Encoder rotor, servo motor, machine tool, rotor installation tool and assembly method

Abstract

The present invention discloses an encoder rotor, a servo motor, a machine tool, a rotor installation tool and an assembly method. The encoder rotor comprises: a stud, the stud comprises: a screw section, a nut fitting section, a force applying section, the nut fitting section is located between the screw section and the force applying section, the force applying section has a non-circular force applying portion; a magnet, the magnet is inserted into the stud from the end where the force applying section is located; a nut, the nut is suitable for threaded engagement with the nut fitting section. According to the encoder rotor of the present invention, by arranging the non-circular force applying portion on the stud, the installation operation of the encoder rotor can be completed along the axial direction of the stud, thereby, while ensuring the installation accuracy, it is beneficial to reduce the axial dimensions of the encoder rotor and the servo motor. The rotor installation tool is used to install the above-mentioned encoder rotor, and the above-mentioned encoder rotor is installed using the above-mentioned rotor installation tool and a corresponding assembly method.

Description

Technical Field

[0001] The present invention relates to the field of general mechanical technology, and more specifically, to an encoder rotor, a servo motor having the encoder rotor, a machine tool having the servo motor, a rotor mounting tool for mounting the encoder rotor, and an assembly method for mounting the encoder rotor using the rotor mounting tool. Background Art

[0002] The general magnetic encoder on the market has an encoder rotor fixed on the motor shaft. There is a circular magnet on the encoder rotor, and the magnet rotates as the motor shaft rotates. The encoder stator senses the rotating magnetic field and obtains the angular position of the motor after analysis. For split encoders, it is necessary to ensure the distance between the magnet and the Hall chip on the encoder stator. The commonly used fixing solution for the encoder rotor is to use a sleeve, and after fixing the position, tighten the set screws on the side to fix the encoder rotor. However, when tightening the set screws on the side, it is necessary to leave space for the wrench in the axial direction, which will cause the overall axial size of the encoder to be larger, which in turn causes the overall axial size of the motor to be larger. Summary of the invention

[0003] The present invention aims to solve at least one of the above-mentioned technical problems in the prior art to a certain extent. To this end, the present invention provides an encoder rotor that can achieve axial fixation without the need for side tightening of set screws.

[0004] The present invention also provides a servo motor comprising the encoder rotor.

[0005] The present invention further proposes a machine tool comprising the servo motor.

[0006] The present invention also proposes a rotor installation tool for installing the encoder rotor.

[0007] The present invention further proposes an assembly method for installing an encoder rotor using the rotor installation tool.

[0008] According to an embodiment of the present invention, the encoder rotor includes: a stud, the stud includes: a screw segment, a nut mating segment, and a force applying segment, the nut mating segment is located between the screw segment and the force applying segment, and the force applying segment has a non-circular force applying portion; a magnet, the magnet is inserted into the stud from the end where the force applying segment is located; and a nut, the nut is suitable for threaded engagement with the nut mating segment.

[0009] According to the encoder rotor of the embodiment of the present invention, by arranging the non-circular force-applying portion on the stud, the installation operation of the encoder rotor can be completed along the axial direction of the stud, thereby facilitating the reduction of the axial dimension of the encoder rotor and the radial dimension of the encoder.

[0010] According to some embodiments of the present invention, the force applying section is constructed as a polygonal column structure.

[0011] According to the second aspect of the present invention, the servo motor comprises: a motor end cover, on which a rotor mounting hole is formed; a motor rotor, through which the rotor mounting hole is formed; and the above-mentioned encoder rotor, on the end of which a threaded hole suitable for threaded engagement with the screw segment is formed, and the magnet at least partially extends into the rotor mounting hole.

[0012] A machine tool according to an embodiment of the third aspect of the present invention includes the above-mentioned servo motor.

[0013] The rotor installation tool according to the fourth aspect of the present invention is used to install the above-mentioned encoder rotor, and the rotor installation tool includes:

[0014] A positioning turntable, wherein the positioning turntable is provided with a rotor matching surface, and the rotor matching surface is suitable for being embedded and matched with the non-circular force-applying portion;

[0015] A spanner sleeve is sleeved outside the rotor matching surface, and the spanner sleeve has a spanner groove that is embedded and matched with the nut.

[0016] Optionally, the non-circular force-applying portion is configured as a polygonal structure, and the rotor mating surface is configured as a polygonal groove suitable for being embedded and mated with the polygonal structure.

[0017] According to some embodiments of the present invention, the wrench socket is axially movable relative to the positioning turntable.

[0018] Specifically, the positioning turntable includes: a turntable body and a rotor matching rod, the turntable body has a turntable through hole, the rotor matching rod is fixed on the turntable body and the rotor matching rod faces the turntable through hole, and the rotor matching surface is formed at the end of the rotor matching rod.

[0019] Furthermore, a turntable protrusion is provided on the edge of the turntable through hole, and the turntable protrusion protrudes out of the outer surface of the turntable body.

[0020] According to some embodiments of the present invention, the rotor installation tool also includes: a positioning seat, which is fixed on the turntable body, and an axial displacement cavity is formed between the positioning seat and the turntable body, the first end of the wrench socket is located in the axial displacement cavity, and the second end of the wrench socket is provided with the wrench groove.

[0021] According to some embodiments of the present invention, an external thread is provided on the outer peripheral surface of the rotor mating rod, and a screw connection section is provided between the wrench sleeve and the rotor mating rod.

[0022] According to a method for assembling an encoder rotor in an embodiment of a fifth aspect of the present invention, the encoder rotor is installed using the above-mentioned rotor installation tool, and the assembly method includes:

[0023] Screw the nut onto the nut mating section, and the screwing position of the nut must ensure that the magnet can contact the rotor mating surface during installation;

[0024] Screw the wrench sleeve onto the rotor matching rod of the positioning turntable;

[0025] Adsorbing the encoder rotor onto the rotor mating surface of the positioning turntable;

[0026] Align the screw section of the stud with the threaded hole at the end of the motor rotor shaft, rotate the positioning turntable, and stop rotating when the raised bottom surface of the positioning turntable contacts the reference surface of the motor end cover;

[0027] Loosen the threaded connection between the wrench sleeve and the positioning turntable to make the wrench sleeve fit with the nut;

[0028] The nut is tightened and fixed by twisting the wrench socket.

[0029] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] Figure 1 is a schematic diagram of the encoder rotor;

[0031] Figure 2 It is a three-dimensional schematic diagram of the stud and the magnet;

[0032] Figure 3 is a schematic cross-sectional view of the stud and the magnet;

[0033] Figure 4 It is a cross-sectional view of the rotor using the rotor mounting fixture and encoder rotor;

[0034] Figure 5 This is the front view of the encoder rotor installed using the rotor installation tool;

[0035] Figure 6 This is a cross-sectional view of installing the encoder rotor using the rotor installation tool;

[0036] Figure 7 is another cross-sectional view of installing the encoder rotor using the rotor installation tool;

[0037] Figure 8 is a schematic diagram of the positioning turntable;

[0038] Fig. 9 It is a schematic diagram of a wrench socket;

[0039] Fig.10 It is a schematic diagram of the positioning seat.

[0040] Reference numerals:

[0041] Encoder rotor 10, stud 1, screw section 11, nut matching section 12, force application section 13, magnet 2, nut 3, rotor installation tooling 20, positioning turntable 21, turntable body 211, rotor matching rod 212, rotor matching surface 213, turntable through hole 214, turntable protrusion 215, wrench socket 22, wrench groove 221, sleeve flange 222, positioning seat 23, positioning seat hole 231, positioning flange 232, positioning side wall 233, positioning bottom wall 234, shaft shift cavity 24, motor rotor 30, motor end cover 40, rotor mounting hole 41, bearing 50. DETAILED DESCRIPTION

[0042] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and should not be construed as limiting the present invention.

[0043] In the description of the present invention, it should be understood that the terms "longitudinal", "lateral", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside" and "outside" etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present invention.

[0044] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection, an electrical connection, or can communicate with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0045] Combine the following Figure 1-Figure 10 The encoder rotor 10 according to the embodiment of the present invention will be described in detail.

[0046] Reference Figure 1-Figure 3 As shown, the encoder rotor 10 according to the embodiment of the present invention may include: a stud 1, a magnet 2, and a nut 3. The stud 1 includes: a screw segment 11, a nut matching segment 12, and a force-applying segment 13. The nut matching segment 12 is located between the screw segment 11 and the force-applying segment 13. The magnet 2 is inserted into the stud 1 from the end where the force-applying segment 13 is located, and the end of the magnet 2 is exposed, so that the encoder stator can record the induced magnetic field of the magnet 2. The nut 3 is suitable for threading with the nut matching segment 12, that is, the nut matching segment 12 has an external thread, the nut 3 has an internal thread, and the external thread of the nut matching segment 12 is threaded with the internal thread of the nut 3.

[0047] The force-applying section 13 is a force-applying part where an operator or a tooling structure (such as the rotor installation tooling 20 mentioned below) applies a rotational force or torque to the screw 1. By applying a rotational force or torque to the force-applying section 13, the stud 1 can be rotated. The force-applying section 13 has a non-circular force-applying portion, and by applying a torque to the non-circular force-applying portion, the stud 1 can be tightened on the motor rotor 30.

[0048] According to the encoder rotor 10 of the embodiment of the present invention, by setting the non-circular force-applying portion on the stud 1, the installation operation of the encoder rotor 10 can be completed along the axial direction of the stud 1, thereby avoiding the encoder rotor 10 from being tightened by the set screws from the side. Therefore, under the premise of ensuring the installation accuracy, it is beneficial to reduce the axial dimension of the encoder rotor 10 and the overall radial dimension of the encoder, thereby shortening the axial dimension and the overall radial dimension of the motor.

[0049] When the encoder rotor 10 is fixedly connected to the motor rotor 30 , the nut 3 can prevent the encoder rotor 10 from loosening.

[0050] In a specific embodiment, the force applying section 13 can be constructed as a multi-prism structure, such as a triangular prism structure or a hexagonal prism structure, so that when a rotational force or torque is applied to the force applying section 13, the force applying section 13 can drive the screw section 11 to rotate synchronously easily.

[0051] Reference Figure 1-Figure 3 , Figure 6-Figure 7 As shown, the servo motor according to the second embodiment of the present invention may include: a motor end cover 40, a motor rotor 30 and the above-mentioned encoder rotor 10, the motor end cover 40 is provided with a rotor mounting hole 41, the motor rotor 30 is penetrated by the rotor mounting hole 41, the end of the motor rotor 30 is provided with a threaded hole suitable for threaded cooperation with the screw segment 11, and the magnet 2 at least partially extends into the rotor mounting hole 41, so that in the axial direction, the magnet 2 and the motor end cover 40 are at least partially overlapped, thereby reducing the axial length of the encoder rotor 10 extending out of the motor end cover 40, thereby ensuring that the axial dimension of the servo motor is small, thereby ensuring that the servo motor has a compact structure and a small size.

[0052] A machine tool according to an embodiment of the third aspect of the present invention includes the above-mentioned servo motor.

[0053] Reference Figure 4-Figure 9 As shown, the rotor installation tool 20 according to the fourth embodiment of the present invention is used to install the encoder rotor 10 of the above embodiment, and the rotor installation tool 20 may include: a positioning turntable 21 and a wrench sleeve 22. The positioning turntable 21 is provided with a rotor mating surface 213, and the rotor mating surface 213 is suitable for being embedded with the non-circular force-applying portion of the force-applying section 13, so that when the rotor mating surface 213 rotates, the stud 1 can be driven to rotate synchronously. The wrench sleeve 22 is sleeved outside the rotor mating surface 213, and the wrench sleeve 22 has a wrench groove 221 embedded with the nut 3, so that when the wrench sleeve 22 rotates, the nut 3 can be driven to rotate synchronously.

[0054] Optionally, the nut 3 can be a hexagonal head nut 3, and the spanner groove 221 is a hexagonal groove. Alternatively, the nut 3 can be a square head nut 3, and the spanner groove 221 is a square groove. Of course, the nut 3 and the spanner groove 221 can also be other shapes, which are not listed here one by one.

[0055] The rotor installation tool 20 is used to install the encoder rotor 10 on the motor rotor 30. The shaft end of the motor rotor 30 is provided with an axially arranged threaded hole. The rotor installation tool 20 is used to screw the stud 1 of the encoder rotor 10 into the threaded hole. Specifically, Figure 4 , Figure 6 As shown, the rotor mating surface 213 is embedded and matched with the non-circular force-applying portion, so that when the positioning turntable 21 rotates, the rotor mating surface 213 drives the stud 1 to rotate synchronously, thereby threading the screw segment 11 of the stud 1 into the threaded hole of the motor rotor 30.

[0056] Optionally, refer to Figure 1-Figure 2 , Figure 8 As shown, the non-circular force-applying portion is constructed as a polygonal structure, and the rotor mating surface 213 is constructed as a polygonal groove suitable for being embedded and matched with the polygonal structure, so that the non-circular force-applying portion and the rotor mating surface 213 can be prevented from rotating relative to each other, ensuring that the non-circular force-applying portion can rotate synchronously with the rotor mating surface 213. When the positioning turntable 21 stops rotating, the wrench sleeve 22 is rotated, and the stud 1 will not be rotated together with the nut 3.

[0057] Reference Figure 4-Figure 7 As shown, the wrench sleeve 22 can move axially relative to the positioning turntable 21. When the wrench sleeve 22 rises to separate from the nut 3, the wrench sleeve 22 cannot tighten the nut 3. When the wrench sleeve 22 falls to cooperate with the nut 3, the wrench sleeve 22 can be used to tighten or loosen the nut 3. Figure 4 , Figure 7 shown.

[0058] Specifically, refer to Figure 4-Figure 8 As shown, the positioning turntable 21 may include: a turntable body 211 and a rotor matching rod 212, the turntable body 211 has a turntable through hole 214, the rotor matching rod 212 is fixed on the turntable body 211, and the rotor matching rod 212 is opposite to the turntable through hole 214, and the rotor matching surface 213 is formed at the end of the rotor matching rod 212.

[0059] Furthermore, a turntable protrusion 215 is provided at the hole edge of the turntable through hole 214 , and the turntable protrusion 215 protrudes from the outer surface of the turntable body 211 .

[0060] The turntable body 211 includes a turntable top wall 2111, a turntable bottom wall 2113, and a turntable vertical wall 2112. The turntable top wall 2111 is separated from the turntable bottom wall 2113. The turntable vertical wall 2112 is used to connect the turntable top wall 2111 and the turntable bottom wall 2113. The rotor matching rod 212 is fixed on the turntable top wall 2111. The turntable through hole 214 is opened on the turntable bottom wall 2113.

[0061] The positioning turntable 21 can also be used to determine the distance between the encoder stator (not shown) and the encoder rotor 10. According to the required distance between the encoder stator and the encoder rotor 10, the distance between the bottom surface of the turntable protrusion 215 and the rotor matching surface 213 is calculated.

[0062] The positioning turntable 21 can be made of magnetic metal or magnetic conductive material, so that the encoder rotor 10 can be adsorbed on the rotor matching surface 213 .

[0063] Reference Figure 6-Figure 7 As shown, a motor end cover 40 is provided at the end of the motor rotor 30. When the turntable protrusion 215 of the positioning turntable 21 abuts against the surface of the motor end cover 40, it indicates that the encoder rotor 10 is installed in place. The motor rotor 30 passes through the motor end cover 40, and a bearing 50 is provided at the matching position of the motor rotor 30 and the motor end cover 40, thereby reducing the friction between the motor rotor 30 and the motor end cover 40, and also making the rotation of the motor rotor 30 more stable.

[0064] Reference Figure 4-Figure 7 , Figure 9-10 As shown, the rotor installation tool 20 may further include: a positioning seat 23, the positioning seat 23 is fixed on the turntable body 211, and an axial displacement cavity 24 is formed between the positioning seat 23 and the turntable body 211, the first end of the wrench sleeve 22 is located in the axial displacement cavity 24, and the second end of the wrench sleeve 22 is provided with a wrench groove 221. The positioning seat 23 connects the positioning turntable 21 and the wrench sleeve 22, limits the maximum moving distance of the wrench sleeve 22, and prevents the wrench sleeve 22 from slipping off during use or the wrench sleeve 22 from pushing away the encoder rotor 10 sucked on the rotor assembly surface 213.

[0065] The positioning seat 23 is provided with a positioning seat hole 231, and the first end of the wrench sleeve 22 has a sleeve flange 222, and the outer diameter of the sleeve flange 222 is larger than the aperture of the positioning seat hole 231. The positioning seat 23 includes a positioning flange 232, a positioning side wall 233 and a positioning bottom wall 234, the positioning flange 232 is separated from the positioning bottom wall 234, the positioning side wall 233 is used to connect the positioning flange 232 and the positioning bottom wall 234, the positioning seat hole 231 is provided on the positioning bottom wall 234, the positioning flange 232 is suitable for fixing with the turntable top wall 2111, specifically, the positioning flange 232 is provided with a flange hole 2321, and the fastener passes through the flange hole 2321 and is fastened in the top wall hole 21111 of the turntable top wall 2111.

[0066] The outer peripheral surface of the rotor matching rod 212 is provided with an external thread, and a screwing section is provided between the wrench sleeve 22 and the rotor matching rod 212. The operator can achieve the rise or fall of the wrench sleeve 22 by rotating the wrench sleeve 22 and / or the positioning turntable 21. And when the wrench sleeve 22 is not in use or needs to be fixed, the wrench sleeve 22 is screwed and connected with the rotor matching rod 212 to prevent the wrench sleeve 22 from moving. The outer surface of the wrench sleeve 22 can reserve a wrench position to facilitate the operator to apply force.

[0067] According to the encoder rotor assembly method of the fifth aspect of the present invention, the encoder rotor 10 is installed using the rotor installation tool 20 described above. The assembly method includes:

[0068] (1) Screw the nut 3 of the encoder rotor 10 into a suitable position on the nut mating section 12. The position should ensure that the magnet 2 of the encoder rotor 10 can contact the rotor mating surface 213 during installation.

[0069] (2) Screw the wrench sleeve 22 onto the rotor matching rod 212 of the positioning turntable 21 to facilitate subsequent operations.

[0070] (3) The encoder rotor 10 is adsorbed onto the rotor mating surface 213 of the positioning turntable 21 .

[0071] (4) Align the screw segment 11 of the stud 1 of the encoder rotor 10 with the threaded hole at the end of the shaft of the motor rotor 30, and rotate the positioning turntable 21. When the bottom surface of the turntable protrusion 215 of the positioning turntable 21 contacts the reference surface of the motor end cover 40, stop the rotation, thereby ensuring that the installation is in place and the installation accuracy is high.

[0072] (5) Loosen the threaded connection between the wrench socket 22 and the positioning turntable 21 to make the wrench socket 22 fit with the nut 3 of the encoder rotor 10.

[0073] (6) Use a wrench to turn the wrench position reserved in the wrench sleeve 22 to tighten the fixing nut 3, thereby fixing the encoder rotor 10 to the shaft end of the motor rotor 30.

[0074] (7) Remove the rotor installation tool 20 to complete the entire operation.

[0075] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example" or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine different embodiments or examples described in this specification.

[0076] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An encoder rotor (10), characterized in that: include: A stud (1), the stud (1) comprising: a screw section (11), a nut fitting section (12), and a force applying section (13), the nut fitting section (12) being located between the screw section (11) and the force applying section (13), the force applying section (13) having a non-circular force applying portion; A magnet (2), wherein the magnet (2) is inserted into the stud (1) from the end where the force-applying section (13) is located; A nut (3), wherein the nut (3) is suitable for threaded engagement with the nut engagement section (12).

2. The encoder rotor (10) according to claim 1, characterized in that The force applying section (13) is constructed as a polygonal column structure.

3. A servo motor, characterized in that: include: A motor end cover (40), wherein the motor end cover (40) is provided with a rotor mounting hole (41); A motor rotor (30), wherein the motor rotor (30) is provided with the rotor mounting hole (41); According to the encoder rotor (10) as described in any one of claims 1 to 2, a threaded hole suitable for threaded engagement with the screw segment (11) is provided at the end of the motor rotor (30), and the magnet (2) at least partially extends into the rotor mounting hole (41).

4. A machine tool, characterized in that: Including the servo motor described in claim 3.

5. A rotor installation tool (20), characterized in that: The rotor installation tool (20) is used to install the encoder rotor (10) according to any one of claims 1 to 2, and the rotor installation tool (20) comprises: A positioning turntable (21), wherein the positioning turntable (21) is provided with a rotor matching surface (213), and the rotor matching surface (213) is suitable for being embedded and matched with the non-circular force-applying portion; A spanner sleeve (22), wherein the spanner sleeve (22) is sleeved outside the rotor matching surface (213), and the spanner sleeve (22) has a spanner groove (221) that is embedded and matched with the nut (3).

6. The rotor installation tool (20) according to claim 5, characterized in that: The non-circular force-applying portion is configured as a polygonal structure, and the rotor matching surface (213) is configured as a polygonal groove suitable for being embedded and matched with the polygonal structure.

7. The rotor installation tool (20) according to claim 5, characterized in that: The wrench sleeve (22) is axially movable relative to the positioning turntable (21).

8. The rotor installation tool (20) according to claim 7, characterized in that: The positioning turntable (21) comprises: a turntable body (211) and a rotor matching rod (212); the turntable body (211) has a turntable through hole (214); the rotor matching rod (212) is fixed on the turntable body (211), and the rotor matching rod (212) is directly opposite to the turntable through hole (214); and the rotor matching surface (213) is formed at the end of the rotor matching rod (212).

9. The rotor installation tool (20) according to claim 8, characterized in that: A turntable protrusion (215) is provided on the edge of the turntable through hole (214), and the turntable protrusion (215) protrudes from the outer surface of the turntable body (211).

10. The rotor installation tool (20) according to claim 9, characterized in that: The rotor installation tool (20) further comprises: a positioning seat (23), wherein the positioning seat (23) is fixed on the turntable body (211), and an axial displacement cavity (24) is formed between the positioning seat (23) and the turntable body (211), the first end of the wrench sleeve (22) is located in the axial displacement cavity (24), and the second end of the wrench sleeve (22) is provided with the wrench groove (221).

11. The rotor installation tool (20) according to claim 9, characterized in that: An external thread is arranged on the outer peripheral surface of the rotor matching rod (212), and a screw connection section is provided between the wrench sleeve (22) and the rotor matching rod (212).

12. A method for assembling an encoder rotor, characterized in that: The encoder rotor (10) is installed using the rotor installation tool (20) according to any one of claims 9 to 11, and the assembly method comprises: The nut (3) is screwed onto the nut mating section (12), and the screwing position of the nut (3) must ensure that the magnet (2) can contact the rotor mating surface (213) during installation; The wrench sleeve (22) is screwed onto the rotor matching rod (212) of the positioning turntable (21); Adsorbing the encoder rotor (10) onto the rotor matching surface (213) of the positioning turntable (21); Align the screw section (11) of the stud (1) with the threaded hole at the end of the motor rotor (30) shaft, rotate the positioning turntable (21), and stop rotating when the bottom surface of the turntable protrusion (215) of the positioning turntable (21) contacts the reference surface of the motor end cover (40); Loosen the threaded connection between the spanner sleeve (22) and the positioning turntable (21) to make the spanner sleeve (22) fit with the nut (3); The nut (3) is tightened and fixed by twisting the wrench sleeve (22).

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