Motor for an electric cylinder and encoder for the motor

Abstract

A motor of an electric cylinder and an encoder for the motor, the motor of the electric cylinder comprising a motor body, an encoder, a rotor joint and an encoder fixing part. The motor body includes a rotor, a stator coil and a rotor magnet combined with the rotor, which are accommodated in a housing. The rotor has a shaft hole to provide a rotation shaft passing through. The encoder is installed on the motor body and includes a fixing ring, a magnet fixing seat, an encoder magnet and a magnetic sensing element, the fixing ring is fixed on the rotation shaft, and the magnet fixing seat is combined with the fixing ring. The encoder magnet is installed on the magnet fixing seat, and the magnetic sensing element is separated from and opposite to the encoder magnet. The magnet fixing seat can rotate relative to the fixing ring to adjust the pole position of the encoder magnet relative to the magnetic sensing element. The rotor joint is provided on the rotor and fixed with the rotation shaft at a first corresponding position, and the encoder fixing part is provided on the fixing ring and fixed with the rotation shaft at a second corresponding position.

Description

TECHNICAL FIELD

[0001] The present invention relates to an electric cylinder, in particular to a motor for an electric cylinder and an encoder for the motor. BACKGROUND

[0002] Electric cylinders or slide devices widely used in industrial machines are powered by a motor, and then driven by a rotating shaft (screw) to move a load linearly. A general electric cylinder mainly comprises a linear track, a sliding unit arranged on the linear track, and a motor. The sliding unit has a rotating shaft connected to the shaft of the motor by a coupling. When the motor is operated, the rotating shaft is driven by the coupling to move the sliding unit linearly along the linear track, so that a load mounted on the sliding unit is driven to move linearly. However, the coupling is easily damaged or loosened after a long time of use. In addition, the coupling increases the length of the electric cylinder in the longitudinal direction, and the volume of the electric cylinder, which cannot effectively save space and achieve the purpose of light weight.

[0003] To improve the above-mentioned problems caused by the coupling connecting the rotating shaft, a hollow motor without a shaft is designed. The hollow motor comprises a housing, a hollow rotor accommodated in the housing, a magnet combined with the rotor, a stator coil, and an encoder. The improved hollow rotor can provide a rotating shaft directly connected to the hollow motor, so that the use of the coupling can be omitted. When the rotor of the hollow motor rotates, the rotating shaft is driven to move the sliding unit linearly along the linear track. Since the hollow motor does not have a shaft, the length of the electric cylinder in the longitudinal direction can be reduced, and the volume of the electric cylinder can be reduced. However, the completion of the magnetic pole angle alignment is achieved after the assembly of the hollow motor and the rotating shaft. When the components of the hollow motor are damaged or the magnet is demagnetized, it is very complicated to replace the assembly of the hollow motor. Customers generally cannot replace it themselves, and the entire electric cylinder needs to be sent back to the factory for repair, which is very time-consuming. Specifically, after the assembly of the hollow motor and the rotating shaft is completed, the magnetic pole phase of the rotor magnet combined with the rotor needs to be aligned with the stator coil before the motor is operated. The alignment operation generally sends power to the stator coil, and then stops the rotor relative to the stator coil at an initial position to complete the alignment. In addition, the magnetic pole position of the encoder magnet of the encoder also needs to be aligned with the magnetic sensing element of the encoder. However, when adjusting the magnetic pole position of the magnet of the encoder, in addition to sending power to the stator coil, the magnetic pole position of the magnet relative to the magnetic sensing element also needs to be adjusted manually. The alignment adjustment operation is quite tedious and time-consuming. SUMMARY

[0004] Therefore, the motor of the electric cylinder and the encoder for the motor have simple structure, convenient operation and maintenance, can overcome the defects of the prior art, can quickly, simply and accurately assemble the motor, and effectively improve the efficiency and competitiveness of the electric cylinder.

[0005] To achieve the above object, the motor of the electric cylinder comprises a rotating shaft extending along a longitudinal direction and having a motor-side rotating shaft portion, and the motor-side rotating shaft portion is provided with a rotating shaft connecting portion and a rotating shaft fixing portion which are spaced apart from each other, and the motor comprises:

[0006] a motor body comprising a housing, a rotor accommodated in the housing, a stator coil, and a rotor magnet connected to the rotor, the rotor has an axial hole extending along the longitudinal direction to provide the motor-side rotating shaft portion of the rotating shaft to pass through, and the rotor magnet has at least one pair of magnetic poles, wherein the rotor can rotate around the central axis of the rotating shaft relative to the stator coil;

[0007] an encoder mounted on the motor body and comprising a fixing ring, a magnet fixing seat, an encoder magnet, and a magnetic sensing element, the motor-side rotating shaft portion of the rotating shaft passes through the fixing ring, the magnet fixing seat is rotatably connected to the fixing ring, the encoder magnet is mounted on the magnet fixing seat and has at least one pair of magnetic poles, and the magnetic sensing element is spaced apart from and arranged opposite to the magnet in the longitudinal direction, wherein the magnet fixing seat can be fixed with the fixing ring;

[0008] a rotor connecting portion provided on the rotor, the rotor connecting portion can be aligned with the rotating shaft connecting portion and connected to the rotating shaft connecting portion by a connecting element; and

[0009] an encoder fixing portion provided on the fixing ring, the encoder fixing portion can be aligned with the rotating shaft fixing portion and fixed to the rotating shaft fixing portion by a fixing element.

[0010] The rotating shaft fixing portion is a first key groove provided on the outer periphery of the motor-side rotating shaft portion and extending along the longitudinal direction, the fixing ring has a through hole extending along the longitudinal direction, the encoder fixing portion is a groove provided on the hole wall of the through hole and extending along the longitudinal direction, and the fixing element is a first key inserted into the first key groove and the groove.

[0011] The rotating shaft connecting portion is a second key groove provided on the outer periphery of the motor-side rotating shaft portion and extending along the longitudinal direction, the rotor connecting portion is a groove provided on the hole wall of the axial hole and extending along the longitudinal direction, and the connecting element is a second key inserted into the second key groove and the groove.

[0012] The shaft coupling portion includes two recesses on the longitudinal direction and opposite to each other around the shaft, the rotor coupling portion includes two recesses on the longitudinal direction and opposite to each other around the rotor, the coupling member includes two sets of a fixed piece and two screws, the two recesses of the rotor coupling portion are respectively corresponding to the two recesses of the shaft coupling portion, the two fixed pieces of the coupling member are respectively abutted in the two recesses of the shaft coupling portion, and the two screws of the coupling member are respectively passed through the two fixed pieces and locked in the two recesses of the rotor coupling portion.

[0013] The fixed ring has a through hole extending along the longitudinal direction, the magnet fixing seat includes a body portion and a positioning portion protruding outward from the inner side of the body portion, the encoder magnet is installed on the body portion, the positioning portion is combined in the through hole of the fixed ring, and the magnet fixing seat and the fixed ring are fixed by the positioning member passing through the positioning hole provided on the fixed ring and abutting against the positioning portion.

[0014] The application further discloses an encoder for a motor connected with a shaft, the encoder being used for detecting the rotation of the shaft, and the encoder comprises:

[0015] a fixed ring fixed on the shaft;

[0016] a magnet fixing seat combined with the fixed ring;

[0017] an encoder magnet installed on the magnet fixing seat and having at least one pair of magnetic poles; and

[0018] a magnetic sensing member separated from the encoder magnet in the longitudinal direction and opposite to the encoder magnet;

[0019] The magnet fixing seat can rotate relative to the fixed ring to adjust the magnetic pole position of the encoder magnet relative to the magnetic sensing member.

[0020] The fixed ring has a through hole extending along the longitudinal direction, the shaft passes through the through hole, the magnet fixing seat includes a body portion and a positioning portion protruding outward from the inner side of the body portion, the encoder magnet is installed on the body portion, the positioning portion is combined in the through hole of the fixed ring, and the magnet fixing seat and the fixed ring are fixed by the positioning member passing through the positioning hole provided on the fixed ring and abutting against the positioning portion.

[0021] Thus, the motor of the present application is a hollow motor without a shaft center and has a hollow rotor connectable with a rotating shaft of an electric cylinder. The motor enables a manufacturer to complete the alignment of the magnetic pole phase of a rotor magnet with a stator coil and the alignment of the magnetic pole position of an encoder magnet with a magnetic sensing element of the encoder in a factory, so that when a client replaces a motor of an electric cylinder, there is no problem of the alignment of the magnetic poles of the rotor magnet and the encoder magnet, and the client can quickly, simply and accurately replace and assemble the motor, thereby improving the competitiveness of the electric cylinder.

[0022] According to an embodiment of the present application, a motor is used in an electric cylinder, the electric cylinder including a rotating shaft extending along a longitudinal direction and having a motor-side rotating shaft portion provided with a rotating shaft coupling portion and a rotating shaft fixing portion, and the motor including a motor body, an encoder, a rotor coupling portion and an encoder fixing portion. The motor body includes a housing, a rotor accommodated in the housing, a stator coil and a rotor magnet coupled to the rotor. The rotor has a shaft hole extending along the longitudinal direction to provide the motor-side rotating shaft portion of the rotating shaft to pass through, and the rotor magnet has at least one pair of magnetic poles. The rotor is rotatable about a central axis of the rotating shaft relative to the stator coil. The encoder is mounted on the motor body and includes a fixing ring, a magnet fixing seat, an encoder magnet and a magnetic sensing element. The motor-side rotating shaft portion of the rotating shaft passes through the fixing ring, the magnet fixing seat is rotatable and coupled to the fixing ring, the encoder magnet is mounted on the magnet fixing seat and has at least one pair of magnetic poles, and the magnetic sensing element is separated from and opposite to the encoder magnet in the longitudinal direction. The magnet fixing seat is fixed with the fixing ring. The rotor coupling portion is provided on the rotor, the rotor coupling portion is aligned with the rotating shaft coupling portion, and a coupling member couples the rotor coupling portion and the rotating shaft coupling portion. The encoder fixing portion is provided on the fixing ring, the encoder fixing portion is aligned with the rotating shaft fixing portion, and a fixing member fixes the encoder fixing portion and the rotating shaft fixing portion.

[0023] In an embodiment, the rotating shaft fixing portion is a first key groove provided on an outer periphery of the motor-side rotating shaft portion and extending along the longitudinal direction, the fixing ring has a through hole extending along the longitudinal direction, the encoder fixing portion is a groove provided on a hole wall of the through hole and extending along the longitudinal direction, and the fixing member is a first key inserted into the first key groove and the groove.

[0024] In an embodiment, the rotating shaft coupling portion is a second key groove provided on an outer periphery of the motor-side rotating shaft portion and extending along the longitudinal direction, the rotor coupling portion is a groove provided on a hole wall of the shaft hole and extending along the longitudinal direction, and the coupling member is a second key inserted into the second key groove and the groove.

[0025] In one embodiment, the shaft coupling portion includes two recesses longitudinally separated and oppositely arranged in a circumferential direction of the shaft, the rotor coupling portion includes two recesses respectively arranged at two ends of the rotor and oppositely arranged in a circumferential direction of the rotor, the coupling member includes two sets of a fixing piece and two screws, the two recesses of the rotor coupling portion respectively correspond to the two recesses of the shaft coupling portion, the two fixing pieces of the coupling member are respectively abutted against the two recesses of the shaft coupling portion, and the two screws of the coupling member are respectively passed through the two fixing pieces and locked into the two recesses of the rotor coupling portion.

[0026] In one embodiment, the magnet fixing seat includes a body portion and a positioning portion protruding outward from an inner side of the body portion, the encoder magnet is mounted on the body portion, the positioning portion is combined in the through hole of the fixing ring, and the magnet fixing seat and the fixing ring are fixed by passing the positioning member through the positioning hole provided on the fixing ring and abutting against the positioning portion.

[0027] According to one embodiment of the present application, an encoder is used for a motor connected with a shaft, and is used for detecting rotation of the shaft. The encoder includes a fixing ring, a magnet fixing seat, an encoder magnet, and a magnetic sensing member. The fixing ring is fixed on the shaft. The magnet fixing seat is combined with the fixing ring. The encoder magnet is mounted on the magnet fixing seat and has at least one pair of magnetic poles. The magnetic sensing member is longitudinally separated from and opposite to the encoder magnet. The magnet fixing seat is rotatable relative to the fixing ring to adjust a magnetic pole position of the encoder magnet relative to the magnetic sensing member.

[0028] Other objects, advantages and features of the present application will be understood and appreciated by those skilled in the art upon studying the following detailed description and upon referring to the appended drawings. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 A cross-sectional view showing a motor for an electric cylinder according to a first embodiment of the present application applied to an electric cylinder.

[0030] Figure 2 A partial exploded view showing the motor for the electric cylinder according to the first embodiment of the present application. Figure 1

[0031] A partial exploded view showing the motor for the electric cylinder according to the first embodiment of the present application. Figure 3 Figure 1 A partial exploded view showing an encoder for a motor according to the first embodiment of the present application.

[0032] Figure 4 A view showing assembly of a motor body for an electric cylinder according to the first embodiment of the present application on a shaft. Figure 2

[0033] A cross-sectional view showing a motor for an electric cylinder according to a second embodiment of the present application applied to an electric cylinder. Figure 5

[0034] A partial exploded view showing the motor for the electric cylinder according to the second embodiment of the present application. Figure 6 Figure 5 ​​Fig. 2 is a partial exploded schematic view of an electric cylinder according to the present application. DETAILED DESCRIPTION

[0035] The present application can have various different structural embodiments. A specific embodiment will now be described by way of example only, and without limitation, with reference to the accompanying drawings, in which the preferred structure of the present application will be described as follows:

[0036] Figures 1 to 4 A motor 10 for an electric cylinder according to the first embodiment of the present application is applied to an electric cylinder 12, which includes a linear rail 14, a sliding unit 16, a rotating shaft 18, a motor body 20, and an encoder 22. The linear rail 14 extends along a longitudinal direction (X), and the sliding unit 16 is mounted on the linear rail 14. The rotating shaft 18 includes a sliding-side rotating shaft portion 24 coupled to the sliding unit 16 and a motor-side rotating shaft portion 26 coupled to the motor body 20. When the motor 10 is operated, the rotating shaft 18 is driven to move the sliding unit 16 reciprocally along the longitudinal direction (X) relative to the linear rail 14. Since the structure of the linear rail 14 and the sliding unit 12 is well known to those skilled in the art, further description will not be given herein.

[0037] The motor-side rotating shaft portion 26 extends outward of the sliding unit 16 and is provided with a rotating shaft coupling portion 28 and a rotating shaft fixing portion 30. The rotating shaft coupling portion 28 is positioned between the load-side rotating shaft portion 24 and the rotating shaft fixing portion 30 in the longitudinal direction (X). In possible embodiments, the rotating shaft coupling portion 28 and the rotating shaft fixing portion 30 can each be constituted by at least one key groove or at least one notch. In the present embodiment, the rotating shaft fixing portion 30 is a first key groove 30a provided on the outer periphery of the rotating shaft 18, and the rotating shaft coupling portion 28 is a second key groove 28a provided on the outer periphery of the rotating shaft 18. The two key grooves 28a, 30a extend in a direction parallel to the central axis of the rotating shaft 18 and are aligned in the longitudinal direction, i.e., the two key grooves 28a, 30a are not angularly offset in the circumferential direction of the rotating shaft 18. In possible embodiments, the two key grooves 28a, 30a are angularly offset in the circumferential direction of the rotating shaft 18 (e.g., by 90 or 180 degrees), but the two key grooves 28a, 30a are provided to be aligned in the longitudinal direction, which is advantageous for manufacturing the rotating shaft coupling portion 28 and the rotating shaft fixing portion 30 on the rotating shaft 18.

[0038] The motor 10 for an electric cylinder of the present application can include the motor body 20 and the encoder 22. The motor body 20 includes a housing 32, a rotor 34 received in the housing 32, a stator coil 36, and a rotor magnet 38 coupled to the rotor 34, and a rear cover 40 having a bearing 41 provided on an inner periphery thereof. The rotor 34 has a shaft hole 42 extending along the longitudinal direction to provide a passage for the motor-side rotor shaft portion 26 to pass through. The rotor 34 is provided with a rotor coupling portion 44, which can be constituted by at least one groove or at least one notch in an embodiment. In the present embodiment, the rotor coupling portion 44 is a groove 44a provided on a hole wall of the shaft hole 42 and extending along the longitudinal direction, which can be aligned with the rotor shaft coupling portion 28 and positioned in the rotor shaft coupling portion 28 (key groove 28a) and the rotor coupling portion 44 (groove 44a) with a coupling member 46 such as a key (second key) to be interposed therebetween to limit the movement of the rotor coupling portion 44 relative to the rotor shaft coupling portion 28 along the longitudinal direction, thereby coupling and fixing the rotor coupling portion 44 and the rotor shaft coupling portion 28 so that the rotor 34 and the rotor shaft 18 can rotate together about the central axis of the rotor shaft 18. In addition, a limiting member 47 such as a set screw is passed through the rotor 34 and abuts against the coupling member 46 to limit the movement of the rotor 34 relative to the rotor shaft 18 along the longitudinal direction. The stator coil 36 is coupled to an inner peripheral wall of the housing 32. The rotor magnet 38 is coupled to an outer periphery of the rotor 34 and has a plurality of pairs of magnetic poles (N poles and S poles). When the stator coil 36 is energized, the rotor 34 and the rotor shaft 18 rotate together relative to the stator coil 36 by an angle.

[0039] The encoder 22 is mounted on the motor body 20 to detect the number of rotations, the direction of rotation, and the angle of rotation of the rotating shaft 18. The encoder 22 includes a fixed ring 48, a magnet fixing seat 50, an encoder magnet 52, and a magnetic sensor 54. In the present embodiment, the fixed ring 48 has a through hole 56 extending along the longitudinal direction to provide an outer end 57 of the motor-side rotating shaft portion 26 to pass through, the outer end 57 has a small outer diameter and protrudes out of the housing 32 of the motor body 20, and the rotating shaft fixing portion 30 is provided on the outer end 57. The fixed ring 48 is provided with at least one encoder fixing portion 58, which in a possible embodiment can be formed by at least one groove or at least one notch. In the present embodiment, the encoder fixing portion 58 is a groove 58a provided on the hole wall of the through hole 56 and extending along the longitudinal direction, the encoder fixing portion 58 can be aligned with the rotating shaft fixing portion 30, and a fixing member 60 such as a key (first key) is inserted into the rotating shaft fixing portion 30 (key groove 30a) and the encoder fixing portion 58 (groove 58a) to limit the position, thereby combining and fixing the encoder fixing portion 58 and the rotating shaft fixing portion 30, so that the encoder magnet 52 and the rotating shaft 18 can rotate together around the central axis of the rotating shaft 18. In addition, a limiting member 61 such as a stop screw passes through the fixed ring 48 and abuts against the fixing member 60 to limit the movement of the fixed ring 48 along the longitudinal direction relative to the rotating shaft 18.

[0040] The magnet fixing seat 50 is rotatably combined with the fixed ring 48. In the present embodiment, the magnet fixing seat 50 includes a body portion 62, a positioning portion 64 protruding outward from the inner side of the body portion 62, and an abutting portion 66 between the body portion 62 and the positioning portion 64. The body portion 62 and the positioning portion 64 respectively have a first recess 68 and a second recess 70 separated by the abutting portion 66. The encoder magnet 52 is mounted in the first recess 68 of the body portion 62. The positioning portion 64 is inserted into the through hole 56 of the fixed ring 48, and the outer end 57 of the motor-side rotating shaft portion 26 is inserted into the second recess 70 and abuts against the abutting portion 66. In the present embodiment, a positioning member 72 such as a stop screw passes through a positioning hole 74 provided on the fixed ring 48 and abuts against the positioning portion 64, so that the magnet fixing seat 50 and the fixed ring 48 are fixed. When the positioning member 72 is loosened, the magnet fixing seat 50 can be rotated relative to the fixed ring 48 to adjust the pole position of the encoder magnet 52. In the present embodiment, the magnetic sensor 54 is mounted on a circuit board 76 fixed to the rear cover 40 of the motor body 20 through two support columns 78. The magnetic sensor 54 and the encoder magnet 52 are separated and opposite in the longitudinal direction, and the magnetic sensor 54 can sense the encoder magnet 52 when the encoder magnet 52 rotates. When the magnet fixing seat 50 is rotated relative to the fixed ring 48, the pole position of the encoder magnet 52 relative to the magnetic sensor 54 will be adjusted.

[0041] As to the assembly of the motor 10 and the rotating shaft 18, first, the shaft hole 42 of the rotor 34 is provided for the motor side rotating shaft portion 26 to pass through, and the rotor joint portion 44 of the rotor 34 is aligned with the rotating shaft joint portion 28 of the rotating shaft 18, the rotor joint portion 44 is jointed with the rotating shaft joint portion 28 by the joint member 46, so as to fix a first corresponding position between the rotor 34 and the rotating shaft 18; then, the housing 32 containing the stator coil 36 is installed on the outer periphery of the rotor 34 and fixed to an end cover 84 of the motor cylinder 12 (see Figure 4 ); then, the fixing ring 48 jointed with the magnet fixing seat 50 is installed on the motor side rotating shaft portion 26 and the encoder fixing portion 58 is aligned with the rotating shaft fixing portion 30, the encoder fixing portion 58 is jointed with the rotating shaft fixing portion 30 by the fixing member 60, so as to fix a second corresponding position between the fixing ring 48 and the rotating shaft 18; finally, the circuit board 76 of the encoder 22 is installed on the motor housing 32 by the support column 72. When the motor 10 and the rotating shaft 18 are assembled, the power supply is sent to the stator coil 36, the rotor 34 is rotated relative to the stator coil 36 to a position and then stopped, so as to complete the alignment of the magnetic pole position of the rotor magnet 38 and the stator coil 36. Then, the magnet fixing seat 50 is rotated relative to the fixing ring 48, so that the magnetic pole position of the encoder magnet 52 is aligned with the magnetic sensing member 54, and then the magnet fixing seat 50 is fixed and jointed to the fixing ring 48 by the positioning member 72, so that the magnetic pole position of the encoder magnet 52 relative to the magnetic sensing member 54 will not change. When the motor 10 assembled on the rotating shaft 18 completes the above alignment procedure, the motor 10 can be operated to drive the rotating shaft of the motor cylinder to rotate, and the encoder 22 can detect the rotation of the rotating shaft 18.

[0042] The motor 10 structure of the present application has an advanced feature that the prior art does not have. This feature is to let the manufacturer with assembly expertise to complete the alignment of the magnetic pole position of the rotor magnet 38 with the stator coil 36 and the alignment of the magnetic pole position of the encoder magnet 52 with the magnetic sensing element 54 of the encoder 52 in the factory in advance. This allows the customer to quickly and easily replace the motor 10 without the need to send the entire electric cylinder back to the factory for repair. In particular, after the motor 10 that has completed the alignment of the magnetic pole position is detached from the shaft 18, if the rotor 34 of the motor 10 is assembled on the shaft 18 according to the first corresponding position between the rotor 34 and the shaft 18 and the encoder 22 of the motor 10 is assembled on the shaft 18 according to the second corresponding position between the fixed ring 48 and the shaft 18, the magnetic pole position of the rotor magnet 38 and the magnetic pole position of the encoder magnet 52 will not be changed. Accordingly, if the motor 10 of the customer needs to be replaced due to damage or demagnetization of the magnet, the manufacturer can provide the motor 10 that has completed the alignment procedure in the factory to the customer. The customer only needs to align the rotor joint part 44 (groove 44a) of the rotor 34 with the shaft joint part 28 (key groove 28a) of the shaft 18 and combine them with the combining element (key) 46, and then align the encoder fixing part 58 (groove 58a) of the fixed ring 48 with the shaft fixing part 30 (key groove 30a) of the shaft 18 and fix them with the fixing element (key) 60, so as to complete the replacement of the motor 10, and there is no problem of alignment of the magnetic pole position of the rotor magnet and the encoder magnet at the customer's end.

[0043] Figure 5 With Figure 6A motor 10 according to a second embodiment of the present application is shown. In this embodiment, the shaft coupling portion 28 provided on the motor side shaft portion 26 includes two recesses 28b which are longitudinally spaced apart and face each other in the circumferential direction of the shaft 18. The rotor coupling portion 44 provided on the rotor 34 includes two notches 44b which are respectively provided at both ends of the rotor 34 and face each other in the circumferential direction of the rotor 34. The coupling member 46 includes two sets of a fixing piece 80 and two screws 82. When the motor side shaft portion 26 is inserted through the shaft hole 42 of the rotor 34, the two notches 44b of the rotor 34 can respectively correspond to the two recesses 28b of the motor side shaft portion 26. Then, the two fixing pieces 80 are respectively abutted against the two recesses 28b (shaft coupling portion 28), and the two screws 82 are inserted through the fixing pieces 80 and locked into the two notches 44b (rotor coupling portion 44) of the rotor 34. Thus, the motor side shaft portion 26 and the rotor 34 are coupled together, so that the rotor 34 and the shaft 18 can rotate together about the central axis of the shaft 18, and the movement of the rotor 34 relative to the shaft 18 in the longitudinal direction can be restricted. The shaft fixing portion 30, the encoder fixing portion 58 and the fixing member 60 in this embodiment have the same structure as those in the first embodiment. The key groove 30a constituting the shaft fixing portion 30 and the two recesses 28b constituting the shaft coupling portion 28 have a predetermined relative positional relationship, for example, the key groove 30a is aligned with one of the two recesses 28b in the longitudinal direction. It is to be noted that the shaft fixing portion 30, the encoder fixing portion 58 and the fixing member 60 in this embodiment can also have the same structure as the shaft coupling portion 28, the rotor coupling portion 44 and the coupling member 46 in this embodiment.

[0044] The foregoing is a description of a specific embodiment of the present application, and various changes or modifications can be made in accordance with the design features of the present application. Therefore, obvious substitutions and modifications made by those skilled in the art are intended to be included within the scope of the patent claimed by the present application.

Claims

1. A motor of an electric cylinder comprising a shaft extending in a longitudinal direction and having a motor-side shaft portion provided with a shaft coupling portion and a shaft fixing portion which are spaced apart from each other, characterized in that The motor comprises: a motor body including a housing, a rotor accommodated in the housing, a stator coil, and a rotor magnet combined with the rotor, the rotor having an axial hole extending along the longitudinal direction to provide the motor-side shaft portion of the rotation shaft to pass through, the rotor magnet having at least one pair of magnetic poles, wherein the rotor is rotatable about the central axis of the rotation shaft relative to the stator coil; an encoder mounted on the motor body and including a fixed ring, a magnet fixed seat, an encoder magnet, and a magnetic sensing element, the fixed ring being mounted on the motor-side shaft portion of the rotation shaft, the magnet fixed seat being rotatable combined with the fixed ring, the encoder magnet being mounted on the magnet fixed seat and having at least one pair of magnetic poles, the magnetic sensing element being separated from and oppositely arranged with the magnet along the longitudinal direction, wherein the magnet fixed seat is fixed with the fixed ring; a rotor combining portion provided on the rotor, the rotor combining portion being alignable with the rotation shaft combining portion and combined with the rotation shaft combining portion by a combining element; and an encoder fixed portion provided on the fixed ring, the encoder fixed portion being alignable with the rotation shaft fixed portion and fixed with the rotation shaft fixed portion by a fixing element, wherein the fixed ring has a through hole extending along the longitudinal direction, the motor-side shaft portion of the rotation shaft passes into the through hole of the fixed ring, and the encoder fixed portion is provided on the hole wall of the through hole, wherein the magnet fixed seat is rotatable relative to the fixed ring to adjust the magnetic pole position of the encoder magnet relative to the magnetic sensing element, and the magnet fixed seat is fixed with the fixed ring so that the magnetic pole position of the encoder magnet relative to the magnetic sensing element does not change relative to the encoder fixed portion; the rotation shaft fixed portion is a first key groove provided on the outer periphery of the motor-side shaft portion and extending along the longitudinal direction, and the encoder fixed portion is a groove extending along the longitudinal direction, and the fixing element is a first key inserted into the first key groove and the groove.

2. The motor of an electric cylinder according to claim 1, characterized in that: the rotation shaft combining portion is a second key groove provided on the outer periphery of the motor-side shaft portion and extending along the longitudinal direction, and the rotor combining portion is a groove provided on the hole wall of the axial hole and extending along the longitudinal direction, and the combining element is a second key inserted into the second key groove and the groove.

3. The motor of the electric cylinder according to claim 1, characterized by: The rotation shaft combining portion includes two notches separated along the longitudinal direction and oppositely arranged in the direction around the rotation shaft, the rotor combining portion includes two notches respectively arranged at both ends of the rotor and oppositely arranged in the direction around the rotor, and the combining element includes two sets of a fixing piece and two screws combined, the two notches correspond to the two notches respectively, the two fixing pieces of the combining element are respectively abutted in the two notches, and the two screws of the combining element are respectively passed through the two fixing pieces and locked into the two notches of the rotor.

4. The motor of the electric cylinder according to claim 1, characterized by: The magnet fixed seat includes a body portion and a positioning portion protruding outward from the inner side of the body portion, the encoder magnet is mounted on the body portion, the positioning portion is combined in the through hole of the fixed ring, and the magnet fixed seat is fixed with the fixed ring by positioning elements passing through positioning holes provided on the fixed ring and abutting on the positioning portion.

5. An encoder for a motor connected to a rotating shaft, the encoder being used to detect the rotation of the rotating shaft, characterized by The encoder comprises: a fixing ring fixed on the rotating shaft, the fixing ring having a through hole extending along the longitudinal direction, a hole wall of the through hole being provided with an encoder fixing portion, the rotating shaft penetrating the through hole and being fixed with the encoder fixing portion; a magnet fixing seat combined with the fixing ring; an encoder magnet installed on the magnet fixing seat and having at least one pair of magnetic poles; and a magnetic sensing member separated from and opposite to the encoder magnet along the longitudinal direction; wherein the magnet fixing seat can rotate relative to the fixing ring to adjust the magnetic pole position of the encoder magnet relative to the magnetic sensing member, and the magnetic pole position of the encoder magnet relative to the magnetic sensing member is not changed relative to the encoder fixing portion by fixing the magnet fixing seat with the fixing ring; the magnet fixing seat comprises a body portion and a positioning portion protruding outward from the inner side of the body portion, the encoder magnet is installed on the body portion, the positioning portion is combined in the through hole of the fixing ring, and the magnet fixing seat is fixed with the fixing ring by positioning members penetrating the positioning holes provided on the fixing ring and abutting against the positioning portion.

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