electric motor

Abstract

By appropriately setting the circumferential angle of the region from the start point to the end point of the ribs formed on the motor housing, both axial and circumferential vibrations of the electric motor are reduced. [Solution] An electric compressor is provided comprising a motor housing 10 and a motor, wherein the motor has a stator fixed inside the motor housing and a rotor positioned on the inner circumference side of the stator, and a rib 10b is formed on the outer circumferential surface 10a of the motor housing 10 so as to extend in a direction inclined at a predetermined angle α from the direction along the axis X and to pivot in the circumferential direction CD about the axis X, and when the angle θ is the angle obtained by dividing 360 degrees of one rotation of the circumferential direction CD by the greatest common divisor of the number of slots of the stator and the number of poles of the rotor, the angle φ of the circumferential direction CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b is set to be greater than 0.5θ and less than 1.5θ.

Description

Technical Field

[0001] The present disclosure relates to an electric motor.

Background Art

[0002] Conventionally, in an electric motor in which a stator core around which a stator coil is wound is composed of a plurality of stator pieces divided in the circumferential direction, and the plurality of stator pieces are held by a cylindrical stator holder, a technique for reducing the action of electromagnetic exciting force caused by magnetic radial attractive force and repulsive force is known (see, for example, Patent Document 1).

[0003] The electric motor disclosed in Patent Document 1 is provided with a plurality of inclined ribs extending on the outer peripheral surface of the stator holder while being inclined in the axial direction. By increasing the axial and circumferential rigidity of the stator holder with the plurality of inclined ribs, it is possible to reduce the axial vibration and circumferential vibration of the electric motor caused by the action of electromagnetic exciting force.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] In the stator and the motor housing that holds the stator, due to the action of electromagnetic exciting force, vibration occurs at the number of vibration modes (the number of waveforms in the circumferential direction) determined by the number of slots of the stator (the number of grooves that accommodate the coils wound around the teeth) and the number of poles of the rotor. However, Patent Document 1 does not disclose how to set the circumferential angle of the region from the start point to the end point of the rib in relation to the number of vibration modes.

[0006] For example, if the length of the ribs is not appropriately set with respect to the wavelength in the circumferential direction of the vibration waves generated according to the number of vibration modes, the ribs cannot adequately reduce circumferential vibrations. Thus, Patent Document 1 had room for improvement in reducing axial and circumferential vibrations of an electric motor due to the action of electromagnetic excitation force.

[0007] This disclosure has been made in view of these circumstances, and aims to provide an electric motor that can reduce both axial and circumferential vibrations of the motor by appropriately setting the circumferential angle of the region from the starting point to the ending point of the rib formed in the motor housing. [Means for solving the problem]

[0008] An electric motor according to one aspect of the present disclosure comprises a motor housing that extends along an axis and is formed in a cylindrical shape, and a motor housed inside the motor housing, wherein the motor has a stator fixed inside the motor housing and a rotor disposed on the inner circumference side of the stator, and a rib is formed on the outer circumferential surface of the motor housing that is formed to rotate in the circumferential direction around the axis and extends in a direction inclined at a predetermined angle from the direction along the axis, and when the angle obtained by dividing 360 degrees of one rotation in the circumferential direction by the greatest common divisor of the number of slots of the stator and the number of poles of the rotor is defined as θ, the circumferential angle in the region from the start point to the end point of the rib is set to be greater than 0.5θ and less than 1.5θ. [Effects of the Invention]

[0009] According to this disclosure, it is possible to provide an electric motor that can reduce both axial and circumferential vibrations of the electric motor by appropriately setting the circumferential angle of the region from the starting point to the ending point of the rib formed in the motor housing. [Brief explanation of the drawing]

[0010] [Figure 1] This is a perspective view showing an electric compressor according to one embodiment of the present disclosure. [Figure 2] This is a perspective view showing a motor included in an electric compressor according to one embodiment of the present disclosure. [Figure 3] This is a perspective view showing the motor housing, first end housing, and second end housing of an electric compressor according to one embodiment of the present disclosure. [Figure 4] This is an exploded view of the outer circumferential surface of the motor housing of the first embodiment. [Figure 5] This is an exploded view of the outer circumferential surface of the motor housing of the second embodiment. [Figure 6] This is an exploded view of the outer circumferential surface of the motor housing of the third embodiment. [Figure 7] This is an exploded view of the outer circumferential surface of the motor housing of the fourth embodiment. [Figure 8] This is an exploded view of the outer circumferential surface of the motor housing of the fifth embodiment. [Figure 9] This is an exploded view of the outer circumferential surface of the motor housing of the sixth embodiment. [Figure 10] This is an exploded view of the outer circumferential surface of the motor housing of the seventh embodiment. [Modes for carrying out the invention]

[0011] Hereinafter, an electric compressor (motor) 100 according to one embodiment of the present disclosure will be described with reference to the drawings. Figure 1 is a perspective view showing an electric compressor 100 according to one embodiment of the present disclosure. The electric compressor 100 shown in Figure 1 is used, for example, in an air conditioning system for a vehicle that regulates the temperature of the air inside the vehicle, and is a device that compresses a refrigerant drawn in from the outside.

[0012] As shown in Figure 1, the electric compressor 100 of this embodiment comprises a motor housing 10, a first end housing 11, a second end housing 12, a motor 20 housed inside the motor housing 10, and a compressor 30.

[0013] The motor housing 10 is a member that extends along the axis X and is formed in a cylindrical shape. The first end housing 11 seals one side in the axial direction along the axis X of the motor housing 10. The second end housing 12 seals the other side in the axial direction along the axis X of the motor housing 10. The motor housing 10, the first end housing 11, and the second end housing 12 form a sealed space in which the motor 20 and the compressor 30 are accommodated. The motor 20 rotationally drives the compressor 30 around the axis X. The compressor 30 obtains a driving force from the motor 20 and rotates around the axis X to compress the refrigerant.

[0014] FIG. 2 is a perspective view showing the motor 20 included in the electric compressor 100 according to an embodiment of the present disclosure. As shown in FIG. 2, the motor 20 includes a stator 21 fixed inside the motor housing 10 and a rotor 22 disposed on the axis X on the inner peripheral side of the stator 21. In FIG. 2, illustration of the coil wound around the teeth 21a of the stator 21 is omitted. The stator 21 of the motor 20 in the present embodiment is provided with slots 21b at twelve locations along the circumferential direction CD. Further, the rotor 22 of the present embodiment has, for example, two poles.

[0015] FIG. 3 is a perspective view showing the motor housing 10, the first end housing 11, and the second end housing 12 included in the electric compressor 100 according to an embodiment of the present disclosure. In FIG. 3, the shapes of the motor housing 10, the first end housing 11, and the second end housing 12 are shown in a simplified manner.

[0016] As shown in FIG. 3, one side in the axis X direction of the motor housing 10 and the first end housing 11 are fastened by a first fastening bolt (first fastener) 10c1 at a first fastening position P1 in the circumferential direction CD around the axis X. Further, the other side in the axis X direction of the motor housing 10 and the second end housing 12 are fastened by a second fastening bolt (second fastener) 10c2 at a second fastening position P2 in the circumferential direction CD around the axis X.

[0017] As shown in FIG. 3, a plurality of ribs 10b are formed on the outer peripheral surface 10a of the motor housing 10. Here, referring to FIGS. 4 to 10, an embodiment of the rib 10b formed on the outer peripheral surface 10a of the motor housing 10 will be described. As shown in FIGS. 4 to 10, the rib 10b is formed on the outer peripheral surface 10a of the motor housing 10 so as to linearly extend in a direction inclined at a predetermined angle α from the direction along the axis X and to turn in the circumferential direction CD around the axis X.

[0018] In the stator 21 and the motor housing 10 that holds the stator 21, due to the action of the electromagnetic excitation force in the stator 21, vibrations of the number of vibration modes (the number of waveforms in the circumferential direction CD) determined by the number of slots in the stator 21 (the number of grooves that accommodate the coils wound around the teeth 21a) and the number of poles of the rotor 22 occur. And the angle θ obtained by dividing 360 degrees for one round in the circumferential direction CD by the greatest common divisor of the number of slots in the stator and the number of poles of the rotor 22 becomes the angle for one wavelength of the wavelength of the vibration wave generated in the circumferential direction CD according to the number of vibration modes.

[0019] In the present embodiment, the angle φ in the circumferential direction CD of the region from the start point to the end point of the rib 10b is set to be larger than 0.5θ and smaller than 1.5θ. When the angle φ is 0.5θ or less, the vibration wave generated in one rib 10b becomes less than half wavelength, and a state occurs in which only one of the components of the vibration wave directed outward in the radial direction centered on the axis X and the component of the vibration wave directed inward in the radial direction acts on one rib 10b.

[0020] In this state, when focusing on one rib 10b, a phenomenon in which the components of the vibration wave are canceled out does not occur because both the component of the vibration wave directed outward in the radial direction and the component of the vibration wave directed inward in the radial direction act on the rib 10b. Therefore, in the present embodiment, the angle φ is set to be larger than 0.5θ.

[0021] Furthermore, if the angle φ is 1.5θ or greater, the vibration wave generated in one rib 10b will be 1.5 wavelengths or greater, resulting in a situation where either the component of the vibration wave directed radially outward or the component directed radially inward around the axis X has a significant effect on the rib 10b.

[0022] In this state, focusing on one rib 10b, a phenomenon occurs where the vibration wave components cancel each other outward and inward in the radial direction act on that rib 10b. However, one of the vibration wave components acts more strongly, weakening the effect of canceling out the vibration wave components. Therefore, in this embodiment, the angle φ is set to be smaller than 1.5θ.

[0023] In the above, the angle φ of the circumferential CD in the region from the start point to the end point of the rib 10b is set to be greater than 0.5θ and less than 1.5θ, but other embodiments are also possible. For example, the angle φ of the circumferential CD in the region from the start point to the end point of the rib 10b may be set to be greater than 0.8θ and less than 1.2θ.

[0024] In this embodiment, the stator 21 of the motor 20 has 12 slots 21b along the circumferential direction CD. The rotor 22 in this embodiment has, for example, 2 poles. Therefore, the angle θ obtained by dividing the 360 ​​degrees of one rotation of the circumferential direction CD by the greatest common divisor of the number of slots in the stator 21 (12) and the number of poles in the rotor 22 (2) is 180 degrees. In this embodiment, the angle φ of the circumferential direction CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b is set to be greater than 0.5θ and less than 1.5θ. In this embodiment, since θ is 180 degrees, the angle φ is set to be greater than 90 degrees and less than 270 degrees.

[0025] [First Example] Figure 4 is an exploded view of the outer circumferential surface 10a of the motor housing 10 of the first embodiment, unfolded in the circumferential direction CD. In this embodiment, the motor housing 10 and the first end housing 11 are fastened together by first fastening bolts 10c1 at a plurality of first fastening positions P1 in the circumferential direction CD. In addition, in this embodiment, the motor housing 10 and the second end housing 12 are fastened together by second fastening bolts 10c2 at a plurality of second fastening positions P2 in the circumferential direction CD.

[0026] In this embodiment, multiple first fastening positions P1 and multiple second fastening positions P2 are arranged at 60-degree intervals in the circumferential direction CD. The first fastening positions P1 and the second fastening positions P2 are at the same position in the circumferential direction CD. The angle φ is set to θ (180 degrees in this embodiment). Multiple ribs 10b are formed at 60-degree intervals along the circumferential direction CD at six locations on the outer surface 10a. The angle φ in the circumferential direction CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b coincides with the angle of one wavelength of the vibration wave generated in one rib 10b. Therefore, focusing on one rib 10b, both the vibration wave component directed radially outward and the vibration wave component directed radially inward act on that rib 10b for half a wavelength each, canceling out the vibration wave components.

[0027] In this embodiment, the starting point 10b1 of the rib 10b coincides with the first fastening position P1, and the ending point 10b2 of the rib 10b coincides with the second fastening position P2. Since the starting point 10b1 and ending point 10b2 of the rib are positioned at the first fastening position P1 and the second fastening position P2, which have higher rigidity compared to other positions, the effect of reducing vibrations in the axial direction X and circumferential direction CD of the electric compressor 100 can be enhanced.

[0028] [Second Example] Figure 5 is an unfolded view of the outer circumferential surface 10a of the motor housing 10 of the second embodiment, unfolded in the circumferential direction CD. The second embodiment is a modification of the first embodiment and is the same as the first embodiment unless otherwise specifically described below, so the following description will be omitted.

[0029] In the first embodiment, the starting point 10b1 of the rib 10b coincided with the first fastening position P1, and the ending point 10b2 of the rib 10b coincided with the second fastening position P2. In contrast, in this embodiment, the starting point 10b1 of the rib 10b does not coincide with the first fastening position P1, and the ending point 10b2 of the rib 10b does not coincide with the second fastening position P2. Even when the starting point 10b1 and ending point 10b2 of the rib are not positioned at the first fastening position P1 and the second fastening position P2, which have higher rigidity compared to other positions, the rib 10b can reduce vibrations of the electric compressor 100 in the axial direction X and circumferential direction CD.

[0030] [Third Example] Figure 6 is an unfolded view of the outer circumferential surface 10a of the motor housing 10 of the third embodiment, unfolded in the circumferential direction CD. The third embodiment is a modification of the first embodiment and is the same as the first embodiment unless otherwise specifically described below, so the following description will be omitted.

[0031] In this embodiment, the angle φ is set to 4θ / 3 (240 degrees in this embodiment). Multiple ribs 10b are formed at three locations on the outer surface 10a along the circumferential direction CD at intervals of 120 degrees. The angle φ of the circumferential direction CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b coincides with the angle of 4 / 3 wavelength of the vibration wave generated in one rib 10b. Therefore, when focusing on one rib 10b, both the vibration wave component directed radially outward and the vibration wave component directed radially inward act on that rib 10b, causing the vibration wave components to cancel each other out.

[0032] In this embodiment, the starting point 10b1 of the rib 10b coincides with the first fastening position P1, and the ending point 10b2 of the rib 10b coincides with the second fastening position P2. Since the starting point 10b1 and ending point 10b2 of the rib are positioned at the first fastening position P1 and the second fastening position P2, which have higher rigidity compared to other positions, the effect of reducing vibrations in the axial direction X and circumferential direction CD of the electric compressor 100 can be enhanced.

[0033] [Fourth Example] Figure 7 is an unfolded view of the outer circumferential surface 10a of the motor housing 10 of the fourth embodiment, unfolded in the circumferential direction CD. The fourth embodiment is a modification of the first embodiment and is the same as the first embodiment unless otherwise specifically described below, so the following description will be omitted.

[0034] In this embodiment, the angle φ is set to 2θ / 3 (120 degrees in this embodiment). Multiple ribs 10b are formed at six locations on the outer surface 10a along the circumferential direction CD at 60-degree intervals. The angle φ of the circumferential direction CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b coincides with the angle of 2 / 3 wavelength of the vibration wave generated in one rib 10b. Therefore, focusing on one rib 10b, both the vibration wave component directed radially outward and the vibration wave component directed radially inward act on that rib 10b, causing the vibration wave components to cancel each other out.

[0035] In this embodiment, the starting point 10b1 of the rib 10b coincides with the first fastening position P1, and the ending point 10b2 of the rib 10b coincides with the second fastening position P2. Since the starting point 10b1 and ending point 10b2 of the rib are positioned at the first fastening position P1 and the second fastening position P2, which have higher rigidity compared to other positions, the effect of reducing vibrations in the axial direction X and circumferential direction CD of the electric compressor 100 can be enhanced.

[0036] [Fifth Example] Figure 8 is an unfolded view of the outer circumferential surface 10a of the motor housing 10 of the fifth embodiment, unfolded in the circumferential direction CD. The fifth embodiment is a modification of the fourth embodiment and is the same as the first embodiment unless otherwise specifically described below, so the following description will be omitted.

[0037] In the fourth embodiment, the starting point 10b1 of the rib 10b coincided with the first fastening position P1, and the ending point 10b2 of the rib 10b coincided with the second fastening position P2. In contrast, in this embodiment, the starting point 10b1 of the rib 10b coincides with the first fastening position P1, while the ending point 10b2 of the rib 10b does not coincide with the second fastening position P2.

[0038] In this embodiment, the starting point 10b1 of the rib 10b coincides with the first fastening position P1. Since the starting point 10b1 of the rib is positioned at the first fastening position P1, which has higher rigidity compared to other positions, the effect of reducing vibrations in the axial direction X and circumferential direction CD of the electric compressor 100 can be enhanced. Furthermore, even if the ending point 10b2 of the rib is not positioned at the second fastening position P2, which has higher rigidity compared to other positions, the rib 10b can still reduce vibrations in the axial direction X and circumferential direction CD of the electric compressor 100.

[0039] [Sixth Example] Figure 9 is an unfolded view of the outer circumferential surface 10a of the motor housing 10 of the sixth embodiment, unfolded in the circumferential direction CD. The sixth embodiment is a modification of the first embodiment and is the same as the first embodiment unless otherwise specifically described below, so the following description will be omitted.

[0040] In this embodiment, the angle φ is set to 2θ / 3 (120 degrees in this embodiment). Multiple ribs 10b are formed at three locations on the outer surface 10a along the circumferential direction CD at 120-degree intervals. The angle φ of the circumferential direction CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b coincides with the angle of 2 / 3 wavelength of the vibration wave generated in one rib 10b. Therefore, focusing on one rib 10b, both the vibration wave component directed radially outward and the vibration wave component directed radially inward act on that rib 10b, causing the vibration wave components to cancel each other out.

[0041] In this embodiment, the starting point 10b1 of the rib 10b coincides with the first fastening position P1, and the ending point 10b2 of the rib 10b coincides with the second fastening position P2. Since the starting point 10b1 and ending point 10b2 of the rib are positioned at the first fastening position P1 and the second fastening position P2, which have higher rigidity compared to other positions, the effect of reducing vibrations in the axial direction X and circumferential direction CD of the electric compressor 100 can be enhanced.

[0042] [Example 7] Figure 10 is an unfolded view of the outer circumferential surface 10a of the motor housing 10 of the seventh embodiment, unfolded in the circumferential direction CD. The seventh embodiment is a modification of the first embodiment and is the same as the first embodiment unless otherwise specifically described below, so the following description will be omitted.

[0043] In this embodiment, the multiple first fastening positions P1 and the multiple second fastening positions P2 are each arranged at 72-degree intervals in the circumferential direction CD. In this embodiment, the angle φ is set to 4θ / 5 (144 degrees in this embodiment). Multiple ribs 10b are formed at 72-degree intervals along the circumferential direction CD at five locations on the outer peripheral surface 10a. The angle φ in the circumferential direction CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b coincides with the angle of 4 / 5 wavelength of the vibration wave generated in one rib 10b. Therefore, focusing on one rib 10b, both the vibration wave component directed radially outward and the vibration wave component directed radially inward act on that rib 10b, canceling out the vibration wave components.

[0044] In this embodiment, the starting point 10b1 of the rib 10b coincides with the first fastening position P1, and the ending point 10b2 of the rib 10b coincides with the second fastening position P2. Since the starting point 10b1 and ending point 10b2 of the rib are positioned at the first fastening position P1 and the second fastening position P2, which have higher rigidity compared to other positions, the effect of reducing vibrations in the axial direction X and circumferential direction CD of the electric compressor 100 can be enhanced.

[0045] The electric compressor 100 of this embodiment, as described above, provides the following functions and effects. In the electric compressor 100 of this embodiment, if the angle of the circumferential CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b is 0.5θ or less, the vibration wave generated in one rib 10b becomes less than half a wavelength, and a state occurs where only one of the vibration wave components directed radially outward or radially inward acts on one rib 10b. In this state, focusing on one rib 10b, the phenomenon of canceling out the vibration wave components by both the radially outward and radially inward vibration wave components acting on that rib 10b does not occur.

[0046] Therefore, in the electric compressor 100 of this embodiment, the angle φ is set to be greater than 0.5θ. In one rib 10b, both the vibration wave component directed radially outward and the vibration wave component directed radially inward act on it, and the vibration wave components can cancel each other out. Thus, by appropriately setting the angle φ of the circumferential CD in the region from the starting point 10b1 to the ending point 10b2 of the rib 10b formed in the motor housing 10, both the axial vibration and the vibration of the circumferential CD of the electric compressor 100 can be reduced.

[0047] Furthermore, according to the electric compressor 100 of this embodiment, the starting point 10b1 and ending point 10b2 of the rib 10b are positioned at the first fastening position P1 and the second fastening position P2, which have higher rigidity compared to other positions. Therefore, the effect of reducing axial vibration and circumferential vibration CD of the electric compressor 100 can be enhanced.

[0048] Furthermore, according to the electric compressor 100 of this embodiment, since the multiple ribs 10b are formed to overlap in the circumferential direction CD, both the axial vibration of the electric compressor 100 and the vibration of the circumferential direction CD can be more reliably reduced at each position in the circumferential direction CD.

[0049] The electric motors described in each of the embodiments described above can be understood, for example, as follows.

[0050] An electric motor according to a first aspect of this disclosure comprises a motor housing (10) that extends along an axis (X) and is formed in a cylindrical shape, and a motor (20) housed inside the motor housing, wherein the motor has a stator (21) fixed inside the motor housing and a rotor (22) arranged on the inner circumference side of the stator, and a rib (10b) is formed on the outer circumferential surface (10a) of the motor housing that extends in a direction inclined at a predetermined angle from the direction along the axis and rotates in the circumferential direction (CD) about the axis, and when the angle θ is obtained by dividing 360 degrees of one rotation in the circumferential direction by the greatest common divisor of the number of slots of the stator and the number of poles of the rotor, the circumferential angle (φ) of the region from the starting point (10b1) to the ending point (10b2) of the rib is set to be greater than 0.5θ and less than 1.5θ.

[0051] In the electric motor according to the first aspect of this disclosure, if the circumferential angle of the region from the start point to the end point of the rib is 0.5θ or less, the vibration wave generated in one rib becomes less than half a wavelength, and a state occurs in which only one of the vibration wave components directed radially outward or radially inward acts on one rib. In this state, focusing on one rib, the phenomenon of canceling out the vibration wave components by both the radially outward and radially inward vibration wave components acting on that rib does not occur.

[0052] Therefore, in the electric motor according to the first aspect of this disclosure, the angle φ is set to be greater than 0.5θ. In a single rib, both the vibration wave component directed radially outward and the vibration wave component directed radially inward act on it, canceling out the vibration wave components. Thus, by appropriately setting the circumferential angle of the region from the start point to the end point of the rib formed in the motor housing, both axial vibration and circumferential vibration of the electric motor can be reduced.

[0053] An electric motor according to a second aspect of the present disclosure further comprises the following configuration in the first aspect: a first end housing (11) that seals one side of the motor housing in the axial direction, and a second end housing (12) that seals the other side of the motor housing in the axial direction, wherein one side of the motor housing in the axial direction and the first end housing are fastened together by a first fastener (10c1) at a plurality of first fastening positions (P1) in the circumferential direction, the other side of the motor housing in the axial direction and the second end housing are fastened together by a second fastener (10c2) at a plurality of second fastening positions (P2) in the circumferential direction, the circumferential position of the starting point of the rib coincides with the first fastening position, and the circumferential position of the ending point of the rib coincides with the second fastening position.

[0054] According to the electric motor of the second aspect of this disclosure, the start and end points of the rib are positioned at the first and second fastening positions, which have higher rigidity compared to other positions, thereby enhancing the effect of reducing axial and circumferential vibrations of the electric motor.

[0055] An electric motor according to a third aspect of this disclosure further comprises the following configuration in the first or second aspect: that is, a plurality of ribs are formed on the outer circumferential surface of the motor housing so as to overlap in the circumferential direction.

[0056] According to the electric motor of the third aspect of this disclosure, since multiple ribs are formed to overlap in the circumferential direction, both axial vibration and circumferential vibration of the electric motor can be more reliably reduced at each position in the circumferential direction.

[0057] An electric motor according to a fourth aspect of this disclosure further comprises the following configuration in the first or second aspect: that the circumferential angle from the starting point (10b1) to the ending point (10b2) of the rib is set to be greater than 0.8θ and less than 1.2θ.

[0058] According to the electric motor of the fourth aspect of this disclosure, by setting the circumferential angle from the start point to the end point of the rib to be greater than 0.8θ and less than 1.2θ, both axial vibration and circumferential vibration of the electric motor can be reduced more reliably.

[0059] An electric motor according to a fifth aspect of the present disclosure further comprises the following configuration in a second aspect: a compressor (30) disposed inside a sealed space formed by the motor housing, the first end housing, and the second end housing, which rotates around the axis to compress a refrigerant, and the motor rotates the compressor around the axis.

[0060] According to the fifth aspect of this disclosure, in an electric motor equipped with a compressor that is rotationally driven by a motor to compress a refrigerant, both axial vibration and circumferential vibration of the electric motor can be reduced. [Explanation of Symbols]

[0061] 10 Motor Housing 10a Outer surface 10b Rib 10b1 Starting point 10b2 End point 10c1 First fastening bolt (first fastener) 10c2 Second fastening bolt (second fastener) 11. First End Housing 12. Second End Housing 20 motors 21 status 21a Teeth 21b slot 22 rotors 30 Compressors 100 Electric Compressors CD circumferential direction P1 1st fastening position P2 2nd fastening position X axis

Claims

1. A motor housing that extends along the axis and is formed in a cylindrical shape, The motor is housed inside the motor housing, The aforementioned motor is A stator fixed inside the motor housing, The stator has a rotor positioned on the inner circumference side, Ribs are formed on the outer circumferential surface of the motor housing, extending in a direction inclined at a predetermined angle from the direction along the axis and pivoting in the circumferential direction around the axis. An electric motor in which, when the angle θ is obtained by dividing the 360 ​​degrees of one full rotation in the circumferential direction by the greatest common divisor of the number of slots in the stator and the number of poles in the rotor, the circumferential angle in the region from the start point to the end point of the rib is set to be greater than 0.5θ and less than 1.5θ.

2. A first end housing that seals one side of the motor housing in the direction along the axis, The motor housing comprises a second end housing that seals the other side of the motor housing in the direction along the axis, One side of the motor housing in the direction along the axis and the first end housing are fastened together by a first fastener at a plurality of first fastening positions in the circumferential direction. The other side of the motor housing in the direction along the axis and the second end housing are fastened together by a second fastener at a plurality of second fastening positions in the circumferential direction. The circumferential position of the starting point of the rib coincides with the first fastening position. The electric motor according to claim 1, wherein the circumferential position of the endpoint of the rib coincides with the second fastening position.

3. The electric motor according to claim 1 or claim 2, wherein a plurality of ribs are formed on the outer circumferential surface of the motor housing so as to overlap in the circumferential direction.

4. The electric motor according to claim 1 or claim 2, wherein the circumferential angle of the rib from the starting point to the ending point is set to be greater than 0.8θ and less than 1.2θ.

5. The system includes a compressor that is positioned inside a sealed space formed by the motor housing, the first end housing, and the second end housing, and rotates around its axis to compress the refrigerant. The motor is an electric motor according to claim 2, which rotates the compressor around its axis.

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