Connecting structure of motor steering output shaft and processing technology thereof

Abstract

The invention discloses a connecting structure of a motor steering output shaft and a processing technology of the connecting structure, and relates to the technical field of motor transmission connection. The connecting structure of the motor steering output shaft comprises a first shaft body, the first shaft body is sleeved with a stop tooth assembly, the stop tooth assembly comprises a plurality of first stop teeth, and the distances between every two adjacent first stop teeth are the same; an insertion groove is formed in the second shaft body, a plurality of second stop teeth are arranged on the inner wall of the insertion groove, and the distances between every two adjacent second stop teeth are the same; the first shaft body is arranged in the insertion groove, the first stop teeth are clamped between the two adjacent second stop teeth, and the first stop teeth are parallel to the second stop teeth. According to the connecting structure, load distribution is improved, centering precision is improved, gaps are reduced through meshing fit, the friction coefficient is reduced, accordingly, abrasion is reduced, the service life is prolonged, and the stability of transmission between the motor steering shaft and related parts is improved through the connecting structure.

Description

Technical Field

[0001] This invention relates to the field of motor drive connection technology, and in particular to a connection structure for a motor steering output shaft and its processing technology. Background Technology

[0002] Currently, the transmission connection between the motor steering shaft and related components generally adopts a conventional mating structure of flat key 1 and keyway 2 (see...). Figure 1 As shown in the figure, this structure has the advantages of simple structure, low cost, convenient installation and disassembly, and mature reliability. However, in long-term high-load, high-frequency start-stop motor operation scenarios, this structure exposes significant technical shortcomings: Concentrated stress makes it prone to damage: The key-slot mating mechanism transmits torque via a single key, concentrating the force entirely on one side of the contact surface between the key and the keyway, resulting in extremely high load per unit area. Under high motor load operation, this can easily lead to key deformation, keyway wear, or even key breakage, causing transmission failure. Poor centering accuracy: The inherent gap between the flat key and the keyway makes it impossible to achieve high-precision centering of the shaft and connecting components. When the motor runs at high speed, the gap will cause coaxiality deviation between the shaft and the connecting components, generating vibration and noise. This not only affects the stability of motor operation but also accelerates the wear of bearings and other related components. Long-term use can easily lead to loosening: The fit between the key and the groove relies on the interference or transition fit of the key and the groove to achieve fixation. Under the action of alternating torque for a long time, the mating surfaces will gradually wear, resulting in an increase in the mating clearance, eventually leading to loosening of the connection, a decrease in transmission efficiency, and in severe cases, it may cause safety hazards.

[0003] Limitations in keyway machining accuracy: Flat keyways are usually machined by milling. Due to the influence of milling cutter accuracy and clamping error, the symmetry and depth tolerance of the keyway are difficult to control precisely (keyway machining is mostly carried out after heat treatment, when the shaft material has high hardness), which further aggravates the centering deviation problem of flat key fit.

[0004] Therefore, there is a need for a connection structure between the motor steering shaft and the associated components, and this connection structure has a more stable transmission effect compared to the prior art. Summary of the Invention

[0005] In view of the deficiencies in the existing technology, the technical problem solved by the present invention is: how to improve the stability of the transmission between the motor steering shaft and related components.

[0006] To achieve the above objectives, in a first aspect, the present invention provides a connection structure for the motor steering output shaft, comprising: A first shaft body is fitted with a stop tooth assembly, which includes multiple first stop teeth, and the distance between two adjacent first stop teeth is the same. The second shaft has an insertion groove, and the inner wall of the insertion groove is provided with multiple second stop teeth, with the distance between two adjacent second stop teeth being the same. The first shaft is disposed inside the insertion groove, and the first stop tooth is engaged between two adjacent second stop teeth, with the first stop tooth and the second stop tooth being parallel.

[0007] By adopting the above technical solution, the end of the first shaft is inserted into the insertion groove of the second shaft, so that the first stop tooth is engaged between two adjacent second stop teeth. The first and second stop teeth are arranged in parallel, so the first and second stop teeth fit together. During transmission, the motor output shaft drives one of the first or second shafts to rotate. Therefore, the meshing action of the first and second stop teeth will drive the other one to drive, thereby transmitting force to the associated component. There is an interaction force between the two adjacent first and second stop teeth, so the torque is evenly distributed, and the load is evenly distributed on each of the first and second stop teeth. Compared with the existing flat key, the load distribution is improved. Moreover, the first and second stop teeth are evenly distributed circumferentially, thus improving the centering accuracy. The meshing not only reduces the gap, but also reduces the coefficient of friction, thereby reducing wear and increasing service life. Therefore, this connection structure improves the stability of the transmission between the motor steering shaft and the associated component.

[0008] In one embodiment, the first stop tooth is positioned at a clamping angle to the axial direction of the first shaft.

[0009] By adopting the above technical solution, the meshing direction is tilted relative to the axial direction, which further improves the meshing effect and thus further enhances the stability of the transmission between the motor steering shaft and related components.

[0010] In one embodiment, the first stop tooth is arranged in a direction parallel to the axial direction of the first shaft; the side of the first stop tooth is provided with a side wing, and the side of the second stop tooth is provided with a guide groove along the axial direction of the second shaft, with the side wing disposed inside the guide groove.

[0011] By adopting the above technical solution, it is convenient to install and position the first stop tooth and the second stop tooth. At the same time, the interaction force between the side wing and the guide groove further increases the contact area between the first stop tooth and the second stop tooth during the transmission process, thereby improving the load distribution.

[0012] In one embodiment, the guide groove has a snap-fit ​​groove inside, which is used to snap the side wing.

[0013] By adopting the above technical solution, the first stop tooth and the second stop tooth are more firmly connected, and at the same time, the first shaft or the second shaft is prevented from axial displacement during transmission.

[0014] In one embodiment, a detection groove is provided inside the snap-fit ​​slot, and a position sensor is installed inside the detection groove.

[0015] By adopting the above technical solution, it is easy to snap the slot and the side wing together.

[0016] In one embodiment, the stop tooth assembly further includes an annular member, which is sleeved on the first shaft, and the first stop teeth are evenly distributed on the circumference of the annular member.

[0017] By adopting the above technical solution, it is easy to replace the first stop tooth of different specifications.

[0018] In one embodiment, multiple mounting grooves are evenly formed along the circumference on the inner wall of the insertion groove, and the bottom surface of the second stop tooth is installed inside the mounting groove.

[0019] By adopting the above technical solution, different numbers of second stop teeth can be selectively installed in the preset positions of the mounting groove according to different specifications of the first stop teeth.

[0020] In one embodiment, the side surface and top surface of the first stop tooth are clamped at an obtuse angle, and the side surface and top surface of the second stop tooth are clamped at an obtuse angle.

[0021] By adopting the above technical solution, the contact surface between the first stop tooth and the second stop tooth is not perpendicular to the transmission direction, which not only avoids damage to the stop teeth, but also further strengthens the meshing effect, thereby further improving the stability of the transmission between the motor steering shaft and related components.

[0022] In one embodiment, the cross-section of the top surface of the first stop tooth is arc-shaped, and the curvature of the top surface of the first stop tooth is the same as the curvature of the inner wall of the insertion groove.

[0023] By adopting the above technical solution, the fit between the first stop tooth and the inner wall of the mounting groove is improved.

[0024] Secondly, the processing technology of the motor steering output shaft connection structure provided by the present invention includes the following steps: Prepare raw materials; The raw materials are cold-extruded to form the first and second shaft prototypes; The first and second axial prototypes are inspected; The first and second shaft prototypes are heat-treated to form the first and second shafts.

[0025] By adopting the above technical solution, cold extrusion extrudes the raw material into the first and second shaft prototypes, then tests and adjusts them, and finally performs heat treatment to avoid centering deviation problems caused by high material hardness and low milling precision after heat treatment.

[0026] In summary, the present invention has at least one of the following beneficial technical effects: 1. By inserting the end of the first shaft into the insertion slot of the second shaft, the first stop tooth is engaged between two adjacent second stop teeth, and the first and second stop teeth are arranged in parallel, thus the first and second stop teeth fit together. During transmission, the motor output shaft drives one of the first or second shafts to rotate, so the meshing of the first and second stop teeth drives the other one to drive, thereby transmitting force to the associated component. There is an interaction force between the two adjacent first and second stop teeth, thus distributing the torque evenly and making the load evenly distributed on each of the first and second stop teeth. Compared with the existing flat key, the load distribution is improved. Furthermore, the first and second stop teeth are evenly distributed circumferentially, thus improving the centering accuracy. The meshing not only reduces the clearance but also reduces the coefficient of friction, thereby reducing wear and increasing service life. Therefore, this connection structure improves the stability of the transmission between the motor steering shaft and the associated component. 2. The specific design of the side wings, guide grooves, and snap-fit ​​grooves facilitates the installation and positioning of the first and second stop teeth. At the same time, the interaction forces between the side wings and guide grooves, and between the side wings and snap-fit ​​grooves, further increase the contact area between the first and second stop teeth during transmission, improve the load distribution, and prevent the first or second shaft from undergoing axial displacement during transmission. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the background technology of this invention; Figure 2 A schematic diagram of the connection structure of the motor steering output shaft in an embodiment of the present invention; Figure 3 This is a schematic diagram of the structure of the first shaft in an embodiment of the present invention; Figure 4 This is a schematic diagram of the structure of the second shaft in an embodiment of the present invention; Figure 5 for Figure 4 AA sectional view.

[0028] In the figure: 1-flat key, 2-keyway, 3-first shaft, 4-second shaft, 5-stop tooth assembly, 501-first stop tooth, 502-ring part, 6-side wing, 7-second stop tooth, 8-guide groove, 9-clamping groove, 10-detection groove. Detailed Implementation

[0029] The embodiments of the present invention will be further described in detail below with reference to the accompanying drawings.

[0030] The connection structure of the motor steering output shaft in this embodiment of the invention is shown in the following figure. Figure 2 , Figure 3 , Figure 4 As shown, the connection structure of the motor steering output shaft includes a first shaft 3, on which a stop tooth assembly 5 is sleeved. The stop tooth assembly 5 includes multiple first stop teeth 501, and the distance between two adjacent first stop teeth 501 is the same. The second shaft 4 has an insertion groove, and the inner wall of the insertion groove is provided with multiple second stop teeth 7. The distance between two adjacent second stop teeth 7 is the same. The first shaft 3 is disposed inside the insertion groove, and the first stop tooth 501 is engaged between two adjacent second stop teeth 7, and the first stop tooth 501 and the second stop tooth 7 are parallel.

[0031] Therefore, it can be seen that in this invention, the end of the first shaft 3 is inserted into the insertion groove of the second shaft 4, so that the first stop tooth 501 is engaged between two adjacent second stop teeth 7, and the first stop tooth 501 and the second stop tooth 7 are arranged in parallel, so the first stop tooth 501 and the second stop tooth 7 are in close contact with each other; during the transmission process, the motor output shaft drives one of the first shaft 3 or the second shaft 4 to rotate, so the meshing action of the first stop tooth 501 and the second stop tooth 7 will drive the other one to drive, thereby transmitting force to the associated components, two adjacent The first stop tooth 501 and the second stop tooth 7 have an interaction force, thus distributing the torque evenly and making the load evenly distributed on each of the first stop tooth 501 and the second stop tooth 7. Compared with the existing flat key 1, the load distribution is improved. Furthermore, the first stop tooth 501 and the second stop tooth 7 are both circumferentially evenly distributed, thus improving the centering accuracy. The meshing not only reduces the clearance but also reduces the coefficient of friction, thereby reducing wear and increasing service life. Therefore, this connection structure improves the stability of the transmission between the motor steering shaft and the associated components.

[0032] Preferably, the first stop tooth 501 is positioned at a clamping angle with the axial direction of the first shaft 3.

[0033] Specifically, the first stop tooth 501 is inclined on the first shaft 3, that is, the setting direction of the first stop tooth 501 is not parallel to the axial direction of the first shaft 3. Correspondingly, the second shaft 4 also needs to be inclined on the inner wall of the insertion groove. During installation, the first shaft 3 needs to be screwed into the insertion groove, which is equivalent to a threaded connection. Therefore, the above design makes the meshing direction inclined to the axial direction, further improving the meshing effect, thereby further improving the stability of the transmission between the motor steering shaft and the associated components.

[0034] Preferred, see Figure 2 , Figure 3 , Figure 4As shown, the first stop tooth 501 is set in a direction parallel to the axial direction of the first shaft 3; a side wing 6 is provided on the side of the first stop tooth 501, and a guide groove 8 is opened on the side of the second stop tooth 7 along the axial direction of the second shaft 4, with the side wing 6 located inside the guide groove 8.

[0035] Specifically, during installation, the first shaft 3 is directly above the second shaft 4, and the two are coaxial. The end of the first shaft 3 is gradually inserted into the insertion groove, and the side wing 6 moves along the opening direction of the guide groove 8, thereby moving the first stop tooth 501 between two adjacent second stop teeth 7 to avoid collision during installation and facilitate the installation and positioning of the first stop tooth 501 and the second stop tooth 7. At the same time, during the transmission process, the side wing 6 and the guide groove 8 are always in contact. The interaction force between the side wing 6 and the guide groove 8 further increases the contact area between the first stop tooth 501 and the second stop tooth 7, and improves the load distribution.

[0036] Furthermore, the guide groove 8 has a snap-fit ​​groove 9 inside, which is used to snap the side wing 6.

[0037] Specifically, the side wing 6 can be designed as an elastic or telescopic structure. When the end of the first shaft 3 is gradually inserted into the insertion groove and the side wing 6 is entirely located on the side of the locking groove 9, the side wing 6 will extend into the locking groove 9, thereby achieving locking with the locking groove 9. Alternatively, the side wing 6 can be designed as a rigid structure, which will have a gap between the first stop tooth 501 and one of the second stop teeth 7. However, during transmission, the first stop tooth 501 only interacts with one of the second stop teeth 7. Therefore, the design of the corresponding side wing 6, guide groove 8, and locking groove 9 needs to be set on a pair of first stop teeth 501 and second stop teeth 7 with interacting forces. The interaction force between the side wing 6 and the locking groove 9 designed above further increases the contact area between the first stop tooth 501 and the second stop tooth 7 during transmission, improves the load distribution, and prevents the first shaft 3 or the second shaft 4 from undergoing axial displacement during transmission.

[0038] Furthermore, a detection groove 10 is provided inside the snap-fit ​​groove 9. A position sensor is installed inside the detection groove 10. The position sensor is used to detect the position to which the side wing 6 has moved or the insertion depth of the first shaft 3, so that the snap-fit ​​groove 9 can snap into the side wing 6.

[0039] Preferred, see Figure 3 As shown, the stop tooth assembly 5 also includes an annular member 502, which is sleeved on the first shaft 3, and the first stop teeth 501 are evenly distributed on the circumference of the annular member 502.

[0040] Specifically, the stop tooth assembly 5 has a variety of different specifications. According to the transmission requirements, different specifications with different stop tooth numbers and different stop tooth widths can be selected to meet different transmission requirements. In addition, the first stop tooth 501 must meet the matching requirements with the second stop tooth 7. After the design and selection are completed, the ring part 502 is sleeved on the first shaft 3 and fixedly connected to improve the applicability of the connection structure.

[0041] Furthermore, multiple mounting grooves are evenly opened along the circumference on the inner wall of the insertion groove, and the bottom surface of the second stop tooth 7 is installed inside the mounting groove.

[0042] Specifically, based on the design of the aforementioned stop tooth assembly 5, different numbers of second stop teeth 7 can be selectively installed in the preset positions of the mounting slot according to different specifications of the first stop teeth 501, so as to achieve the effect that the first stop teeth 501 and the second stop teeth 7 meet the matching requirements.

[0043] Preferably, the side surface of the first stop tooth 501 and the top surface are clamped at an obtuse angle, and the side surface of the second stop tooth 7 and the top surface are clamped at an obtuse angle.

[0044] Specifically, the contact surfaces of the first stop tooth 501 and the second stop tooth 7 are not perpendicular to the transmission direction, which not only avoids damage to the stop teeth, but also further strengthens the meshing effect, thereby further improving the stability of the transmission between the motor steering shaft and the associated components.

[0045] Preferably, the top surface of the first stop tooth 501 has a circular arc shape, and the curvature of the top surface of the first stop tooth 501 is the same as the curvature of the inner wall of the insertion groove, thereby improving the fit between the first stop tooth 501 and the inner wall of the mounting groove.

[0046] The processing technology of the connection structure of the motor steering output shaft in this embodiment of the invention includes the following steps: Prepare raw materials; The raw materials are cold-extruded to form the first and second shaft prototypes; The first and second axial prototypes are inspected; The first and second shaft prototypes are heat-treated to form the first shaft 3 and the second shaft 4.

[0047] Specifically, cold extrusion processes extrude the raw material into the initial shape of the first shaft body 3 and the second shaft body 4. After inspection and adjustment, heat treatment is performed to avoid centering deviation problems caused by high material hardness and low milling precision after heat treatment. The machining process for the first shaft 3 is as follows: Raw material and blank preparation: 45#CL steel is selected, with an outer diameter of ø17.9+0.04mm after cold drawing and a hardness of HRA58-64; the raw materials must meet the requirements of GB / T699 chemical composition, GB / T4162 Class A flaw detection, and grain size ≥5. Rough machining: GB4030 saw blanking (length 208+0.5mm) → CK6136I CNC lathe rough turning (flat surface, outer diameter, calibrate chuck runout <0.03mm); Stop teeth forming: YF32-100 / YF32-200 hydraulic press extrusion (pressure 12~18MPa), the left and right end stop teeth are processed in two stages; clean the mold after processing 48 pieces, and check the tooth surface for scratches; Finishing: Deep hole drilling machine to machine the inner hole (ensuring effective length ø6.576~0.07mm) → TMCZK-16 CNC lathe to finish turn the outer diameter (calibrate center runout <0.02mm) → MMB1320 CNC grinding machine to finish grind the outer diameter (grinding wheel once / 50 pieces, rough and finish grinding time 20~25s); Inspection and post-processing: Coordinate measuring machine (CMM) inspection of tooth profile error and coaxiality (≤0.01mm) → cleaning and rust prevention → coding and marking.

[0048] The machining process for the second shaft 4 is as follows: Raw material and blank preparation: S45C (CL3) steel is selected, with an outer diameter of 28.3±0.02mm after cold drawing and a hardness of HRA58-64; the raw materials need to be tested by eddy current and magnetic particle testing; Rough machining: blanking on a GZK4230 CNC saw → rough turning on a TC30 CNC lathe (flat surface, outer diameter, drilling, calibrating the three-jaw runout <0.1mm); Stop tooth forming: HJS32-100 hydraulic press extrusion (pressure 10-25MPa, total blank length 84±0.1mm) → Y5120B CNC gear shaping machine to shape the right end stop tooth (cutting speed S800~1000mm / min); the tooth profile of each piece is checked with a go gauge; Finishing: The inner hole (ø13.576~0.014mm) and outer diameter are precision turned on a QSM100 CNC lathe → the outer diameter is finely ground on an H3008 CNC grinding machine (rough grinding 16~18s, fine grinding 6~8s). Inspection and post-processing: Inspect the stop tooth span distance (22.964+0.07mm) and outer diameter accuracy → Deburr → Clean and prevent rust.

[0049] The above description is merely a specific embodiment of this application, enabling those skilled in the art to understand or implement this application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of this application. Therefore, this application is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A connection structure for a motor steering output shaft, characterized in that, It includes: The first shaft body (3) is sleeved with a stop tooth assembly (5), the stop tooth assembly (5) includes a plurality of first stop teeth (501), and the distance between two adjacent first stop teeth (501) is the same; The second shaft body (4) is provided with a plurality of second stop teeth (7) on the inner wall of the insertion slot, the distance between two adjacent second stop teeth (7) is the same; the first shaft body (3) is arranged in the insertion slot, the first stop tooth (501) is clamped between two adjacent second stop teeth (7), and the first stop tooth (501) and the second stop tooth (7) are parallel.

2. The connection structure of the motor steering output shaft according to claim 1, characterized by: The setting direction of the first stop tooth (501) has a clamping angle with the axial direction of the first shaft body (3).

3. The connecting structure of the motor steering output shaft according to claim 1, characterized by: The setting direction of the first stop tooth (501) is parallel to the axial direction of the first shaft body (3); the side surface of the first stop tooth (501) is provided with a side wing (6), the side surface of the second stop tooth (7) is provided with a guide groove (8) along the axial direction of the second shaft body (4), and the side wing (6) is arranged in the guide groove (8).

4. The connection structure of the motor steering output shaft according to claim 3, characterized by: The guide groove (8) is provided with a clamping groove (9) in the inside, and the clamping groove (9) is used for clamping the side wing (6).

5. The connection structure of the motor steering output shaft according to claim 4, characterized by: The clamping groove (9) is provided with a detection groove (10) in the inside, and the detection groove (10) is provided with a position sensor in the inside.

6. The connecting structure of the motor steering output shaft according to claim 1, characterized by: The stop tooth assembly (5) further includes a ring member (502), the ring member (502) is sleeved on the first shaft body (3), and the first stop tooth (501) is uniformly distributed on the circumference of the ring member (502).

7. The connection structure of the motor steering output shaft according to claim 6, characterized by: The inner wall of the insertion slot is uniformly provided with a plurality of mounting grooves along the circumference, and the bottom surface of the second stop tooth (7) is mounted in the mounting groove.

8. The connecting structure of the motor steering output shaft according to claim 1, characterized by: The side surface and the top surface of the first stop tooth (501) are included as an obtuse angle, and the side surface and the top surface of the second stop tooth (7) are included as an obtuse angle.

9. The connection structure of the motor steering output shaft according to claim 8, characterized by: The cross section of the top surface of the first stop tooth (501) is a circular arc, and the arc of the top surface of the first stop tooth (501) is the same as the arc of the inner wall of the insertion slot.

10. A process for machining a connection structure of an electric machine steering output shaft according to any one of claims 1-9, characterized in that, It includes the following steps: Prepare raw materials; The raw materials are cold extruded to form a first shaft body and a second shaft body; The first shaft body and the second shaft body are detected; The first shaft body and the second shaft body are heat treated to form a first shaft body (3) and a second shaft body (4).

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