Assembly method of electric motor

Abstract

To prevent a rotor from contacting a stator.SOLUTION: A stator includes a plurality of exciting magnetic poles, and a rotor includes a plurality of first magnetization parts magnetized to an N-pole and a plurality of second magnetization parts magnetized to an S-pole. The first magnetization parts and the second magnetization parts are alternately arranged along a circumferential direction around an axis line. An assembly method of a scroll compressor includes: a fixing step S101 for fixing a rotation position of the rotor so that the rotor does not rotate around the axis line; a current supply step for supplying magnetization current to the exciting magnetic poles of prescribed phases, which are included in the plurality of exciting magnetic poles; and an insertion step S103 for inserting the rotor whose rotation position is fixed by the fixing step into the stator along the axis line and causing a tip part of the rotor to be supported by a bearing part in a state in which a position in the circumferential direction of the first magnetization part or the second magnetization part whose polarity becomes the same as the exciting magnetic pole of the prescribed phase, which is magnetized by the current supply step, is matched with the position in the circumferential direction of the exciting magnetic pole of the prescribed phase.SELECTED DRAWING: Figure 5

Description

Technical Field

[0001] The present disclosure relates to a method for assembling an electric motor.

Background Art

[0002] Conventionally, an electric supercharger including a motor for driving a compressor has been known (see, for example, Patent Document 1). Patent Document 1 discloses that when inserting and assembling a stator with respect to a rotor provided with a strong permanent magnet, in order to avoid the stator and other metal members coming into contact with and sticking to the rotor due to magnetic force or being damaged, a protective cylinder formed of a material such as non-magnetic nylon is attached to the rotor. Patent Document 1 also discloses that after the stator is inserted and assembled with respect to the rotor, the protective cylinder is pulled out and removed from the rotor.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, for example, when inserting and assembling a rotor with respect to a fixed stator, in a structure where the protective cylinder cannot be removed from the rotor after the rotor is inserted, the rotor and the stator cannot be protected by members such as the protective cylinder disclosed in Patent Document 1.

[0005] The present disclosure has been made in view of such circumstances, and an object thereof is to provide a method for assembling an electric motor capable of preventing the rotor from contacting the stator when the rotor is inserted into the stator.

Means for Solving the Problems

[0006] In a method of assembling an electric motor according to an aspect of the present disclosure, the electric motor includes a housing formed in a cylindrical shape extending along an axis, a stator disposed inside the housing so as to extend along the axis, a rotor disposed on the inner circumferential side of the stator, a drive unit rotationally driven by the motor, and a bearing unit fixed to the bottom of the housing and supporting the tip of the rotor. The stator has a plurality of exciting magnetic poles corresponding to a plurality of phases of exciting current, and the rotor has a plurality of first magnetized portions magnetized to the N pole and a plurality of second magnetized portions magnetized to the S pole. The first magnetized portion and the second magnetized portion are alternately arranged along the circumferential direction around the axis. A fixing step of fixing the rotational position of the rotor so that the rotor does not rotate around the axis, a current supply step of supplying a magnetization current to the exciting magnetic pole of a predetermined phase included in the plurality of exciting magnetic poles, and the first magnetized portion or the second magnetized portion having the same polarity as the exciting magnetic pole of the predetermined phase magnetized in the current supply step. With the circumferential position of the exciting magnetic pole of the predetermined phase, the rotor whose rotational position is fixed by the fixing step is inserted into the stator along the axis so that the tip of the rotor is supported by the bearing unit. An insertion step is provided.

Effect of the Invention

[0007] According to the present disclosure, it is possible to provide a method of assembling an electric motor that can prevent the rotor from contacting the stator when the rotor is inserted into the stator.

Brief Description of the Drawings

[0008]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

MODE FOR CARRYING OUT THE INVENTION

[0009] A method of assembling a scroll compressor (motor) 100 according to an embodiment of the present disclosure will be described with reference to the drawings. The scroll compressor 100 of the present embodiment is used, for example, in a vehicle air conditioner.

[0010] FIG. 1 is a longitudinal sectional view showing a schematic configuration of the scroll compressor 100 according to the present embodiment, showing a state in which the scroll compressor 100 is assembled. As shown in FIG. 1, the scroll compressor 100 includes a bearing housing (first housing) 10, a rear housing (second housing) 20, a front housing (third housing) 30, a scroll compression mechanism (drive unit; compression unit) 40, a motor 50, a first bearing unit 60, a second bearing unit 65, an inverter 70, and a gasket 80.

[0011] The bearing housing 10, the rear housing 20, and the front housing 30 form the outer shell of the scroll compressor 100 and are formed of an aluminum alloy. The bearing housing 10 is formed in a cylindrical shape along an axis X1 that is the center around which the orbiting scroll 42 orbits. The bearing housing 10 has an internal space for accommodating the first bearing unit 60 and the scroll compression mechanism 40.

[0012] The rear housing 20 seals one end along the axis X1 of the bearing housing 10, and is provided with a discharge port (not shown) for the refrigerant gas compressed by the scroll compression mechanism 40. The front housing 30 seals the other end along the axis X1 of the bearing housing 10, and is provided with an internal space for housing the motor 50 and the inverter 70. The internal space of the front housing 30 that houses the motor 50 communicates with the internal space of the bearing housing 10 that houses the first bearing portion 60. The internal space that houses the motor 50 and the internal space that houses the inverter 70 are independent spaces that do not communicate with each other.

[0013] The front housing 30 is provided with a suction port 31 for sucking the refrigerant. The refrigerant supplied from the outside is introduced into the internal space of the front housing 30 through the suction port 31. The refrigerant introduced into the front housing 30 passes through the motor 50 along the axis X1 and is guided toward the scroll compression mechanism 40. The refrigerant sucked from the suction port 31 is a mixed refrigerant (fluid) containing lubricating oil and refrigerant gas.

[0014] Insertion holes for inserting the fastening bolts 90 are formed in the bearing housing 10 and the rear housing 20. At the end of the front housing 30 on the side of the bearing housing 10, fastening holes (not shown) for fastening the male threads formed at the tip of the fastening bolts 90 are formed. The bearing housing 10 is fixed in a state of being sandwiched along the axis X1 between the rear housing 20 and the front housing 30 by fastening the fastening bolts 90 to the fastening holes formed in the front housing 30.

[0015] The scroll compression mechanism 40 is a device that is disposed inside the bearing housing 10 and rotates about the axis X1 to compress the refrigerant gas. The scroll compression mechanism 40 is rotationally driven about the axis X1 by the motor 50. The scroll compression mechanism 40 includes a fixed scroll 41 that is sandwiched and fixed between the bearing housing 10 and the rear housing 20, and a orbiting scroll 42 that meshes with the fixed scroll 41. The scroll compression mechanism 40 compresses the refrigerant gas by causing the orbiting scroll 42 to revolve around the fixed scroll 41 by the driving force of the motor 50.

[0016] The fixed scroll 41 has a spiral wrap (first wall body) 41B that is a wall body erected on one side surface of an end plate (first end plate) 41A. A discharge port 41C through which the refrigerant gas compressed by the fixed scroll 41 and the orbiting scroll 42 is discharged is formed in the end plate 41A.

[0017] The orbiting scroll 42 has a spiral wrap (second wall body) 42B that is a wall body erected on one side surface of an end plate (second end plate) 42A. The orbiting scroll 42 is connected to an eccentric shaft (not shown) connected to the motor 50 and is supported so as to be capable of revolving and orbiting through a rotation prevention mechanism (not shown). The orbiting scroll 42 is supported so as to be capable of revolving and orbiting while being meshed with the spiral wrap 41B of the fixed scroll 41 to prevent rotation.

[0018] As shown in FIG. 1, the scroll compression mechanism 40 has a reed valve 43 attached to the fixed scroll 41 so as to close the discharge port 41C. The reed valve 43 is in an open state when the pressure of the refrigerant gas in the compression chamber 40A becomes a predetermined pressure or more, and guides the refrigerant gas discharged from the discharge port 41C to the discharge space 41D. The refrigerant gas guided to the discharge space 41D is guided to the outside through a discharge port (not shown).

[0019] The motor 50 is a device that rotationally drives the orbiting scroll 42 of the scroll compression mechanism 40 around the axis X1 with respect to the fixed scroll 41. The motor 50 is connected to the orbiting scroll 42 via an eccentric shaft (not shown). Here, with reference to FIG. 2, the details of the motor 50 will be described. FIG. 2 is a cross-sectional view taken along the line A-A of the scroll compressor 100 shown in FIG. 1, and is a view with the front housing 30 omitted. As shown in FIGS. 1 and 2, the motor 50 includes a stator 51 and a rotor 52 disposed on the inner circumferential side of the stator 51.

[0020] The stator 51 is configured by laminating a predetermined number of electromagnetic steel sheets punched into an annular shape. The stator 51 is disposed inside the bearing housing 10 so as to extend along the axis X1. As shown in FIG. 2, a plurality of teeth portions 51a are provided on the inner circumferential side of the stator 51. Coil windings 51b are wound around each of the plurality of teeth portions 51a of the stator 51 via bobbins (not shown).

[0021] The stator 51 has a first excitation pole 51c1 corresponding to the excitation current of the U phase, a second excitation pole 51c2 corresponding to the excitation current of the V phase, and a third excitation pole 51c3 corresponding to the excitation current of the W phase during the normal operation of the motor 50. As shown in FIG. 2, the first excitation pole 51c1 is arranged at three locations at 120-degree intervals along the circumferential direction CD around the axis X1, the second excitation pole 51c2 is arranged at three locations at 120-degree intervals along the circumferential direction CD around the axis X1, and the third excitation pole 51c3 is arranged at three locations at 120-degree intervals along the circumferential direction CD around the axis X1.

[0022] In this embodiment, it is assumed that the stator 51 has the first excitation pole 51c1, the second excitation pole 51c2, and the third excitation pole 51c3 corresponding to the three phases of the U phase, V phase, and W phase, but other embodiments may also be possible. The excitation poles may be arranged at intervals along the circumferential direction CD so as to correspond to a plurality of phases other than the three phases.

[0023] The rotor 52 has a plurality of first magnetized portions 52a1 magnetized to the N pole and a plurality of second magnetized portions 52a2 magnetized to the S pole. The first magnetized portions 52a1 and the second magnetized portions 52a2 are alternately arranged along the circumferential direction CD around the axis X1.

[0024] The first bearing portion 60 is a member that supports one end of the rotor 52 that rotates around the axis X1 by the motor 50. An eccentric shaft is provided at the end of the rotor 52 on the scroll compressor mechanism 40 side, which is arranged eccentrically with respect to the axis X1.

[0025] Here, with reference to FIGS. 3 and 4, the second bearing portion 65 will be described. FIG. 3 is a longitudinal sectional view showing a schematic configuration of the scroll compressor 100 according to an embodiment of the present disclosure, showing a state before assembling the scroll compressor 100. FIG. 4 is a sectional view taken along the line B-B of the scroll compressor 100 shown in FIG. 3, with the front housing 30 omitted.

[0026] As shown in FIGS. 3 and 4, the second bearing portion 65 is a member that supports the tip portion 52a of the rotor 52 that rotates around the axis X1 by the motor 50. The second bearing portion 65 is fixed to the bottom portion 30a of the front housing 30.

[0027] The inverter 70 is a device that generates a drive voltage for driving the motor 50 and controls the rotation speed of the motor 50.

[0028] The gasket 80 is disposed between the end face 20a on the rear housing 20 side of the bearing housing 10 and the end face of the rear housing 20 on the bearing housing 10 side, and is a member that forms a sealing region so that the refrigerant does not flow out between the end faces 10a and 20a.

[0029] Next, with reference to FIG. 5, a method for assembling the scroll compressor 100 of the present embodiment will be described. FIG. 5 is a flowchart showing a method for assembling the scroll compressor 100 according to an embodiment of the present disclosure. The method for assembling the scroll compressor 100 of the present embodiment is a method for changing the state before assembling the scroll compressor 100 shown in FIG. 3 to the state after assembling the scroll compressor 100 shown in FIG. 1.

[0030] As shown in FIG. 3, in the scroll compressor 100 before assembly, the stator 51 is fixed inside the front housing 30 by shrink fitting, and the rotor 52 is removed from the front housing 30.

[0031] In step S101, the operator attaches the fixing jig 110 to the rotor 52 so that the rotor 52 does not rotate around the axis X1, and fixes the rotational position of the rotor 52 around the axis X1 (fixing step). Note that the operation in step S101 may be performed not by the operator but by an automatic attachment device (not shown) that attaches the fixing jig 110 to the rotor 52. In step S101, as shown in FIG. 2, the rotational position of the rotor 52 around the axis X1 is fixed so that the positions of the plurality of first magnetizing portions 52a1 in the circumferential direction CD coincide with the positions of the second exciting magnetic poles 51c2 in the circumferential direction CD.

[0032] In step S102, the operator operates the current supply source 120 to start supplying the magnetizing current to the plurality of second exciting magnetic poles 51c2 corresponding to the V phase. In response to being instructed by the operator to start supplying the magnetizing current, the current supply source 120 starts supplying the magnetizing current to the plurality of second exciting magnetic poles 51c2 via the current supply line 121. The second exciting magnetic poles 51c2 are magnetized to the N pole, which has the same polarity as the first magnetizing portion 52a1, by the magnetizing current supplied from the current supply source 120.

[0033] Note that the instruction in step S102 may be performed not by the operator but by a control device (not shown). The supply of the magnetizing current to the second exciting magnetic poles 51c2 started in step S102 is executed until it is stopped in step S104.

[0034] In step S103, the operator moves the rotor 52 along the axis X1 toward the front housing 30 so as to insert the rotor 52, whose rotational position is fixed in step S101, into the stator 51 along the axis X1. For example, the operator moves the rotor 52 along the axis X1 toward the front housing 30 by operating a holding jig (not shown) that holds the rotor 52 on the axis X1. Note that the operation in step S103 may be performed not by the operator but by a control device (not shown).

[0035] As shown in FIG. 2, when the rotor 52 moves along the axis X1 toward the front housing 30, the position in the circumferential direction CD of the first magnetized portion 52a1 magnetized to the N pole is maintained in a state of being coincident with the position in the circumferential direction CD of the plurality of second exciting magnetic poles 51c2 by the fixing jig 110. The plurality of second exciting magnetic poles 51c2 are the magnetic poles corresponding to the V phase magnetized to the N pole by the exciting current in step S102.

[0036] Since the position in the circumferential direction CD of the first magnetized portion 52a1 magnetized to the N pole coincides with the position in the circumferential direction CD of the second exciting magnetic poles 51c2 magnetized to the N pole, the rotor 52 receives an equal magnetic force (repulsive force) directed from the stator 51 toward the axis X1 at three locations in the circumferential direction CD. Therefore, the rotor 52 is maintained such that its central axis is arranged on the axis X1 without contacting the stator 51.

[0037] In step S103, the operation of moving the rotor 52 along the axis X1 toward the front housing 30 is executed until the tip portion 52a of the rotor 52 is supported by the second bearing portion 65. When the tip portion 52a of the rotor 52 is supported by the second bearing portion 65, the operation of moving the rotor 52 along the axis X1 toward the front housing 30 is stopped.

[0038] In step S104, the operator operates the current supply source 120 to stop supplying the magnetization current to the plurality of second excitation magnetic poles 51c2 corresponding to the V phase. In response to the instruction from the operator to stop supplying the magnetization current, the current supply source 120 stops supplying the magnetization current to the plurality of second excitation magnetic poles 51c2 via the current supply line 121.

[0039] Through the above steps S101 to S104, the scroll compressor 100 becomes the assembled state shown in FIG. 1. In the state shown in FIG. 1, the operator fastens the fastening bolt 90 to the fastening hole formed in the front housing 30, so that the bearing housing 10 is fixed in a state of being sandwiched along the axis X1 between the rear housing 20 and the front housing 30, and the bearing housing 10, the rear housing 20, and the front housing 30 are integrated.

[0040] The actions and effects of the assembly method of the scroll compressor 100 of the present embodiment described above will be described. According to the assembly method of the scroll compressor 100 of the present embodiment, the position of the circumferential direction CD of the first magnetization portion 52a1 having the same polarity as the second excitation magnetic pole 51c2 of the V phase magnetized by the current supply process (steps S102 to S104) coincides with the position of the circumferential direction CD of the second excitation magnetic pole 51c2 of the V phase. In this state, the rotor 52 whose rotational position is fixed by the fixing process (step S101) is inserted into the stator 51 along the axis X1. Since the first magnetization portion 52a1 having the same polarity (N pole) as the magnetized second excitation magnetic pole 51c2 of the V phase is arranged at the position where the circumferential direction CD coincides, the rotor 52 receives an equal magnetic force (repulsive force) directed from the stator 51 toward the axis X1. Since the rotor 52 is maintained so that the central axis is arranged on the axis X1 without contacting the stator 51, it is possible to provide an assembly method of the scroll compressor 100 that prevents the rotor 52 from contacting the stator 51 when the rotor 52 is inserted into the stator 51.

[0041] According to the assembly method of the scroll compressor 100 of the present embodiment, when the position of the first magnetized portion 52a1 in the circumferential direction CD, which has the same polarity as the second exciting magnetic pole 51c2 of the V phase magnetized by the current supply process (from step S102 to step S104), does not completely coincide with the position of the second exciting magnetic pole 51c2 of the V phase in the circumferential direction CD, the rotor 52 does not receive an equal magnetic force directed from the stator 51 toward the axis X1, and the rotor 52 moves in the direction of rotating around the axis X1 with respect to the stator 51.

[0042] Here, in the current supply process (from step S102 to step S104), the direction of the magnetizing current is switched so that the polarity of the second exciting magnetic pole 51c2 of the V phase temporarily becomes the reverse polarity. By this switching, the direction in which the rotor 52 rotates around the axis X1 with respect to the stator 51 becomes the reverse direction, and the rotational position of the rotor 52 is pulled back. By repeating this operation, the position of the first magnetized portion 52a1 in the circumferential direction CD, which has the same polarity as the second exciting magnetic pole 51c2 of the V phase magnetized by the current supply process (from step S102 to step S104), is made to completely coincide with the position of the second exciting magnetic pole 51c2 of the V phase in the circumferential direction CD, and by switching the direction of the exciting current again in that state, the rotor 52 can receive an equal magnetic force (repulsive force) directed from the stator 51 toward the axis X1.

[0043] According to the assembly method of the scroll compressor 100 of the present embodiment, the rotational position of the rotor 52 is fixed so that the rotor 52 can swing within a predetermined range of rotational angles. Therefore, in the current supply process (from step S102 to step S104), when the direction of the magnetizing current is switched so that the polarity of the second exciting magnetic pole 51c2 of the V phase temporarily becomes the reverse polarity, the rotor 52 is swung around the axis X1 to create a state where the position of the first magnetized portion 52a1 in the circumferential direction CD, which has the same polarity as the second exciting magnetic pole 51c2 of the V phase magnetized by the current supply process, completely coincides with the position of the second exciting magnetic pole 51c2 of the V phase in the circumferential direction CD.

[0044] 〔Other Embodiments〕 In the above description, in steps S102 to S104, the magnetization current is supplied to the plurality of second excitation magnetic poles 51c2 corresponding to the V phase, but other embodiments may also be possible. For example, the magnetization current may be supplied to the first excitation magnetic pole 51c1 corresponding to the U phase. Further, the magnetization current may be supplied to the third excitation magnetic pole 51c3 corresponding to the W phase.

[0045] In the above description, in steps S102 to S104, the magnetization current is supplied so as to magnetize the plurality of second excitation magnetic poles 51c2 corresponding to the V phase to the N pole, but other embodiments may also be possible. For example, in steps S102 to S104, the magnetization current may be supplied so as to magnetize the plurality of second excitation magnetic poles 51c2 corresponding to the V phase to the S pole. In this case, in step S101, the rotational position of the rotor 52 around the axis X1 is fixed so that the positions in the circumferential direction CD of the plurality of second magnetized portions 52a2 magnetized to the S pole coincide with the positions in the circumferential direction CD of the second excitation magnetic poles 51c2.

[0046] In the above description, the magnetization current is supplied so as to magnetize the plurality of second excitation magnetic poles 51c2 corresponding to the V phase to the N pole, but other embodiments may also be possible. For example, in the state where the magnetization current is supplied so as to magnetize the plurality of second excitation magnetic poles 51c2 corresponding to the V phase to the N pole in steps S102 to S104, the flow direction of the magnetization current may be switched so that the plurality of second excitation magnetic poles 51c2 are temporarily magnetized to the S pole. For example, it is preferable to switch the flow direction of the magnetization current so that the plurality of second excitation magnetic poles 51c2 are temporarily magnetized to the S pole at a frequency of 1 to 5 Hz.

[0047] When switching the direction of the exciting current so as to temporarily magnetize a plurality of second exciting poles 51c2 magnetized to the N pole to the S pole, in step S101, the fixing jig 110 fixes the rotational position of the rotor 52 so that the rotor 52 can swing within a predetermined range of rotational angles. As shown in FIG. 4, when the angle in the circumferential direction CD of the adjacent tooth portions 51a along the circumferential direction CD is θ, the predetermined rotational angle at which the fixing jig 110 allows the rotor 52 to swing is preferably set to be θ or more and 2θ or less.

[0048] The method for assembling the motor according to the embodiment described above can be understood as follows, for example. In the method for assembling a motor (100) according to the first aspect of the present disclosure, the motor includes a housing (10, 20, 30) formed in a cylindrical shape extending along an axis (X1), a stator (51) disposed inside the housing so as to extend along the axis, a rotor (52) disposed on the inner circumferential side of the stator, a drive unit (40) rotationally driven by the motor, and a bearing unit (65) fixed to the bottom portion (30a) of the housing and supporting the tip of the rotor. The stator has a plurality of exciting poles (51c1, 51c2, 51c3) corresponding to exciting currents of a plurality of phases. The rotor has a plurality of first magnetized portions (52a1) magnetized to the N pole and a plurality of second magnetized portions (52a2) magnetized to the S pole. The first magnetized portion and the second magnetized portion are alternately arranged along the circumferential direction around the axis. A fixing step (S101) of fixing the rotational position of the rotor so that the rotor does not rotate around the axis, a current supply step (S102 to S104) of supplying an exciting current to the exciting pole of a predetermined phase included in the plurality of exciting poles, and the rotational position is fixed by the fixing step in a state where the position in the circumferential direction of either the first magnetized portion or the second magnetized portion having the same polarity as the exciting pole of the predetermined phase magnetized by the current supply step coincides with the position in the circumferential direction of the exciting pole of the predetermined phase. An insertion step (S103) of inserting the rotor into the stator along the axis so that the tip of the rotor is supported by the bearing unit.

[0049] According to the method for assembling an electric motor according to the first aspect of the present disclosure, with the circumferential position of either the first magnetizing portion or the second magnetizing portion having the same polarity as the magnetized exciting poles of a predetermined phase being in agreement with the circumferential position of the exciting poles of the predetermined phase in the current supply step, the rotor whose rotational position is fixed by the fixing step is inserted into the stator along the axis. Since the first magnetizing portion or the second magnetizing portion having the same polarity is arranged at a position where the circumferences match with respect to the magnetized exciting poles of the predetermined phase, the rotor receives uniform magnetic force (repulsive force) directed from the stator toward the axis. Since the rotor is maintained so that the central axis is arranged on the axis without contacting the stator, it is possible to provide a method for assembling an electric motor that can prevent the rotor from contacting the stator when the rotor is inserted into the stator.

[0050] The method for assembling an electric motor according to the second aspect of the present disclosure further includes the following configuration in the first aspect. That is, in the current supply step, the direction of flow of the magnetizing current is switched so that the polarity of the exciting poles of the predetermined phase temporarily becomes the reverse polarity.

[0051] According to the method for assembling an electric motor according to the second aspect of the present disclosure, when the circumferential position of either the first magnetizing portion or the second magnetizing portion having the same polarity as the magnetized exciting poles of a predetermined phase does not completely match the circumferential position of the exciting poles of the predetermined phase, the rotor does not receive uniform magnetic force directed from the stator toward the axis, and the rotor moves in the direction of rotating around the axis with respect to the stator.

[0052] Here, in the current supply step, the flow direction of the magnetization current is switched so that the polarity of the exciting magnetic pole of a predetermined phase temporarily becomes the reverse polarity. By this switching, the direction in which the rotor rotates around the axis with respect to the stator becomes the reverse direction, and the rotational position of the rotor is pulled back. By repeating this operation, a state is created in which the circumferential position of either the first magnetized portion or the second magnetized portion, which has the same polarity as the exciting magnetic pole of the predetermined phase magnetized in the current supply step, exactly coincides with the circumferential position of the exciting magnetic pole of the predetermined phase. Then, by switching the flow direction of the exciting current again in that state, the rotor 52 can receive an equal magnetic force (repulsive force) directed from the stator 51 toward the axis X1.

[0053] According to the method of assembling an electric motor according to the third aspect of the present disclosure, in the second aspect, it further includes the following configuration. That is, in the fixing step, the rotational position of the rotor is fixed so that the rotor can swing within a predetermined range of rotational angles.

[0054] According to the method of assembling an electric motor according to the third aspect of the present disclosure, the rotational position of the rotor is fixed so that the rotor can swing within a predetermined range of rotational angles. Therefore, in the current supply step, when the flow direction of the magnetization current is switched so that the polarity of the exciting magnetic pole of a predetermined phase temporarily becomes the reverse polarity, the rotor is swung around the axis, and the circumferential position of either the first magnetized portion or the second magnetized portion, which has the same polarity as the exciting magnetic pole of the predetermined phase magnetized in the current supply step, can be gradually brought closer to a state where it exactly coincides with the circumferential position of the exciting magnetic pole of the predetermined phase.

Explanation of Reference Numerals

[0055] 10 Bearing housing 20 Rear housing 30 Front housing 30a Bottom 40 Scroll compression mechanism (drive unit; compression unit) 41 Fixed scroll 42 Orbiting scroll 50 Motor 51 Stator 51a Tooth part 51b Coil winding 51c1 First excitation magnetic pole 51c2 Second excitation magnetic pole 51c3 Third excitation magnetic pole 52 Rotor 52a Tip part 52a1 First magnetization part 52a2 Second magnetization part 60 First bearing part 65 Second bearing part 70 Inverter 80 Gasket 90 Fastening bolt 100 Scroll compressor (motor) 110 Fixing jig 120 Current supply source 121 Current supply line CD Circumferential direction X1 Axis

Claims

1. A method for assembling an electric motor, comprising: The electric motor includes: A housing formed in a cylindrical shape extending along an axis; A stator disposed inside the housing and extending along the axis, and a rotor disposed on the inner circumferential side of the stator; A drive unit rotationally driven by the motor; A bearing unit fixed to the bottom of the housing and supporting the tip of the rotor; The stator has a plurality of exciting magnetic poles corresponding to exciting currents of a plurality of phases; The rotor has a plurality of first magnetized portions magnetized to the N pole and a plurality of second magnetized portions magnetized to the S pole; The first magnetized portions and the second magnetized portions are alternately arranged along the circumferential direction around the axis; A fixing step of fixing the rotational position of the rotor so that the rotor does not rotate around the axis; A current supply step of supplying a magnetization current to a predetermined-phase exciting magnetic pole included in the plurality of exciting magnetic poles; With the rotational position of the rotor fixed by the fixing step in a state where the circumferential position of either the first magnetized portion or the second magnetized portion having the same polarity as the predetermined-phase exciting magnetic pole magnetized by the current supply step coincides with the circumferential position of the predetermined-phase exciting magnetic pole, inserting the rotor along the axis into the stator so that the tip of the rotor is supported by the bearing unit; an assembling method of an electric motor comprising an insertion step.

2. The method for assembling an electric motor according to claim 1, wherein in the current supply step, the flow direction of the magnetization current is switched so that the polarity of the predetermined-phase exciting magnetic pole temporarily becomes the reverse polarity.

3. The method for assembling an electric motor according to claim 2, wherein in the fixing step, the rotational position of the rotor is fixed so that the rotor can swing within a predetermined rotation angle range.

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