Actuator

Abstract

An actuator (1) provided with a motor (5) and an encoder unit (40) is provided with: a first structure section (19) that determines the relative angle between a housing (12) and a plurality of coils (13) of a stator core (11); a second structural section (29) that determines the relative angle between the magnetic poles of the rotor core (12) and a fixed reference portion (P) of a rotating disk (41) provided on the shaft (23); a third structure (39) that determines the relative angle between the shaft (23) and the rotating disk (41); and a fourth structure section (48) that determines the relative angle between the housing (12) and the detection section (42).

Description

Technical Field

[0001] The present disclosure relates to an actuator. Background Art

[0002] In an actuator including an encoder and a motor, such as a servo motor, it is necessary to attach a rotating disk of the encoder to a hollow shaft of the motor (for example, Japanese Patent Application Laid-Open No. 2017-203645).

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-203645 Summary of the invention

[0006] Problems to be solved by the invention

[0007] The relative angle between the rotating disk and the rotor of the motor is determined according to the positional relationship between the rotating disk and the hollow shaft.

[0008] Furthermore, since the housing of the stator of the motor and the stator core are generally shrink-fitted with cylindrical surfaces, the relative angles of the housing and the coils wound around the stator core for each phase are uncertain.

[0009] Furthermore, since the hollow shaft and the rotor core of the motor rotor are usually shrink-fitted with cylindrical surfaces, the relative angle between the fixing portion of the rotating disk of the encoder provided on the hollow shaft of the rotor and the magnetic poles of the magnet mounted on the rotor core is also uncertain.

[0010] Therefore, when the rotating disk is mounted, the angle between the coil and the magnetic pole of the motor viewed from the Z phase (the angle of the Z phase when the coil and the magnetic pole are aligned at a predetermined position) cannot be adjusted.

[0011] Therefore, it is desirable to accurately adjust the angle of the Z phase by determining the angle of the rotating disk through DC excitation.

[0012] Solutions to Solve Problems

[0013] According to a first aspect of the present disclosure, an actuator is provided, comprising a stator, the stator including a housing and a stator core fixed in the housing and wound with a plurality of coils, a rotor arranged opposite to the stator, the rotor including a rotor core forming a plurality of magnetic poles and a shaft connected to the rotor core, an encoder unit including a rotating disk connected to the shaft, a detection unit for detecting the rotation of the rotating disk, and a fixing unit fixed to the housing, and further comprising: a first structural unit for determining a relative angle between the plurality of coils of the stator core and the housing; a second structural unit for determining a relative angle between the magnetic poles of the rotor core and a fixed reference position of the rotating disk arranged on the shaft; a third structural unit for determining a relative angle between the shaft and the rotating disk; and a fourth structural unit for determining and adjusting a relative angle between the housing and the detection unit.

[0014] The objects, features, and advantages of the present disclosure will become more apparent from the following description of the embodiments in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is an axial cross-sectional view of the actuator according to the first embodiment.

[0016] Figure 2A It is a radial cross-sectional view of the shell.

[0017] Figure 2B It is a radial cross-sectional view of the stator core.

[0018] Figure 3 It is a perspective view showing the hollow shaft and the rotating disk.

[0019] Figure 4 It is an axial cross-sectional view of the actuator for explaining a modified example of the second structure portion.

[0020] Figure 5 yes Figure 1 Another axial cross-sectional view of the actuator shown.

[0021] Figure 6 This is an axial cross-sectional view of an actuator according to another embodiment.

[0022] Figure 7 This is the front view of the encoder fixing part.

[0023] Fig. 8A This is a partial cross-sectional view in the axial direction of an actuator according to another embodiment.

[0024] Figure 8B yes Figure 7 A is a radial cross-sectional view of the actuator. DETAILED DESCRIPTION

[0025] Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In all the drawings, corresponding components are denoted by common reference symbols.

[0026] Figure 1 This is an axial cross-sectional view of the actuator according to the first embodiment. Figure 1 The actuator 1 shown mainly includes a motor 5, such as a servo motor, which is composed of a stator 10 and a rotor 20, and an encoder 40 connected to the motor 5. The encoder 40 having a rotating disk 41 is, for example, an incremental encoder, and outputs signals of phases A, B, and Z. The encoder 40 may also be an optical encoder or a magnetic encoder.

[0027] The stator 10 includes a stator core 11 disposed in a housing 12. The stator core 11 includes a plurality of coils 13 disposed around the central axis of the motor 5. The rotor 20 is rotatably disposed inside the stator core 11. The rotor 20 includes a rotor core 21 having a plurality of magnets 22, such as permanent magnets, disposed on the outer circumference thereof, and a hollow shaft 23 that rotates integrally with the rotor core 21 on the central axis of the motor 5. The hollow shaft 23 is rotatably disposed in the housing 12 via bearings 51 and 52.

[0028] Figure 2A is the radial cross-sectional view of the shell. Figure 2A As shown, a pair of key grooves 16 are formed on the inner circumferential surface of the housing 12. These key grooves 16 are formed at positions opposite to each other in the diameter direction of the housing 12. The number of key grooves 16 is preferably more than one. In addition, a plurality of key grooves 16 may also be formed at unequal intervals in the circumferential direction of the housing 12.

[0029] Figure 2B is a radial cross-sectional view of the stator core. Figure 2B As shown in FIG. 1 , a plurality of coils 13 are fixed at equal intervals on the inner circumferential surface of the stator core 11. A plurality of slots 17 are formed on the outer circumferential surface of the stator core 11 at positions corresponding to the central portions of the plurality of coils 13. Furthermore, parallel keys 15 extending parallel to the axial direction of the hollow shaft 23 are inserted into a pair of slots 17 corresponding to each other along the diameter direction of the stator core 11. The number of parallel keys 15 is preferably one or more. Figure 2B In the embodiment, the parallel key 15 is inserted into a pair of grooves 17 that are opposite to each other in the diameter direction. However, the parallel key 15 may be inserted into another groove 17 located at a position corresponding to the key groove 16. Furthermore, the groove 17 may be formed at a position different from the central portion of the coil 13, for example, at a position corresponding to between two adjacent coils 13.

[0030] The position of one or more key slots 16 formed in the housing 12 is known in advance, and the positional relationship between the slot 17 and the coil 13 is also known in advance. Therefore, by inserting one or more parallel keys 15 into the slot 17 of the stator core 11 in a manner engaged with such a key slot 16, the relative angle between the plurality of coils 13 of the stator core 11 and the housing 12 can be determined. Therefore, the one or more parallel keys 15, the one or more key slots 16, and the one or more slots 17 function as the first structural portion 19 for determining the relative angle between the plurality of coils 13 of the stator core 11 and the housing 12. In addition, the same effect can be obtained when the parallel key 15 is integrated with the slot 17 and a part of the parallel key 15 protrudes from the slot 17 as a convex portion.

[0031] Generally speaking, the rotor core 21 and the hollow shaft 23 of the rotor 20 are separate components, and they are connected to each other. Figure 1 It can be seen that the hollow shaft 23 is formed integrally with the rotor core 21. That is, the hollow shaft 23 and the rotor core 21 are a single component.

[0032] in addition, Figure 3 is a three-dimensional diagram showing the hollow shaft and the rotating disk. Figure 3 As shown in the figure, in order to accurately detect the Z phase by the rotating disk 41, a fixed reference part P for the rotating disk 41, such as a mark, is formed on a part of the outer peripheral surface of the hollow shaft 23. And the rotating disk 41 is attached to the hollow shaft 23 in such a manner that the fixed reference part P for the rotating disk corresponds to the slit S for the Z phase formed in advance on the rotating disk 41. Typically, the rotating disk 41 is attached to the hollow shaft 23 as described later in such a manner that the circumferential position of the fixed reference part P for the rotating disk and the circumferential position of the slit S for the Z phase coincide with each other.

[0033] As described above, the hollow shaft 23 is integrally formed with the rotor core 21, so the relative angle between the magnetic poles of the rotor core 21 and the fixed reference portion P provided on the hollow shaft 23 is automatically determined in a fixed manner. Therefore, the integrally formed hollow shaft 23 and the rotor core 21 function as the second structural portion 29 for determining the positional relationship between the fixed reference portion P for the rotating disk of the hollow shaft 23 and the magnetic poles of the magnet 22 mounted on the rotor core 21.

[0034] Figure 4 FIG. 2 is a cross-sectional view of the actuator in the axial direction for explaining a modified example of the second structural portion. Figure 4 In the actuator 1' shown, the rotor core 21 and the hollow shaft 23 are separate components. One or more grooves (not shown) are formed on the inner circumference of the rotor core 21 and the outer circumference of the hollow shaft 23, respectively.

[0035] Furthermore, one or more parallel keys 26 extending parallel to the axial direction of the hollow shaft 23 are engaged with the grooves of the rotor core 21 and the grooves of the hollow shaft 23, thereby coupling the rotor core 21 and the hollow shaft 23. The number and position of the parallel keys 26 are the same as those of the parallel keys 15 described above.

[0036] The rotor core 21 and the hollow shaft 23 are connected to each other through the parallel keys 26 and the grooves, so the relative angle between the magnetic poles of the rotor core 21 and the fixed reference portion P provided in the hollow shaft 23 is automatically determined in a fixed manner. Therefore, the groove formed on the inner circumference of the rotor core 21, the groove formed on the outer circumference of the hollow shaft 23, and the parallel keys 26 function as the second structural portion 29. In addition, the parallel keys 26 are integrated with the corresponding grooves, and a part of the parallel keys 26 protrudes from the grooves as a convex portion, and the same effect can be obtained.

[0037] like Figure 1 As shown, the hollow shaft 23 includes an expansion portion 23A whose thickness expands toward the inner side of the hollow shaft 23 in the radial direction between the rotating disk 41 and the motor 5. The expansion portion 23A is formed at one end of the hollow shaft 23 on the encoder 40 side. Due to the presence of such an expansion portion 23A, the inner diameter D1 of the hollow shaft 23 is larger than the inner diameter D2 of the expansion portion 23A. In one embodiment, (D1-D2) / D1 is preferably 0.1 to 0.2. The length and thickness of the expansion portion 23A in the axial direction of the hollow shaft 23 are large enough to accommodate the rotating disk fixing portion 35 described later.

[0038] exist Figure 1 In the embodiment, the rotating disk 41 of the encoder 40 is fixed to the end surface of the expansion part 23A by the rotating disk fixing part 35. Typically, the rotating disk fixing part 35 is a combination of a plurality of first screws 35 extending parallel to the axial direction of the hollow shaft 23 and a plurality of holes formed on the end surface of the expansion part 23A in a manner corresponding to the plurality of first screws 35. However, other types of rotating disk fixing parts 35 capable of fixing the rotating disk 41 to the expansion part 23A may also be used.

[0039] Therefore, in the first embodiment, the rotating disk 41 of the encoder 40 can be easily connected to the end surface of the hollow shaft 23. In addition, the number of the plurality of first screws 35 and the number of the plurality of holes may be different, and the plurality of first screws 35 may not be arranged at equal intervals in the circumferential direction of the hollow shaft 23.

[0040] Figure 5 yes Figure 1 Another axial cross-sectional view of the actuator shown. Figure 5In the embodiment, at least one filament C, such as a cable or a pipe for supplying power, signal or material, passes through the inner space of the hollow shaft 23 and penetrates the actuator 1. At least one filament C is connected to the actuator 1 by a fixing portion ( Figure 1 , Figure 5 (not shown) fixed.

[0041] according to Figure 1 as well as Figure 5 It can be seen that the thickness of the expanded portion 23A is sufficiently smaller than the inner diameter of the hollow shaft 23, so even if the expanded portion 23A is formed, it is not necessary to reduce the number of linear bodies C, and the slack of these linear bodies C can be maintained.

[0042] Strictly speaking, in Figure 1 as well as Figure 5 In the embodiment, the rotating disk 41 is fixed to the end face of the expansion part 23A via the boss 25 by using a plurality of first screws 35. The boss 25 is preferably mounted on the rotating disk 41 by an adhesive or the like. In addition, the rotating disk 41 may also be directly fixed to the end face of the expansion part 23A. In this case, it is possible to more easily connect the rotating disk 41 of the encoder to the hollow shaft 23. It can be seen that the expansion part 23A, the hole formed in the expansion part 23A, and the first screws 35 serve as the third structural part 39 for determining the relative angle between the hollow shaft 23 and the rotating disk 41.

[0043] in addition, Figure 6 The actuator 1a in the other embodiment has an expansion portion 23B whose thickness expands toward the radial outer side of the hollow shaft 23 between the rotating disk 41 and the motor 5 instead of the expansion portion 23A. Figure 6 As shown, the inner diameter D1 of the hollow shaft 23 is equal to the inner diameter D2' of the expansion portion 23B. In other words, even if the expansion portion 23B is formed, the inner diameter of the hollow shaft 23 does not change in the entire hollow shaft 23. In addition, the rotating disk 41 of the encoder 40 is fixed to the end surface of the expansion portion 23B by a plurality of first screws 35 extending parallel to the axial direction of the hollow shaft 23.

[0044] In this case, the inner diameter of the expansion portion 23B is equal to the inner diameter of the other portions of the hollow shaft 23, and thus Figure 1 Compared with the embodiment shown in the figure, more than one linear body C can be passed through the hollow shaft 23 with a margin. In addition, as described above, the case where the rotating disk 41 is directly fixed to the end surface of the expansion part 23B without passing through the boss 25 is also included in the scope of the present disclosure. Furthermore, the case where both the expansion part 23A and the expansion part 23B are formed at one end of the hollow shaft 23 is also included in the scope of the present disclosure.

[0045] Reference Figure 1 The detection unit 42 provided on the substrate 49 of the encoder 40 detects the absolute position PA1 and the total number of rotations PB1 of the hollow shaft 23 within one rotation by a known method. The detected information is stored in a memory (not shown), such as a volatile memory.

[0046] Figure 7 This is the front view of the encoder fixing part. Figure 1 as well as Figure 7 It can be seen that a plurality of long holes 46 are formed on the base plate 49 of the encoder fixing portion 43 of the encoder 40. The portion of each long hole 46 extending in the circumferential direction of the hollow shaft 23 is longer than the portion extending in the radial direction of the hollow shaft 23. The long hole 46 is typically an oblong or elliptical shape, but may also be other shapes.

[0047] Furthermore, the plurality of second screws 45 are inserted into the plurality of long holes 46 of the base plate 49 and fixed to the housing 12. For this purpose, holes for the plurality of second screws 45 are formed in the housing 12. The second screws 45 preferably extend parallel to the axial direction of the hollow shaft 23. The long holes 46 are not circular, so after the second screws 45 are screwed together, the position of the encoder fixing portion 43 can be finely adjusted in the circumferential direction within the range of the circumferential length of the long holes 46.

[0048] The detection part 42 is located at a predetermined position relative to the fixing part 43 of the encoder 40, so the detection part 42 can be arranged at a desired position relative to the housing 12. Therefore, the plurality of second screws 45 and the long holes 46, as well as the hole of the housing 12, function as a fourth structure part 48 for determining and adjusting the relative angle between the housing 12 and the detection part 42. The fourth structure part 48 can leave a margin for adjusting the position of the detection part 42 in the rotation direction after the encoder 40 is mounted.

[0049] Fig. 8A is a partial cross-sectional view in the axial direction of an actuator according to another embodiment. Figure 8B yes Fig. 8A The radial cross-sectional view of the actuator is shown in FIG. Fig. 8A In FIG. 4 , the encoder 40 is omitted for the sake of simplicity. Fig. 8A The housing 12 of the actuator 1b shown has a plurality of through holes formed in parallel with the axial direction of the hollow shaft 23. The stator core 11 has a flange 11a extending radially outward from the hollow shaft 23 to the outer peripheral surface of the housing 12.

[0050] like Fig. 8A As shown, the flange 11a is configured to engage with the notch portion of the housing 12. In other words, the flange 11a is sandwiched by the housing 12 from the upstream and downstream sides of the hollow shaft 23 in the axial direction.

[0051] The flange 11a of the stator core 11 is also formed with a plurality of through holes corresponding to the through holes of the housing 12. In other words, the plurality of through holes of the flange 11a communicate with the plurality of through holes of the housing 12, respectively.

[0052] The tie rods TL are positioned in the through holes of the flange 11a. The length of the tie rods TL is longer than the length of the flange 11a in the axial direction of the hollow shaft 23, and shorter than the length of the housing 12 in the axial direction of the hollow shaft 23. Therefore, both ends of each tie rod TL do not reach both ends of the housing 12 in the axial direction of the hollow shaft 23.

[0053] Depend on Figure 8B It can be seen that the plurality of tie rods TL are arranged at equal intervals in the circumferential direction of the hollow shaft 23. However, the plurality of tie rods TL may be arranged at unequal intervals in the circumferential direction of the hollow shaft 23.

[0054] And, if Fig. 8A As shown, a plurality of tie bolts TB are inserted into the aforementioned through holes from both ends of the housing 12 in the axial direction of the hollow shaft 23, and are respectively connected with the plurality of tie rods TL. For this purpose, it is preferred that internal threads are formed at both ends of each of the plurality of tie rods TL. In this way, the plurality of tie bolts TB and the plurality of tie rods TL fix the housing 12 and the stator core 11.

[0055] Therefore, the relative angle between the coil 13 of the stator core 11 and the housing 12 is fixed. In other words, the flange 11a, the tie rod TL, and the tie bolt TB function as the first structural portion 19. In addition, the tie rod TL may be absent, and the tie bolt TB may be screwed with the thread formed on the inner surface of the through hole of the flange 11a and the through hole of the housing 12.

[0056] Furthermore, in an embodiment not shown in the figure, a plurality of tie rods TL may be used which are longer than the length of the housing 12 in the axial direction of the hollow shaft 23 and have external threads formed on both ends thereof. In this case, the external threads of the plurality of tie rods TL protrude from both ends of the through hole, so that nuts are screwed into the external threads instead of the tie bolts TB.

[0057] Alternatively, in other embodiments not shown, multiple tie rods TL may be eliminated and multiple bolts longer than the length of the housing 12 in the axial direction of the hollow shaft 23 may be used. Then, the bolts are screwed into the internal threads of the through hole pre-formed in the flange 11a and the through hole of the housing 12.

[0058] In these embodiments not shown in the figure, the relative angle between the coil 13 of the stator core 11 and the housing 12 can be fixedly determined in the same manner as described above. Therefore, the nuts and bolts described above also function as the first structural portion 19.

[0059] Thus, in the present disclosure, the relative angle between the plurality of coils 13 of the stator core 11 and the housing 12 is determined by the first structural portion 19, the relative angle between the magnetic pole of the rotor core 21 and the fixed reference position of the rotating disk 41 provided on the shaft 23 is determined by the second structural portion 29, the relative angle between the shaft 23 and the rotating disk 41 is determined by the third structural portion 39, and the relative angle between the housing 12 and the detection portion 42 can be determined and adjusted by the fourth structural portion 48. Therefore, the angle of the Z phase of the encoder unit can be accurately adjusted.

[0060] The method disclosed

[0061] According to a first embodiment, an actuator is provided, comprising a stator including a housing and a stator core fixed in the housing and wound with a plurality of coils, a rotor arranged relative to the stator and including a rotor core forming a plurality of magnetic poles and a shaft connected to the rotor core, an encoder unit including a rotating disk connected to the shaft, a detection unit for detecting the rotation of the rotating disk, and a fixing unit fixed to the housing, and further comprising: a first structural unit for determining a relative angle between the plurality of coils of the stator core and the housing; a second structural unit for determining a relative angle between the magnetic poles of the rotor core and a fixed reference portion of the rotating disk arranged on the shaft; a third structural unit for determining a relative angle between the shaft and the rotating disk; and a fourth structural unit for determining and adjusting a relative angle between the housing and the detection unit.

[0062] According to a second aspect, in the first aspect, the third structure includes: a plurality of first screws that fix a boss mounted on the rotating disk or the rotating disk and the shaft; and a plurality of threaded holes that engage with the plurality of first screws and are formed on the shaft.

[0063] According to a third aspect, in the first or second aspect, the fourth structure portion includes: a plurality of long holes formed in the fixing portion of the encoder unit; and a plurality of second screws respectively inserted into the plurality of long holes.

[0064] According to a fourth aspect, in any one of the first to third aspects, the first structure portion includes: a plurality of key grooves formed in the stator core and the housing; and a plurality of parallel keys respectively engaged with the plurality of key grooves.

[0065] According to a fifth aspect, in any one of the first to third aspects, the first structural portion includes: a plurality of key slots formed in one of the housing and the stator core; and a plurality of protrusions provided in the other of the housing and the stator core, respectively engaging with the plurality of key slots.

[0066] According to the sixth aspect, in the first aspect, the first structural portion includes: a flange, which is provided on the stator core and engaged with the housing; a plurality of through holes, which are formed in the housing and the flange and are interconnected; and a plurality of tightening bolts, which are threadedly connected to the plurality of through holes.

[0067] According to a seventh aspect, in any one of the first to sixth aspects, the second structure portion includes: a plurality of key grooves formed in the rotor core and the shaft; and a plurality of parallel keys respectively engaged with the plurality of key grooves.

[0068] According to the eighth aspect, in any one of the first to sixth aspects, the second structural portion includes: a plurality of key grooves formed on one of the rotor core and the shaft; and a plurality of protrusions provided on the other of the rotor core and the shaft and respectively engaged with the plurality of key grooves.

[0069] According to a ninth aspect, in any one of the first to sixth aspects, in the second structure portion, the rotor core and the shaft are formed integrally.

[0070] According to a tenth aspect, in any one of the first to ninth aspects, the encoder is an optical encoder or a magnetic encoder.

[0071] Effect of method

[0072] In the first aspect, the Z-phase angle of the encoder unit can be accurately adjusted.

[0073] In the second mode, the relative angle between the shaft and the rotating disk can be fixedly determined.

[0074] In the third aspect, the relative angle between the housing and the detection portion is determined, and the relative angle is adjusted after the encoder is mounted.

[0075] In the fourth aspect, the relative angle between the plurality of coils of the stator core and the housing can be fixedly determined.

[0076] In the fifth aspect, the relative angle between the plurality of coils of the stator core and the housing can be fixedly determined.

[0077] In the sixth aspect, the relative angle between the plurality of coils of the stator core and the housing can be fixedly determined.

[0078] In the seventh aspect, the angle between the magnetic pole of the rotor core and the shaft can be fixedly determined.

[0079] In the eighth aspect, the angle between the magnetic pole of the rotor core and the shaft can be fixedly determined.

[0080] In the ninth aspect, the second structure portion can be easily configured.

[0081] The embodiments of the present disclosure are described in detail, but the present disclosure is not limited to the above-mentioned embodiments. These embodiments can be variously added, replaced, changed, partially deleted, etc. without departing from the scope of the main purpose of the invention, or without departing from the ideas and main purpose of the present invention derived from the contents recorded in the scope of the technical solution and its equivalents. For example, in the above-mentioned embodiments, the order of each action and the order of each processing are shown as an example, but are not limited to this. In addition, the same is true for the case where numerical values ​​or mathematical formulas are used in the description of the above-mentioned embodiments. Furthermore, several appropriately combined schemes in the above-mentioned embodiments are included in the scope of the present disclosure.

[0082] Explanation of symbols

[0083] 1, 1a - actuator, 5 - motor, 10 - stator, 11 - stator core, 11a - flange, 12 - housing, 13 - coil, 15 - parallel key, 19 - first structural part, 20 - rotor, 21 - rotor core, 22 - magnet, 23 - hollow shaft, 23A, 23B - expansion part, 25 - boss, 26 - parallel key, 29 - second structural part, 30 - reducer, 31 - low speed pipe, 32 - output shaft, 35 - first screw, 39 - third structural part, 40 - encoder, 41 - rotating disk, 42 ​​- detection part, 43 - encoder fixing part, 46 - long hole, 48 - fourth structural part, 49 - substrate, 51, 52 - bearings, 61, 62 - fixing part, C - line body, P - fixing reference part, S - slit for Z phase, TL - pull rod, TB - tightening bolt.

Claims

1. An actuator, characterized in that: With stator, The stator comprises a housing and a stator core fixed in the housing and wound with a plurality of coils. It also includes a rotor arranged opposite to the stator, The rotor includes a rotor core forming a plurality of magnetic poles and a shaft coupled to the rotor core. It also has an encoder unit. The encoder unit includes a rotating disk connected to the shaft, a detection unit for detecting the rotation of the rotating disk, and a fixing unit fixed to the housing. Also available: a first structural part that determines a relative angle between the plurality of coils of the stator core and the housing; a second structural part that determines a relative angle between a magnetic pole of the rotor core and a fixed reference portion of the rotating disk provided on the shaft; a third structural part, which determines a relative angle between the shaft and the rotating disk; as well as The fourth structural part determines and adjusts the relative angle between the housing and the detection part.

2. The actuator according to claim 1, characterized in that The third structure part includes: a plurality of first screws that fix a boss mounted on the rotating disk or the rotating disk and the shaft; and a plurality of threaded holes that are engaged with the plurality of first screws and are formed on the shaft.

3. The actuator according to claim 1 or 2, characterized in that: The fourth structure portion includes: a plurality of long holes formed in the fixing portion of the encoder unit; and a plurality of second screws respectively inserted into the plurality of long holes.

4. The actuator according to any one of claims 1 to 3, characterized in that: The first structure portion includes: a plurality of key slots formed in the stator core and the housing; and a plurality of parallel keys respectively engaged with the plurality of key slots.

5. The actuator according to any one of claims 1 to 3, characterized in that: The first structure portion includes: a plurality of key grooves formed in one of the housing and the stator core; and a plurality of protrusions provided in the other of the housing and the stator core and respectively engaged with the plurality of key grooves.

6. The actuator according to claim 1, characterized in that The first structural part comprises: A flange, which is disposed on the stator core and is engaged with the housing; a plurality of through holes formed in the housing and the flange and communicating with each other; and A plurality of tie bolts are threadedly coupled to the plurality of through holes.

7. The actuator according to any one of claims 1 to 6, characterized in that: The second structure portion includes: a plurality of key grooves formed in the rotor core and the shaft; and a plurality of parallel keys respectively engaged with the plurality of key grooves.

8. The actuator according to any one of claims 1 to 6, characterized in that: The second structure portion includes: a plurality of key grooves formed in one of the rotor core and the shaft; and a plurality of protrusions provided in the other of the rotor core and the shaft and respectively engaged with the plurality of key grooves.

9. The actuator according to any one of claims 1 to 6, characterized in that: In the second structure portion, the rotor core and the shaft are formed integrally.

10. The actuator according to any one of claims 1 to 9, characterized in that The encoder is an optical encoder or a magnetic encoder.

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