Direct drive servo motor, assembly method and use method

Abstract

The application provides a direct drive servo motor with compact installation and convenient disassembly, comprising a shell assembly, a stator assembly, a rotor assembly, an output shaft fixedly connected with the rotor assembly, an axial extension shaft sleeve mounting hole arranged at one end of the output shaft, and a hydraulic shaft sleeve arranged in the shaft sleeve mounting hole and fixedly connected with the output shaft, wherein an oil cavity for containing hydraulic oil is arranged between the outer wall of the hydraulic shaft sleeve and the hole wall of the shaft sleeve mounting hole, the output shaft is provided with an oil pressure adjusting piece and an oil injection channel communicated with the oil cavity, the oil pressure adjusting piece is arranged in the oil injection channel, and the oil pressure adjusting piece blocks the hydraulic oil in the oil cavity. The application can conveniently and reliably connect the connecting shaft of a load device, has large holding force, stable connection, high concentricity and precision, can be operated in the radial direction during installation, requires small axial space, makes the positions of the direct drive servo motor and the load device compact, and is convenient to disassemble and assemble.

Description

Technical Field

[0001] This invention relates to an electric motor, specifically a direct-drive servo motor, and belongs to the field of electric motor manufacturing technology. Background Technology

[0002] Direct-drive servo motors are servo motors that directly drive the load device. There are no reducers, synchronous belts, worm gears, or other transmission mechanisms between the direct-drive servo motor and the driven load device, and there is no transmission backlash between them. Therefore, this improves the system's transmission rigidity, control bandwidth, and response speed. Direct-drive servo motors typically include two types: frameless direct-drive motors and framed direct-drive motors. Frameless direct-drive motors do not have a housing and are embedded in the load device, making installation more cumbersome. Framed direct-drive motors are easier to install and connect to the load device, but require the load device to have a certain degree of freedom; otherwise, over-positioning can easily occur, where the same degree of freedom of a component is repeatedly restricted by two or more support points. Furthermore, framed direct-drive motors are usually connected to the load device using flanges or mechanical expansion sleeves, requiring locking operations. Therefore, the load device needs to have axial operating space, which affects the system's structural compactness. Summary of the Invention

[0003] Based on the above background, the purpose of this invention is to provide a direct-drive servo motor that combines compact installation and convenient assembly / disassembly, stably connects to load devices, and has high connection accuracy.

[0004] To achieve the above-mentioned objectives, the present invention provides the following technical solution:

[0005] A direct-drive servo motor, comprising:

[0006] The housing assembly has an internal cavity;

[0007] A stator assembly is disposed in the inner cavity of the housing assembly, the stator assembly is fixedly connected to the housing assembly, and the stator assembly is provided with a first through hole extending along the axial direction of the housing assembly;

[0008] The rotor assembly is disposed in the first through hole of the stator assembly. The rotor assembly is rotatable relative to the stator assembly with the central axis of the stator assembly as the center. The rotor assembly is provided with a second through hole extending along the axial direction of the housing assembly.

[0009] An output shaft is disposed within the second through hole of the rotor assembly. The output shaft is fixedly connected to the rotor assembly, and its two ends are movably connected to the housing assembly. One end of the output shaft has a bushing mounting hole extending axially along the housing assembly; and...

[0010] A hydraulic bushing is disposed in the bushing mounting hole, and the hydraulic bushing is fixedly connected to the output shaft.

[0011] The hydraulic bushing has an oil cavity for accommodating hydraulic oil between its outer wall and the wall of the bushing mounting hole. The output shaft has an oil pressure regulating component and an oil injection channel connected to the oil cavity. The oil pressure regulating component is located in the oil injection channel and blocks the hydraulic oil in the oil cavity.

[0012] This direct-drive servo motor can tighten or loosen the hydraulic bushing by adjusting the pressure of the hydraulic oil in the oil chamber, which can conveniently and reliably connect the connecting shaft of the load equipment. Because it uses the elastic deformation of the hydraulic bushing to tighten the connecting shaft, the holding force is large, the connection is stable, and it has high concentricity and precision. During installation, the direct-drive servo motor is placed radially and close to the load equipment. Only a small amount of axial space between the two is needed for axial operation to complete the connection, making the position of the direct-drive servo motor and the load equipment compact and convenient for disassembly and assembly.

[0013] Preferably, the hydraulic pressure regulating component includes a hydraulic screw and a piston, the hydraulic screw and the piston are arranged sequentially along the oil injection channel, the hydraulic screw and the oil injection channel are connected by threads, and the outer wall of the piston is provided with a first sealing ring, the first sealing ring abutting against the channel wall of the oil injection channel.

[0014] Preferably, the hydraulic bushing includes a sleeve portion and a stop portion. The outer diameter of the stop portion is larger than the outer diameter of the sleeve portion, and the stop portion is located at the end of the sleeve portion. The stop portion is fixedly connected to the end face of the output shaft. The surface of the sleeve portion is provided with a groove that surrounds the sleeve portion in the circumferential direction. The space formed by the groove and the hole wall of the bushing mounting hole is configured as the oil cavity. A second sealing ring is provided on both sides of the groove that surrounds the surface of the sleeve portion in the circumferential direction.

[0015] Preferably, the housing assembly includes an outer shell, a front cover, and a rear cover. The front cover and the rear cover are respectively located at both ends of the outer shell. The end of the output shaft with a bushing mounting hole is clearance-fitted with the front cover. The other end of the output shaft is provided with a bearing. The inner wall of the bearing is connected to the output shaft, and the outer wall of the bearing is connected to the rear cover.

[0016] Preferably, the front end cover is provided with an adjustment hole, an auxiliary hole, a first positioning hole, and a second positioning hole. The adjustment hole is connected to the oil injection channel. The first positioning hole is located adjacent to the adjustment hole, and the second positioning hole is located adjacent to the auxiliary hole. The first positioning hole and the second positioning hole are perpendicular to each other, and the extended line of the central axis of the first positioning hole and the extended line of the central axis of the second positioning hole intersect at the central axis of the output shaft. The surface of the output shaft is provided with a first blind hole and a second blind hole that are perpendicular to each other, and the extended line of the central axis of the first blind hole and the extended line of the central axis of the second blind hole intersect at the central axis of the output shaft. The first blind hole is connected to the first positioning hole, and the second blind hole is connected to the second positioning hole.

[0017] Preferably, both the adjusting hole and the auxiliary hole are provided with a sealing bolt and a first countersunk head, and both the first positioning hole and the second positioning hole are provided with a positioning bolt and a second countersunk head. The depth of the first countersunk head is less than the depth of the second countersunk head, and the length of the sealing bolt head is less than the length of the positioning bolt head. The positioning bolt head can be inserted into the first blind hole and the second blind hole respectively.

[0018] Preferably, the housing assembly further includes a lifting ring, which is fixedly connected to the surface of the housing.

[0019] A method for assembling a direct-drive servo motor, the method comprising the following steps:

[0020] Install the rotor assembly on the output shaft, install the hydraulic bushing in the bushing mounting hole of the output shaft, inject hydraulic oil into the oil chamber through the oil injection channel, install the oil pressure regulating component in the oil injection channel, so that the hydraulic oil is sealed in the oil chamber and surrounds the outer wall of the hydraulic bushing;

[0021] The outer casing is heated to expand it, and the stator assembly is pressed into the outer casing. After the outer casing cools down, the stator assembly is sealed with glue.

[0022] The output shaft, which contains the rotor assembly and hydraulic bushing, is installed in the first through hole of the stator assembly, and the front end cover and rear end cover are installed on both ends of the housing, respectively.

[0023] Preferably, after the front cover and the rear cover are respectively installed on both ends of the housing, the method further includes the following steps:

[0024] Install a positioning bolt in the first positioning hole so that the head of the positioning bolt is inserted into the first blind hole. Install another positioning bolt in the second positioning hole so that the head of the positioning bolt is inserted into the second blind hole. This aligns the end of the output shaft with the bushing mounting hole with the front cover and fixes the position of the output shaft relative to the front cover.

[0025] A method for using a direct-drive servo motor, the method comprising the following steps:

[0026] Insert the connecting shaft of the load device into the hydraulic bushing of the direct drive servo motor, so that the front end cover of the direct drive servo motor abuts against the stop portion of the load device.

[0027] By inserting a tool into the adjustment hole and rotating the hydraulic pressure adjusting component, the hydraulic pressure adjusting component moves towards the oil chamber in the oil injection channel, thereby increasing the pressure of the hydraulic oil in the oil chamber. This causes the hydraulic bushing to undergo elastic deformation and bulge inward, thus gripping the connecting shaft of the load equipment.

[0028] A sealing bolt is installed in the first positioning hole, a positioning bolt is installed in the adjustment hole, another positioning bolt is installed in the auxiliary hole, and another sealing bolt is installed in the second positioning hole. At this time, the heads of the sealing bolts and the positioning bolts are spaced apart from the surface of the output shaft, so that the output shaft can rotate relative to the front cover, and the direct drive servo motor can drive the connecting shaft of the load device to rotate.

[0029] Compared with the prior art, the present invention has the following advantages:

[0030] The present invention provides a direct-drive servo motor that can be conveniently and reliably connected to the connecting shaft of the load device, with a large holding force, stable connection, and high concentricity and precision; the space required for axial operation during installation is small, making the direct-drive servo motor and the load device compact and easy to assemble and disassemble.

[0031] This invention achieves alignment between the end of the output shaft with the bushing mounting hole and the front cover by interlocking two positioning bolts that are perpendicular to each other. There is no need to install a bearing between the end of the output shaft with the bushing mounting hole and the front cover, thereby avoiding over-positioning of the connecting shaft of the load device. After the direct drive servo motor and the load device are connected, the bearing at the end of the load device can be used to radially fix the connecting shaft and the direct drive servo motor.

[0032] This invention achieves the positioning of the output shaft and the release of the limit by interchangeably swapping the positions of the positioning bolts and the sealing bolts, making it easy to operate and convenient to disassemble and assemble. Attached Figure Description

[0033] To more clearly illustrate the technical solutions in the embodiments of the present 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 embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on the provided drawings without creative effort.

[0034] Figure 1 This is a three-dimensional structural diagram of a direct-drive servo motor according to the present invention;

[0035] Figure 2 This is a schematic diagram of the internal structure of a direct-drive servo motor according to the present invention;

[0036] Figure 3 This is a schematic diagram of the end of the output shaft with a bushing mounting hole in this invention;

[0037] Figure 4 yes Figure 3 Enlarged view of part A in the middle;

[0038] Figure 5 This is a schematic diagram of the hydraulic bushing structure in this invention;

[0039] Figure 6 This is a schematic diagram of the structure of the output shaft, hydraulic bushing, and rotor assembly in this invention;

[0040] Figure 7 This is a schematic diagram of the internal structure of the front cover in this invention;

[0041] Figure 8 This is a schematic diagram of the assembly of the rotor assembly and the output shaft in this invention;

[0042] Figure 9 This is a schematic diagram of the assembly of the stator assembly and the housing in this invention;

[0043] Figure 10 This is an assembly diagram of the outer shell, front cover, and rear cover in this invention;

[0044] Figure 11 This is a schematic diagram of the connection between a direct-drive servo motor and a load device according to the present invention;

[0045] Figure 12 This is a schematic diagram of the hydraulic bushing not clamping the connecting shaft in this invention;

[0046] Figure 13 This is a schematic diagram of the hydraulic bushing clamping the connecting shaft in this invention;

[0047] Figure 14 This is a schematic diagram of the installation of the positioning bolt and sealing bolt after the hydraulic bushing clamps the connecting shaft in this invention.

[0048] In the diagram: 1. Housing assembly; 2. Stator assembly; 3. Rotor assembly; 4. Output shaft; 5. Hydraulic bushing; 6. Bearing; 7. Encoder; 8. Load device; 9. Connecting shaft; 10. Stop; 101. Inner cavity; 102. Outer shell; 103. Front cover; 104. Rear cover; 105. Lifting ring; 106. Pressure plate; 107. Adapter plate; 108. Rear cover; 1031. Adjustment hole; 1032. Auxiliary hole; 1033. First positioning hole; 1034. Second positioning hole; 1035. Sealing bolt; 103 6. First countersunk head; 1037. Positioning bolt; 1038. Second countersunk head; 201. First through hole; 301. Second through hole; 401. Bushing mounting hole; 402. Hydraulic pressure adjusting component; 403. Oil injection channel; 404. Stepped portion; 405. First blind hole; 406. Second blind hole; 4021. Hydraulic screw; 4022. Piston; 4023. First sealing ring; 4024. Washer; 501. Oil chamber; 502. Sleeve portion; 503. Stop portion; 504. Groove; 505. Second sealing ring. Detailed Implementation

[0049] The technical solution of the present invention will be further described in detail below through specific embodiments and in conjunction with the accompanying drawings. It should be understood that the implementation of the present invention is not limited to the following embodiments, and any modifications and / or alterations made to the present invention will fall within the protection scope of the present invention.

[0050] In this invention, unless otherwise specified, all parts and percentages are by weight, and the equipment and raw materials used are commercially available or commonly used in the art. Unless otherwise specified, the methods in the following embodiments are conventional methods in the art. Unless otherwise specified, the components or equipment in the following embodiments are general standard parts or components known to those skilled in the art, and their structures and principles can be learned by those skilled in the art through technical manuals or conventional experimental methods.

[0051] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings. In this detailed description, numerous specific details are set forth to facilitate explanation and provide a thorough understanding of the embodiments of the present invention. However, one or more embodiments may be practiced by those skilled in the art without these specific details.

[0052] like Figure 1-4 The direct-drive servo motor shown includes a housing assembly 1, a stator assembly 2, a rotor assembly 3, an output shaft 4, and a hydraulic bushing 5. The housing assembly 1 has an inner cavity 101. The stator assembly 2 is disposed within the inner cavity 101 of the housing assembly 1 and is fixedly connected to the housing assembly 1. The stator assembly 2 has a first through hole 201 extending axially along the housing assembly 1. The rotor assembly 3 is disposed within the first through hole 201 of the stator assembly 2 and is rotatable relative to the stator assembly 2 about its central axis. The rotor assembly 3 has a second through hole 301 extending axially along the housing assembly 1. The output shaft 4 is disposed within the second through hole 301 of the rotor assembly 3 and is fixedly connected to the rotor assembly 3. Both ends of the output shaft 4 are movably connected to the housing assembly 1, and one end of the output shaft 4 has a bushing mounting hole 401 extending axially along the housing assembly 1. The hydraulic bushing 5 is disposed within the bushing mounting hole 401 and is fixedly connected to the output shaft 4. An oil cavity 501 for accommodating hydraulic oil is provided between the outer wall of the hydraulic bushing 5 and the hole wall of the bushing mounting hole 401. The output shaft 4 is provided with an oil pressure regulating component 402 and an oil injection channel 403 connected to the oil cavity 501. The oil pressure regulating component 402 is located in the oil injection channel 403 and blocks the hydraulic oil in the oil cavity 501.

[0053] The housing assembly 1 includes a housing 102, a front cover 103, and a rear cover 104. The front cover 103 and the rear cover 104 are respectively located at both ends of the housing 102. The end of the output shaft 4 with a bushing mounting hole 401 is clearance-fitted with the front cover 103. The other end of the output shaft 4 is provided with a bearing 6. The inner wall of the bearing 6 is connected to the output shaft 4, and the outer wall of the bearing 6 is connected to the rear cover 104. In order to facilitate the movement of the direct drive servo motor with tools during disassembly and assembly, the housing assembly 1 also includes a lifting ring 105, which is fixedly connected to the surface of the housing 102.

[0054] The hydraulic pressure regulating component 402 includes a hydraulic screw 4021 and a piston 4022. The hydraulic screw 4021 and the piston 4022 are arranged sequentially along the oil injection channel 403. The hydraulic screw 4021 is threadedly connected to the oil injection channel 403. A first sealing ring 4023 is provided on the outer wall of the piston 4022, and the first sealing ring 4023 abuts against the channel wall of the oil injection channel 403. A washer 4024 is also provided at the bottom of the root of the hydraulic screw 4021.

[0055] like Figure 5 As shown, the hydraulic bushing 5 includes a sleeve portion 502 and a stop portion 503. The outer diameter of the stop portion 503 is larger than the outer diameter of the sleeve portion 502, and the stop portion 503 is located at the end of the sleeve portion 502. The stop portion 503 is fixedly connected to the end face of the output shaft 4. The surface of the sleeve portion 502 is provided with a groove 504 that surrounds the sleeve portion 502 in the circumferential direction. The space formed by the groove 504 and the hole wall of the bushing mounting hole 401 is configured as an oil cavity 501. A second sealing ring 505 is provided on both sides of the groove 504 that surrounds the surface of the sleeve portion 502 in the circumferential direction.

[0056] To facilitate the installation and positioning of bearing 6, such as Figure 6 As shown, the output shaft 4 has multiple stepped portions 404 on its surface. The rear end cover 104 is also provided with a pressure plate 106 and an adapter plate 107. The pressure plate 106 and the adapter plate 107 are respectively located at the two ends of the rear end cover 104. There is a space between the pressure plate 106 and the adapter plate 107 for accommodating the bearing 6. One side of the pressure plate 106 abuts against the side of one stepped portion 404 of the output shaft 4, and one side of the adapter plate 107 abuts against the side of the other stepped portion 404 of the output shaft 4. The end of the rear end cover 104 is also provided with a rear cover 108. An encoder 7 is installed at the end of the output shaft 4. The encoder 7 is located in the space formed by the end of the rear end cover 104 and the rear cover 108.

[0057] like Figure 7As shown, the front cover 103 is provided with an adjustment hole 1031, an auxiliary hole 1032, a first positioning hole 1033, and a second positioning hole 1034. The adjustment hole 1031 is connected to the oil injection channel 403. The first positioning hole 1033 is located adjacent to the adjustment hole 1031, and the second positioning hole 1034 is located adjacent to the auxiliary hole 1032. The first positioning hole 1033 and the second positioning hole 1034 are perpendicular to each other, and the extension line of the central axis of the first positioning hole 1033 and the extension line of the central axis of the second positioning hole 1034 intersect at the central axis of the output shaft 4. The surface of the output shaft 4 is provided with a first blind hole 405 and a second blind hole 406 that are perpendicular to each other, and the extension line of the central axis of the first blind hole 405 and the extension line of the central axis of the second blind hole 406 intersect at the central axis of the output shaft 4. The first blind hole 405 is connected to the first positioning hole 1033, and the second blind hole 406 is connected to the second positioning hole 1034.

[0058] Both the adjustment hole 1031 and the auxiliary hole 1032 are provided with a sealing bolt 1035 and a first countersunk head 1036. Both the first positioning hole 1033 and the second positioning hole 1034 are provided with a positioning bolt 1037 and a second countersunk head 1038. The depth of the first countersunk head 1036 is less than the depth of the second countersunk head 1038. The length of the head of the sealing bolt 1035 is less than the length of the head of the positioning bolt 1037. The head of the positioning bolt 1037 can be inserted into the first blind hole 405 and the second blind hole 406 respectively.

[0059] The direct-drive servo motor can tighten or loosen the hydraulic bushing 5 by adjusting the pressure of the hydraulic oil in the oil chamber 501, which can conveniently and reliably connect the connecting shaft 9 of the load device 8. Since the connecting shaft 9 is tightened by the elastic deformation of the hydraulic bushing 5, the holding force is large, the connection is stable, and it has high concentricity and precision. During installation, the direct-drive servo motor is placed radially and close to the load device 8. Only a small axial space is needed between the two for axial operation to complete the connection, making the position of the direct-drive servo motor and the load device 8 compact and convenient for disassembly and assembly.

[0060] An embodiment of the present invention also discloses an assembly method for a direct-drive servo motor, the method comprising the following steps:

[0061] The rotor assembly 3 is mounted on the output shaft 4, and the hydraulic bushing 5 is installed in the bushing mounting hole 401 of the output shaft 4. Hydraulic oil is injected into the oil chamber 501 through the oil injection channel 403. The oil pressure regulating component 402 is installed in the oil injection channel 403, so that the hydraulic oil is sealed in the oil chamber 501 and surrounds the outer wall of the hydraulic bushing 5, thereby obtaining... Figure 8 The components shown;

[0062] Heating the outer casing 102 causes it to expand, pressing the stator assembly 2 into it. After the outer casing 102 cools, the stator assembly 2 is sealed with adhesive to obtain the desired result. Figure 9The components shown;

[0063] The output shaft 4, which houses the rotor assembly 3 and the hydraulic bushing 5, is installed in the first through hole 201 of the stator assembly 2. The front end cover 103 and the rear end cover 104 are then installed at both ends of the housing 102, resulting in the following: Figure 10 The direct-drive servo motor shown;

[0064] Refer again Figure 7 One positioning bolt 1037 is installed in the first positioning hole 1033, so that the head of the positioning bolt 1037 is inserted into the first blind hole 405. Another positioning bolt 1037 is installed in the second positioning hole 1034, so that the head of the positioning bolt 1037 is inserted into the second blind hole 406. This aligns the end of the output shaft 4 with the bushing mounting hole 401 with the front cover 103 and fixes the position of the output shaft 4 relative to the front cover 103.

[0065] An embodiment of the present invention also discloses a method for using a direct-drive servo motor, the method comprising the following steps:

[0066] like Figure 11 As shown, the connecting shaft 9 of the load device 8 is inserted into the hydraulic bushing 5 of the direct drive servo motor, so that the front end cover 103 of the direct drive servo motor abuts against the stop portion 10 of the load device 8, as shown. Figure 12 As shown, there is a gap between the inner wall of the hydraulic bushing 5 and the outer wall of the connecting shaft 9 at this time;

[0067] By inserting a tool into the adjusting hole 1031 and rotating the hydraulic pressure adjusting component 402, the hydraulic pressure adjusting component 402 moves towards the oil chamber 501 within the oil injection channel 403, causing the hydraulic oil pressure in the oil chamber 501 to rise. This causes the hydraulic bushing 5 to undergo elastic deformation under force, bulging inward and gripping the connecting shaft 9 of the load device 8. Figure 13 As shown, at this time, the inner wall of the hydraulic bushing 5 undergoes elastic deformation under the pressure of the hydraulic oil, and a part of the inner wall of the hydraulic bushing 5 abuts against the outer wall of the connecting shaft 9.

[0068] like Figure 14 As shown, a sealing bolt 1035 is installed in the first positioning hole 1033, a positioning bolt 1037 is installed in the adjustment hole 1031, another positioning bolt 1037 is installed in the auxiliary hole 1032, and another sealing bolt 1035 is installed in the second positioning hole 1034. At this time, the head of the sealing bolt 1035 and the head of the positioning bolt 1037 are both spaced from the surface of the output shaft 4, so that the output shaft 4 can rotate relative to the front cover 103, and the direct drive servo motor can drive the connecting shaft 9 of the load device 8 to rotate.

[0069] The direct-drive servo motor, assembly method, and usage method of the present invention have the following advantages:

[0070] 8. Directly drives the load device, eliminates transmission backlash, and improves positioning accuracy;

[0071] The connecting shaft 9 can conveniently and reliably connect the load device 8, has a large holding force, stable connection, high concentricity and precision, adopts a hard connection method, keyless connection, eliminates backlash, and reduces the weakening of the connecting shaft 9;

[0072] The small space required for axial operation during installation allows for a compact placement of the direct drive servo motor and load device 8, and facilitates easy assembly and disassembly.

[0073] The output shaft 4 with bushing mounting hole 401 is aligned with the front cover 103 by interlocking two positioning bolts 1037 that are perpendicular to each other. The end of the output shaft 4 with bushing mounting hole 401 is not required to be set between the end of the output shaft 4 with bushing mounting hole 401 and the front cover 103, thereby avoiding over-positioning of the connecting shaft 9 of the load device 8. After the direct drive servo motor and the load device 8 are connected, the bearing 6 at the end of the load device 8 can be used to radially fix the connecting shaft 9 and the direct drive servo motor.

[0074] By swapping the positions of the positioning bolts 1037 and the sealing bolts 1035, the output shaft 4 can be positioned and the limit can be released. This is convenient to operate and easy to disassemble and assemble, while maintaining the original protection level of the direct drive servo motor.

[0075] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention. It should be noted that those skilled in the art can make several improvements and modifications to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A direct drive servo motor, characterized by: The direct-drive servo motor includes: The housing assembly (1) has an inner cavity (101); The stator assembly (2) is located in the inner cavity (101) of the housing assembly (1). The stator assembly (2) is fixedly connected to the housing assembly (1). The stator assembly (2) is provided with a first through hole (201) extending axially along the housing assembly (1). The rotor assembly (3) is located in the first through hole (201) of the stator assembly (2). The rotor assembly (3) is able to rotate relative to the stator assembly (2) with the central axis of the stator assembly (2) as the center. The rotor assembly (3) is provided with a second through hole (301) extending axially along the housing assembly (1). An output shaft (4) is disposed within the second through hole (301) of the rotor assembly (3). The output shaft (4) is fixedly connected to the rotor assembly (3), and both ends of the output shaft (4) are movably connected to the housing assembly (1). One end of the output shaft (4) is provided with a bushing mounting hole (401) extending axially along the housing assembly (1); and, A hydraulic bushing (5) is provided in the bushing mounting hole (401), and the hydraulic bushing (5) is fixedly connected to the output shaft (4); The hydraulic bushing (5) has an oil cavity (501) for accommodating hydraulic oil between its outer wall and the wall of the bushing mounting hole (401). The output shaft (4) has an oil pressure regulating component (402) and an oil injection channel (403) connected to the oil cavity (501). The oil pressure regulating component (402) is located in the oil injection channel (403) and blocks the hydraulic oil in the oil cavity (501). The housing assembly includes a front cover (103), which has an adjustment hole (1031), an auxiliary hole (1032), a first positioning hole (1033), and a second positioning hole (1034). The adjustment hole (1031) communicates with the oil injection channel (403). The first positioning hole (1033) is located adjacent to the adjustment hole (1031), and the second positioning hole (1034) is located adjacent to the auxiliary hole (1032). The first positioning hole (1033) and the second positioning hole (1034) are perpendicular to each other. The extension line of the central axis of the first positioning hole (1033) and the extension line of the central axis of the second positioning hole (1034) intersect the central axis of the output shaft (4). The surface of the output shaft (4) is provided with a first blind hole (405) and a second blind hole (406) that are perpendicular to each other. The extension line of the central axis of the first blind hole (405) and the extension line of the central axis of the second blind hole (406) intersect the central axis of the output shaft (4). The first blind hole (405) is connected to the first positioning hole (1033), and the second blind hole (406) is connected to the second positioning hole (1034). Both the adjustment hole (1031) and the auxiliary hole (1032) are provided with a sealing bolt (1035) and a first countersunk head (1036). Both the first positioning hole (1033) and the second positioning hole (1034) are provided with a positioning bolt (1037) and a second countersunk head (1038). The depth of the first countersunk head (1036) is less than the depth of the second countersunk head (1038). The length of the head of the sealing bolt (1035) is less than the length of the head of the positioning bolt (1037). The head of the positioning bolt (1037) can be inserted into the first blind hole (405) and the second blind hole (406) respectively. In use, the positioning bolt and the sealing bolt are swapped in pairs.

2. The direct drive servo motor of claim 1, wherein: The hydraulic pressure regulating component (402) includes a hydraulic screw (4021) and a piston (4022). The hydraulic screw (4021) and the piston (4022) are arranged sequentially along the oil injection channel (403). The hydraulic screw (4021) and the oil injection channel (403) are connected by threads. The outer wall of the piston (4022) is provided with a first sealing ring (4023), which abuts against the channel wall of the oil injection channel (403).

3. A direct-drive servo motor according to claim 1, characterized in that: The hydraulic bushing (5) includes a sleeve portion (502) and a stop portion (503). The outer diameter of the stop portion (503) is larger than the outer diameter of the sleeve portion (502), and the stop portion (503) is located at the end of the sleeve portion (502). The stop portion (503) is fixedly connected to the end face of the output shaft (4). The surface of the sleeve portion (502) is provided with a groove (504) that surrounds the sleeve portion (502) in the circumferential direction. The space formed by the groove (504) and the hole wall of the bushing mounting hole (401) is configured as the oil cavity (501). A second sealing ring (505) is provided on both sides of the groove (504) that surrounds the surface of the sleeve portion (502) in the circumferential direction.

4. A direct-drive servo motor according to claim 1, characterized in that: The housing assembly (1) includes a housing (102), a front cover (103) and a rear cover (104). The front cover (103) and the rear cover (104) are respectively located at both ends of the housing (102). The end of the output shaft (4) with a bushing mounting hole (401) is clearance-fitted with the front cover (103). The other end of the output shaft (4) is provided with a bearing (6). The inner wall of the bearing (6) is connected to the output shaft (4), and the outer wall of the bearing (6) is connected to the rear cover (104).

5. A direct-drive servo motor according to claim 4, characterized in that: The housing assembly (1) also includes a lifting ring (105) which is fixedly connected to the surface of the housing (102).

6. A method for assembling a direct-drive servo motor as described in claim 1, characterized in that: The method includes the following steps: The rotor assembly (3) is installed on the output shaft (4), the hydraulic bushing (5) is installed in the bushing mounting hole (401) of the output shaft (4), hydraulic oil is injected into the oil chamber (501) through the oil injection channel (403), and the oil pressure regulating component (402) is installed in the oil injection channel (403) so that the hydraulic oil is sealed in the oil chamber (501) and surrounds the outer wall of the hydraulic bushing (5); Heating the outer shell (102) causes it to expand, pressing the stator assembly (2) into the outer shell (102). After the outer shell (102) cools down, the stator assembly (2) is sealed with glue. The output shaft (4) with the rotor assembly (3) and hydraulic bushing (5) is installed in the first through hole (201) of the stator assembly (2), and the front cover (103) and the rear cover (104) are installed at both ends of the housing (102).

7. The assembly method of a direct-drive servo motor according to claim 6, characterized in that: After the front cover (103) and the rear cover (104) are respectively installed on both ends of the housing (102), the method further includes the following steps: Install a positioning bolt (1037) in the first positioning hole (1033) so that the head of the positioning bolt (1037) is inserted into the first blind hole (405). Install another positioning bolt (1037) in the second positioning hole (1034) so ​​that the head of the positioning bolt (1037) is inserted into the second blind hole (406). This will align the end of the output shaft (4) with the bushing mounting hole (401) with the front cover (103) and fix the position of the output shaft (4) relative to the front cover (103).

8. A method of using the direct-drive servo motor as described in claim 1, characterized in that: The method includes the following steps: Insert the connecting shaft (9) of the load device (8) into the hydraulic bushing (5) of the direct drive servo motor, so that the front end cover (103) of the direct drive servo motor abuts against the stop portion (10) of the load device (8). By inserting a tool into the adjustment hole (1031) and rotating the hydraulic pressure adjustment component (402), the hydraulic pressure adjustment component (402) moves in the oil injection channel (403) toward the direction of the oil chamber (501), thereby increasing the pressure of the hydraulic oil in the oil chamber (501), causing the hydraulic bushing (5) to undergo elastic deformation and bulge inward, thus gripping the connecting shaft (9) of the load device (8). A sealing bolt (1035) is installed in the first positioning hole (1033), a positioning bolt (1037) is installed in the adjustment hole (1031), another positioning bolt (1037) is installed in the auxiliary hole (1032), and another sealing bolt (1035) is installed in the second positioning hole (1034). At this time, the heads of the sealing bolt (1035) and the positioning bolt (1037) are spaced from the surface of the output shaft (4), so that the output shaft (4) can rotate relative to the front cover (103), and the direct drive servo motor can drive the connecting shaft (9) of the load device (8) to rotate.

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