Vehicle generator rotor and vehicle generator

Abstract

The present invention discloses a vehicle generator and rotor, comprising a motor shaft (1), an excitation coil (3) and a pair of claw poles (2), wherein the excitation coil (3) is fixed by the pair of claw poles (2); the motor shaft (1) is fixed to the motor housing via a bearing (15); a motor shaft boss (17) is provided on the motor shaft (1), and the two end faces of the motor shaft boss (17) respectively contact the end faces of the claw poles (2) and the bearing (15) to achieve positioning. By adopting the above technical solution, by improving the matching structure between the various components of the rotor assembly, the risks of the generator assembly pulley falling off, the rotor breaking, etc. are fundamentally avoided, and the rotor stability and reliability are improved.

Description

Technical Field

[0001] The present invention belongs to the technical field of motor structures. More specifically, the present invention relates to a rotor for a vehicle generator. The present invention also relates to a vehicle generator using the rotor. Background Art

[0002] The AC generator is the main power supply component of the automobile, and its rotor is the main rotating component. It has the characteristics of high operating speed and high rapid acceleration and deceleration in the whole vehicle, especially the vehicle with a high transmission ratio gear train. The rotor will generate relative centrifugal force and inertia force under rapid acceleration conditions, and the magnitude of the force depends on the magnitude of acceleration.

[0003] At present, the rotor assembly mostly relies on insulating varnish to fix the excitation coil and the claw pole end surface to fix the excitation coil. The centrifugal force of the coil becomes greater as it moves toward the outside. Using a smaller clamping force on the claw pole surface cannot guarantee the reliability of the outer coil, while using a larger clamping force will pose a risk of damage to the inner coil.

[0004] For vehicles that work for a long time, such as taxis, there will be long periods of rapid acceleration and deceleration. Due to the certain rotational inertia of the rotor itself, a very large centrifugal force will be generated in the above working conditions. Under the action of centrifugal force, the rotor assembly will produce axial and circumferential micro-motion creep. There is a risk of rotor disintegration if it is operated for a long time under harsh working conditions. The structure of the existing technology is as follows Figure 1 As shown, the specific problems are analyzed as follows:

[0005] Risk 1: Since the rotor assembly is driven by pulleys and bearings, when the contact surfaces of the rotor and bearings are worn out and a gap exists, it will cause the pulley to idle or fall off.

[0006] Risk 2: During the generator assembly process, the drive end is driven by a belt through a pulley. If the belt tension is too large, the bearing stress will increase, and the rotor shaft end may break due to tension.

[0007] Risk 3: Currently, to avoid the above problems, motor manufacturers often thicken the rotor shaft to improve reliability. This method results in an overall thicker shaft, increasing component costs. Furthermore, since thickening the shaft increases the pressing force required during production, the shaft end may deform during press-fitting, and this runout can reduce the life of the rotor bearing.

[0008] Risk 4: During operation, the rotor assembly's excitation coil experiences greater centrifugal force the closer it is to the center due to varying distances from the center. Currently, rotor failures in the aftermarket are often caused by a broken excitation coil. When the excitation coil breaks, the generator's excitation circuit is disconnected, rendering the vehicle's warning function ineffective and posing a safety risk. Therefore, ensuring the reliability of the rotor and the excitation coil at high speeds has become a major technical challenge in this field.

[0009] Risk 5: In the existing technology, the rotor assembly is mostly fixed by straight-groove pressing or knurled riveting structure, which can only ensure the axial or circumferential fixation of the rotor, and cannot ensure both axial and axial reliability at the same time; and because the contact surface with the pulley and the bearing is the shaft fixing surface, when problems occur in the pressing process or the shaft produces micro-movement and creep, gaps will inevitably appear on the pulley contact surface, which will cause the pulley to idle or fall off; such as the existing patent CN200920181003.4; and when the rotor shaft adopts a straight-groove pressing structure, the iron chips generated by the interference fit during the straight-groove pressing process cannot be discharged, and the pressing force will increase linearly during the rear-end pressing process. The existing production process cannot guarantee the stability of the assembly process. Summary of the Invention

[0010] The present invention provides a vehicle generator rotor, the purpose of which is to improve the stability and reliability of the generator rotor structure.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] The vehicle generator rotor of the present invention includes a motor shaft, an excitation coil and a pair of claw poles, wherein the excitation coil is fixed by the pair of claw poles; a motor shaft boss is provided on the motor shaft, and the two end faces of the motor shaft boss respectively contact the end faces of the claw poles and the bearing to achieve positioning.

[0013] The section of the motor shaft where the bearing is installed is a bearing step, and the bearing step is adjacent to the step where the pulley is installed; the diameter of the bearing step is larger than the diameter of the claw pole section where the motor shaft is installed.

[0014] The motor shaft is provided with a claw pole section, and straight knurling structures are respectively arranged at both ends thereof; and a sawtooth knurling structure is arranged at the outer end thereof.

[0015] The outer end of the sawtooth knurling is provided with a press-fitting guide angle.

[0016] A claw pole chip removal groove is provided in the inner hole where the claw pole cooperates with the motor shaft; the claw pole chip removal groove is an annular groove at the opening of the claw pole inner hole.

[0017] The inner cavity of the claw pole fixed excitation coil is respectively provided with an inner circular inclined surface of the claw pole inner cavity, an inner end inclined surface of the claw pole inner cavity and an outer circular inclined surface of the claw pole inner cavity; the inclination direction of the inner circular inclined surface of the claw pole inner cavity and the outer circular inclined surface of the claw pole inner cavity is such that the opening size is larger than the inner end; the inclination direction of the inner end inclined surface of the claw pole is such that the outer edge pressure of the inner end inclined surface of the claw pole is greater than the inner edge pressure.

[0018] In order to achieve the same inventive purpose as the above technical solution, the present invention also provides a vehicle generator using the above-mentioned vehicle generator rotor; the vehicle generator also includes a generator stator and a motor housing, and the motor shaft is fixed to the motor housing through a bearing; the generator stator is pressed into the motor housing shown.

[0019] The present invention adopts the above technical solution and fundamentally avoids the risks of generator assembly pulley falling off, rotor breaking, etc. by improving the matching structure between the various components of the rotor assembly, thereby improving the stability and reliability of the rotor. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] The contents shown in the accompanying drawings and the symbols in the drawings are briefly described as follows:

[0021] Figure 1 It is a structural diagram of the prior art;

[0022] Figure 2 Schematic diagram of the rotor structure of the present invention;

[0023] Figure 3 Schematic diagram of the shaft structure;

[0024] Figure 4 for Figure 3 An enlarged schematic diagram of the press-fitting guide structure of the serrated knurling;

[0025] Figure 5 Schematic diagram of the claw pole structure of the present invention;

[0026] Figure 6 This is a schematic diagram of the improved structure of the present invention;

[0027] Figure 7 It is a schematic diagram of the assembly structure of the present invention.

[0028] The following are marked in the figure:

[0029] 1. Motor shaft, 2. Claw pole, 3. Excitation coil, 4. Fan, 5. Collector ring, 6. Serrated knurling, 7. Straight knurling, 8. Bearing locating end face, 9. Bearing step, 10. Press-fit guide angle, 11. Inner circular inclined surface of claw pole cavity, 12. Inner end inclined surface of claw pole, 13. Outer circular inclined surface of claw pole cavity, 14. Claw pole chip groove, 15. Bearing, 16. Pulley, 17. Motor shaft boss, 18. Riveting structure. DETAILED DESCRIPTION

[0030] The specific implementation methods of the present invention will be further explained in detail below by describing the embodiments with reference to the accompanying drawings, so as to help those skilled in the art to have a more complete, accurate and in-depth understanding of the inventive concept and technical solution of the present invention.

[0031] like Figures 2 to 7 The structure of the present invention is a highly reliable automotive generator rotor, comprising a motor shaft 1, an excitation coil 3, and a pair of claw poles 2. The excitation coil 3 is secured by the claw poles 2. The motor shaft 1 is secured to the motor housing via bearings 15. A gap between the contact surface of the motor shaft 1 and the bearings 15 can cause the pulley to move forward and backward, potentially causing the pulley 16 to fall off after prolonged operation.

[0032] The vehicle generator further comprises a generator stator and a motor housing, wherein the generator stator is pressed into the motor housing as shown.

[0033] In order to solve and overcome the problems and defects of the prior art and achieve the invention purpose of improving the stability and reliability of the generator rotor structure, the technical solution adopted by the present invention is as follows:

[0034] like Figures 2 to 7 As shown, in the vehicle generator rotor of the present invention, a motor shaft boss 17 is provided on the motor shaft 1, and two end faces of the motor shaft boss 17 respectively contact with the end faces of the claw pole 2 and the bearing 15 to achieve positioning.

[0035] Motor shaft rotor assembly Figure 2 The rotor assembly consists of a motor shaft 1, claw poles 2, excitation coils 3, front and rear fans 4, excitation slip rings (collector rings 5), and other parts. The above technical solution changes the contact surface between the bearing 15 and the claw pole 2 to the contact surface between the bearing 15 and the motor shaft boss 17. Since the motor shaft boss 17 and the motor shaft 1 are integral, there will be no gap between the contact surface of the bearing 15 and the motor shaft boss 17 due to micro-motion or creep during the operation of the rotor. Direct rigid contact between the two parts is achieved, ensuring that no gap is generated on the contact surface.

[0036] like Figure 6 As shown, the assembly method is: the claw pole 2 is assembled with the excitation coil 3 by pre-pressing, and after assembly, the motor shaft 1 is pressed in by press-fitting, and the pressure is maintained after pressing in, and the knurled section on the motor shaft 1 is press-riveted to fix it. The position of the riveting structure 18 is shown in FIG. Figure 7 After the motor shaft and rotor assembly are press-fitted, the front and rear fans 4 are welded and the slip rings 5 are assembled.

[0037] like Figure 7 As shown, the section of the motor shaft 1 where the bearing 15 is installed is a bearing step 9, and the bearing step 9 is adjacent to the step where the pulley 16 is installed; the diameter of the bearing step 9 is larger than the diameter of the section of the motor shaft 1 where the claw pole 2 is installed.

[0038] like Figure 3 As shown, the side of the motor shaft boss 17 that contacts the bearing 15 is the bearing positioning end face 8, and the axial positioning of the bearing 15 is achieved through the bearing positioning end face 8.

[0039] The present invention utilizes a three-section shaft structure, with a large diameter in the section contacting bearing 15 and a small diameter in the section contacting claw poles 2. This improves the rationality and reliability of the rotor shaft end's load-bearing capacity. Furthermore, since the drive end only needs to ensure load-bearing capacity in the section contacting bearing 15, the required shaft length does not need to be too long. Therefore, a hot forging process can be used, reducing the motor shaft material usage and lowering the cost of shaft components.

[0040] The motor shaft 1 is provided with a claw pole 2, and straight knurling structures 7 are provided at both ends thereof; and a serrated knurling structure 6 is provided at the outer end thereof.

[0041] The present invention employs a structure with straight knurling 7 at both ends and a serrated knurling 6 at the section of the motor shaft 1 where the claw poles 2 are mounted. The straight knurling 7 ensures circumferential rotational performance of the rotor assembly, while the serrated knurling 6 ensures axial rotational performance. Furthermore, because the rotor assembly's driving end is subject to significant forces, primarily circumferential rotational forces, the straight knurling 7 is located at the driving end, requiring only the knurling structure to ensure reliable rotor press-fit closure. Furthermore, this knurling structure utilizes three serrated knurling sections. After riveting, all three sections simultaneously secure the rotor, increasing the riveting withdrawal force by one-third and enhancing reliability.

[0042] like Figure 3 and Figure 4 As shown, the outer end of the sawtooth knurling 6 is provided with a press-fitting guide angle 10. The provision of the press-fitting guide angle 10 makes it easier to press-fit the claw pole 2 without getting stuck.

[0043] like Figure 5 As shown, a claw pole chip removal groove 14 is provided in the inner hole where the claw pole 2 and the motor shaft 1 cooperate; the claw pole chip removal groove 14 is an annular groove at the opening of the inner hole of the claw pole 2 .

[0044] The present invention provides a claw pole chip removal groove 14 in the inner hole where the claw pole 2 and the shaft 1 meet. The groove is in the shape of a T-shaped hole, so as to ensure that the debris generated by the straight knurling 7 of the motor shaft 1 during the press-fitting process will not have a significant impact on the pressing force.

[0045] like Figure 5 As shown:

[0046] In the inner cavity of the claw pole 2 fixing the excitation coil 3, a claw pole inner cavity inner circular inclined surface 11, a claw pole inner end inclined surface 12 and a claw pole inner cavity outer circular inclined surface 13 are respectively provided; the inclination direction of the claw pole inner cavity inner circular inclined surface 11 and the claw pole inner cavity outer circular inclined surface 13 is such that the opening size is larger than the inner end; the inclination direction of the claw pole inner end inclined surface 12 is such that the outer edge pressure of the claw pole inner end inclined surface 12 is greater than the inner edge pressure.

[0047] The present invention employs a stepped, beveled transition on the inner end face of the claw pole 2, ensuring that the excitation coil 3 experiences greater clamping force the further outward it approaches during press-fitting. Furthermore, a nearly 90-degree angle is designed at the base of the claw pole 2's inner cavity, allowing the outer clamping force acting on the copper wire to simultaneously compress and secure the inner surface of the claw pole 2. This four-sided fixing method—the inner end face of the claw pole 2, the inner end face of the lower claw pole, the beveled surfaces at the base of the upper and lower claw poles, and the circular surface of the yoke—ensures the operational reliability of the excitation coil 3.

[0048] The three surfaces in contact with the excitation coil 3 are clamped and fixed. Since the inner end surface of the claw pole 2 is an inclined surface, the clamping force becomes greater the closer to the outside. The inner cavity of the claw pole is designed at a nearly 90-degree angle, which will further fix the copper wire displaced on the outside of the excitation coil during the claw pole extrusion process.

[0049] The present invention is described above by way of example in conjunction with the accompanying drawings. It is obvious that the specific implementation of the present invention is not limited to the above-mentioned method. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, or the concept and technical solution of the present invention are directly applied to other occasions without improvement, they are all within the scope of protection of the present invention.

Claims

1. A vehicle generator rotor, comprising a motor shaft (1), an excitation coil (3) and a pair of claw poles (2), wherein the excitation coil (3) is fixed by the pair of claw poles (2); Its characteristics are: A motor shaft boss (17) is provided on the motor shaft (1), and two end faces of the motor shaft boss (17) respectively contact the end faces of the claw pole (2) and the bearing (15) to achieve axial positioning; The section of the motor shaft (1) on which the bearing (15) is mounted is a bearing step (9), and the bearing step (9) is adjacent to the step on which the motor shaft (1) is mounted with the pulley (16); the diameter of the bearing step (9) is larger than the diameter of the section on which the claw pole (2) is mounted on the motor shaft (1); The motor shaft (1) is provided with a claw pole (2) mounted thereon, and a straight knurling (7) structure is provided at both ends thereof; and a sawtooth knurling (6) structure is provided at the outer end thereof; The outer end of the sawtooth knurling (6) is provided with a press-fitting guide angle (10); A claw pole chip removal groove (14) is provided in the inner hole where the claw pole (2) and the motor shaft (1) cooperate; the claw pole chip removal groove (14) is an annular groove at the opening of the inner hole of the claw pole (2); The claw pole (2) is fixed to the inner cavity of the excitation coil (3), and a claw pole inner cavity inner circular inclined surface (11), a claw pole inner end inclined surface (12), and a claw pole inner cavity outer circular inclined surface (13) are respectively provided; the claw pole inner cavity outer circular inclined surface (13) is located inside the claw pole inner cavity inner circular inclined surface (11), and the claw pole inner end inclined surface (12) connects the claw pole inner cavity inner circular inclined surface (11) and the claw pole inner cavity outer circular inclined surface (13); the inclination direction of the claw pole inner cavity inner circular inclined surface (11) and the claw pole inner cavity outer circular inclined surface (13) is such that the opening size is larger than the inner end; the inclination direction of the claw pole inner end inclined surface (12) is such that the outer edge pressure of the claw pole inner end inclined surface (12) is greater than the inner edge pressure.

2. A vehicle generator using the vehicle generator rotor according to claim 1, characterized in that: The vehicle generator further comprises a generator stator and a motor housing, wherein the motor shaft (1) is fixed to the motor housing via a bearing (15); and the generator stator is pressed into the motor housing.

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