Direct drive motor

Abstract

The utility model is suitable for the technical field of motors, and provides a direct drive motor which comprises a stator assembly, a rotor assembly and a time grating encoder. The rotor assembly has the freedom degree of rotating around the axis of the rotor assembly relative to the stator assembly. The time grating encoder comprises a fixed part and a moving part and is used for detecting the rotation angle of the rotor assembly through induction between the fixed part and the moving part, the fixed part is connected to the stator assembly, and the moving part is connected to the rotor assembly and can rotate along with the rotor assembly. Compared with the prior art in which a grating encoder is adopted to detect the rotation angle, the time grating encoder is adopted to detect the rotation angle of the rotor assembly, and the time grating encoder still works normally after being interfered by pollutants, so that the measurement of the rotation angle of the rotor assembly is always kept accurate, and the measurement accuracy is improved. And the working stability of the whole direct-drive motor is improved.

Description

Technical Field

[0001] The utility model belongs to the technical field of motors, and in particular relates to a direct-drive motor. Background Art

[0002] In order to accurately control the rotation angle of the rotor, the existing direct drive motor usually needs to be equipped with a grating encoder. However, the direct drive motor uses a grating encoder to detect the rotation angle of the rotor. After long-term use, the grating encoder is prone to measurement errors due to interference from pollutants such as oil and dust, which will affect the stability of the motor. Utility Model Content

[0003] The utility model aims to provide a direct drive motor, aiming to solve the technical problem in the prior art that the direct drive motor using a grating encoder is easily disturbed by pollutants and affects the stability of the motor.

[0004] The utility model is implemented as follows: a direct drive motor comprises:

[0005] stator assembly;

[0006] A rotor assembly having the freedom to rotate about its own axis relative to the stator assembly; and

[0007] The time-grid encoder comprises a fixed part and a moving part, wherein the fixed part is connected to the stator assembly, and the moving part is connected to the rotor assembly. Electromagnetic induction exists between the moving part and the fixed part, and the rotation angle of the rotor assembly can be detected by the electromagnetic induction.

[0008] In an optional embodiment, the stator assembly includes a main cylinder, and the two ends of the main cylinder are respectively covered with a first end cover and a second end cover, the rotor assembly is located in the main cylinder, and the rotor assembly is rotatably connected to the first end cover and the second end cover.

[0009] In an optional embodiment, the fixed portion is fixed to the first end cover or the second end cover, and the fixed portion and the moving portion are spaced apart from each other in a direction along the axis of the rotor assembly.

[0010] In an optional embodiment, a protective structure is provided on the end cover provided with the fixing part, and the protective structure is used to accommodate the fixing part and the moving part.

[0011] In an optional embodiment, the protective structure includes a accommodating groove and a protective cover, the accommodating groove is arranged on a surface of the corresponding end cover that is away from the other end cover, the corresponding end cover is an end cover provided with the fixed part, the fixed part and the moving part are both located in the accommodating groove, and the protective cover is arranged at the opening of the accommodating groove.

[0012] In an optional embodiment, a supporting structure is provided on the side wall of the accommodating groove, the fixing portion is fixed in the accommodating groove through the supporting structure and is spaced apart from the bottom surface of the accommodating groove, and the moving portion is located between the bottom surface and the fixing portion.

[0013] In an optional embodiment, the support structure includes a step surface arranged on a side wall of the accommodating groove, and the step surface is arranged around the accommodating groove.

[0014] In an optional embodiment, a first bearing is arranged between the rotor assembly and the first end cover, a second bearing is arranged between the rotor assembly and the second end cover, and the first bearing and the second bearing are coaxial and spaced apart.

[0015] In an optional embodiment, the first end cover is provided with a first mounting groove for accommodating and fixing the first bearing, and the first end cover is also provided with a bearing stopper, and the bearing stopper is used to prevent the first bearing from escaping from the first mounting groove.

[0016] In an optional embodiment, the first bearing is a cross roller bearing, and the second bearing is a deep groove ball bearing.

[0017] The technical effect of the utility model relative to the prior art is: a time grating encoder is arranged between the stator assembly and the rotor assembly, wherein the fixed part of the time grating encoder is connected to the stator assembly, and the moving part is connected to the rotor assembly. When the rotor assembly rotates relative to the stator assembly, the rotation angle of the stator assembly can be detected through the inductive relationship between the fixed part and the moving part. Compared with the method of using a grating encoder to detect the rotation angle in the prior art, the time grating encoder is used to detect the rotation angle of the rotor assembly. After the time grating encoder is disturbed by contaminants, it still works normally, ensuring that the measurement of the rotation angle of the rotor assembly is always accurate, thereby improving the working stability of the entire direct drive motor. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the embodiments of the utility model or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 It is a structural schematic diagram of a direct drive motor provided by an embodiment of the utility model;

[0020] Figure 2It is a schematic diagram of the exploded structure of the direct drive motor provided by the embodiment of the utility model;

[0021] Figure 3 It is a cross-sectional structural schematic diagram of a direct drive motor provided by an embodiment of the utility model;

[0022] Figure 4 yes Figure 3 A schematic diagram of the enlarged structure at A in the middle;

[0023] Figure 5 It is a schematic diagram of the first end cover used in the embodiment of the utility model.

[0024] Description of reference numerals:

[0025] 1. Stator assembly; 11. Main cylinder; 12. First end cover; 13. Second end cover; 14. Coil assembly; 15. First mounting slot; 16. Second mounting slot; 2. Rotor assembly; 21. Rotating shaft; 22. Magnet assembly; 3. Time grid encoder; 31. Fixed part; 32. Moving part; 4. First bearing; 5. Second bearing; 6. Bearing stopper; 7. Protective structure; 71. Accommodating groove; 72. Protective cover; 8. Support structure; 81. Step surface; 9. Locking ring. DETAILED DESCRIPTION

[0026] The embodiments of the present invention are described in detail below, and examples of the embodiments 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.

[0027] In the description of the present invention, it should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship 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 cannot be understood as a limitation on the present invention.

[0028] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include one or more of the features. In the description of the present utility model, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0029] In the present invention, unless otherwise clearly specified and limited, the terms "install", "connect", "connect", "fix" 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 or an electrical connection; 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.

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0031] Please refer to Figures 1 to 5 As shown, in an embodiment of the utility model, a direct drive motor is provided, and the direct drive motor includes a stator assembly 1, a rotor assembly 2, and a time grating encoder 3. The rotor assembly 2 has the freedom to rotate around its own axis relative to the stator assembly 1. The time grating encoder 3 includes a fixed portion 31 and a moving portion 32, the fixed portion 31 is connected to the stator assembly 1, the moving portion 32 is connected to the rotor assembly 2, and can rotate with the rotor assembly 2, there is electromagnetic induction between the moving portion 32 and the fixed portion 31, and the rotation angle of the rotor assembly 2 can be detected by electromagnetic induction.

[0032] Specifically, the stator assembly 1 refers to the fixed part of the motor, and the rotor assembly 2 refers to the rotatable part of the motor; the rotor assembly 2 has the freedom to rotate around its own axis relative to the stator assembly 1, and can rotate under the action of electric energy and magnetic field to output torque. The rotor assembly 2 can be located outside the entire motor or inside the stator assembly 1, which can be freely selected according to the situation.

[0033] The time grid encoder 3 refers to a displacement encoder established based on the principle of space coordinate conversion (measuring space with time). The fixed part 31 and the moving part 32 in the time grid encoder 3 can be induced by a magnetic field or an electric field, and the clock pulse is used as a displacement measurement reference. During measurement, the clock pulses can be accumulated and counted to finally achieve the measurement of displacement. Among them, the shape of the fixed part 31 can be disc-shaped, block-shaped or ring-shaped, and the shape of the moving part 32 can also be disc-shaped, block-shaped or ring-shaped, and the shapes of the fixed part 31 and the moving part 32 can be kept matched to ensure that the two have the maximum facing area.

[0034] The direct-drive motor provided by the embodiment of the utility model is provided with a time grating encoder 3 between the stator assembly 1 and the rotor assembly 2, wherein the fixed portion 31 of the time grating encoder 3 is connected to the stator assembly 1, the moving portion 32 is connected to the rotor assembly 2, and the moving portion 32 can rotate with the rotor assembly 2. When the rotor assembly 2 rotates relative to the stator assembly 1, the rotation angle of the stator assembly 1 can be detected through the induction relationship between the fixed portion 31 and the moving portion 32. Compared with the method of using a grating encoder to detect the rotation angle in the prior art, the time grating encoder 3 is used to detect the rotation angle of the rotor assembly 2. After the time grating encoder 3 is disturbed by contaminants, it can still work normally, so that the measurement of the rotation angle of the rotor assembly 2 remains accurate, and the working stability of the entire direct-drive motor is improved. In addition, the use of the time grating encoder 3 also has the advantages of easy installation and reduced maintenance frequency of the direct-drive motor.

[0035] In one embodiment, see Figure 2 and Figure 3 The stator assembly 1 includes a main cylinder 11, and the two ends of the main cylinder 11 are respectively covered with a first end cover 12 and a second end cover 13. The rotor assembly 2 is located in the main cylinder 11, and the rotor assembly 2 is rotatably connected to the first end cover 12 and the second end cover 13. Specifically, the main cylinder 11 refers to a cylindrical component with a certain internal space. The first end cover 12 and the second end cover 13 both refer to components with a certain area, and the first end cover 12 and the second end cover 13 can be plate-shaped, disc-shaped or block-shaped. The first end cover 12 and the second end cover 13 are sealed at the openings at both ends of the main cylinder 11. The rotor assembly 2 is located in the main cylinder 11, and in order to ensure the stability of the rotation of the rotor assembly 2, the axis of the rotor assembly 2 can be parallel to or overlap the axis of the main cylinder 11. The rotor assembly 2 is rotatably connected to the first end cover 12 and the second end cover 13, so that the rotor assembly 2 can be installed in the main cylinder 11 under the support of the first end cover 12 and the second end cover 13, and can also rotate relative to the first end cover 12 and the second end cover 13, so that the assembly of the entire stator assembly 1 is more convenient, and the installation and fixation of the rotor assembly 2 is also more convenient.

[0036] In addition, the rotor assembly 2 can be arranged to penetrate the first end cover 12 and / or the second end cover 13, so that at least a portion of the rotor assembly 2 can extend to the outside of the stator assembly 1 after penetrating the first end cover 12 or the second end cover 13, thereby facilitating the connection between the end of the rotor assembly 2 and the external load.

[0037] It should be noted that if Figure 2As shown, a coil assembly 14 may be provided on the inner wall of the main cylinder 11, and the coil assembly 14 may be electrically connected to an external power supply. The rotor assembly 2 may include a rotating shaft 21 and a magnet assembly 22 disposed outside the rotating shaft 21. The magnet assembly 22 may be composed of a plurality of magnets surrounding the rotating shaft 21, and may adopt an 18-slot 20-level (magnet). After the coil assembly 14 is energized, the coil assembly 14 may interact with the magnet assembly 22 on the rotor assembly 2, and drive the rotor assembly 2 to rotate according to the principle of electromagnetic induction, so as to achieve the purpose of outputting torque, making the use of the direct drive motor more convenient.

[0038] Among them, the interior of the rotating shaft 21 can be a hollow structure, which can reduce the weight of the entire rotating shaft 21 on the one hand, making the direct-drive motor lighter as a whole; on the other hand, the connecting shaft of the load can be inserted into the rotating shaft 21, so as to realize the connection between the load and the rotating shaft 21, making the connection between the direct-drive motor and the load more convenient, and can also reduce the space occupied when the direct-drive motor is connected to the load connecting shaft.

[0039] In one embodiment, see Figure 3 The fixed portion 31 is fixed to the first end cover 12 or the second end cover 13, and the fixed portion 31 and the moving portion 32 are spaced apart from each other in the direction along the axis of the rotor assembly 2. Specifically, the fixed portion 31 can be fixed to the first end cover 12 by means of pasting, welding or fasteners. The moving portion 32 can also be fixed to the rotor assembly 2 by means of pasting, welding or fasteners. And the moving portion 32 is arranged in the area of ​​the rotor assembly 2 close to the first end cover 12, and is spaced apart from the fixed portion 31 in the direction along the axis of the rotor assembly 2, so that the moving portion 32 can still maintain mutual induction with the fixed portion 31 when the rotor assembly 2 rotates, making the use and installation of the entire time grid encoder 3 more convenient.

[0040] In an alternative embodiment, see Figure 2 The fixed part 31 and the moving part 32 are both disc-shaped, which can further save the space occupied by the entire time grid encoder 3. In addition, the fixed part 31 and the moving part 32 are both provided with avoidance holes for avoiding the rotating shaft 21 of the rotor assembly 2, so that the rotating shaft 21 of the rotor assembly 2 can conveniently pass through the fixed part 31 and the moving part 32 through the avoidance holes.

[0041] In addition, the fixed portion 31 and the moving portion 32 may be arranged parallel to each other to ensure that the distance between the fixed portion 31 and the moving portion 32 is always kept consistent, thereby ensuring the detection stability of the time grid encoder 3 .

[0042] In one embodiment, see Figure 2 and Figure 3, the end cap provided with the fixed portion is also provided with a protective structure 7, the protective structure 7 is used to accommodate the fixed portion 31 and the moving portion 32, specifically, the protective structure 7 refers to a structure with a certain internal space, and the protective structure 7 can be a groove, a cavity, etc. provided on the end cap. When the fixed portion 31 is provided on the first end cap 12, the protective structure 7 is provided on the first end cap 12, and when the fixed portion 31 is provided on the second end cap 13, the protective structure 7 is provided on the second end cap 13. In the following, the protective structure 7 is provided on the first end cap 12 as an example, at least part of the rotor assembly 2 passes through the first end cap 12 and extends to the inside of the protective structure 7, when the time grid encoder 3 is installed, the fixed portion 31 can be provided in the protective structure 7, wherein the fixed portion 31 is connected to the first end cap 12 to keep its position fixed, and the moving portion 32 can be connected to the part of the rotor assembly 2 located in the protective structure 7, so that the moving portion 32 can rotate with the rotor assembly 2 while being located in the protective structure 7. In addition, the protective structure 7 located on the second end cover 13 is the same as that arranged on the first end cover 12, and will not be described in detail here.

[0043] By arranging both the fixed part 31 and the moving part 32 in the protective structure 7, the fixed part 31 and the moving part 32 are protected, thereby extending the service life of the entire time-grid encoder 3. At the same time, by arranging the time-grid encoder 3 in the protective structure 7, the installation of the time-grid encoder 3 can be more space-saving, thereby making the overall volume of the direct-drive motor more compact.

[0044] In one embodiment, see Figure 5 , the protective structure 7 includes a receiving groove 71 and a protective cover 72. The receiving groove 71 is arranged on the side of the corresponding end cover away from the other end cover. The corresponding end cover is an end cover provided with a fixed portion 31. The fixed portion 31 and the moving portion 32 are both located in the receiving groove 71. The protective cover 72 is provided at the opening of the receiving groove 71. Specifically, the receiving groove 71 refers to a groove structure recessed on the end cover. The receiving groove 71 can be formed on the end cover by die casting, machining or casting. Taking the receiving groove arranged on the first end cover 12 as an example, one end of the rotor assembly 2 can extend into the receiving groove 71 after passing through the first end cover 12, and a protective cover 72 is provided at the opening of the receiving groove 71. The opening of the receiving groove 71 can be sealed after the time grid encoder 3 is installed to ensure the stability of the time grid encoder 3. The protective structure 7 adopts the receiving groove 71, which can make the processing and manufacturing of the protective structure 7 more convenient. At the same time, the overall structure of the first end cover 12 can also be made simpler. At the same time, the protective cover 72 covers the opening of the accommodating groove 71 to form a relatively closed area, which can also play a role in isolating external pollutants such as oil and dust, making the use of the time grid encoder 3 more stable.

[0045] In addition, a relief hole may also be provided on the protective cover 72, and the rotating shaft 21 of the rotor assembly 2 may extend through the relief hole on the protective cover 72, so that the connection between the rotor assembly 2 and the load is more convenient.

[0046] In one embodiment, see Figure 4 A support structure 8 is provided on the side wall of the receiving groove 71, and the fixing portion 31 is fixed in the receiving groove 71 through the support structure 8, and the fixing portion 31 is spaced apart from the bottom surface of the receiving groove 71; the moving portion 32 is located between the bottom surface and the fixing portion 31. Specifically, the support structure 8 refers to a structure that can support an object, wherein the support structure 8 can be a step surface, a protrusion or a groove structure, etc., provided on the side wall of the receiving groove 71. The setting of the support structure 8 can support and fix the fixing portion 31, so that the time grid encoder 3 is fixed at a position spaced apart from the bottom surface of the receiving groove 71, and at the same time, the installation of the time grid encoder 3 can be made more convenient and stable.

[0047] In one embodiment, see Figure 5 The support structure 8 includes a step surface 81 arranged on the side wall of the accommodating groove 71, and the step surface 81 is arranged around the accommodating groove 71. Specifically, the step surface 81 refers to a planar structure with a certain height difference from the bottom surface of the accommodating groove 71, wherein the step surface 81 is generally parallel to the bottom surface of the accommodating groove 71. When the fixing part 31 is installed, the side surface of the fixing part 31 can be abutted against the step surface 81, and the fixing part 31 is supported by the step surface 81, so as to keep the fixing part 31 connected to the first end cover 12. At the same time, the step surface 81 is arranged around the accommodating groove 71 to form an annular structure, which can support the fixing part 31 along the circumferential direction of the fixing part 31, so that the fixing part 31 can be installed more stably, and the deformation of the fixing part 31 itself can be avoided to a certain extent.

[0048] In an optional embodiment, if Figure 4 As shown, the fixing portion 31 can be fixed to the step surface 81 by a fastener. A threaded hole is provided on the step surface 81. The fastener penetrates the fixing portion 31 and is inserted into the threaded hole, thereby achieving the purpose of pressing and fixing the fixing portion 31 on the step surface 81.

[0049] In one embodiment, see Figure 3, a first bearing 4 is arranged between the rotor assembly 2 and the first end cover 12, a second bearing 5 is arranged between the rotor assembly 2 and the second end cover 13, and the first bearing 4 and the second bearing 5 are coaxial and spaced apart. Specifically, the first bearing 4 and the second bearing 5 both refer to components that support the mechanical rotating body and reduce the friction coefficient during its movement. Among them, the inner ring of the first bearing 4 can be mounted on the rotor assembly 2, and the outer ring of the first bearing 4 can be connected to the first end cover 12, so that the rotor assembly 2 can be rotated relative to the first end cover 12 while providing support for the rotor assembly 2. Similarly, the inner ring of the second bearing 5 can be mounted on the rotor assembly 2, and the outer ring of the second bearing 5 can be connected to the second end cover 13, so that the rotor assembly 2 can be rotated relative to the second end cover 13 while providing support for the rotor assembly 2. The arrangement of the first bearing 4 and the second bearing 5 can make the installation of the rotor assembly 2 more stable, and also make the rotation of the rotor assembly 2 more convenient.

[0050] In one embodiment, see Figure 4 The first end cover 12 is provided with a first mounting groove 15 for accommodating and fixing the first bearing 4, and the first end cover 12 is also provided with a bearing stopper 6, which is used to prevent the first bearing 4 from coming out of the first mounting groove 15. The first mounting groove 15 refers to a groove structure with a certain depth. When the first bearing 4 is installed, the first bearing 4 can be installed in the first mounting groove 15, and the outer ring of the first bearing 4 is abutted against the inner wall of the first mounting groove 15. The limiting effect of the first mounting groove 15 can make the installation of the first bearing 4 more stable. At the same time, the first end cover 12 is also provided with a bearing stopper 6. After the first bearing 4 is installed in the first mounting groove 15, the bearing stopper 6 can be pressed against the outer ring of the first bearing 4, which can prevent the first bearing 4 from coming out of the first mounting groove 15, thereby further enhancing the stability of the first bearing 4 installed in the first mounting groove 15.

[0051] In addition, a limiting boss is also provided on the rotating shaft 21 of the rotor assembly 2, and after the first bearing 4 is mounted on the rotating shaft 21, the limiting boss can abut against the inner ring of the first bearing 4. At the same time, a locking ring 9 is also mounted on the rotating shaft 21, and can abut against the other side of the inner ring of the first bearing 4 after the first bearing 4 is installed. The limiting boss and the locking ring 9 can limit the first bearing 4 outside the rotating shaft 21 through the joint action, so that the inner ring of the first bearing 4 and the rotating shaft 21 are more firmly connected.

[0052] In an optional embodiment, if Figure 2 and Figure 3As shown, a second mounting groove 16 for accommodating the second bearing 5 is also provided on the second end cover 13, and the first mounting groove 15 is arranged opposite to the second mounting groove 16. Specifically, the second mounting groove 16 refers to a groove structure with a certain depth. When the second bearing 5 is installed, the second bearing 5 can be placed in the second mounting groove 16, and the installation of the second bearing 5 is more stable through the limiting effect of the side wall of the second mounting groove 16. At the same time, the first mounting groove 15 and the second mounting groove 16 are arranged opposite to each other, which means that the opening directions of the first mounting groove 15 and the second mounting groove 16 are opposite to each other. In this way, after the rotor assembly 2 is installed through the first bearing 4 and the second bearing 5, the bottom surface of the first mounting groove 15 and the bottom surface of the second mounting groove 16 can be used to apply opposite forces to the rotor assembly 2 respectively, so as to prevent the rotating shaft 21 from moving along its own axial direction, so as to make the installation of the rotor assembly 2 more stable.

[0053] In one embodiment, see Figure 3 , the first bearing 4 is a cross roller bearing, and the second bearing 5 is a deep groove ball bearing. Specifically, the cross roller bearing is also called a cross roller bearing, which is mainly composed of an outer ring, an inner ring, a plurality of rollers and a plurality of spacers. The rollers are located between the inner ring and the outer ring, and are arranged in a staggered manner at a 90-degree angle. This structure allows the bearing to withstand loads from different directions. The rollers are separated from each other by spacers to prevent the rollers from rubbing against each other, thereby preventing the increase of rotational torque. At the same time, the surface of the rollers and the rolling track are in line contact, so that when the bearing is loaded, it can have a larger load-bearing area, reducing the amount of elastic deformation, thereby extending the service life of the bearing. Deep groove ball bearing refers to a rolling bearing structure, and its working principle is that grooves are provided on the inner ring and outer ring of the bearing, and the balls roll in the grooves to achieve relative rotation between the inner ring and the outer ring. By using a cross roller bearing and a deep groove ball bearing, the rotor assembly 2 can rotate while being able to withstand loads from different directions, so that the rotor assembly 2 always remains stable during the rotation process, reducing the vibration of the motor itself and improving the overall rigidity of the motor.

[0054] The above description is only a preferred embodiment of the utility model, and only specifically describes the technical principle of the utility model. These descriptions are only for explaining the principle of the utility model and cannot be interpreted as limiting the protection scope of the utility model in any way. Based on the explanation here, any modification, equivalent replacement and improvement made within the spirit and principle of the utility model, and other specific implementation methods of the utility model that can be associated with the technicians in this field without creative labor, should be included in the protection scope of the utility model.

Claims

1. A direct drive motor, characterized in that: include: stator assembly; A rotor assembly having a degree of freedom to rotate about its own axis relative to the stator assembly; as well as The time-grid encoder comprises a fixed part and a moving part, wherein the fixed part is connected to the stator assembly, and the moving part is connected to the rotor assembly. Electromagnetic induction exists between the moving part and the fixed part, and the rotation angle of the rotor assembly can be detected by the electromagnetic induction.

2. The direct drive motor according to claim 1, characterized in that: The stator assembly comprises a main cylinder, and two ends of the main cylinder are respectively covered with a first end cover and a second end cover. The rotor assembly is located in the main cylinder, and the rotor assembly is rotatably connected to the first end cover and the second end cover.

3. The direct drive motor according to claim 2, characterized in that: The fixed portion is fixed on the first end cover or the second end cover, and the fixed portion and the moving portion are spaced apart from each other in a direction along the axis of the rotor assembly.

4. The direct drive motor according to claim 3, characterized in that: A protective structure is arranged on the end cover provided with the fixing part, and the protective structure is used to accommodate the fixing part and the moving part.

5. The direct drive motor according to claim 4, characterized in that: The protective structure includes a accommodating groove and a protective cover. The accommodating groove is arranged on a side of the corresponding end cover that is away from the other end cover. The corresponding end cover is an end cover provided with the fixing part. The fixing part and the moving part are both located in the accommodating groove. The protective cover is arranged at the opening of the accommodating groove.

6. The direct drive motor according to claim 5, characterized in that: A supporting structure is arranged on the side wall of the accommodating groove, the fixing part is fixed in the accommodating groove through the supporting structure and is spaced apart from the bottom surface of the accommodating groove, and the moving part is located between the bottom surface and the fixing part.

7. The direct drive motor according to claim 6, characterized in that: The support structure includes a step surface arranged on a side wall of the accommodating groove, and the step surface is arranged around the accommodating groove.

8. The direct drive motor according to any one of claims 2 to 7, characterized in that: A first bearing is arranged between the rotor assembly and the first end cover, a second bearing is arranged between the rotor assembly and the second end cover, and the first bearing and the second bearing are coaxial and spaced apart.

9. The direct drive motor according to claim 8, characterized in that: The first end cover is provided with a first mounting groove for accommodating and fixing the first bearing, and the first end cover is also provided with a bearing stopper, and the bearing stopper is used to prevent the first bearing from escaping from the first mounting groove.

10. The direct drive motor according to claim 9, characterized in that: The first bearing is a cross roller bearing, and the second bearing is a deep groove ball bearing.

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