WO2017006430A1 - Rotor - Google Patents

Abstract

A rotor is provided with: a plurality of rotor cores comprising magnetic steel plates and formed in a column shape; and cooling paths that are formed by openings opened through the magnetic steel plates, and that are provided in each of the rotor cores. The openings penetrate in the direction of the rotational axis of the rotor cores and are opened in an arc shape when viewed in a plane perpendicular to the rotational axis. The rotor cores are stacked in the direction of the rotational axis. The cooling paths are arranged in such a way that the phases thereof are shifted in a circumferential direction about the rotational axis and in such a way that the cooling paths have: a communication portion through which the cooling paths adjacent to each other in the rotational axis direction communicate with each other; and wall portions for generating the flow of a refrigerant in the circumferential direction.

Description

Rotor

The present invention relates to a rotor.

A permanent magnet motor in which a magnetic iron plate is laminated to constitute a rotor core, a rotor magnet is arranged on the rotor iron core to constitute a rotor, and this rotor is fixedly arranged. It has been known. In this permanent magnet type motor, cooling unit holes are formed in the stator core, and a large number of magnetic steel plates are slightly shifted in the rotation direction and stacked, thereby cooling holes by a group of cooling unit holes. However, it is formed substantially obliquely with respect to the axis (Patent Document 1).

JP 2003-18775 A

However, in the above permanent magnet type motor, there is a problem that the cooling efficiency is low because the flow of the refrigerant in the circumferential direction around the rotation axis is difficult to occur when the rotor rotates.

The problem to be solved by the present invention is to provide a rotor with high cooling efficiency.

The present invention includes a plurality of rotor cores formed in a cylindrical shape, and cooling paths respectively provided in the plurality of rotor cores, and a plurality of rotor cores are stacked in a direction along the rotation axis, and the circumference around the rotation axis A plurality of cooling paths are arranged so as to shift the phase of the direction, a communication section that communicates between adjacent cooling paths in the direction of the rotation axis, and a wall section that generates a flow of refrigerant in the circumferential direction. The above-described problem is solved by providing the cooling path.

According to the present invention, when the rotor rotates, the refrigerant hits the wall portion, so that the flow of the refrigerant in the circumferential direction is generated, so that the contact area between the refrigerant and the rotor is increased, and the cooling efficiency is increased. There is an effect.

FIG. 1 is an exploded perspective view of a rotor according to an embodiment of the present invention. FIG. 2 is a perspective view of the rotor according to the embodiment of the present invention. FIG. 3 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 2, and is a perspective view of the cooling path. FIG. 4 is a plan view of the cooling path. FIG. 5 is a perspective view of a rotor core 11 in a rotor according to another embodiment of the present invention. FIG. 6 is a perspective view of a rotor according to another embodiment of the present invention. FIG. 7 is a perspective view of a rotor according to another embodiment of the present invention. FIG. 8 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 7, and is a perspective view of the cooling path. FIG. 9 is a perspective view of a rotor according to another embodiment of the present invention. FIG. 10 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 9, and is a perspective view of the cooling path. FIG. 11 is a perspective view of the cooling path in which only the cooling path is extracted in the rotor according to the modification of the present invention. FIG. 12 is a perspective view of a rotor according to another embodiment of the present invention. 13 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 12, and is a perspective view of the cooling path.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

<< First Embodiment >>
FIG. 1 is an exploded perspective view of a rotor according to an embodiment of the present invention. FIG. 2 is a perspective view of the rotor. FIG. 3 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 2, and is a perspective view of the cooling path. The rotor according to the present embodiment is used for, for example, a synchronous motor (motor). The motor includes a rotor formed in a columnar shape and a stator. The stator is a member that generates a rotational force with respect to the rotor, and has a coil. The stator is provided on the outer periphery of the rotor with a clearance from the rotor. And if an electric current is sent through the coil provided in the stator, a magnetic field will generate | occur | produce and a rotational force will generate | occur | produce with respect to a rotor.

The rotor 1 includes a plurality of rotor cores 11 to 13, a plurality of cooling paths 21 to 23, and a plurality of permanent magnets 31 to 33. The rotor core 11 has a plurality of laminated steel plates. The laminated steel plate is formed in a disc shape, and a circular hole is provided in the center of the laminated steel plate for passing the shaft. Moreover, the hole for forming the cooling path 21 is provided in the laminated steel plate. The rotor core 11 is configured by laminating a plurality of laminated steel plates. When laminating a plurality of laminated steel plates, the laminated steel plates are laminated so that the holes for the shaft and the holes for cooling are combined. The central axis of the shaft hole is the rotation axis of the rotor 1.

The hole for the cooling path 21 is formed in an arc shape on a vertical plane (yz plane in FIGS. 1 to 3) perpendicular to the rotation axis. In other words, the hole for the cooling path 21 is formed in the laminated steel plate so as to be a part of a circle with the center of the laminated steel plate as the origin on the yz plane. A plurality of holes for the cooling passage 21 are formed per one laminated steel plate. In the present embodiment, the number of holes is four, but at least one is sufficient. The plurality of cooling holes are arranged at equal intervals on the same circle on the yz plane. In the example of FIG. 1, when the position of the hole for the cooling path 21 is represented by an angle on the yz plane with the center of the laminated steel plate as the center point, they are 0 degree, 90 degrees, 180 degrees, and 270 degrees. When a plurality of laminated steel plates are laminated, a plurality of cooling holes are also laminated to form a passage penetrating along an axis parallel to the rotation axis of the rotor 1. This passage becomes the cooling passage 21. The cooling path 21 is formed in a shape in which a columnar space is curved so as to have an arc shape on the yz plane.

The cooling path 21 is a passage (flow path) through which the coolant flows in the rotor 1. In this embodiment, oil is used as the refrigerant. The refrigerant is not limited to oil but may be a gas such as air or a liquid other than oil.

The permanent magnet 31 is embedded in the laminated steel plate. In the example of FIG. 1, eight magnets are arranged at equal intervals on the same circle on the yz plane. It is not necessary to limit the number of permanent magnets to eight.

The rotor cores 12 and 13 have the same configuration as the rotor core 11. The cooling paths 22 and 23 have the same configuration as the cooling path 21. The cooling path 22 is provided in the rotor core 12, and the cooling path 23 is provided in the rotor core 13. The permanent magnets 32 and 33 have the same configuration as the permanent magnet 31. The permanent magnet 32 is provided on the rotor core 12, and the permanent magnet 33 is provided on the rotor core 13.

The rotor 1 is configured by stacking a plurality of rotor cores 11, 12, and 13. When laminating a plurality of rotor cores 11 and 12, as shown in FIG. 1, a plurality of cooling paths 21 and cooling paths 22 adjacent in the direction along the rotation axis of the rotor 1 are shifted in the circumferential direction. The rotor cores 11 and 12 are stacked. The circumferential direction is a direction along a circle on the yz plane with the center of the laminated steel plate as a central point (a point serving as the rotation axis of the rotor 1). In addition, when the cooling path 21 and the cooling path 22 are shifted, the cooling path 21 and the cooling path 22 are partly overlapped with a part of the opening part of the cooling path 21.

When laminating a plurality of rotor cores 12 and 13, like the lamination of the rotor cores 11 and 12, the adjacent cooling path 22 and cooling path 23 in the direction along the rotation axis of the rotor 1 are shifted in the circumferential direction. A plurality of rotor cores 12 and 13 are stacked. Further, when the cooling path 22 and the cooling path 23 are shifted, the cooling path 22 and the cooling path 23 are partly overlapped with a part of the opening part of the cooling path 22.

When a plurality of rotor cores 11 to 13 are stacked, a rotor 1 as shown in FIG. 2 is formed. The cooling paths 21 to 23 are formed such that the phase shifts from the upstream to the downstream in the flow of the refrigerant, and the phase shifts backward from the rotation direction (forward rotation direction) of the rotor 1. The direction indicated by the arrow R in FIG. 2 is the normal rotation direction (in other drawings, the arrow R indicates the normal rotation direction).

The configuration of the cooling paths 21 and 22 will be described with reference to FIG. 4 is an arrow view of the cooling paths 21 and 22 indicated by an arrow A in FIG. FIG. 4 shows the cooling paths 21 and 22 in a plan view.

The cooling path 21 has a communication part 21a, a wall part 21b, a side wall part 21c, and an opening part 21d. The cooling path 22 includes communication portions 22a and 22d, wall portions 22b and 22e, and a side wall portion 22c. The communication portion 21a is a portion opened to allow communication between adjacent cooling paths 21 and 22 in the x-axis direction. The communication part 21a serves as an inlet or outlet for the refrigerant. The wall portion 21b is a wall for generating a refrigerant flow in the circumferential direction around the rotation axis (x-axis). The side wall portion 21c is a wall portion along the circumferential direction around the rotation axis. The opening 21d is a portion that opens toward the positive direction of the x-axis. The opening 21d is formed on the surface opposite to the surface including the communication portion 21a and the wall portion 21b.

The communicating portion 22a is a portion opened to communicate between the cooling paths 21 and 22 adjacent in the x-axis direction. The communicating part 22d is a part opened to communicate between the cooling paths 22 and 23 adjacent in the x-axis direction. The communication portions 22a and 22d serve as an inlet or an outlet for the refrigerant. The communication part 21a and the communication part 22a are the same hole. The communication part 22 d also functions as a communication part formed in the cooling path 23. The wall portions 22b and 22e are walls for generating a refrigerant flow in the circumferential direction around the rotation axis (x-axis). The wall portion 22b is formed so as to be flush with the communication portion 22a. The wall portion 22e is formed so as to be flush with the communication portion 22d. The side wall portion 22c is a wall portion along the circumferential direction around the rotation axis.

The circumferential length of the communicating portion 21a and L _1, the circumferential length of the wall portion 21b and L _2, the length along the x-axis direction of the side wall portion 21c and L _3. Communicating portions 22a, 22 d circumferential length _{L 1} next to the wall portion 22b, the circumferential length of the 22e is _{L 2,} and the length along the x-axis direction of the side wall portion 22c becomes _{L 3} . In the present embodiment, L ₁ is shorter than L ₂ and shorter than L ₃ .

When the rotor 1 rotates in the direction indicated by the arrow R in FIG. 2, the cooling path 23 is on the upstream side and the cooling path 21 is on the downstream side. The refrigerant retention spaces are arranged so that the refrigerant stays in the rotor 1 with respect to the flow of the refrigerant in the direction along the rotation axis of the rotor 1. The staying space corresponds to the space in the cooling paths 21 to 23. In the present embodiment, the communication portions 21a, 22a, 22d and the wall portions 21b, 22b, 22e are formed on the surfaces of the adjacent cooling paths 21 to 23 as described above. The refrigerant flowing in the direction along the rotation axis hits the walls 21b, 22b, and 22e. Therefore, a refrigerant flow in the circumferential direction occurs. Since the rotor 1 is rotating at this time, the relative speed of the rotor and the refrigerant in the circumferential direction increases in the cooling paths 21 to 23. That is, the relative speed in the circumferential direction of the refrigerant in the walls 21b, 22b, and 22e is larger than the relative speed in the circumferential direction of the refrigerant that passes through the communication portions 21a, 22a, and 22d. As a result, the time during which the refrigerant stays in the cooling paths 21 to 23 becomes longer, and the contact area between the refrigerant and the rotor cores 11 to 13 becomes larger (the contact time becomes longer). As a result, the cooling efficiency can be increased.

3 indicates the refrigerant flow in the entire rotor. In this embodiment, the bias of the refrigerant in the rotor 1 is reduced. Therefore, the contact area between the refrigerant and the rotor cores 11 to 13 is increased, the thermal conductivity is increased, and the cooling efficiency is improved.

As described above, in the present embodiment, the plurality of rotor cores 11 to 13 formed in a cylindrical shape and the cooling paths 21 to 23 respectively provided in the plurality of rotor cores 11 to 13 are provided in a direction along the rotation axis. A plurality of rotor cores 11 to 13 are stacked. A plurality of cooling paths 21 to 23 are arranged so as to shift the phase in the circumferential direction around the rotation axis, and communication portions 21a, 22a, 22d communicating between the cooling paths 21 to 23, and the circumference Wall portions 21b, 22b, and 22e that generate a refrigerant flow in the direction are provided in the cooling paths 21 to 23. As a result, a plurality of spaces in which the refrigerant is retained are formed from the upstream side to the downstream side of the refrigerant, and the phases of the plurality of spaces are shifted backward in the rotation direction of the rotor 1 as going downstream. Therefore, since the flow of the refrigerant in the circumferential direction is generated, the contact area between the refrigerant and the rotor is increased, and the cooling efficiency can be improved.

Further, in this embodiment, the holes for the cooling paths 21 to 23 are formed in the magnetic steel plate so as to form an arc shape in a plane perpendicular to the rotation axis of the rotor 1. Thereby, since the flow of the refrigerant | coolant to the circumferential direction generate | occur | produces, the area which a refrigerant | coolant and a rotor contact increases and it can improve cooling efficiency.

In the present embodiment, the rotor cores 11 to 13 are configured by laminating a plurality of magnetic steel plates, but the rotor cores 11 to 13 may each be configured by one magnetic steel plate.

<< Second Embodiment >>
A rotor according to another embodiment of the present invention will be described. FIG. 5 is a perspective view of the rotor core 11. FIG. 6 is a perspective view of the rotor 1. The basic configuration of the rotor 1 is the same as that of the first embodiment, and the description thereof is incorporated as appropriate.

As shown in FIG. 5, the phase when the rotor cores 11 to 13 are shifted and arranged is θ, the circumferential length of the communication portion 21a is α, and the circumferential length of the cooling passage 21 is φ. The interval in the circumferential direction between adjacent cooling paths 21 (the length from the center of one cooling path 21 to the center of the other cooling path 21 in the circumferential direction) is denoted by ψ. The phase, the length in the circumferential direction, and the interval in the circumferential direction are represented as angles on a plane (yz plane) perpendicular to the rotation axis of the rotor 1. The angle display is an angle on a circle having the center of the rotor core 11 as a center point, and is an angle on a circle in which a plurality of cooling paths 21 are arranged.

The shape of the plurality of cooling paths 21 and the positional relationship between the plurality of cooling paths 21 satisfy the following expressions (1) and (2). Note that n represents a natural number, and in this embodiment, n = 1.

The shape and positional relationship of the plurality of cooling paths 22 provided in the rotor core 12 also satisfy the expressions (1) and (2), and the shape and position relationship of the plurality of cooling paths 23 provided in the rotor core 13 are also expressed by the formula ( 1) and formula (2) are satisfied. That is, the rotor cores 11 to 13 are formed to have the same shape, and the cooling paths 21 to 23 are formed to have the same shape and the same arrangement.

The plurality of rotor cores 11 to 13 are stacked while being shifted by the phase (θ) represented by the above formulas (1) and (2), so that the rotor 1 shown in FIG. 6 is formed. As a result, in the rotor cores 11 to 13, the cooling paths 21 to 23 can be formed while keeping the relative positional relationship between the magnets 31 to 33 and the cooling paths 21 to 23 the same. What is necessary is just to prepare one type of required type | mold. Therefore, the processing cost can be reduced.

As described above, in this embodiment, the rotor cores 11 to 13 are shifted by the phase (θ) while forming the rotor cores 11 to 13 and the cooling paths 21 to 23 so as to satisfy the expressions (1) and (2). Arrange. As a result, when the rotor cores 11 to 13 and the cooling paths 21 to 23 are manufactured, only one type of punching die is required, so that the manufacturing cost can be suppressed.

Note that n is not limited to 1 and may be a natural number of 2 or more.

<< Third Embodiment >>
A rotor according to another embodiment of the present invention will be described. FIG. 7 is a perspective view of the rotor 1. FIG. 8 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 7, and is a perspective view of the cooling path. This embodiment differs from the first embodiment described above in that communication portions are provided at both ends of the cooling path. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first and second embodiments are incorporated as appropriate. In addition, the arrow R of FIG. 7 has shown the normal rotation direction, and the arrow S has shown the reverse rotation direction. Further, an arrow F _{1 in} FIG. 8 indicates the flow of the refrigerant when the rotor 1 is rotating in the forward rotation direction, and an arrow F ₂ is the refrigerant when the rotor 1 is rotating in the reverse rotation direction. Shows the flow.

The cooling path 21 has a communication part 21a, a wall part 21b, a side wall part 21c, and an opening part 21d. The cooling path 22 has communication portions 22a and 22d, wall portions 22b and 22e, and a side wall portion 22c. The cooling path 23 has a communication part 23a, a wall part 23b, a side wall part 23c, and an opening part 23d.

The communicating portion 21a is a portion opened to allow communication between the adjacent cooling paths 21 and 22 in the x-axis direction, and is provided at both ends of the cooling path 21 in the circumferential direction. The communication part 21a is located at both ends of the wall part 21b. The two communication portions 21a and the wall portion 21b are formed on the same plane. The communicating portion 21a and the communicating portion 22a of the cooling path 22 are the same hole.

The communication portion 22a is a hole opened to allow communication between the adjacent cooling paths 21 and 22 in the x-axis direction, and is provided at both ends of the cooling path 22 in the circumferential direction. The communication part 22a is located at both ends of the wall part 22b. The two communication portions 22a and the wall portion 22b are formed so as to be on the same plane. The communication part 22d is a part opened to communicate between the cooling paths 22 and 23 adjacent in the x-axis direction, and is provided at both ends of the cooling path 22 in the circumferential direction. The communication part 22d is located at both ends of the wall part 22e. The two communicating portions 22d and the wall portion 22e are formed so as to be on the same plane. The communicating portion 22d and the communicating portion 23a of the cooling path 23 are the same hole.

The communication portion 23a is a portion opened to communicate between the cooling paths 22 and 23 adjacent in the x-axis direction, and is provided at both ends of the cooling path 23 in the circumferential direction. The communication part 23a is located at both ends of the wall part 23b. The two communication parts 23a and the wall part 23b are formed so as to be on the same plane. The opening 23d is a hole that is formed at a position facing the two communication portions 23a and the wall portion 23b in the x-axis direction and opens in the negative direction of the x-axis.

The circumferential length (α) of the communication portion 21a, the phase (θ) when the rotor cores 11 to 13 are shifted and the circumferential length (φ) of the cooling path are expressed by the following formula (3 ) Is satisfied. However, the display of α, θ, and φ is the same as in the second embodiment.

As described above, in the present embodiment, communication portions 21a, 22a, 22d, and 23a are provided at both ends in the circumferential direction of the cooling paths 21 to 23, respectively. As a result, the adjacent cooling paths 21 to 23 communicate with each other on both the front side and the rear side in the rotation direction of the rotor 1, so that the same refrigerant flow can be formed even when the rotor 1 rotates in the reverse direction. . As a result, the cooling efficiency can be increased.

<< 4th Embodiment >>
A rotor according to another embodiment of the present invention will be described. FIG. 9 is a perspective view of the rotor 1. FIG. 10 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 9, and is a perspective view of the cooling path. This embodiment differs from the first embodiment described above in that a skew is provided in the rotor. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first to third embodiments are incorporated as appropriate.

The rotor 1 is divided by a yz plane including the center of the rotor 1 in the rotation axis direction, and is laminated while having a slight phase shift on the division plane. And the shift | offset | difference of the rotor core in a division surface becomes a skew. The skew is provided to reduce the excitation force of the motor. In the present embodiment, a skew is provided at the position of the rotor core 12. The deviation in the rotational direction of the rotor 1 when providing the skew is sufficiently small compared to the phase (θ).

As shown in FIG. 10, by providing a skew at the position of the rotor core 12, a step 22f is formed at the center of the cooling path 22 in the direction along the rotation axis of the rotor. The length of the stepped portion 22f in the circumferential direction corresponds to a phase shift for providing a skew. Further, the size of the opening 22g of the cooling path 22 on the same surface as the stepped portion 22f is larger than the communicating portions 22a and 22d. The step portion 22f due to skew is a slight step and is not provided for generating a circumferential flow of the refrigerant. The circumferential length of the step portion 22f is shorter than the circumferential length of the wall portion 22b, and the circumferential length of the opening 22g is the circumferential length of the communication portions 22a and 22d. Shorter than that.

As a modification of the present embodiment, the same skew as described above may be provided in the rotor 1 according to the third embodiment. FIG. 11 is a diagram in which only the cooling path is extracted from the rotor according to the modification, and is a perspective view of the cooling path. As shown in FIG. 11, a step 22 f is formed in the cooling path 22 by providing a skew.

<< 5th Embodiment >>
A rotor according to another embodiment of the present invention will be described. FIG. 12 is a perspective view of the rotor 1. 13 is a diagram in which only the cooling path is extracted from the rotor shown in FIG. 12, and is a perspective view of the cooling path. In the present embodiment, the position of the communication part 22d and the flow of the refrigerant in the rotor are different from those of the first embodiment described above. Other configurations are the same as those of the first embodiment described above, and the descriptions of the first to fourth embodiments are incorporated as appropriate. In addition, the arrow shown in FIG. 13 represents the flow of the refrigerant.

The communication portion 22a and the communication portion 22d are formed at positions that are coaxial with each other in the x-axis direction. The refrigerant is supplied into the rotor core 12 from a position that is the center of the rotor 1 in the direction along the rotation axis of the rotor 1 and enters the cooling path 22. Then, the refrigerant in the cooling path 22 branches and flows into the communication part 22a and the communication part 22d, and is discharged from the cooling path 21 and the cooling path 23 to the outside of the rotor 1, respectively.

In this embodiment, skew may be provided as in the fourth embodiment.

DESCRIPTION OF SYMBOLS 1 ... Rotor 11-13 ... Rotor core 21-23 ... Cooling path 21a, 22a, 22d, 23a ... Communication part 21b, 22b, 22e, 23b ... Wall part 21c, 23c ... Side wall part 21d, 22g, 23d ... Opening part 22f Level | step difference 31-33 Permanent magnet

Claims (5)

A plurality of rotor cores having magnetic steel plates and formed in a columnar shape;
Formed by holes formed in the magnetic steel plate, and provided with cooling paths respectively provided in the plurality of rotor cores,
The hole penetrates along the rotation axis of the rotor core and is formed in an arc shape in a plane perpendicular to the rotation axis;
The plurality of rotor cores are stacked in a direction along the rotation axis,
The plurality of cooling paths are:
A communication portion that is arranged with a phase shift in the circumferential direction around the rotation axis and communicates between the cooling paths adjacent to each other in the direction of the rotation axis, and a flow of the refrigerant in the circumferential direction. A rotor having a wall to be generated. The rotor according to claim 1, wherein a length of the communication portion in the circumferential direction is shorter than a length of the wall portion in the circumferential direction. The rotor according to claim 1, wherein the hole is formed in an arc shape on a plane perpendicular to the rotation axis. The rotor core has a plurality of the cooling paths,
The rotor according to claim 3, wherein φ = n · θ + α and ψ = 2 · n · θ are satisfied.
However,
n is a natural number,
θ, α, φ, ψ represents the length in the circumferential direction as an angle in a plane perpendicular to the rotation axis,
θ represents the phase,
α represents the circumferential length of the communicating portion φ represents the circumferential length of the cooling path,
ψ represents an interval in the circumferential direction between the cooling paths adjacent in the circumferential direction. The rotor according to any one of claims 1 to 4, wherein the cooling path has the communication portions at both ends in the circumferential direction.

Images