JP6915196B2 - Rotating machine - Google Patents

Description

The present invention relates to a rotary electric machine such as an electric motor, and more particularly to a rotary electric machine in which a permanent magnet is arranged in a rotor. The rotary electric machine includes a motor that converts electrical energy into rotational force (force running) and a motor that converts electrical energy into electrical energy (regeneration). Hereinafter, the motor that converts electrical energy into rotational force will be represented. explain.

Generally, as a motor that requires high output for hybrid vehicles, EV vehicles, etc., a synchronous motor in which a permanent magnet is arranged in a rotor (rotor) and a coil (armature winding) is arranged in a stator (stator) is used. Has been done. In the rotor of the synchronous motor, a plurality of steel plates are laminated in the axial direction of the rotor, and a permanent magnet is incorporated in the laminated steel plate, and the permanent magnet is embedded in the laminated steel plate with an embedded magnet structure. There is a surface magnet structure built into the surface of the steel plate.

Conventionally, a motor has been proposed in which a cooling flow path penetrating in the axial direction is formed in the vicinity of the inner diameter side of a magnet in the rotor, and lubricating oil is supplied to the flow path to improve cooling efficiency (Patent Document 1). ).

Japanese Unexamined Patent Publication No. 2015-89316

The rotor is assembled by fitting a large number of laminated steel plates to the shaft, and a plurality of the cooling flow paths penetrating in the axial direction are formed in the outer diameter portions of the laminated steel plates. Therefore, the lubricating oil supplied to these flow paths leaks from between the laminated steel sheets due to the centrifugal force due to the rotation of the rotor or the repulsive force generated between the rotor and the stator, and the air between the outer peripheral surface thereof and the stator. Infiltrate the gap. In particular, since many laminated steel plates are fastened to the shaft with nuts at the center thereof, there is a gap between the laminated steel plates in the outer diameter side portion where the cooling flow path in the axial direction is formed. It is likely to occur, and lubricating oil is likely to leak from the cooling flow path.

The lubricating oil that has entered the air gap from the rotor becomes a drag resistance of the rotor with the stator, resulting in a drag loss of the motor.

Therefore, an object of the present invention is to provide a rotary electric machine that prevents the lubricating oil (cooling liquid) from seeping out from between the laminated steel plates to the outer peripheral surface of the rotor and thus solves the above-mentioned problems. ..

In the present invention, the stator (5) around which the coil (7) is wound and the stator (5)
A rotor (3) having a plurality of laminated steel plates (6) fixed to a shaft (2) and laminated, and a plurality of magnets (16) incorporated in the laminated steel plates.
Tightening means (11, 15) for fixing the rotor (3) by tightening the inner diameter side of the rotor (3) with respect to the shaft (2) in the axial direction.
It is arranged on the outer diameter side of the tightening means (11, 15), a cooling liquid is supplied from the shaft (2), and is formed by axially penetrating the laminated steel plate in the vicinity of the magnet (16). Cooling flow path (19) and
A welded portion (26) continuously formed on the outer diameter side wall surface of the cooling flow path in the axial direction,
It is in the rotary electric machine (1), which is characterized by being equipped with.

For example, referring to FIG. 2, the cooling flow path (19) has a substantially triangular cross section, and the welded portion (26) is formed on the outer diameter side top portion of the substantially triangular shape.

In the plurality of magnets (16), adjacent magnets are arranged so as to be inclined alternately with the inclination directions reversed.
In the cooling flow path (19), the substantially triangular outer diameter side top portion faces the intermediate portion (C) of the outer diameter direction ends of adjacent magnets, and the substantially triangular outer diameter side wall surface. (19a) is arranged so as to be substantially parallel to each of the magnets (16).

The inner side wall surface (19c) in which the communication passage (21) for supplying the cooling liquid from the shaft (2) to the cooling flow path faces the welded portion (26) of the cooling flow path (19). It opens in.

The reference numerals in parentheses are for comparison with the drawings, but do not affect the description of the claims.

The rotary electric machine according to the present invention is efficiently cooled by a cooling flow path formed by penetrating a laminated steel plate constituting a rotor in the axial direction. Welded portions are formed continuously in the axial direction on the outer diameter side wall surface of the cooling flow path, and the cooling liquid of the cooling flow path is suppressed from leaking from the gaps of the laminated steel sheets. Further, since the outer diameter side wall surface of the cooling flow path is continuously welded, the laminated steel sheets are brought into close contact with each other due to heat shrinkage, and the cooling liquid is prevented from leaking. As a result, the cooling liquid leaked from the gap between the laminated steel sheets is suppressed from entering the air gap between the rotor and the stator, and the drag loss can be reduced.

Since the cooling flow path has a substantially triangular shape and the welded portion is formed on the outer diameter side top portion thereof, the cooling liquid can be used as a laminated steel plate even when centrifugal force due to rotation of the rotor is applied. While cooling, leakage from the space between them is prevented, and the liquid flows in the axial direction and is discharged from the opening at the end.

The outer diameter side tops of the substantially triangular cooling flow paths are located so as to face each other between the outer diameter ends of the adjacent magnets with respect to the magnets arranged alternately with the inclination directions reversed. Therefore, the cooling flow path can be arranged on the outer diameter side of the rotor, and since the welded portion is formed on the outer diameter side top portion, heat shrinkage acts on the outer diameter side portion of each laminated steel plate. The outer diameter portion of the laminated steel plate can be brought into close contact with each other to prevent the cooling liquid from entering the air gap with high efficiency. Further, since the outer diameter side wall surface of the substantially triangular cooling flow path is substantially parallel to each magnet, the cooling efficiency can be improved.

Since the cooling liquid from the shaft is supplied from the inner side wall surface facing the welded portion of the cooling flow path, even if the cooling liquid is vigorously ejected from the continuous passage to the cooling flow path by centrifugal force, It is received at the welded portion without penetrating between the laminated steel plates, and it is possible to prevent the cooling liquid from leaking between the laminated steel plates.

A rotary electric machine (motor) according to an embodiment of the present invention is shown, and is a cross-sectional view taken along the line AA of FIG. A side sectional view showing a rotor of a rotary electric machine. In the front sectional view showing the outline of the outer peripheral part of a rotor, (A) shows the case where welding is not performed, and (B) shows the case where welding is performed.

Hereinafter, embodiments in which the present invention is used in a synchronous motor (rotary electric machine) will be described with reference to the drawings. As shown in FIG. 1, the synchronous motor 1 has a rotor 3 incorporated in a shaft 2 and a stator 5 fixed to a case (not shown) which is a fixing member. A large number of silicon steel plates 6 ... Are laminated in the axial direction in the rotor 3, and a coil 7 is wound around the stator 5. The shaft 2 is rotatably supported by a bearing in the case, has an oil hole 9 in the center, has a key groove 10 formed in the outer peripheral portion, and has a flange 11 protruding in the outer diameter direction in one axial direction. Is formed, and a screw groove 12 is formed on the other side in the axial direction.

The steel plate 6 constituting the rotor 3 has a protrusion protruding in the inner diameter direction fitted into the key groove 10, is fitted into the shaft 2, and is laminated on the shaft 2 by being prevented from rotating in large numbers. One end (the first one) of these laminated steel plates 6 is brought into contact with the flange 11, the washer 13 is brought into contact with the other end (the last one), and the nut 15 is screwed into the thread groove 12. Is tightened to form the rotor 3. As shown in FIG. 2, a large number of through holes that are alternately inclined in the opposite directions are formed in the outer diameter side portion of these laminated steel sheets, and permanent magnets 16 are embedded in these through holes. Therefore, the front surface side and the back surface side of the magnet 16 alternately become S poles and N poles, and a large number of magnets 16 are embedded in the outer peripheral portion of the rotor 3 by alternately inclining a predetermined amount in a circumferential shape.

The steel plate 6 constituting the rotor 3 is provided with a substantially triangular shape for cooling, which is inclined alternately and spreads in the circumferential direction in the side view (see FIG. 2) with the intermediate portion C on the outer diameter side of the adjacent magnets 16 as the center. The oil (flow) passage 19 is formed through the passage. The cooling oil passage 19 is formed so as to penetrate the rotor 3 in the axial direction, the outer diameter side wall surface 19a thereof is substantially parallel to the inner diameter side surface of the inclined magnet 16, and the outer diameter side top portion thereof is the magnet 16. It is arranged so as to face the central portion of the outer diameter side adjacent spacing C and close to the inner diameter side of each magnet. A large number of holes 20 penetrating the oil holes 9 and the outer peripheral surface are formed in the axially central portion of the rotor 3 of the shaft 2. As shown by a broken line in FIG. 2, each hole 20 and each cooling oil passage 19 are communicated with each other by a communication passage 21 formed in the steel plate 6 of the rotor 3 and supplied to the oil hole 9 of the shaft 2. The lubricated oil (cooling liquid) is guided to each cooling oil passage 19 through the communication passage 21.

Specifically, as shown in FIG. 1, a predetermined number (for example, two) of laminated steel plates 6 on the central side in the axial direction of the rotor 3 has a notch 22 communicating with the hole 20 of the shaft 2 in the inner diameter side portion thereof. Is formed, and a notch 23 communicating with the notch 22 is formed in a radial intermediate portion of a predetermined number (for example, two) of laminated steel plates 6 adjacent to the laminated steel plate 6 in the axial direction, and the laminated steel plate is formed. A notch 25 communicating with the notch 23 is formed in an outer diameter side portion of a predetermined number (for example, two) of laminated steel plates 6 adjacent to the sixth in the axial direction, and the notch 23 is used for cooling each of the above. It opens in the central portion of the arcuate inner diameter side wall surface 19c in the oil passage 19. Therefore, the inner diameter side notch 22, the intermediate portion notch 23, and the outer diameter side notch 25 formed in the laminated steel plate 6 form the communication passage 21.

Then, in the rotor 3 made of the laminated steel plate 6 tightened and assembled with the nut 15 as described above, the welded portion 26 is formed on the substantially triangular outer diameter side top portion of the cooling oil passage 19 by laser welding or the like. It is formed continuously in the axial direction. Each laminated steel plate 6 is melted and joined to the welded portion 26 by high energy such as a laser. Further, each laminated steel sheet 6 causes heat shrinkage when the molten metal cools, and each laminated steel sheet 6 constituting the outer diameter side of the rotor 3 attracts each other so as to be in close contact with each other.

In the motor (rotary electric machine) 1 described above, when electric power is supplied to the coil of the stator 5, the rotor 3 rotates and is transmitted from the shaft 2 to the traveling device of the vehicle. Further, the inertial force of the vehicle or the rotational torque from the engine is transmitted to the shaft 2, and when the rotor 3 rotates, the electric power generated in the stator 5 is sent to the battery or the like. In either case, the rotor 3 rotates at a high speed, a field is generated in the laminated steel plate 6 near the magnet 16 in the rotor 3, a current flows through the coil 7 of the stator 5, and heat is generated.

Lubricating oil from the oil pump is supplied to the oil hole 9 of the shaft 2, and the lubricating oil is supplied to each cooling oil passage 19 through the hole 20 in the radial direction of the shaft 2 and the communication passage 21. The lubricating oil in the cooling oil passage 19 flows left and right in the axial direction while cooling the heat generated by the magnet 16 of the rotor 3 and the laminated steel plate 6 due to the field magnetism, and is discharged from the opening at the side end of the rotor 3. The lubricating oil is scattered in the outer diameter direction by the centrifugal force accompanying the rotation of the rotor 3 to cool the heat generated at the coil end portion of the stator 5.

The laminated steel plate 6 of the rotor 3 is tightened by a flange 11 and a nut 15 on the inner diameter side portion of the rotor, and the space between the laminated steel plates 6 is packed and brought into close contact with each other. The amount of lubricating oil leaking from the communication passage 21 to each steel plate is small. As shown in FIG. 3A, when the outer diameter side wall surface of the cooling oil passage 19 is not welded, the tightening force of the nut 15 on the inner diameter side of the rotor 3 is almost the same on the outer diameter side of the rotor 3. It does not work, and the stacking interval s of each steel plate 6 tends to occur. In this state, the lubricating oil (cooling oil) in the cooling oil passage 19 leaks from the stacking interval s of the steel plates 6, and the leaked cooling oil penetrates into the air gap G between the rotor 3 and the stator 5. Therefore, the drag loss of the rotation of the rotor 3 becomes large, and the efficiency of the motor 1 is lowered by that amount.

In the motor 1 according to the present embodiment, as shown in FIG. 3 (B), the outer diameter side wall surface of the cooling oil passage 19 is welded, and the welded portion 26 in which each laminated steel plate 6 is continuously integrally bonded. It has become. The lubricating oil supplied from the communication passage 21 to the cooling oil passage 19 is supplied to the central portion in the circumferential direction of the inner diameter side wall surface 19c of the cooling oil passage 19 by centrifugal force, and the cooling oil passage 19 having a substantially triangular cross section. The lubricating oil concentrates on the outer diameter side top portion. The top portion of the cooling oil passage 19 is welded, and the ejection pressure of the lubricating oil is received by the welded portion 26 to effectively suppress the leakage of the lubricating oil between the steel plates 6.

Further, due to heat shrinkage due to the welding, the laminated steel plates 6 on the outer diameter side portion of the rotor 3 are joined to each other so as not to form a gap, and the lubricating oil flowing through the cooling oil passage 19 is Even if centrifugal force acts, it does not leak from between the laminated layers of the steel sheets 6 and infiltrate into the air gap G, and suppresses the occurrence of drag loss as shown in FIG. 3 (A). Further, even if there is lubricating oil leaking from the communication passage 21, the steel plates 6 of the outer diameter portion are in close contact with each other due to the heat shrinkage, and the infiltration of the lubricating oil into the air gap G is prevented.

The rotor 3 of the motor 1 has an embedded magnet structure in which a magnet 16 is embedded inside the laminated steel plate 6, but this may be a surface magnet structure in which a magnet is assembled on the outer peripheral surface of the rotor. Further, the arrangement of the magnets 16 is not limited to the eight-shaped structure as shown in FIG. 2, and any arrangement structure may be used. Further, although the outer diameter side wall surface of the cooling oil passage 19 is welded by laser welding, this is not limited to laser welding, and other welding such as electric resistance welding may be used. The cooling oil passage 19 is not limited to a substantially triangular shape, but may have another shape such as a circular cross section or a rectangular cross section, and the cooling oil can be arranged with respect to the magnet 16 while the outer diameter side ends of the inclined magnets are adjacent to each other. It is arranged so that the center of the road is opposed to each other, but this may be any arrangement. It is suitable for a vehicle drive motor (rotary electric machine) that requires high output, but it is not limited to this and is not applied to any motor.

1 Rotating electric machine (motor)
2 Shaft 3 Rotor 5 Stator 6 Laminated steel plate 7 Coil 9 Oil hole 16 Magnet 19 Cooling flow path (oil passage)
19a Outer diameter side wall surface 19c Inner diameter side wall surface 21 Continuous passage 26 Welded part

Claims (4)

With the stator around which the coil is wound,
A rotor having a plurality of laminated steel plates fixed to a shaft and laminated, and a plurality of magnets incorporated in the laminated steel plates,
A tightening means for fixing the rotor by tightening the inner diameter side of the rotor in the axial direction with respect to the shaft.
A cooling flow path arranged on the outer diameter side of the tightening means, to which a cooling liquid is supplied from the shaft, and which is formed by axially penetrating the laminated steel plate in the vicinity of the magnet.
A welded portion formed continuously in the axial direction on the outer diameter side wall surface of the cooling flow path,
A rotating electric machine characterized by being equipped with. The cooling flow path has a substantially triangular cross section, and the welded portion is formed on the outer diameter side top portion of the substantially triangular shape.
The rotary electric machine according to claim 1. In the plurality of magnets, adjacent magnets are arranged so as to be inclined alternately with the inclination directions reversed.
In the cooling flow path, the substantially triangular outer-diameter side top portion faces the intermediate portion between the outer-diameter end portions of the adjacent magnets, and the substantially triangular outer-diameter side wall surface is substantially attached to each magnet. Arranged so that they are parallel,
The rotary electric machine according to claim 2. The communication passage for supplying the cooling liquid from the shaft to the cooling flow path opens on the inner side wall surface of the cooling flow path facing the welded portion.
The rotary electric machine according to claim 2 or 3.

Images