating material, and its inner wall has an annular oil storage structure. The oil storage structure stores lubricating medium, continuously providing lubrication for the rotation of shaft 1, ensuring the coaxiality of shaft 1 during rotation, and reducing axial movement. Three mounting holes 22 are evenly arranged circumferentially on flange 2, symmetrically distributed around the axis of flange 2. 2. The inner wall is provided with a conical structure. A weak shear section 3 is inserted into the mounting hole 22. The weak shear section 3 is a columnar shear structure, which is made of an alloy material with suitable torsional strength. Its structural strength is compatible with the maximum safe working torque of the starter. The two ends of the weak shear section 3 are provided with conical positioning heads. The conical positioning heads are adapted to fit the conical surface of the inner wall of the mounting hole 22. A small interference or transition fit is used to achieve assembly pre-tightening and facilitate removal and replacement after failure. It realizes quick positioning and pre-tightening fixation during assembly, and also has the dual functions of connection fixation and overload protection.

[0026] Working principle and usage process of this utility model: During assembly, the wear-resistant bearing 4 is first press-fitted into the mounting groove 21 of the flange 2 using an interference fit, ensuring that the outer wall of the wear-resistant bearing 4 is completely fitted with the inner wall of the mounting groove 21, and that the oil storage structure can properly store and release the lubricating medium. Then, the stepped shaft 111 at the top of the shaft body 1 is aligned with the transmission mating parts of the starter motor through a positioning chamfer, and the shaft system is connected. Simultaneously, the spiral spline section 12 at the bottom of the shaft section 11 is precisely engaged with the inner spline of the starter one-way device, ensuring that the meshing surfaces are completely fitted without gaps. Subsequently, the weak shear section 3 is inserted axially along the mounting hole 22. The tapered positioning heads at both ends of the weak shear section 3 are fitted with the tapered surfaces of the inner wall of the mounting hole 22 to achieve pre-positioning and pre-tightening fixation, thereby completing the stable assembly of the drive shaft assembly and the starter housing.

[0027] When the starter motor is working, power is transmitted through the rotating shaft section 11 of the shaft body 1 to the lower spiral spline section 12. The engagement of the spiral spline section 12 with the spline inside the starter one-way valve drives the one-way valve to rotate, thereby driving the engine flywheel. During this process, the self-lubricating characteristics of the wear-resistant bearing 4 and the continuous lubrication of the oil reservoir structure significantly reduce the rotational friction loss between the shaft body 1 and the wear-resistant bearing 4. The weak shear section 3 resists the influence of high-speed rotational vibration of the shaft body 1 through the tight fit between the tapered positioning head and the tapered surface of the mounting hole 22, preventing loosening. The standard tooth shape and smooth tooth surface of the spiral spline section 12 ensure smooth and reliable meshing and disengagement. At the same time, the integral molding structure of the shaft body 1 and the flange 2 further improves the overall structural rigidity and transmission stability.

[0028] When the starter experiences overload, mechanical jamming, or engine over-revving, and the torque exceeds the starter's maximum safe operating torque, the weak shear segment 3 within the mounting hole 22 will fracture due to its structural strength not being adapted to the starter's safe torque setting. After the weak shear segment 3 fractures, the contact between the tapered positioning heads at both ends and the tapered surface of the mounting hole 22 fails, the fixed connection between the drive shaft assembly and the starter housing is released, and the shaft 1 quickly separates from the starter's core components under inertia, effectively cutting off the transmission path of abnormal torque and preventing secondary damage to the starter motor, gears, and other core components due to overload, thus achieving the safety protection function for the starter.

[0029] During maintenance, the broken weak shear segment 3 can be removed from the three mounting holes 22, replaced with a new weak shear segment 3, and pre-tightened by fitting the tapered positioning head with the tapered surface of the mounting hole 22. This restores the functionality of the drive shaft assembly without disassembling the shaft section 11, the spiral spline section 12, and the stepped shaft 111 of the shaft body 1. The operation is convenient and the maintenance cost is low, significantly reducing maintenance investment during use.

[0030] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A starter drive shaft assembly, comprising a shaft body (1) and a flange (2), wherein the shaft body (1) and the flange (2) are integrally formed, characterized in that: The shaft (1) includes an integrally formed rotating shaft section (11), a spiral spline section (12), and a stepped shaft (111), with the stepped shaft (111) located at the top of the rotating shaft section (11). The flange (2) has a mounting groove (21) in the center, and multiple mounting holes (22) are evenly distributed around the flange (2). A wear-resistant bearing (4) adapted to the groove is embedded in the mounting groove (21). A weak shear section (3) is inserted into the mounting hole (22), and the weak shear section (3) has a positioning structure that is adapted to the mounting hole (22) to achieve pre-tightening and fixing, and also has the functions of connection fixing and overload protection.

2. The starter drive shaft assembly according to claim 1, characterized in that, The positioning structure of the weak shear segment (3) is a conical positioning head, which is adapted to fit the conical surface of the inner wall of the mounting hole (22).

3. A starter drive shaft assembly according to claim 1, characterized in that, The wear-resistant bearing (4) is made of self-lubricating material, and its inner wall is provided with an oil storage structure for storing lubricating medium.

4. A starter drive shaft assembly according to claim 1, characterized in that, The spiral spline section (12) is located at the lower part of the shaft section (11), and its tooth profile is the standard tooth profile adapted to the starter one-way valve.

5. A starter drive shaft assembly according to claim 1, characterized in that, The shaft (1) is made of high-strength alloy material and heat-treated, and the shaft section (11) has anti-torsion properties.

6. A starter drive shaft assembly according to claim 1, characterized in that, The mounting groove (21) and the wear-resistant bearing (4) are fixed by an interference fit.

7. A starter drive shaft assembly according to claim 1, characterized in that, The number of mounting holes (22) is three, the diameter of the stepped shaft (111) is smaller than the diameter of the main body of the rotating shaft section (11), and it is adapted to be connected to the starter transmission components.

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