Motor and servo control system having the same

Abstract

The present invention discloses a motor and a servo control system having the same. The motor comprises: an encoder, the encoder comprises: an encoder stator and an encoder rotor, the encoder rotor is rotatable relative to the encoder stator; an end cover, the end cover has a rotor cavity, and the encoder rotor is at least partially located in the rotor cavity. According to the motor of the present invention, by arranging a rotor cavity for installing the encoder rotor in the end cover, the length of the position where the encoder is located can be significantly shortened, thereby shortening the total length of the motor.

Description

Technical Field

[0001] The present invention relates to the technical field of motors, and in particular to a motor and a servo control system having the same. Background Art

[0002] The encoder is usually installed inside the motor to measure the angular displacement of the motor rotor. The traditional encoder is fastened to the end cover by screws, and the end cover is provided with a boss for positioning the encoder, and then the encoder installation structure is covered with a back cover to achieve mechanical protection and IP protection. The encoder installation is positioned by the boss and screwed, and the back cover only plays a protective role. And for the motor as a whole, the entire encoder structure is very long and cannot meet the compact requirements, making the motor less competitive in the application market. 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 a motor that can significantly shorten the length of the motor.

[0004] The invention also provides a servo control system having the motor.

[0005] The motor according to the embodiment of the present invention comprises: an encoder, the encoder comprising: an encoder stator and an encoder rotor, the encoder rotor being rotatable relative to the encoder stator; an end cover, the end cover having a rotor cavity, the encoder rotor being at least partially located in the rotor cavity.

[0006] According to the motor of the embodiment of the present invention, by providing a rotor cavity for installing the encoder rotor in the end cover, the length of the position where the encoder is located can be significantly shortened, thereby shortening the overall length of the motor.

[0007] According to some embodiments of the present invention, the motor further comprises: a motor housing, a motor rotor and a motor stator, the motor rotor passes through the end cover and is fixedly connected to the encoder rotor, and the motor stator is fixed to the motor housing.

[0008] Specifically, the end cover includes: an end cover body, a first protrusion of the end cover, and a second protrusion of the end cover. The first protrusion of the end cover is arranged at the first end of the end cover body, and the rotor cavity extends from the first protrusion of the end cover into the end cover body. The second protrusion of the end cover is arranged at the second end of the end cover body, and the second protrusion of the end cover extends into the central area surrounded by the stator of the motor.

[0009] Furthermore, the length of the second protrusion of the end cover extending into the central area surrounded by the motor stator is not less than half of the length of the second protrusion of the end cover itself.

[0010] Optionally, a potting compound for fixing the motor stator to the motor housing is provided at one end of the motor stator facing the end cover, and the second protrusion of the end cover extends into a central area surrounded by the potting compound.

[0011] According to some embodiments of the present invention, a bearing cavity extending into the end cover body is provided at the second protrusion of the end cover, a bearing is provided in the bearing cavity, an inner ring of the bearing is relatively fixed to the motor rotor, an outer ring of the bearing is relatively fixed to the cavity wall of the bearing cavity, and the inner ring and outer ring of the bearing can rotate relatively.

[0012] Furthermore, a stop positioning wall is provided between the bearing cavity and the rotor cavity, and a mounting through hole for connecting the motor rotor and the encoder rotor is provided on the stop positioning wall.

[0013] According to some embodiments of the present invention, the motor further includes: a back cover, the back cover is suitable for being fixedly connected to the end cover, and a receiving cavity is formed between the back cover and the end cover, the back cover has a limiting structure, and the encoder stator is fixed in the receiving cavity by the limiting structure.

[0014] Specifically, the encoder stator has a stator flange, and the limiting structure includes: an axial positioning surface of a rear cover and a radial positioning surface of a rear cover located in the accommodating cavity, the axial positioning surface of the rear cover is suitable for at least partially fitting with the end surface of the stator flange facing away from the end cover, the radial positioning surface of the rear cover is suitable for at least partially fitting with the outer peripheral surface of the stator flange, the radial positioning surface of the rear cover is also suitable for at least partially fitting with the outer peripheral surface of the first protrusion of the end cover, and the stator flange is at least partially fitted with the end surface of the first protrusion of the end cover.

[0015] Furthermore, a first sealing groove is provided on the outer peripheral surface of the first protrusion of the end cover, a first sealing ring is provided in the first sealing groove, and the first sealing ring is suitable for fitting with the radial positioning surface of the rear cover and the first protrusion of the end cover.

[0016] According to some embodiments of the present invention, the rear cover radial positioning surface includes: a stator positioning segment and an end cover positioning segment, and the end cover positioning segment is at least partially constructed as an elastic positioning segment made of an elastic material.

[0017] According to some embodiments of the present invention, a third protrusion of the end cover is arranged between the second protrusion of the end cover and the end cover body, the outer diameter of the third protrusion of the end cover is larger than the outer diameter of the second protrusion of the end cover, and a second sealing groove is opened on the outer circumferential surface of the third protrusion of the end cover, a second sealing ring is arranged in the second sealing groove, and the second sealing ring is suitable for fitting with the inner circumferential surface of the motor housing and the second protrusion of the end cover.

[0018] A servo control system according to another embodiment of the present invention includes the above-mentioned motor.

[0019] The advantages of the servo control system and the above-mentioned motor over the prior art are the same, which will not be described in detail here.

[0020] 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

[0021] Figure 1 It is a cross-sectional assembly diagram of the motor;

[0022] Figure 2 yes Figure 1 A local enlarged schematic diagram of the middle A;

[0023] Figure 3 It is a cross-sectional exploded schematic diagram of the motor;

[0024] Figure 4 It is an exploded schematic diagram of the motor;

[0025] Figure 5 is a three-dimensional schematic diagram of the encoder;

[0026] Figure 6 is a cross-sectional view of the encoder;

[0027] Figure 7 It is a first-person perspective stereoscopic diagram of the back cover;

[0028] Figure 8 It is a second-view stereoscopic diagram of the back cover;

[0029] Fig. 9 is a cross-sectional view of the rear cover;

[0030] Fig.10 is a three-dimensional schematic diagram of the end cap;

[0031] Fig.11 is a cross-sectional view of the end cover of the first embodiment;

[0032] Fig.12 is a cross-sectional assembly schematic diagram of a motor according to another embodiment;

[0033] Fig.13 yes Fig.12 A partial enlarged schematic diagram of point B in the middle;

[0034] Fig.14 is a cross-sectional view of the end cover of the second embodiment;

[0035] Fig.15 is a cross-sectional view of an end cap of a third embodiment; Fig.16is a cross-sectional view of the end cover of the fourth embodiment.

[0036] Reference numerals:

[0037] Motor 10, encoder 1, encoder stator 11, stator flange 111, stator body 112, encoder rotor 12, rotor screw 121, end cover 2, end cover first protrusion 21, end cover body 22, plug hole 221, mounting through hole 23, end cover second protrusion 24, rotor cavity 25, bearing cavity 26, stop positioning wall 27, end cover third protrusion 28, rear cover 3, limiting structure 31, rear cover axial positioning surface 311, rear cover radial positioning surface 312, rear cover top plate 32, rear cover side panel 33, top plate hole 34, recessed portion 35, outlet hole 36, elastic positioning section 37, accommodating cavity 4, first sealing groove 5, second sealing groove 51, first sealing ring 6, second sealing ring 61, fastening screw 7, threaded section 71, screw head 72, adapter screw 8, motor rotor 9, motor stator 91, motor housing 92, potting glue 93. DETAILED DESCRIPTION

[0038] 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.

[0039] 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.

[0040] 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 invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0041] 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.

[0042] Combine the following Figure 1-Figure 16 The motor 10 according to the embodiment of the present invention will be described in detail.

[0043] Reference Figure 1-Figure 4 , Figure 12-13 As shown, the motor 10 according to the embodiment of the present invention may include: an encoder 1 and an end cover 2. Figure 5-Figure 6 As shown, the encoder 1 includes: an encoder stator 11 and an encoder rotor 12 . The encoder rotor 12 is rotatable relative to the encoder stator 11 . The end cover 2 has a rotor cavity 25 . The encoder rotor 12 is at least partially located in the rotor cavity 25 .

[0044] In the axial direction, the encoder stator 11 and the encoder rotor 12 can be arranged separately, and the encoder rotor 12 is completely located in the rotor cavity 25. Figure 1-Figure 2 , Figure 12-13 shown.

[0045] In other embodiments not shown, a portion of the encoder rotor 12 may be located inside the encoder stator 11 , and another portion of the encoder rotor 12 may be located inside the rotor cavity 25 .

[0046] According to the motor 10 of the embodiment of the present invention, by providing a rotor cavity 25 for installing the encoder rotor 12 in the end cover 2, the total length of the encoder 1 and the end cover 2 can be significantly shortened, thereby shortening the length of the position where the encoder 1 is located, and further shortening the total length of the motor 10.

[0047] Reference Figure 1-Figure 4 , Figure 12-13As shown, the motor 10 further includes: a motor housing 92, a motor rotor 9 and a motor stator 91. The motor rotor 9 is provided with an end cover 2, and the motor rotor 9 is fixedly connected with the encoder rotor 12. In some embodiments, a through hole may be provided on the encoder rotor 12, and a threaded connection hole may be provided on the motor rotor 9. After the rotor screw 121 is provided through the through hole, it is screwed with the threaded connection hole on the motor rotor 9, thereby realizing the fixed connection between the encoder rotor 12 and the motor rotor 9. In this way, when the motor rotor 9 rotates, the encoder rotor 12 rotates synchronously with the motor rotor 9, and the encoder rotor 12 moves relative to the encoder stator 11. The rotation parameters of the motor rotor 9 can be known by detecting the rotation parameters of the encoder rotor 12. The rotation parameters may be angular displacement, rotation speed, etc.

[0048] The motor stator 91 is suitable for fixing with the motor housing 92. Figure 1-Figure 3 , Figure 12-13 As shown, the end of the motor stator 91 facing the end cover 2 is provided with a potting glue 93 for fixing the motor stator 91 and the motor housing 92. The potting glue 93 can further strengthen the fixing effect of the motor stator 91 and the motor housing 92. That is to say, in addition to using the potting glue 93 to fix the motor stator 91 and the motor housing 92, other fixing methods can also be used to achieve fixation, or the potting glue 93 can be used in combination with other methods to achieve fixation. In addition, the potting glue 93 is often made of resin material, which can also improve the heat dissipation performance of the motor 10.

[0049] Reference Figure 7-Figure 9 As shown, the end cover 2 may include: an end cover body 22, a first end cover protrusion 21, and an end cover second protrusion 24. The first end cover protrusion 21 is disposed at a first end of the end cover body 22, and the first end cover protrusion 21 protrudes from a first end surface of the end cover body 22. The rotor cavity 25 extends from the first end cover protrusion 21 into the end cover body 22. The second end cover protrusion 24 is disposed at a second end of the end cover body 22, and the second end cover protrusion 24 protrudes from a second end surface of the end cover body 22. Figure 1-Figure 3 , Figure 12-13 As shown, the second protrusion 24 of the end cover extends into the central area surrounded by the motor stator 91. In other words, the central area surrounded by the motor stator 91 is an annular space, and the second protrusion 24 of the end cover extends into the annular space, thereby shortening the distance between the end cover 2 and the motor stator 91, thereby further shortening the axial length of the motor 10, making the internal structure of the motor 10 more compact.

[0050] Furthermore, the length of the second protrusion 24 of the end cover extending into the central area surrounded by the motor stator 91 is not less than half the length of the second protrusion 24 of the end cover. This ensures that the second protrusion 24 of the end cover extends into the central area surrounded by the motor stator 91 as much as possible, thereby significantly shortening the length of the motor 10.

[0051] Reference Figure 1-Figure 3 , Figure 12-13 As shown, the potting glue 93 is disposed on one end of the motor stator 91 facing the end cover 2 , and the second protrusion 24 of the end cover extends into the central area surrounded by the potting glue 93 .

[0052] Reference Figure 1-Figure 3 , Figure 7-Figure 9 , Figure 12-13 As shown, a bearing cavity 26 extending into the end cover body 22 is provided at the second protrusion 24 of the end cover, and a bearing 94 is provided in the bearing cavity 26. The inner ring of the bearing 94 is relatively fixed to the motor rotor 9, and the outer ring of the bearing 94 is relatively fixed to the cavity wall of the bearing cavity 26, and the inner ring and the outer ring of the bearing 94 can rotate relative to each other. In this way, when the motor rotor 9 and the encoder rotor 12 rotate synchronously, the inner ring of the bearing 94 can rotate synchronously with the motor rotor 9, while the outer ring of the bearing 94 is fixed, so that the bearing 94 can support the rotation of the motor rotor 9, thereby making the rotation of the motor rotor 9 more stable.

[0053] Further, refer to Figure 7-Figure 9 As shown, there is a stop positioning wall 27 between the bearing cavity 26 and the rotor cavity 25, and a mounting through hole 23 for connecting the power supply rotor 9 and the encoder rotor 12 is opened on the stop positioning wall 27. Figure 1-Figure 3 , Figure 12-13 As shown, the motor rotor 9 is suitable for being provided with a mounting through hole 23 to facilitate the fixed connection of the rotor screw 121 , thereby achieving a fixed connection between the motor rotor 9 and the encoder rotor 12 .

[0054] Reference Figure 1-Figure 4 , Figure 12-13 As shown, the motor 10 may further include: a rear cover 3, which is suitable for being fixedly connected to the end cover 2, and referring to Figure 1 , Fig.12 As shown, a receiving cavity 4 is formed between the rear cover 3 and the end cover 2. Figure 1-Figure 2 , Figure 10-Figure 16 As shown, the rear cover 3 has a limiting structure 31, and the encoder stator 11 is fixed in the accommodating cavity 4 through the limiting structure 31, thereby realizing the installation and fixation of the encoder 1 in the motor 10. The rear cover 3 can provide good mechanical protection for the encoder 1 and the wiring harness in the accommodating cavity 4.

[0055] Only the rear cover 3 is fixed to the end cover 2 , and no fixing structure is provided between the encoder 1 and the end cover 2 . In this way, the fasteners between the encoder 1 and the end cover 2 can be omitted, thereby reducing the weight of the motor 10 and saving the manufacturing cost of the motor 10 .

[0056] According to the motor 10 of the embodiment of the present invention, the encoder stator 11 is positioned on the end cover 2 by using the limiting structure 31 of the rear cover 3 itself, thereby eliminating the screw fasteners between the encoder stator 11 and the end cover 2, which is conducive to cost saving. At the same time, it is not necessary to set a special positioning structure on the end cover 2 to position the encoder stator 11, which is conducive to further reducing the axial length of the motor 10, and the structure of the end cover 2 is simplified, which is conducive to saving the manufacturing cost of the end cover 2. In addition, the rear cover 3 not only plays a role in mechanical protection and IP protection, but also plays a role in positioning the encoder stator 11.

[0057] Reference Figure 1-Figure 2 , Figure 5-Figure 6 , Figure 10-Figure 16 As shown, the encoder stator 11 has a stator flange 111, and the limiting structure 31 includes: a rear cover axial positioning surface 311 and a rear cover radial positioning surface 312 located in the accommodating cavity 4, the rear cover axial positioning surface 311 and the rear cover radial positioning surface 312 are perpendicular to each other, the rear cover axial positioning surface 311 is suitable for at least partially fitting with the end surface of the stator flange 111 away from the end cover 2, the rear cover radial positioning surface 312 is suitable for at least partially fitting with the outer peripheral surface of the stator flange 111, and the stator flange 111 is at least partially fitted with the end surface of the first protrusion 21 of the end cover. The rear cover axial positioning surface 311 presses the encoder stator 11 against the end cover 2 to limit the axial position of the encoder stator 11, and the rear cover radial positioning surface 312 can limit the radial position of the encoder stator 11, thereby realizing the positioning of the encoder stator 11 in the accommodating cavity 4.

[0058] Reference Figure 6 As shown, the stator flange 111 has a first axial positioning surface 1111, a radial positioning surface 1112, and a second axial positioning surface 1113. The first axial positioning surface 1111 is perpendicular to the radial positioning surface 1112, and the first axial positioning surface 1111 is parallel to the second axial positioning surface 1113. The rear cover axial positioning surface 311 is suitable for fitting with the first axial positioning surface 1111, and the rear cover radial positioning surface 312 is suitable for fitting with the stator radial positioning surface 1112. The end cover 2 is suitable for fitting with the second axial positioning surface 1113 of the stator. Specifically, the second axial positioning surface 1113 of the stator flange 111 is fitted with the end cover axial positioning surface 211 of the first protrusion 21 of the end cover, thereby ensuring that the axial position of the encoder stator 11 is reliable.

[0059] Preferably, the rear cover radial positioning surface 312 and the stator radial positioning surface 1112 are both constructed as circumferential surfaces, so that the rear cover radial positioning surface 312 can radially position the entire circle of the stator radial positioning surface 1112 to ensure more reliable positioning.

[0060] Reference Figure 1-Figure 2 , Figure 12-13As shown, the outer diameters of the stator flange 111 and the first protrusion 21 of the end cover are equal, so that the radial positioning surface 312 of the rear cover can have the same diameter, which is beneficial to simplify the structure and processing procedures of the rear cover 3.

[0061] Reference Figure 5-Figure 6 As shown, the encoder stator 11 also includes: a stator body 112, the outer diameter of the stator body 112 is smaller than the outer diameter of the stator flange 111, so that when the stator flange 111 is in contact with the radial positioning surface 312 of the rear cover, the stator body 112 is separated from the radial positioning surface 312 of the rear cover, thereby, it is not necessary to set the entire outer circumferential surface of the encoder stator 11 to be in contact with the radial positioning surface 312 of the rear cover, and only the stator flange 111 is in contact with the radial positioning surface 312 of the rear cover. In this way, only the manufacturing accuracy of the stator flange 111 can be ensured to be high, while the manufacturing accuracy of the stator body 112 can be appropriately reduced, which is beneficial to saving the manufacturing cost of the encoder stator 11.

[0062] The rear cover radial positioning surface 312 is also suitable for at least partially fitting with the outer peripheral surface of the first protrusion 21 of the end cover, thereby limiting the relative radial position of the rear cover 3 and the end cover 2.

[0063] The first protrusion 21 of the end cover has an axial positioning surface 211 of the end cover and a first radial positioning surface 212 of the end cover. The second axial positioning surface 1113 of the stator is suitable for fitting with the axial positioning surface 211 of the end cover, thereby, the end cover 2 can limit the axial position of the encoder stator 11, and the radial positioning surface 312 of the rear cover is suitable for fitting with the first radial positioning surface 212 of the end cover, thereby, the end cover 2 can limit the radial position of the rear cover 3.

[0064] Furthermore, a first sealing groove 5 is opened on the outer peripheral surface of the first protrusion 21 of the end cover, and a first sealing ring 6 is arranged in the first sealing groove 5. The first sealing ring 6 is suitable for fitting with the radial positioning surface 312 of the rear cover and the first protrusion 21 of the end cover, thereby facilitating the sealing performance between the rear cover 3 and the end cover 2, so that the rear cover 3 plays a good IP protection role.

[0065] The rear cover 3 is connected to the end cover body 22 by fasteners, thereby achieving a fixed connection between the rear cover 3 and the end cover 2. Figure 3-Figure 4 As shown, the fastener may include: a fastening screw 7 and a transfer screw 8 fixedly disposed on the end cover body 22, and the fastening screw 7 is suitable for passing through the rear cover 3 and being threadedly connected with the transfer screw 8. Figure 7-Figure 8 As shown, an insertion hole 221 for inserting the adapter screw 8 is opened on the end cover body 22, and at least a part of the adapter screw 8 is suitable for being inserted and fixed in the insertion hole 221, thereby achieving the fixation of the adapter screw 8 on the end cover body 22.

[0066] Specifically, refer to Figure 10-11 , Figure 14-16As shown, the rear cover 3 may include: a rear cover top plate 32 and a rear cover side panel 33, the rear cover side panel 33 is fixed to the rear cover top plate 32, the limiting structure 31 is arranged on the rear cover side panel 33, the rear cover top plate 32 is separated from the end cover 2, and a top plate hole 34 for the fastening screw 7 and the adapter screw 8 to pass through is opened at the connection between the rear cover top plate 32 and the rear cover side panel 33, and the top plate hole 34 passes through the rear cover side panel 33. The adapter screw 8 is passed through the top plate hole 34, the fastening screw 7 passes through the top plate hole 34 and is screwed with the adapter screw 8 in the top plate hole 34, thereby fully utilizing the height dimension of the rear cover 3 to complete the fixation of the rear cover 3 and the end cover 2, thereby facilitating the reduction of the axial dimension of the motor 10.

[0067] Reference Figure 3-Figure 4 As shown, the fastening screw 7 includes: a threaded section 71 and a screw head 72. A recessed portion 35 is provided on the rear cover top plate 32, and the top plate hole 34 is opened at the position of the recessed portion 35. In this way, since the screw head 72 remains outside the top plate hole 34, the recessed portion 35 can accommodate the screw head 72, thereby further reducing the axial size of the motor 10.

[0068] Reference Figure 1 , Figure 4 , Figure 10-12 , Figure 14-16 As shown, the rear cover 3 is provided with a wire outlet hole 36 , and the wire harness of the encoder 1 etc. can pass through the wire outlet hole 36 .

[0069] In a specific embodiment, the rear cover radial positioning surface 312 includes: a stator positioning section and an end cover positioning section, the stator positioning section is used to radially position the encoder stator 11, and the end cover positioning section is used to radially position the first protrusion 21 of the end cover, Figure 12-Figure 16 As shown, the end cover positioning section is at least partially constructed as an elastic positioning section 37 made of elastic material, thereby reducing the damage of the rear cover radial positioning surface 312 to the first sealing ring 6 on the first protrusion 21 of the end cover.

[0070] Specifically, the back cover 2 is prone to scratching the first sealing ring 6 during installation. For this reason, the back cover 2 is improved by adding an elastic positioning section 37. The elastic positioning section 37 can ensure that the sharp angle of the back cover radial positioning surface 312 of the back cover 2 does not scratch the first sealing ring 6 during installation, thereby facilitating high-quality installation. After the installation is completed, the elastic positioning section 37 can be directly opposite to the first sealing ring 6, and the elastic positioning section 37 can be elastically deformed, which is beneficial to further enhance the sealing effect of the connection between the back cover 3 and the end cover 2.

[0071] Optionally, the elastic positioning section 37 may be a soft rubber structure.

[0072] The structure of the elastic positioning section 37 may have Figure 14-16 As shown in the various forms. Fig.14As shown, the elastic positioning section 37 can be constructed as a wedge shape; Fig.15 As shown, the elastic positioning section 37 can be constructed in an "L" shape; Fig.16 As shown, the elastic positioning section 37 can be constructed in an "I" shape.

[0073] Reference Figure 7-Figure 9 As shown, a third end cover protrusion 28 is provided between the second end cover protrusion 24 and the end cover body 22. The outer diameter of the third end cover protrusion 28 is greater than the outer diameter of the second end cover protrusion 24. Figure 1-Figure 2 , Figure 12-13 As shown, a second sealing groove 51 is opened on the outer peripheral surface of the third protrusion 28 of the end cover, and a second sealing ring 61 is arranged in the second sealing groove 51. The second sealing ring 61 is suitable for fitting with the inner peripheral surface of the motor housing 92 and the second protrusion 24 of the end cover, thereby realizing the sealing between the end cover 2 and the motor housing 92.

[0074] Further, refer to Figure 1-Figure 2 , Fig. 9 , Figure 12-13 As shown, the third protrusion 28 of the end cover has a second radial positioning surface 218 of the end cover, and the second radial positioning surface 218 of the end cover is suitable for fitting with the inner circumferential surface of the motor housing 92, thereby making the relative radial position of the end cover 2 and the motor housing 92 accurate. In addition, the end cover body 22 can play an axial limiting role on the motor housing 92, thereby making the relative axial position of the end cover 2 and the motor housing 92 accurate.

[0075] Optionally, the encoder 1 may be a magnetic encoder or a photoelectric encoder.

[0076] According to the motor 10 of the embodiment of the present invention, a rotor cavity 25 for installing the encoder rotor 12 is provided in the end cover 2, and a positioning structure specifically used for positioning the encoder stator 11 is no longer provided on the end cover 2, which is conducive to shortening the axial length of the motor 10, and the length can be shortened by 6-15mm, so that the motor 10 can reach the same size specifications as Japanese benchmark products in terms of length dimension; the number of screws between the end cover 2 and the encoder 1 is reduced, for example, the use of 2-6 screws is reduced, and the number of threaded holes on the end cover 2 and the encoder 1 is reduced, thereby reducing the manufacturing cost of parts; the encoder 1 is positioned by using the rear cover 3, which reduces the working hours consumed in the assembly process of the motor 10 and further reduces the manufacturing cost; by providing the elastic positioning section 37, the scratches on the first sealing ring 6 can be reduced, the service life of the first sealing ring 6 is increased, and at the same time, it is conducive to further improving the sealing effect of the connection between the rear cover 3 and the end cover 2.

[0077] The motor 10 of the present invention may be a servo motor, and the motor 10 may be applied to various machines using servo motors.

[0078] According to another aspect of the present invention, the servo control system includes the motor 10 of the above embodiment. The servo control system can be: a six-axis or four-axis robot system (such as Delta, Scara robot) and an automatic control production system that needs to control the displacement position accuracy of an object (mostly customized products to meet specific needs, such as textile production lines, automatic packaging production lines, sorting systems, automatic welding systems, and medical machinery systems, etc.).

[0079] 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.

[0080] 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. A motor (10), characterized in that: include: An encoder (1), the encoder (1) comprising: an encoder stator (11) and an encoder rotor (12), the encoder rotor (12) being rotatable relative to the encoder stator (11); An end cover (2), the end cover (2) having a rotor cavity (25), the encoder rotor (12) being at least partially located in the rotor cavity (25); The motor (10) further comprises: a motor housing (92), a motor rotor (9) and a motor stator (91), wherein the motor rotor (9) passes through the end cover (2) and is fixedly connected to the encoder rotor (12), and the motor stator (91) is fixed to the motor housing (92); The end cover (2) comprises: End cap body (22); A first protrusion (21) of the end cover, wherein the first protrusion (21) of the end cover is arranged at a first end of the end cover body (22), and the rotor cavity (25) extends from the first protrusion (21) of the end cover into the end cover body (22); A second protrusion (24) of the end cover, wherein the second protrusion (24) of the end cover is arranged at the second end of the end cover body (22), and the second protrusion (24) of the end cover extends into a central area surrounded by the motor stator (91); A third end cover protrusion (28) is provided between the second end cover protrusion (24) and the end cover body (22); the outer diameter of the third end cover protrusion (28) is greater than the outer diameter of the second end cover protrusion (24); a second sealing groove (51) is provided on the outer circumference of the third end cover protrusion (28); a second sealing ring (61) is provided in the second sealing groove (51); the second sealing ring (61) is adapted to fit both the inner circumference of the motor housing (92) and the second end cover protrusion (24); The end cover third protrusion (28) has an end cover second radial positioning surface (218), and the end cover second radial positioning surface (218) is suitable for fitting with the inner circumferential surface of the motor housing (92).

2. The electric machine (10) according to claim 1, characterized in that The length of the second protrusion (24) of the end cover extending into the central area surrounded by the motor stator (91) is not less than half the length of the second protrusion (24) of the end cover itself.

3. The electric machine (10) according to claim 2, characterized in that One end of the motor stator (91) facing the end cover (2) is provided with a potting glue (93) for fixing the motor stator (91) and the motor housing (92), and the second protrusion (24) of the end cover extends into the central area surrounded by the potting glue (93).

4. The electric machine (10) according to claim 1, characterized in that A bearing cavity (26) extending into the end cover body (22) is provided at the second protrusion (24) of the end cover, and a bearing (94) is provided in the bearing cavity (26). The inner ring of the bearing (94) is relatively fixed to the motor rotor (9), the outer ring of the bearing (94) is relatively fixed to the cavity wall of the bearing cavity (26), and the inner ring and outer ring of the bearing (94) are relatively rotatable.

5. The electric machine (10) according to claim 4, characterized in that A stop positioning wall (27) is provided between the bearing cavity (26) and the rotor cavity (25), and a mounting through hole (23) for connecting the motor rotor (9) and the encoder rotor (12) is provided on the stop positioning wall (27).

6. The electric machine (10) according to claim 1, characterized in that The motor (10) further comprises: a rear cover (3), the rear cover (3) being adapted to be fixedly connected to the end cover (2), and a receiving cavity (4) being formed between the rear cover (3) and the end cover (2), the rear cover (3) having a limiting structure (31), and the encoder stator (11) being fixed in the receiving cavity (4) via the limiting structure (31).

7. The electric machine (10) according to claim 6, characterized in that The encoder stator (11) has a stator flange (111), and the limiting structure (31) comprises: a rear cover axial positioning surface (311) and a rear cover radial positioning surface (312) located in the accommodating cavity (4), wherein the rear cover axial positioning surface (311) is adapted to at least partially fit with the end surface of the stator flange (111) facing away from the end cover (2), and the rear cover radial positioning surface (312) is adapted to at least partially fit with the outer peripheral surface of the stator flange (111), and the rear cover radial positioning surface (312) is also adapted to at least partially fit with the outer peripheral surface of the first protrusion (21) of the end cover, and the stator flange (111) is at least partially fitted with the end surface of the first protrusion (21) of the end cover.

8. The electric machine (10) according to claim 7, characterized in that A first sealing groove (5) is provided on the outer peripheral surface of the first protrusion (21) of the end cover, a first sealing ring (6) is arranged in the first sealing groove (5), and the first sealing ring (6) is suitable for fitting with the radial positioning surface (312) of the rear cover and the first protrusion (21) of the end cover.

9. The electric machine (10) according to claim 7 or 8, characterized in that The rear cover radial positioning surface (312) comprises: a stator positioning section and an end cover positioning section, and the end cover positioning section is at least partially constructed as an elastic positioning section (37) made of elastic material.

10. A servo control system, characterized in that: The invention comprises the electric motor (10) according to any one of claims 1 to 9.

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