One-time clamping and grinding process for drum-shaped surface, reference surface A and reference surface B of motor shaft

Abstract

The invention relates to the technical field of motor shafts, in particular to a one-time clamping and grinding process for a drum-shaped surface, a reference surface A and a reference surface B. Multi-surface grinding is completed through one-time clamping, reference offset caused by multiple times of clamping is avoided, the coaxiality and relative position precision of the reference surface A / B, the drum-shaped surface and a rotary change outer circle surface are remarkably improved, the bore sweeping risk is reduced, and the machining efficiency is improved. Accumulative errors are eliminated, and precision is improved. The stepped grinding wheel is adopted to integrate multi-feature grinding, the grinding wheel replacement frequency is reduced, and the auxiliary time is shortened. And from center hole pretreatment to clamping run-out detection to differential grinding parameter setting, full-process precision closed-loop control is achieved, and the rejection rate is reduced. The high-pressure directional cooling scheme effectively takes away grinding heat, reduces the influence of thermal deformation on the precision of shafts, and guarantees the stability of the machining size. And the drum-shaped surface and the rotary variable outer circular surface can be synchronously machined, and the complex requirement of a high-precision motor shaft is met.

Description

Technical Field

[0001] This invention relates to the field of motor shaft technology, and in particular to a one-time clamping and grinding process for a motor shaft with a drum-shaped surface, A reference surface, and B reference surface. Background Technology

[0002] The motor shaft is a core transmission component inside an electric motor (motor). It is typically a rigid metal cylinder (or irregularly shaped structure), fixedly connected to the rotor core at one end and extending to the outside of the motor at the other. It is the key carrier for the motor to convert internal electromagnetic energy into external mechanical energy. During the manufacturing process, the motor shaft requires surface grinding. One end of the motor shaft has a drum-shaped surface and reference surface A, while the other end has a reference surface B and the outer cylindrical surface of the resolver. Both ends of the motor shaft need to be ground. Currently, separate clamping and grinding are used, with the drum-shaped surface and reference surfaces A and B ground separately. This results in a relatively large runout of the drum-shaped surface, typically around 0.012 mm. This process can no longer meet the requirements of modern high-speed motor shafts, which require runout within 0.007 mm. Therefore, a grinding process that clamps one grinding wheel at a time is needed, making the solution to this problem essential. Summary of the Invention

[0003] In view of this, the purpose of this invention is to propose a one-time clamping grinding process for the drum-shaped surface, A reference surface, and B reference surface of a motor shaft, thereby solving the problems in the prior art.

[0004] To achieve the above objectives, the present invention provides a one-time clamping grinding process for the drum-shaped surface, A reference surface, and B reference surface of a motor shaft, comprising the following steps: Step 1: Remove burrs / wear from the center holes at both ends of the motor, clean the surface oil, and ensure that the center holes are coaxial with the shaft centerline; Step 2: Clamp the motor shaft with the center hole of the motor shaft as the sole reference. Use double center clamping to ensure the coaxiality of the machined surface and the reference, and ensure the coaxiality of the workpiece is stable during the grinding process to avoid cumulative errors. Step 3: Use a grinding wheel to perform semi-finish grinding on datum surfaces A and B, and use the same grinding wheel to perform semi-finish grinding on the drum-shaped surface and the outer cylindrical surface of the rotary transformer. Step four: Use the same grinding wheel to fine grind the A reference surface and the B reference surface, and use the same grinding wheel to fine grind the drum-shaped surface and the outer cylindrical surface of the rotary transformer. Step 5: After the motor shaft has cooled to room temperature, loosen the clamp. Step six: Clean the motor shaft and check its size, shape, and positional accuracy.

[0005] Preferably, in step three, the transverse feed of the A reference surface and the B reference surface is 0.02-0.05 mm / time for semi-finish grinding, and the grinding is carried out until the allowance is 0.1-0.2 mm.

[0006] Preferably, in step three, the transverse feed for semi-finishing the drum-shaped surface and the outer cylindrical surface of the rotary mill is 0.005 mm / time, grinding to a remaining amount of 0.05-0.1 mm.

[0007] Preferably, in step four, the transverse feed rate for fine grinding of reference surfaces A and B is 0.005-0.01 mm / time, and the grinding wheel speed is 3000-3500 r / min.

[0008] Preferably, in step four, the transverse feed rate for fine grinding of the drum-shaped surface and the outer cylindrical surface of the rotary mill is 0.002-0.005 mm / time, and the grinding wheel speed is 3000-3500 r / min.

[0009] Preferably, after step two, a dial indicator is used to detect the runout of the outer circle, and the movable pin is adjusted to make the runout ≤0.01mm to ensure coaxiality before proceeding to step three.

[0010] Preferably, the end face of the grinding wheel is a stepped portion, the recessed part of the stepped portion is the A reference surface grinding surface, the protrusion of the stepped portion near the A reference surface grinding surface is the drum-shaped grinding surface, and the protrusion of the stepped portion away from the A reference surface grinding surface is the B reference surface and the rotational outer cylindrical surface grinding surface.

[0011] Preferably, the cooling in step five uses high-pressure internal cooling with a directional nozzle, with a cooling pressure of 3-5 MPa, a flow rate of 15-20 L / min, and the nozzle distance from the grinding zone is 10-15 mm.

[0012] The beneficial effects of this invention are as follows: This invention completes multi-face grinding in a single clamping, avoiding datum offset caused by multiple clampings, significantly improving the coaxiality and relative position accuracy of the A / B datum surfaces, the drum-shaped surface, and the resolver outer cylindrical surface, reducing the risk of "steering," eliminating cumulative errors, and improving precision. The use of a stepped grinding wheel integrates multi-feature grinding, reducing the number of grinding wheel changes, shortening auxiliary time, adapting to batch production scenarios, and optimizing processing efficiency. From center hole pretreatment to clamping runout detection, and then to differentiated grinding parameter settings, a closed-loop control of precision is achieved throughout the entire process, reducing scrap rate and stabilizing product quality. The high-pressure directional cooling scheme effectively removes grinding heat, reducing the impact of thermal deformation on shaft precision, ensuring dimensional stability, and suppressing thermal deformation. It can simultaneously process the drum-shaped surface and the resolver outer cylindrical surface, meeting the complex requirements of high-precision motor shafts and adapting to complex structures. High-precision machining reduces subsequent assembly wear, improving motor transmission efficiency and overall machine lifespan. These effects comprehensively balance precision, efficiency, and quality, making it particularly suitable for manufacturing motor shafts with stringent requirements for multiple datums and special curved surfaces. Attached Figure Description

[0013] To more clearly illustrate the technical solutions in this invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only for this invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0014] Figure 1 This is a schematic diagram of the grinding wheel of the present invention; Figure 2 This is a cross-sectional view of the grinding wheel end face of the present invention; Figure 3 This is a schematic diagram of the motor shaft of the present invention.

[0015] The diagram is marked as follows: 1-Drum-shaped surface, 2-A reference surface, 3-B reference surface, 4-Resolved outer cylindrical surface, 5-Stepped portion, 6-Grinding surface of A reference surface, 7-Grinding surface of drum-shaped surface, 8-Grinding surface of B reference surface and resolved outer cylindrical surface. Detailed Implementation

[0016] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments.

[0017] It should be noted that, unless otherwise defined, the technical or scientific terms used in this invention should have the ordinary meaning understood by one of ordinary skill in the art to which this invention pertains. The terms "first," "second," and similar terms used in this invention do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as "comprising" or "including" mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as "connected" or "linked" are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as "upper," "lower," "left," and "right" are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0018] like Figures 1 to 3 As shown, this embodiment provides a one-time clamping grinding process for the drum-shaped surface, A reference surface, and B reference surface of a motor shaft, including the following steps: S1, remove burrs / wear from the center holes at both ends of the motor, clean the surface oil stains, and ensure that the center holes are coaxial with the shaft centerline; S2. Use a dial indicator to detect the runout of the outer circle, and adjust the movable pin to make the runout ≤0.01mm to ensure coaxiality; S3 uses the center hole of the motor shaft as the sole reference to clamp the motor shaft. The coaxiality between the machined surface and the reference is ensured by double center clamping, which ensures the coaxiality of the workpiece is stable during the grinding process and avoids cumulative errors. S4. Use a grinding wheel to perform semi-finish grinding on datum surface 2 (A) and datum surface 3 (B). The transverse feed of the grinding wheel is 0.02 mm / time, and the grinding is performed until the allowance is 0.1 mm. S5, using the S4 grinding wheel, performs semi-finish grinding on the drum-shaped surface 1 and the outer cylindrical surface 4 of the rotary millimeter. The transverse feed of the grinding wheel is 0.005mm / time, and the grinding is performed until the allowance is 0.05mm. S6, still using the above grinding wheel to fine grind A reference surface 2 and B reference surface 3, the transverse feed of the grinding wheel is 0.005 / time, and the grinding wheel speed is 3000r / min; S7, still using the above-mentioned grinding wheel to fine grind the drum-shaped surface 1 and the outer cylindrical surface 3, the transverse feed of the grinding wheel is 0.002 / time, and the grinding wheel speed is 3000r / min; Multi-face grinding can be completed in one clamping, avoiding the reference offset caused by multiple clamping, significantly improving the coaxiality and relative position accuracy of the A / B reference surface, the drum-shaped surface and the rotary outer cylindrical surface, reducing the risk of "sweeping" and eliminating cumulative errors, thus improving accuracy; S8, after the motor shaft is cooled to room temperature, the clamping is released. High-pressure internal cooling + directional nozzle is used, with a cooling pressure of 5MPa, a flow rate of 20L / min, and the nozzle distance from the grinding zone is 15mm. The high-pressure directional cooling scheme effectively removes grinding heat, reduces the impact of thermal deformation on shaft accuracy, ensures the stability of machining dimensions, and suppresses thermal deformation. S9 cleans the motor shaft and checks its size, shape, and positional accuracy.

[0019] like Figure 3 As shown, the end face of the grinding wheel is a stepped portion 5. The recessed part of the stepped portion is the A datum surface grinding surface 6. The protruding part of the stepped portion, on the side closer to the A datum surface grinding surface, is the drum-shaped grinding surface 7. The protruding part of the stepped portion, on the side farther from the A datum surface grinding surface, is the B datum surface and the rotational outer cylindrical surface grinding surface 8. This stepped grinding wheel integrates multi-feature grinding, reducing the number of grinding wheel changes, shortening auxiliary time, adapting to mass production scenarios, and optimizing processing efficiency.

[0020] The technical solution in this embodiment has high processing efficiency, and the outer diameter runout of 0.007 / AB is fully guaranteed, as shown in the table below: Therefore, it can be seen that the runout of the outer circle of the motor shaft obtained in this embodiment meets the requirements.

[0021] Those skilled in the art should understand that the discussion of any of the above embodiments is merely exemplary and is not intended to imply that the scope of the invention is limited to these examples; within the framework of the invention, the technical features of the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and many other variations of different aspects of the invention as described above exist, which are not provided in detail for the sake of brevity. Any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the invention should be included within the scope of protection of the invention.

Claims

1. A one-time clamping grinding process for the drum-shaped surface, A datum surface, and B datum surface of a motor shaft, characterized in that, It includes the following steps: Step 1: Remove burrs / wear from the center holes at both ends of the motor, clean the surface oil, and ensure that the center holes are coaxial with the shaft centerline; Step 2: Clamp the motor shaft with the center hole of the motor shaft as the sole reference. Use double center clamping to ensure the coaxiality of the machined surface and the reference, and ensure the coaxiality of the workpiece is stable during the grinding process to avoid cumulative errors. Step 3: Use a grinding wheel to perform semi-finish grinding on datum surfaces A and B, and use the same grinding wheel to perform semi-finish grinding on the drum-shaped surface and the outer cylindrical surface of the rotary transformer. Step four: Use the same grinding wheel to fine grind the A reference surface and the B reference surface, and use the same grinding wheel to fine grind the drum-shaped surface and the outer cylindrical surface of the rotary transformer. Step 5: After the motor shaft has cooled to room temperature, loosen the clamp. Step six: Clean the motor shaft and check its size, shape, and positional accuracy.

2. The one-time clamping grinding process for the drum-shaped surface, A datum surface, and B datum surface of the motor shaft according to claim 1, characterized in that, In step three, semi-finish grinding is performed on reference surfaces A and B with a transverse feed of 0.02-0.05 mm / time, grinding to a remaining amount of 0.1-0.2 mm.

3. The one-time clamping grinding process for the motor shaft drum-shaped surface, A datum surface, and B datum surface according to claim 2, is characterized in that, In step three, the drum-shaped surface and the outer cylindrical surface of the rotary mill are semi-finished with a transverse feed of 0.005 mm / time, grinding to a remaining amount of 0.05-0.1 mm.

4. The one-time clamping grinding process for the drum-shaped surface, A datum surface, and B datum surface of the motor shaft according to claim 3, is characterized in that, In step four, the transverse feed rate for fine grinding of reference surfaces A and B is 0.005-0.01 mm / time, and the grinding wheel speed is 3000-3500 r / min.

5. The one-time clamping grinding process for the motor shaft drum-shaped surface, A datum surface, and B datum surface according to claim 4, is characterized in that, In step four, the transverse feed rate for fine grinding of the drum-shaped surface and the outer cylindrical surface of the rotary mill is 0.002-0.005 mm / time, and the grinding wheel speed is 3000-3500 r / min.

6. The one-time clamping grinding process for the drum-shaped surface, A datum surface, and B datum surface of the motor shaft according to claim 1, characterized in that, After step two, use a dial indicator to check the runout of the outer circle, adjust the movable pin to make the runout ≤0.01mm, ensure coaxiality, and then proceed to step three.

7. The one-time clamping grinding process for the drum-shaped surface, A datum surface, and B datum surface of the motor shaft according to claim 1, characterized in that, The end face of the grinding wheel is a stepped part. The recessed part of the stepped part is the A reference surface grinding surface. The protruding part of the stepped part is the drum-shaped grinding surface on the side closer to the A reference surface grinding surface. The protruding part of the stepped part is the B reference surface and the rotational outer cylindrical grinding surface on the side away from the A reference surface grinding surface.

8. The one-time clamping grinding process for the drum-shaped surface, A datum surface, and B datum surface of the motor shaft according to claim 1, characterized in that, Step five cooling adopts high-pressure internal cooling + directional nozzle, with a cooling pressure of 3-5MPa, a flow rate of 15-20L / min, and the nozzle distance from the grinding zone is 10-15mm.

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