JP2022185890A - Electric motor, compressor, and refrigeration cycle device - Google Patents

Abstract

To provide an electric motor, a compressor, and a refrigeration cycle device capable of preventing a reduction in efficiency and a reduction in output torque, improving the insulation performance between a winding and a core, and improving the life against wear of an insulation sheet without increasing the thickness of the insulation sheet and reducing the volume of the winding occupied in a slot.SOLUTION: A teeth tip 42b of an electric motor 12 includes a rotation direction first protrusion 61 that protrudes in the rotation direction R of a rotor 22, and a reverse direction first protrusion 62 that protrudes in a direction opposite to the rotation direction of the rotor 22, and insulating end plates 45A and 45B include a rotation direction second protrusion 65 covering the rotation direction first protrusion 61, and a reverse direction second protrusion 66 that covers the reverse direction first protrusion 62. The reverse direction first protrusion 62 is smaller than the rotation direction first protrusion 61, the rotation direction second protrusion 65 is closer to a winding 47 than the rotation direction first protrusion 61, and the reverse direction second protrusion 66 is closer to the winding 47 than the reverse direction first protrusion 62.SELECTED DRAWING: Figure 5

Description

Embodiments of the present invention relate to electric motors, compressors, and refrigeration cycle devices.

2. Description of the Related Art Electric motors are known that have teeth having tip shapes that are left-right asymmetric with respect to the center line of the teeth in order to eliminate uneven magnetic flux and reduce vibration and electromagnetic noise. Protrusions protruding in the rotational direction of the rotor are provided at the tips of the teeth.

The center line of the tooth is a line segment that bisects the tooth in the direction of rotation of the rotor when viewed from the direction along the center line of rotation of the rotor. The stator as a whole has the same number of line segments as there are teeth, and each line segment extends radially from the rotation center line of the rotor in the radial direction of the rotor. If the rotor is rotated across the center line of the teeth from right to left when the rotor is viewed from the radially outer side of the iron core, the protrusion projects leftward with respect to the center line of the teeth.

JP-A-8-23646

The stator of the electric motor includes a cylindrical yoke, an iron core having a plurality of teeth protruding inward from the yoke and arranged in a circumferential direction at intervals, a plurality of insulating end plates provided on each end surface of the iron core, and the teeth. and a plurality of insulating sheets disposed in respective slots between adjacent teeth and sandwiched between the windings and the teeth. The insulating sheet is interposed between the winding and the core to electrically insulate them.

In some cases, the tips of the teeth are provided with a first protrusion that protrudes in the rotation direction of the rotor and a second protrusion that protrudes in the reverse rotation direction of the rotor.

By the way, an electric motor produces periodic displacement between the windings and the insulating sheet as the Lorentz force is generated between the windings when the windings are energized. In other words, the winding vibrates due to the Lorentz force, so that the winding rubs against the insulating sheet. The friction between the windings and the insulating sheet may wear the insulating sheet. If the insulating sheet is worn too much, the windings and core will short circuit.

Therefore, by making the insulating sheet thicker, the insulation performance between the winding and the core is improved, and the life of the insulating sheet against wear is improved.

However, if the thickness of the insulating sheet is increased, the volume of the insulating sheet occupied by the space called a slot that accommodates the windings increases, and the cross-sectional area of the insulating sheet in a cross-sectional view perpendicular to the rotation centerline of the rotor increases. In other words, increasing the thickness of the insulating sheet reduces the volume of the windings occupying the slot, and reduces the cross-sectional area of the windings in a cross-sectional view perpendicular to the rotation centerline of the rotor. As a result, the efficiency and output torque of the electric motor are reduced.

Therefore, the present invention prevents a decrease in efficiency and a decrease in output torque without increasing the thickness of the insulating sheet and without reducing the volume of the windings occupying the slots, and provides insulation performance between the windings and the core. It is an object of the present invention to provide an electric motor, a compressor, and a refrigerating cycle device capable of improving the life of an insulating sheet against wear.

In order to solve the above problems, an electric motor according to an embodiment of the present invention includes a cylindrical stator and a rotor arranged inside the stator, the stator includes a cylindrical yoke, and a core having a plurality of teeth projecting inward of the yoke and arranged in a circumferential direction at intervals, a plurality of insulating end plates provided on respective end faces of the core, each of the teeth and the insulating end plate and a plurality of insulating sheets arranged in respective slots between the adjacent teeth and sandwiched between the respective windings and the respective teeth; When viewed from the direction along the rotation center line of the child, the tip of each of the teeth protrudes in the direction opposite to the rotation direction of the rotor from the rotation direction first protrusion that protrudes in the rotation direction of the rotor. The insulating end plate has a second rotation-direction protrusion that covers the first rotation-direction protrusion, and a second rotation-direction protrusion that covers the first rotation-direction protrusion. and a protrusion, wherein the reverse direction first protrusion is smaller than the rotation direction first protrusion, and the rotation direction second protrusion is closer to the winding than the rotation direction first protrusion. Nearby, the reverse direction second protrusion is closer to the winding than the reverse direction first protrusion.

Further, a compressor according to an embodiment of the present invention includes a closed container, a compression mechanism portion housed in the closed container and capable of compressing a refrigerant, and the with an electric motor.

Further, in the refrigeration cycle apparatus according to the embodiment of the present invention, the compressor, the radiator, the expansion device, the heat absorber, and the compressor, the radiator, the expansion device, and the heat absorber are connected. and a refrigerant pipe for circulating the refrigerant.

BRIEF DESCRIPTION OF THE DRAWINGS The schematic diagram of the refrigerating-cycle apparatus and compressor which concern on embodiment of this invention. 1 is a schematic exploded perspective view of a stator of an electric motor according to an embodiment of the present invention; FIG. 1 is a schematic plan view of a stator of an electric motor according to an embodiment of the present invention; FIG. The vector diagram which shows an example of the analysis example of the Lorentz force which acts on winding. The figure which shows the principal part of the electric motor which concerns on embodiment of this invention. FIG. 4 is a diagram showing the relationship between the cross-sectional area ratio between the rotation-direction first protrusion and the reverse-direction first protrusion and the increase/decrease in torque ripple in the electric motor according to the embodiment of the present invention. The figure which shows the other example of the principal part of the electric motor which concerns on embodiment of this invention.

Embodiments of an electric motor, a compressor, and a refrigeration cycle device according to the present invention will be described with reference to FIGS. 1 to 7. FIG. In addition, the same code|symbol is attached|subjected to the structure which is the same or corresponds in several drawings.

FIG. 1 is a schematic diagram of a refrigeration cycle device and a compressor according to an embodiment of the invention.

As shown in FIG. 1, the refrigeration cycle device 1 according to the present embodiment includes a hermetic compressor 2, a radiator 3, an expansion device 5, a heat absorber 6, an accumulator 7, a refrigerant pipe 8, It has A refrigerant pipe 8 connects the compressor 2, the radiator 3, the expansion device 5, the heat absorber 6, and the accumulator 7 in order to distribute the refrigerant.

The compressor 2 sucks in the refrigerant that has passed through the heat absorber 6 through the refrigerant pipe 8 , compresses it, and discharges high-temperature, high-pressure refrigerant to the radiator 3 through the refrigerant pipe 8 .

The compressor 2 includes a cylindrical closed container 11 placed vertically, an electric motor 12 arranged in the upper half of the closed container 11 , and a compression mechanism section 13 arranged in the lower half of the closed container 11 . , a rotating shaft 15 that transmits the rotational driving force of the electric motor 12 to the compression mechanism 13, a main bearing 16 that rotatably supports the rotating shaft 15, and a main bearing 16 that cooperates with the rotating shaft 15 to rotatably support the rotating shaft 15. and a sub-bearing 17 that

The sealed container 11 includes a vertically extending cylindrical body 11a, a hemispherical or elliptical end plate 11b that closes the upper end of the body 11a, and a hemispherical or elliptical end plate that closes the lower end of the body 11a. 11c.

A discharge pipe 8a for discharging the refrigerant is connected to the end plate 11b on the upper side of the sealed container 11. As shown in FIG. The discharge pipe 8 a is connected to the refrigerant pipe 8 . Further, the end plate 11b on the upper side of the sealed container 11 is provided with a sealed terminal portion 18 for power supply.

The electric motor 12 generates driving force for rotating the compression mechanism portion 13 . The electric motor 12 is, for example, a three-phase induction motor. The electric motor 12 includes a cylindrical stator 21 fixed to the inner wall of the closed container 11 , a rotor 22 arranged inside the stator 21 and fixed to the rotating shaft 15 , and a rotor 22 drawn out from the stator 21 . and a plurality of lead wires 23 connected to the sealed terminal portion 18 .

The rotor 22 includes a rotor core 25 having magnet accommodation holes (not shown) and permanent magnets accommodated in the magnet accommodation holes. The rotor 22 is rotatable with respect to the stator 21 and supported by the rotating shaft 15 . Rotation centerline C of rotor 22 and rotating shaft 15 substantially coincides with centerline P of stator 21 .

The plurality of lead wires 23 are wires that supply power to the stator 21 through the sealed terminal portion 18, and are so-called lead wires. A plurality of lead wires 23 are wired according to the type of the electric motor 12 . When the lead wires 23 are used in an open winding type, two lead wires 23 are provided for each of the U-phase, V-phase, and W-phase, that is, a total of six lead wires 23 are wired. When the electric motor 12 is used in star connection, one lead wire 23 is wired for each of the U-phase, V-phase, and W-phase, that is, a total of three lead wires 23 are wired.

The rotating shaft 15 connects the electric motor 12 and the compression mechanism section 13 . The rotating shaft 15 transmits the rotational driving force generated by the electric motor 12 to the compression mechanism portion 13 .

An intermediate portion 15 a of the rotary shaft 15 connects the electric motor 12 and the compression mechanism portion 13 and is rotatably supported by a main bearing 16 . A lower end portion 15 b of the rotating shaft 15 is rotatably supported by a sub-bearing 17 . The main bearing 16 and the sub-bearing 17 are also part of the compression mechanism section 13 . In other words, the rotating shaft 15 passes through the compression mechanism portion 13 .

The rotary shaft 15 also has an eccentric portion 26 between the intermediate portion 15 a supported by the main bearing 16 and the lower end portion 15 b supported by the sub-bearing 17 . The eccentric portion 26 is a disc or cylinder having a center that does not coincide with the rotation centerline of the rotating shaft 15 .

The compression mechanism section 13 can compress a refrigerant, that is, a single refrigerant or a mixed refrigerant. When the electric motor 12 rotates the rotary shaft 15 , the compression mechanism section 13 sucks gaseous refrigerant from the refrigerant pipe 8 , compresses it, and discharges it into the sealed container 11 .

The compression mechanism portion 13 includes a cylinder 32 having a circular cylinder chamber 31, an annular roller 33 arranged in the cylinder chamber 31, and reciprocating motions in contact with the outer peripheral surface of the roller 33, and moves inside the cylinder chamber 31 into the suction chamber. and a blade 35 partitioning into a compression chamber.

The cylinder 32 is fixed to the sealed container 11 at a plurality of points by welding, for example, spot welding.

The cylinder chamber 31 is a space inside the cylinder 32 and is closed by the main bearing 16 and the sub-bearing 17 . The cylinder chamber 31 accommodates the eccentric portion 26 of the rotating shaft 15 .

The main bearing 16 is fixed to the cylinder 32 with a fastening member 38 such as a bolt. The main bearing 16 is provided with a discharge valve mechanism (not shown) for discharging refrigerant compressed in the cylinder chamber 31 and a discharge muffler 37 covering the discharge valve mechanism. The discharge valve mechanism opens the discharge port when the pressure difference between the pressure in the cylinder chamber 31 and the pressure in the discharge muffler 37 reaches a predetermined value due to the compression action of the compression mechanism 13 to release the compressed refrigerant. is discharged into the discharge muffler 37 . The discharge muffler 37 has a discharge hole (not shown) that connects the inside and outside of the discharge muffler 37 . The compressed refrigerant discharged into the discharge muffler 37 is discharged into the sealed container 11 through the discharge holes.

The secondary bearing 17 is fixed to the cylinder 32 with a fastening member 38 such as a bolt.

The roller 33 is fitted on the peripheral surface of the eccentric portion 26 . The outer peripheral surface of the roller 33 is in line contact with the inner peripheral surface of the cylinder chamber 31 . As the rotating shaft 15 rotates, the roller 33 moves eccentrically while its outer peripheral surface is in line contact with the inner peripheral surface of the cylinder chamber 31 .

The contact between the roller 33 and the cylinder 32 is not a direct contact, but an indirect one with an oil film (not shown) of the lubricating oil 39 interposed. The contact made is simply referred to as "contact". The same applies between roller 33 and eccentric 26 , between roller 33 and main bearing 16 , and between roller 33 and sub-bearing 17 .

The suction pipe 7 a is connected to the cylinder chamber 31 of the cylinder 32 through the closed container 11 . The cylinder 32 has a suction hole (not shown) that is connected to the suction pipe 7 a and reaches the cylinder chamber 31 .

The lower portion of the sealed container 11 is filled with lubricating oil 39 . Most of the compression mechanism 13 is immersed in the lubricating oil 39 inside the closed container 11 .

Next, the stator 21 of the electric motor 12 will be described in detail.

FIG. 2 is a schematic exploded perspective view of the stator of the electric motor according to the embodiment of the invention.

FIG. 3 is a schematic plan view of the stator of the electric motor according to the embodiment of the invention.

As shown in FIGS. 2 and 3, the electric motor 12 according to this embodiment is of the three-phase 3N slot type (N is a positive integer). The electric motor 12 in FIGS. 2 and 3 is of the three-phase nine-slot type (N=3). In order to facilitate the explanation, a three-phase nine-slot type electric motor 12 will be explained below, but N≧4 or N≦2 may be satisfied. That is, the electric motor 12 may be of a 3-phase 12-slot type, a 3-phase 15-slot type, or may have more slots.

The stator 21 of the electric motor 12 according to this embodiment is a concentrated winding stator. The stator 21 includes a cylindrical yoke 41 (a so-called yoke), a stator core 43 having a plurality of teeth 42 protruding inward from the yoke 41 and arranged in the circumferential direction at intervals. a plurality of insulating end plates 45A and 45B provided on the respective end faces 43a and 43b; windings 47 wound around the respective teeth 42 and the insulating end plates 45A and 45B; and a plurality of insulating sheets 48 sandwiched between.

Note that the winding 47 is omitted in FIG. 2, and the insulating sheet 48 is omitted in FIG.

The extending direction of the center line P of the stator 21 is called "axial direction". A centerline P of the stator 21 substantially coincides with a rotation centerline C of the rotor 22 . A direction passing through the center line P of the stator 21 on a plane perpendicular to the center line P of the stator 21 is called a "radial direction", and a circumferential direction centered on the center line P of the stator 21, that is, a radial direction A direction perpendicular to the direction is called a “circumferential direction”.

The stator core 43 is a laminate of electromagnetic steel sheets. That is, the stator core 43 has a plurality of thin plates (not shown) laminated in the axial direction and integrated. Each thin plate is, for example, an electromagnetic steel plate punched by a press. The stator core 43 has a pair of parallel end faces 43a, 43b. A normal to the pair of end faces 43a, 43b extends in the axial direction. It is close to the upper surface of the stator 21 , that is, the upper end plate 11 b of the sealed container 11 . The other end surface 43b of the stator core 43 is closer to the lower surface of the stator 21, that is, to the lower end plate 11c of the sealed container 11, and closer to the compression mechanism section 13 than the one end surface 43a. An insulating end plate 45A is provided on one end face 43a, and an insulating end plate 45B is provided on the other end face 43b.

The centerline of the tubular yoke 41 matches the centerline P of the stator 21 .

The plurality of teeth 42 are arranged radially at substantially equal intervals in the circumferential direction of the stator 21 . Each tooth 42 extends radially inward from the yoke 41 . Each tooth 42 has a tooth base portion 42a protruding from the yoke 41 radially inwardly of the yoke 41, and a tooth tip portion 42b provided at the tip portion of the tooth base portion 42a and extending in the circumferential direction. . The tips of the tooth bases 42 a are arranged on the innermost periphery of the stator 21 . The tooth tip portion 42 b has a tooth tip surface 42 c facing the inside of the yoke 41 . Teeth end surface 42 c faces stator 21 .

A tooth tip portion 42b of each tooth 42 projects in the rotation direction of the rotor 22 (solid line arrow R direction in FIG. 2) and a rotation direction first projection 61 projects in the direction opposite to the rotation direction of the rotor 22. and a reverse-direction first projecting portion 62 .

Each tooth tip surface 42c is formed in an arc shape centered on the center line P of the stator 21. As shown in FIG. The rotor 22 is arranged in a rotor housing space 43c defined by a plurality of tooth tip surfaces 42c. A gap is provided between the outer peripheral surface of the rotor 22 and the tooth tip surface 42c.

The yoke 41 and two circumferentially adjacent teeth 42 define a slot 49 . There are as many slots 49 as there are teeth 42 . The slot 49 has a slot opening between the tooth tips 42b of two adjacent teeth 42. As shown in FIG.

Further, the stator core 43 has a first hole extending from one end face 43a of the stator core 43 to the other end face 43b. The first holes are arranged at the outer peripheral edge of the stator core 43 and at the base of the teeth 42 . The first hole extends substantially parallel to the centerline P of the stator 21 .

The insulating end plates 45A and 45B are made of, for example, polybutylene terephthalate (PBT), liquid crystal polymer (Liquid Crystal Polymer, Liquid Crystal Plastic, LCP, semi- or wholly aromatic polyester), polyphenylene sulfide (PPS), or polyamide (PA). is an integrally molded product. The insulating end plates 45A and 45B have the same construction. Therefore, in the following description, description of the insulating end plate 45B will be omitted, and the insulating end plate 45A will be described.

The insulating end plate 45A includes an annular outer wall portion 51, a plurality of inner wall portions 52 disposed inside the outer wall portion 51 and arranged in the circumferential direction at intervals, and connecting the outer wall portion 51 and the respective inner wall portions 52. A plurality of bridging portions 53 are provided.

The outer wall portion 51 is a radially thin, axially extending, circumferentially continuous ring.

Each inner wall portion 52 is an arcuate plate that is thin in the radial direction and extends in the axial and circumferential directions. The plurality of inner wall portions 52 are arranged annularly. Each inner wall portion 52 includes a rotation direction second protrusion 65 that covers the rotation direction first protrusion 61 of the tooth tip portion 42b when viewed from the direction along the rotation center line C of the rotor 22, and the tooth tip portion 42b. and a reverse direction second protrusion 66 that covers the reverse direction first protrusion 62 of .

The bridging portion 53 spans between the inner peripheral surface of the outer wall portion 51 and the radially outer surface of the inner wall portion 52 .

The outer wall portion 51 , the plurality of inner wall portions 52 , and the plurality of bridging portions 53 define a plurality of spaces that accommodate the windings 47 . Each space overlaps the teeth 42 in the direction along the center line P of the stator 21

Also, the insulating end plate 45A has an end face (not shown) in contact with the end face 43a of the stator core 43. As shown in FIG. The end surface of the insulating end plate 45A straddles the outer wall portion 51, the inner wall portion 52, and the bridging portion 53. As shown in FIG.

In the direction along the centerline P of the stator 21 , a space 45 a defined by the radially inner surface 52 a (inner peripheral surface 52 a ) of the plurality of inner wall portions 52 faces the rotor housing space 43 c of the stator core 43 . is doing. A space 45 b defined by the outer wall portion 51 , two adjacent inner wall portions 52 and the bridging portion 53 faces the slots 49 of the stator core 43 in the direction along the center line P of the stator 21 .

The outer wall portion 51, the inner wall portion 52, and the bridging portion 53 of the insulating end plate 45A are arranged adjacent to the yoke 41 of the stator core 43, the tooth tip portions 42b, and the tooth base portions 42a of the teeth 42, respectively.

The outer wall portion 51 of the insulating end plate 45A is arranged adjacent to the yoke 41 of the stator core 43, the inner wall portion 52 is arranged adjacent to the tip end portion 42b of the tooth 42 of the stator core 43, and the bridging portion 53 is , are arranged adjacent to the tooth base portions 42 a of the teeth 42 of the stator core 43 .

In addition, the inner peripheral surface 52a of the inner wall portion 52 does not protrude toward the rotor 22, that is, radially inward from the tip end surface 42c of the tooth 42. As shown in FIG. Further, the radially outer surface 51a (outer peripheral surface 51a) of the outer wall portion 51 does not protrude radially outward from the outer peripheral surface 41a of the yoke 41 .

The tooth tip surface 42 c is the inner peripheral surface of the stator core 43 , and the outer peripheral surface 41 a of the yoke 41 is the outer peripheral surface of the stator core 43 . The inner peripheral surface 52a of the inner wall portion 52 is the inner peripheral surface of the insulating end plate 45A, and the outer peripheral surface 51a of the outer wall portion 51 is the outer peripheral surface of the insulating end plate 45A.

Each insulating sheet 48 is inserted into each slot 49 . The insulating sheet 48 is a sheet of polyethylene terephthalate (PET) or polyethylene naphthalate (PEN), for example. The insulating sheets 48 axially protrude from the end surfaces 43 a and 43 b of the stator core 43 . Therefore, the insulating sheet 48 can prevent poor insulation at the boundary between the end face 43a of the stator core 43 and the insulating end plate 45A and at the boundary between the end face 43b of the stator core 43 and the insulating end plate 45B. .

Note that FIG. 2 shows the insulating sheet 48 in the middle of being inserted into the slot 49 .

The windings 47 are wound around the tooth base portions 42a of the teeth 42 of the stator core 43, the bridging portions 53 of the insulating end plate 45A, and the bridging portions 53 of the insulating end plate 45B by a concentrated winding method.

By the way, in the electric motor 12, the Lorentz force that periodically fluctuates acts on the windings 47 as the windings 47 are energized. Therefore, the inventors analyzed the Lorentz force acting on the windings 47 as the rotor 22 is rotationally driven.

FIG. 4 is a vector diagram showing an example of analysis of the Lorentz force acting on the winding.

FIG. 5 is a diagram showing essential parts of the electric motor according to the embodiment of the present invention.

FIG. 5 is a view of the stator 21 along the rotation center line C of the rotor 22, that is, the center line P of the stator 21, from the stator core 43 side to the insulating end plate 45A (45B) side, It is a figure which shows the tooth front-end|tip part 42b and 45 A of insulation end plates (45B) in detail.

First, as shown in FIG. 4, the tooth tip portion 42b of each tooth 42 includes a rotation-direction first protrusion 61 that protrudes in the rotation direction of the rotor 22 (solid-line arrow R direction in FIG. 2), and a rotor 22, and a reverse direction first protrusion 62 that protrudes in a direction opposite to the rotation direction of 22.

4, the first projections 61 in the rotational direction and the first projections 62 in the reverse direction extend radially from the rotation center C of the rotor 22 to move the teeth 42 in the rotation direction R of the rotor 22. It has a symmetrical shape with the bisected imaginary line VL as the line of symmetry.

The inventors have found that the Lorentz force acting on the winding 47 (in FIG. 4, vectors indicated by numerous arrows with different lengths and directions) is applied to the base of the reverse direction first projection 62 (reverse direction first It was found that it occurs largely in the vicinity of the boundary portion between the protruding portion 62 and the tooth base portion 42a. Note that FIG. 4 illustrates the state of the Lorentz force at a certain point in the rotation of the rotor 22 .

The Lorentz force increases and decreases along with fluctuations in the armature magnetic flux generated by the rotational driving of the rotor 22 and the energization of the windings 47, and the direction thereof also changes. Therefore, a periodic displacement, that is, an amplitude is generated between the root of the reverse-direction first projecting portion 62 and the nearby winding 47 . This amplitude produces a force that wears the insulating sheet 48 sandwiched between the teeth 42 and the windings 47 . If the insulating sheet 48 wears too much, the windings 47 and the stator core 43 will short circuit.

In FIG. 4, a portion of the insulating sheet 48 that is likely to be worn is indicated by a chain double-dashed line region HRA.

According to the inventors' analysis, the variation width of the Lorentz force applied to each winding according to the frequency of the current flowing through the winding 47 has a bias, and in particular, the Lorentz force has a large fluctuation range. Friction between the winding 47 and the insulating sheet 48 was found to be significant in the vicinity of the root portion of the reverse-direction first projecting portion 62 due to the large fluctuation of the Lorentz force. On the other hand, in the vicinity of the rotation-direction first projecting portion 61, the variation width of the Lorentz force at the root portion is not so excessive. Therefore, it was found that the friction between the winding 47 and the insulating sheet 48 does not occur so much in the vicinity of the rotation direction first projecting portion 61 . It was found that the fluctuation range of the Lorentz force at the tip tends to be relatively large.

Therefore, as shown in FIG. 5, the reverse rotation direction first protrusions 62 of the tooth tip portions 42b according to the present embodiment are smaller than the rotation direction first protrusions 61 of the tooth tip portions 42b, and the insulating end plates 45A (45B) ) is closer to the winding 47 than the first rotation direction projection 61, and the reverse rotation direction second projection 66 of the insulating end plate 45A (45B) is closer to the reverse rotation direction first projection 62 closer to winding 47 than

The rotation direction first protrusion 61 and the reverse rotation direction first protrusion 62 extend radially from the rotation center C of the rotor 22 and bisect the teeth 42 in the rotation direction R of the rotor 22. has an asymmetric shape as When viewed in the direction along the rotation center line C of the rotor 22, the cross-sectional area of the reverse rotation direction first projections 62 is smaller than the cross-sectional area of the rotation direction first projections 61, and the teeth 42 are folded back along the virtual line VL. When the rotation direction first protrusion 61 and the reverse rotation direction first protrusion 62 are overlapped with each other, the reverse rotation direction first protrusion 62 fits into the rotation direction first protrusion 61 .

The tooth base portion 42a extends radially inward of the stator 21 with a substantially uniform width. The tooth bases 42a have the same width dimension in the rotation direction R and the reverse rotation direction of the rotor 22 with respect to the virtual line VL, and extend along the virtual line VL.

The first rotation-direction protrusion 61 and the first reverse-direction protrusion 62 of the tooth tip portion 42b are both the innermost circumferential surface of the stator core 43 and are continuous with the arcuate tooth tip surface 42c. Also, the projection amount of the reverse rotation direction first protrusions 62 with reference to the tooth base 42a is substantially the same as the projection amount of the rotation direction first protrusions 61 with reference to the tooth base 42a. The projection amount of the reverse rotation direction first projection 62 is the projection length of the rotor 22 in the rotation direction, and the projection amount of the rotation direction first projection 61 is the projection length of the rotor 22 in the rotation direction R. is. Therefore, the radially outer surface 62 a of the reverse rotation direction first projecting portion 62 facing the windings 47 facing the radially outer side of the stator core 43 faces the radially outer side of the stator core 43 and faces the windings 47 . The reverse rotation direction first protrusion 62 is smaller than the rotation direction first protrusion 61 because it is located closer to the center of the stator 21 than the radially outer surface 61 a of the rotation direction first protrusion 61 . .

The winding 47 is wound in a symmetrical shape with the imaginary line VL of the teeth 42 as a line of symmetry. Therefore, the reverse rotation direction first protrusion 62 smaller than the rotation direction first protrusion 61 is farther from the winding 47 than the rotation direction first protrusion 61 is.

The position of the winding 47 in the vicinity of the tooth tip 42b is determined by the inner wall 52 of the insulating end plate 45A (45B). In order to wind the winding 47 in a symmetrical shape with the imaginary line VL of the teeth 42 as a line of symmetry, the rotation direction second protrusion 65 and the reverse rotation direction second protrusion 66 are symmetrical with the imaginary line VL of the teeth 42 as a line of symmetry. have a shape. The radially outer surface 66 a of the reverse rotation direction second projecting portion 66 faces the radially outer side of the stator core 43 and faces the windings 47 , and the radially outer surface 66 a of the stator core 43 faces the windings 47 . , and the radially outer surface 65a of the rotation-direction second projecting portion 65 are symmetrical with respect to the virtual line VL of the tooth 42, the winding 47 is symmetrical with respect to the virtual line VL of the tooth 42. rolled into shape. In other words, in order to wind the winding 47 in a symmetrical shape with the imaginary line VL of the teeth 42 as a line of symmetry, the rotation direction second projecting portion 65 and the reverse direction second projecting portion 66 are arranged at least with the imaginary line VL as a line of symmetry. It is sufficient to have radially outer surfaces 65a and 66a having a symmetrical shape.

As described above, the rotational direction second protrusion 65 of the insulating end plate 45A (45B) is closer to the winding 47 than the rotational direction first protrusion 61 of the tooth 42, and the insulation end plate 45A (45B) is reversed. The direction second projecting portion 66 is closer to the winding 47 than the reverse direction first projecting portion 62 of the teeth 42 . In other words, the radially outer surface 66 a of the reverse rotation second protrusion 66 is closer to the winding 47 than the radial outer surface 62 a of the reverse rotation first protrusion 62 , and the radial direction of the rotation direction second protrusion 65 is The outer surface 65 a is closer to the windings 47 than the radially outer surface 61 a of the first projection 61 in the rotational direction. Therefore, when the insulating end plate 45A (45B) is viewed from the stator core 43 side along the center line P of the stator core 43, as shown in FIG. It is located radially outside the direction first projecting portion 61 , and part of the reverse direction second projecting portion 66 is located radially outside the reverse direction first projecting portion 62 . These portions separate the windings 47 from the insulating sheet 48 and prevent the insulating sheet 48 from being sandwiched between the teeth 42 and the windings 47 . In particular, the reverse direction second protrusion 66 forms a larger gap between the winding 47 and the reverse direction first protrusion 62 than between the winding 47 and the rotation direction first protrusion 61. .

In other words, the electric motor 12 according to the present embodiment forms a larger gap between the winding 47 and the reverse direction first projecting portion 62, so that the winding 47 is periodically and locally greatly affected. The Lorentz force prevents the insulating sheet 48 provided between the windings 47 and the stator core 43 from wearing.

In addition, these portions have sheet holding grooves 71 that hold a part of the edge of the insulating sheet 48 protruding from the end surface of the stator core 43 .

The sheet holding groove 71 is a groove provided in the end face of the insulating end plate 45A (45B) that is substantially flush with the end face of the stator core 43 and recessed in the direction away from the stator core 43. . The sheet holding groove 71 forms a gap between the winding 47 and the insulating sheet 48 in the vicinity of the rotation direction first protrusion 61 of the tooth 42 and in the vicinity of the reverse rotation direction first protrusion 62 of the tooth 42, This reliably prevents the insulating sheet 48 from being sandwiched between the teeth 42 and the windings 47. - 特許庁

In addition, by increasing the cross-sectional area of the first protrusion 61 in the rotation direction rather than the first protrusion 62 in the reverse rotation direction, the winding 47 is susceptible to the Lorentz force. can be secured.

FIG. 6 is a diagram showing the relationship between the cross-sectional area ratio of the rotation-direction first protrusion and the reverse-direction first protrusion and the increase or decrease in torque ripple in the electric motor according to the embodiment of the present invention.

As the rotor 22 is driven to rotate, a torque ripple is generated in which the output torque periodically increases or decreases.

The horizontal axis of FIG. 6 is a cross section perpendicular to the center line P of the stator core 43, with the cross-sectional area of the rotation direction first projections 61 as the denominator and the cross-sectional area of the reverse rotation direction first projections 62 as the numerator. is the area ratio AR. That is, the cross-sectional area ratio AR is calculated by (cross-sectional area of the first projecting portion 62 in the reverse rotation direction)/(cross-sectional area of the first projecting portion 61 in the rotating direction). The vertical axis in FIG. 6 is the ratio normalized by the torque ripple when the cross-sectional area ratio AR=1, and is expressed as the torque ripple ratio α.

As shown in FIG. 6, when the cross-sectional area ratio AR is smaller than 1, that is, when the cross-sectional area of the reverse rotation direction first projection 62 is smaller than the cross-sectional area of the rotation direction first projection 61, the torque ripple ratio α is less than 1. On the other hand, when the cross-sectional area ratio AR is greater than 1, that is, when the cross-sectional area of the reverse rotation direction first protrusion 62 is greater than the cross-section area of the rotation direction first protrusion 61, the torque ripple ratio α increases from one. Therefore, by making the cross-sectional area ratio AR smaller than 1, the refrigerating cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment smooth the magnetic flux change in the air gap between the rotor 22 and the stator 21, and the torque It can be seen that the ripple can be reduced. When the torque ripple is reduced, noise and vibration caused by the rotation of the rotor 22 are suppressed, and the reliability and quietness of the compressor 2 are improved.

FIG. 7 is a diagram showing another example of the main part of the electric motor according to the embodiment of the invention.

As shown in FIG. 7, in the stator core 43A of the stator 21A according to the present embodiment, when viewed from the direction along the rotation center line C of the rotor 22, the base portion of each reverse direction first protrusion 62 is , are recessed toward an imaginary line VL that bisects the teeth 42A in the rotational direction R of the rotor 22 from the insulating end plate 45A (45B). The teeth 42A of the stator core 43A are different from the teeth 42 of the stator core 43 that extend with a uniform width from the root portion to the projecting end portion, and extend toward the imaginary line VL at the root portion of each reverse direction first projecting portion 62. It has a groove-shaped recess 75 that is recessed at the bottom.

On the other hand, the bridging portion 53 of the insulating end plate 45A (45B) extends with substantially the same and uniform width as most of the tooth base portions 42a of the teeth 42A. Therefore, the winding 47 is wound around the tooth 42A without being blocked by the bridging portion 53 of the insulating end plate 45A (45B) and entering the concave portion 75 of the tooth 42A. Therefore, at the root portion of the reverse direction first projecting portion 62, the tooth 42 is closer to the virtual line VL than the insulating end plate 45A (45B). Therefore, teeth 42</b>A and windings 47 are separated from each other by the concave portion 75 . This gap reliably prevents the insulating sheet 48 from being sandwiched between the teeth 42 and the windings 47 at the root portion of the reverse-direction first projecting portion 62 .

As described above, the refrigeration cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment include the teeth 42 having the reverse rotation direction first protrusions 62 smaller than the rotation direction first protrusions 61, and the rotation direction first protrusions 61. Insulated end plate 45A having a rotational direction second projection 65 closer to the winding 47 than the direction first projection 61 and a reverse direction second projection 66 closer to the winding 47 than the reverse direction first projection 62, 45B and . Therefore, in the refrigerating cycle apparatus 1, the compressor 2, and the electric motor 12, the Lorentz force that periodically acts on the winding 47 wears the insulating sheet 48 provided between the winding 47 and the stator core 43. prevent. That is, the refrigerating cycle device 1, the compressor 2, and the electric motor 12 can reduce efficiency and output torque without increasing the thickness of the insulating sheet 48 and without decreasing the volume of the windings 47 occupying the slots 49. In addition, the insulation performance between the windings 47 and the stator core 43 can be improved, and the life of the insulation sheet 48 against wear can be improved.

Further, in the refrigeration cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment, the windings 47 are separated from the insulating sheets 48 in the vicinity of the rotation direction first protrusion 61 and in the vicinity of the reverse rotation direction first protrusion 62. and increase the distance between them. That is, the refrigerating cycle device 1, the compressor 2, and the electric motor 12 widen the distance between the charged portion (the conductor and the conductive portion to which the voltage is applied in normal use) and the non-charged portion, thereby protruding first in the rotation direction. It is possible to improve the partial discharge inception voltage in the vicinity of the portion 61 and in the vicinity of the reverse direction first projecting portion 62 and prevent deterioration of the insulating sheet 48 due to discharge.

Further, the refrigeration cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment include teeth 42 having reverse rotation direction first protrusions 62 farther from the windings 47 than the rotation direction first protrusions 61. . Therefore, in the refrigerating cycle device 1, the compressor 2, and the electric motor 12, the insulation sheet 48 between the stator core 43 and the winding 47 in the vicinity of the root of the reverse direction first protrusion 62 where the Lorentz force acts remarkably large. wear can be reliably prevented.

Further, even if the insulation sheet 48 and the coating of the winding 47 are worn due to the abrasion between the windings 47 due to the increase and decrease of the Lorentz force and the friction between the winding 47 and the insulation sheet 48, the winding 47 and the stator An insulation distance with the iron core 43 is ensured. When the insulation distance between the windings 47 and the stator core 43 is ensured, further wear and deterioration of the insulation sheet 48 and the insulation portion of the windings 47 due to partial discharge can be prevented. As a result, the wear and deterioration of the insulating sheet 48 and the windings 47 can be suppressed, the occurrence of a short circuit can be prevented, and the failure of the electric motor 12 can be prevented.

Furthermore, the refrigerating cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment are provided with the insulating end plates 45A and 45B having the reverse direction second protrusion 66 having the same shape as the rotation direction second protrusion 65. there is Therefore, the refrigerating cycle apparatus 1, the compressor 2, and the electric motor 12 have substantially symmetrical windings 47 wound around the teeth 42 having an asymmetrical shape with respect to the imaginary line VL passing through the center, and the Lorentz force is pronounced. It is possible to reliably prevent abrasion of the insulating sheet 48 between the winding 47 and the stator core 43 in the vicinity of the root of the first projecting portion 62 in the reverse direction, which greatly acts on the rotation.

Further, in the refrigerating cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment, the root portion of the reverse direction first projecting portion 62 is closer to the imaginary line VL passing through the center than the insulating end plates 45A and 45B. It has Therefore, the refrigerating cycle device 1, the compressor 2, and the electric motor 12 are located in the vicinity of the base of the reverse direction first projecting portion 62 where the Lorentz force acts remarkably large. The wear of the insulating sheet 48 between the windings 47 and the stator core 43 can be more reliably prevented.

Therefore, according to the refrigerating cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment, the teeth 42A can rotate without increasing the thickness of the insulating sheet 48 and without reducing the volume of the windings 47 occupying the slots 49. It is possible to have a stator core 43 that minimizes the volume reduction of , preventing a decrease in efficiency and a decrease in output torque, and improving the insulation performance between the windings 47 and the stator cores 43, 43A. can be improved, and the life of the insulating sheet 48 against wear can be improved. In addition, the refrigeration cycle apparatus 1, the compressor 2, and the electric motor 12 according to the present embodiment can suppress abrasion of the coatings of the insulating sheet 48 and the windings 47, and when the coatings of the insulating sheet 48 and the windings 47 are worn, Even so, it suppresses partial discharge at the worn portion, suppresses further wear and deterioration of the coating of the insulating sheet 48 and the windings 47, and prevents short circuits between the windings 47 and the stators 21 and 21A. can be prevented. That is, the refrigeration cycle device 1 and the compressor 2 can be provided with the electric motor 12 with higher reliability.

While several embodiments of the invention have been described, these embodiments have been presented by way of example and are not intended to limit the scope of the invention. These novel embodiments can be implemented in various other forms, and various omissions, replacements, and modifications can be made without departing from the scope of the invention. These embodiments and modifications thereof are included in the scope and gist of the invention, and are included in the scope of the invention described in the claims and equivalents thereof.

DESCRIPTION OF SYMBOLS 1... Refrigeration cycle apparatus, 2... Compressor, 3... Radiator, 5... Expansion device, 6... Heat absorber, 7... Accumulator, 7a... Suction pipe, 8... Refrigerant pipe, 8a... Discharge pipe, 11... Closed container, DESCRIPTION OF SYMBOLS 11a... Body part, 11b, 11c... Head plate, 12... Electric motor, 13... Compression mechanism part, 15... Rotating shaft, 15a... Intermediate part, 15b... Lower end part, 16... Main bearing, 17... Sub bearing, 18... Sealing terminal Part 21, 21A Stator 22 Rotor 23 Lead wire 25 Rotor core 26 Eccentric part 31 Cylinder chamber 32 Cylinder 33 Roller 35 Blade 36 Fastening Member 37 Discharge muffler 38 Fastening member 39 Lubricating oil 41 Yoke 41a Peripheral surface 42, 42A Teeth 42a Teeth base 42b Teeth tip 42c Teeth tip surface 43 , 43A... Stator core, 43a, 43b... End face, 43c... Rotor accommodation space, 45A... Insulated end plate, 45B... Insulated end plate, 45a, 45b... Space, 47... Winding wire, 48... Insulating sheet, 49... Slot 51 Outer wall portion 51a Outer peripheral surface 52 Inner wall portion 52a Inner peripheral surface 53 Bridge portion 61 Rotational direction first projection 61a Radial direction outer surface 62 Reversal direction first One projection 62a radially outer surface 65 rotational direction second projection 65a radially outer surface 66 reverse direction second projection 66a radially outer surface 71 sheet holding Groove, 75... Recess.

Claims (6)

a cylindrical stator;
a rotor disposed inside the stator,
The stator is
an iron core having a cylindrical yoke and a plurality of teeth protruding inward from the yoke and arranged in a circumferential direction at intervals;
a plurality of insulating end plates provided on respective end surfaces of the iron core;
a winding wound around each of the teeth and the insulating end plate;
a plurality of insulating sheets arranged in respective slots between the adjacent teeth and sandwiched between the respective windings and the respective teeth;
Seen from the direction along the rotation center line of the rotor,
Each tip of the tooth has a rotation direction first projection projecting in the rotation direction of the rotor and a reverse direction first projection projecting in the direction opposite to the rotation direction of the rotor,
The insulating end plate has a rotation direction second protrusion covering the rotation direction first protrusion and a reverse rotation direction second protrusion covering the rotation direction first protrusion,
The reverse direction first protrusion is smaller than the rotation direction first protrusion,
The second projection in the rotational direction is closer to the winding than the first projection in the rotational direction,
The reverse direction second protrusion is closer to the winding than the reverse direction first protrusion. 2. The electric motor according to claim 1, wherein the reverse direction first protrusion is farther from the winding than the rotation direction first protrusion. 3. The electric motor according to claim 1, wherein the rotation direction second protrusion and the reverse rotation direction second protrusion have the same shape. 4. The electric motor according to any one of claims 1 to 3, wherein a root portion of each of said reverse direction first protrusions is recessed when viewed from a direction along the rotation center line of said rotor. a closed container;
a compression mechanism that is housed in the sealed container and capable of compressing a refrigerant;
and the electric motor according to any one of claims 1 to 4, which is housed in the closed container and drives the compression mechanism. A compressor according to claim 5, a radiator, an expansion device, a heat absorber, and a refrigerant pipe that connects the compressor, the radiator, the expansion device, and the heat absorber and circulates the refrigerant. , a refrigeration cycle device.

Images