JP6025683B2 - Embedded magnet type motor - Google Patents

Description

  The present invention relates to an embedded magnet type motor having a structure in which a bonded magnet embedded in a slot of a rotor or stator made of laminated steel plates is retained.

  When a bonded magnet is filled by injection molding in a motor with a structure in which the magnet is embedded in the rotor or stator slot, the slot may be damaged due to thermal shrinkage of the bond magnet, vibration during motor operation, vibration applied to the motor, etc. There is a concern that the bonded magnet embedded in may fall off. Therefore, conventionally, the opening of the slot is closed with a cover, or the bonded magnet is molded into a shape in which one end of the bonded magnet is hooked on the edge of the slot as disclosed in Patent Document 1. A retaining structure was provided.

JP 11-136888 A

  Since the conventional retaining structure is configured as described above, it is necessary to use a cover and a fixing member (such as a rivet), or to form a bonded magnet latch shape outside the rotor. There was a problem that a mold structure was necessary.

  The present invention has been made to solve the above-described problems, and has an object of realizing the retaining of a bonded magnet injection-molded on a laminated steel rotor or stator with a simple configuration. To do.

An embedded magnet type motor according to the present invention is an axial slot provided in a laminated steel rotor or stator filled with a bond magnet by injection molding, and the inside of the slot is A gate for injection molding of a bond magnet having a stepped portion that engages with a bond magnet to prevent axial slippage, and is smaller than a slot in a steel plate on one end side in the axial direction forming a rotor or a stator. A hole is provided, and the steel plate on the other end side in the axial direction is provided with an air vent hole for injection molding, which is smaller than the slot, and the stepped portion is a gate hole, an air vent hole, and a steel plate on one end side. a it shall be constituted by a slot provided in sandwiched steel between the other end of the steel sheet.

According to the present invention, the steel plate on one end side in the axial direction that forms the rotor or the stator is provided with a step portion that engages with the bond magnet to prevent the axial detachment inside the slot. A smaller gate hole for injection molding of the bonded magnet is provided, and the steel plate on the other end side in the axial direction is provided with an air vent hole for injection molding smaller than the groove hole. And an air vent hole and a slot provided in a steel plate sandwiched between a steel plate on one end and a steel plate on the other end. Can be realized.

It is a longitudinal cross-sectional view which shows the structure of the interior magnet type motor which concerns on Embodiment 1 of this invention. FIGS. 2A and 2B show a configuration of a rotor of an embedded magnet type motor according to Embodiment 1, in which FIG. 2A is a plan view and FIG. 2B is a cross-sectional view taken along line AA. It is sectional drawing which shows the example of the conventional retaining structure. It is sectional drawing which shows the metal mold | die structure which injection-molds a bond magnet, The right half of a figure is the metal mold | die structure of this Embodiment 1, and the left half is the metal mold | die structure of the prior art example of FIG.3 (b). FIG. 5A is a plan view, and FIG. 5B is a cross-sectional view taken along the line BB, illustrating the configuration of the rotor of the interior magnet type motor according to the second embodiment of the present invention. FIG. 6A is a plan view and FIG. 6B is a cross-sectional view taken along line CC, showing a modification of the rotor of the embedded magnet type motor according to the second embodiment. FIG. 7A is a plan view and FIG. 7B is a cross-sectional view taken along the line DD, showing a modification of the rotor of the embedded magnet type motor according to the second embodiment. FIG. 8A shows a configuration of a rotor of an embedded magnet type motor according to Embodiment 3 of the present invention, FIG. 8A is a plan view, and FIG. 8B is a cross-sectional view taken along line EE. FIG. 9 (a) is a plan view, FIG. 9 (b) is a cross-sectional view taken along the FF line, and FIG. 9 (c) shows the configuration of a rotor of an embedded magnet type motor according to Embodiment 4 of the present invention. FIG. 4 is a cross-sectional view taken along line GG. It is sectional drawing which shows the structure of the rotor of the interior magnet type motor which concerns on Embodiment 5 of this invention. FIG. 9 is a cross-sectional view showing a modified example of the rotor of the embedded magnet type motor according to the fifth embodiment. FIG. 9 is a cross-sectional view showing a modified example of the rotor of the embedded magnet type motor according to the fifth embodiment.

Embodiment 1 FIG.
The interior magnet type motor shown in FIG. 1 includes a shaft 4 rotatably supported by two bearings 3 inside a case 1 and a housing 2, a rotor 5 fixed to the shaft 4, and a rotor 5. And a stator 6 disposed so as to surround the outer periphery.

The rotor 5 and the stator 6 are produced by laminating a large number of steel plates in the axial direction X. One of the laminated steel rotor 5 and stator 6 is provided with a slot 7 communicating in the axial direction X, and a bond magnet 8 (resin mixed with magnetic powder such as neodymium) is provided in the slot 7. ) Is filled by injection molding.
Although FIG. 1 shows an example in which the slot 7 and the bond magnet 8 are provided in both the rotor 5 and the stator 6, the slot 7 and the bond magnet are provided in either the rotor 5 or the stator 6. 8 may be provided.

Hereinafter, the present invention will be described by taking as an example a configuration in which the rotor 5 is provided with the slot 7 and the bond magnet 8.
An insulator bobbin 10 is mounted on the stator 6, and a coil wire 9 is wound. An end of the coil wire 9 is connected to a terminal 12 of the connector 11. The connector 11 is connected to a motor control device (not shown) and receives power supply. A sensor magnet 15 is fixed to the shaft 4, and the sensor 14 on the sensor substrate 13 reads the magnetic pole of the sensor magnet 15 to detect the rotational position of the rotor 5. A motor control device (not shown) controls energization to the coil wire 9 based on the rotational position of the rotor 5 to generate a rotating magnetic field in the stator 6, and causes the rotor 5 to be moved by a magnetic action with the bond magnet 8. Rotate.
1 illustrates a motor of the type including the sensor substrate 13, the sensor 14, and the sensor magnet 15. However, the type of the motor is not limited to this, and may be, for example, a sensorless motor.

Next, a structure for preventing the bonded magnet 8 from coming off in the axial direction X will be described.
2A is a plan view of the rotor 5, and FIG. 2B is a cross-sectional view of the rotor 5 taken along line AA. The rotor 5 is formed by laminating disk-shaped steel plates 5-1 to 5-n (n is an arbitrary number) with a hole through which the shaft 4 is inserted in the axial direction X. Of this laminated steel plate, a gate hole for injection molding is provided in the steel plate 5-1 on one end side, and this gate hole is made into a slot 7-1. Further, an air vent hole for injection molding is provided in the steel plate 5-n on the other end side, and this air vent hole is made into a slot 7-n. At the time of injection molding, the gate of the mold for injecting the bond magnet 8 is communicated with the gate hole (groove hole 7-1), and the air vent of the mold for bleeding the air from the groove hole 7 is made into the air vent hole (groove hole 7-2). ).

In the steel plates 5-2 to 5-m (m = n−1) sandwiched between the steel plates 5-1 and 5-n at both ends, a slot 7-2 larger than the slots 7-1 and 7-n is provided. 1 to 7-m are provided, and the slots 7-1 to 7-n are communicated in the axial direction X to form the slot 7 of FIG. At the upper end side of the rotor 5, a step portion 20 is formed by the small slot 7-1 and the large slot 7-2, and at the lower end side, a step portion is formed by the small slot 7-n and the large slot 7-m. By forming 20, the bonded magnet 8 can be engaged by the upper and lower step portions 20, and the axial direction X can be prevented from coming off.
The arrangement, shape, and the like of the bond magnet 8 may be arbitrary and are not limited to the example of FIG.

Here, in order to explain the effect of the retaining structure of the first embodiment, an example of a conventional retaining structure is shown in FIG.
3A, the rivets 100 are used to attach covers 101 to the upper and lower surfaces of the rotor 5a to close the upper and lower openings of the slot 7, and the axial direction of the bond magnet 8 embedded in the slot 7 Prevents X from coming off. In the case of this configuration, a cover 101 which is a separate part and a structure (such as a rivet 101) for fixing the cover 101 are required.
On the other hand, in the first embodiment, the step 20 for retaining is formed inside the slot 7 in which the bonded magnet 8 is embedded, so that a separate part is unnecessary.

In the conventional example of FIG. 3 (b), the hook magnet 102 is integrally provided at the upper end of the bond magnet 8 and hooked to the edge of the slot 7, whereby the bond magnet 8 embedded in the slot 7 is axial. Prevents X from coming off. When the retaining structure by the latching portion 102 is realized, since the latching portion 102 is formed by a mold, a mold structure provided with a recess 103 as shown in the “conventional example” in FIG. 4 is required.
Thus, in the past, a complicated mold structure was required to form the retaining portion 102 for retaining the outer portion of the rotor 5, whereas in the first embodiment, it is made of laminated steel sheets. Since the laminated steel plate itself is formed with a step 20 for retaining it in the slot 7 of the rotor 5, the bond is made with a relatively simple mold structure as shown in “present invention” in FIG. 4. The magnet 8 can be injection molded.

  Further, in the conventional injection molded product, there is a tendency that burrs are likely to occur at the boundary between the mold and the molded part (bonded magnet 8 and the hooking part 102). Since there are only a slot 7-1 as a gate hole and a slot 7-n as an air vent hole at the boundary with (bonded magnet 8), there are few burrs, and the processing and countermeasures are easy. .

  As described above, according to the first embodiment, in the embedded magnet type motor in which the slot 7 in the axial direction X provided in the rotor 5 made of laminated steel plates is filled with the bond magnet 8 by injection molding, Since the step portion 20 that engages with 8 and prevents the axial direction X from coming off is provided inside the slot 7, it is possible to prevent the bonded magnet 8 from coming off with a simple configuration.

  Moreover, according to Embodiment 1, while providing the gate hole (groove hole 7-1) for the injection molding of the bond magnet 8 in the steel plate 5-1 of the one end side among laminated steel plates, the steel plate of the other end side is provided. 5-n is provided with air injection holes (groove holes 7-n) for injection molding, and these gate holes (groove holes 7-1), air vent holes (groove holes 7-n), Since the stepped portion 20 is constituted by the slots 7-2 to 7-m provided in the steel plates 5-2 to 5-m sandwiched between the steel plates 5-1 and 5-n, the injection molding is performed. There are few burrs that occur and the treatment and countermeasures are easy.

Embodiment 2. FIG.
5 and 6 show the configuration of the rotor 5 of the interior magnet type motor according to the second embodiment. FIGS. 5 (a) and 6 (a) are plan views, and FIG. 5 (b) and FIG. 6 (b) is a cross-sectional view of the rotor 5 cut along a BB line and a CC line. 5 and FIG. 6, the same or equivalent parts as in FIG. 1 and FIG.

  In FIG. 5, in the laminated steel plate constituting the rotor 5, the slots 7-1 and 7-n of the upper and lower steel plates 5-1 and 5 -n are sandwiched between the steel plates 5-2 to 5 -m. The step portion 20 is formed inside the slot 7 so as to be smaller than the slots 7-2 to 7-m. By engaging the bonded magnets 8 injection-molded in the slots 7-1 to 7-n with the two step portions 20, the axial direction X can be prevented from coming off.

  In FIG. 6, in the laminated steel plate constituting the rotor 5, the slots 7-1 and 7-n of the upper and lower steel plates 5-1 and 5 -n are sandwiched between the steel plates 5-2 to 5 -m. The step portion 20 is formed inside the slot 7 so as to be larger than the slots 7-2 to 7-m. In the case of the configuration of FIG. 6 as well, similar to FIG. 5, the bonded magnet 8 formed by injection molding in the slots 7-1 to 7-n is engaged with the two step portions 20 to prevent the axial direction X from coming off. it can.

  As described above, according to the second embodiment, the stepped portion 20 for preventing the bond magnet 8 from coming off is the steel plates 5-1 and 5-n at both ends constituting the laminated steel plates and the steel plates 5-2 to 5 sandwiched between them. It is made up of slots 7-1, 7-n and 7-2 to 7-m having different sizes from -m. For this reason, in the laminated steel plates constituting the rotor 5, the shape of the slot is different only for the upper and lower ends in total, and the difference in the shape of the slot between the upper and lower end steel plates and the steel plate therebetween is Since there are few, the difference of the magnet volume which can be filled to the rotor 5 in FIG. 5 and FIG. 6 is smaller compared with the case where there is no retaining structure. When the amount of magnet filled in the rotor 5 changes, the motor characteristics change. However, even if a retaining structure is added, the change in the magnet quantity is small, so the influence on the motor characteristics and rebound are small.

  5 and 6, the sizes of the upper and lower slots 7-1 and 7-n are changed, but the present invention is not limited to this. For example, the steel plates 5-2 sandwiched therebetween The retaining structure may be realized by changing the size of at least one slot among 5-m.

5 and 6, the size of the slots 7-1 to 7-n is changed. However, the retaining structure may be realized by changing the shape.
For example, as shown in FIG. 7 (a) and FIG. 7 (b), one or more pieces are provided in the peripheral portions of the slots 7-1 and 7-n of the upper and lower steel plates 5-1 and 5-n (FIG. 7 (a). ) Is provided with three projections, and these projections are referred to as stepped portions 20. By engaging the bond magnet 8 with the upper and lower step portions 20, the axial direction X can be prevented from coming off. Even in the example of FIG. 7, the difference in magnet volume between the case where there is no retaining structure and the case where there is no retaining structure is small, so that the influence on motor characteristics and rebound are small.

  In the example of FIG. 7, the convex portions are projected inward from the peripheral portions of the slots 7-1 and 7-n, but conversely, the peripheral portions may be cut out to form concave portions. Further, the convex portions are not formed in the slots 7-1 and 7-n of the steel plates 5-1 and 5-n at the upper and lower ends, but at least one of the steel plates 5-2 to 5-m sandwiched therebetween. You may form in a slot.

Embodiment 3 FIG.
FIG. 8 shows the configuration of the rotor 5 of the interior magnet type motor according to the third embodiment, FIG. 8 (a) is a plan view, and FIG. 8 (b) is a cross section of the rotor 5 taken along the line EE. FIG. 8 that are the same as or equivalent to those in FIG. 1 and FIG.

  In the third embodiment, two types of steel plates having large slots and small steel plates are prepared and laminated alternately to constitute the rotor 5. In the example of FIG. 8, the slots 7-1, 7-3,... Of the odd-numbered steel plates 5-1, 5-3,. , 5-4,... Are enlarged. A plurality of step portions 20 are formed by the difference in the sizes of the odd-numbered and even-numbered slots, and the inside of the slot 7 has a multi-stage shape, so that the strength of engaging the bond magnet 8 is large and reliable. A high retaining structure can be realized.

  In the example of FIG. 8, the retaining structure is realized by alternately changing the size of the slot one by one, but may be changed by several sheets. In addition, although the size of the slot is two types, the size may be three or more. Further, the stepped portion 20 may be configured by changing the shape of the slot alternately for each steel plate.

  As described above, according to the third embodiment, the steel plates 5-1, 5- provided with the grooves 7-1, 7-3,..., 7-2, 7-4,. 3 and 5-2, 5-4, and the like are alternately laminated so that the stepped portion 20 that prevents the bonded magnet 8 from coming off is configured in a multistage shape. Since the inside of the groove 7 composed of the slots 7-1 to 7-n has a multi-stage shape and the number of engaging portions with the bond magnet 8 increases, it is possible to realize a retaining structure with higher strength and higher reliability.

Embodiment 4 FIG.
FIG. 9 shows the configuration of the rotor 5 of the interior magnet type motor according to the fourth embodiment, FIG. 9 (a) is a plan view, and FIG. 9 (b) is a cross section of the rotor 5 cut by FF line. FIG. 9C is a cross-sectional view of the rotor 5 taken along line GG. In FIG. 9, the same or corresponding parts as those in FIGS. 1 and 2 are denoted by the same reference numerals, and description thereof is omitted.

  In the fourth embodiment, steel plates 5-1 to 5-n provided with slots 7-1 to 7-n having the same size and shape are prepared, and the upper half steel plates 5-1 to 5-j and the lower plate are provided. Half of the steel plates 5-k to 5-n are stacked while being shifted in the circumferential direction. Accordingly, the upper half slot 7-1 to 7-j and the lower half slot 7-k to 7-n are shifted in the circumferential direction, and the shifted portion becomes the stepped portion 20.

  In the example of FIG. 9, the retaining structure is realized by shifting the upper half and the lower half of the laminated steel plates in the circumferential direction. However, the steel plates may be shifted in the circumferential direction by several sheets (or one sheet at a time).

  As described above, according to the fourth embodiment, the positions of the slots 7-1 to 7-n are shifted in the circumferential direction and the steel plates 5-1 to 5-n are stacked to prevent the bond magnet 8 from coming off. The step portion 20 is configured. For this reason, since each sheet of steel has the same shape, only one type of punching die is required, and costs can be reduced.

Embodiment 5. FIG.
In the fifth embodiment, at least one or more of the steel plates 5-1 to 5-n constituting the rotor 5 and the other steel plates are different in size or shape of the slot 7, so that the step portion 20 is configured to realize a retaining structure.
FIGS. 10-12 is sectional drawing which shows the structure of the rotor 5 of the interior magnet type motor based on this Embodiment 5. FIGS. 10 to 12, the same or corresponding parts as those in FIGS. 1 and 2 are denoted by the same reference numerals and description thereof is omitted.

  In the example of FIG. 10, in the laminated steel plate forming the rotor 5, the upper two steel plates 5-1, 5-2 and the lower two steel plates 5-m and 5-n slots 7-1, 7-2, 7-m and 7-n are made larger than the slots 7-3 to 7-g of the other steel plates 5-3 to 5-g, and the stepped portion 20 is formed inside the slot 7. ing.

  In the example of FIG. 11, in the laminated steel plate constituting the rotor 5, the upper and lower steel plates 5-1, 5-n and the slots 7-1, 7-n, 7-h of the steel plate 5-h sandwiched therebetween. Are made larger than the slots 7-2 to 7-g and 7-i to 7-m of the other steel plates 5-2 to 5-g and 5-i to 5-m, Part 20 is formed.

  In the example of FIG. 12, in the laminated steel plate forming the rotor 5, the slot 7-h of one steel plate 5-h is formed in the grooves of the other steel plates 5-1 to 5-g and 5-i to 5-n. A step portion 20 is formed inside the slot 7 so as to be larger than the holes 7-1 to 7-g and 7-i to 7-n.

  10 to 12, the size of a part of the slot 7 is changed, but the retaining structure may be realized by changing the shape. Moreover, FIGS. 10-12 is an example, Comprising: The part of the slot 7 which changes the magnitude | size or shape may be arbitrary.

  In the first to fifth embodiments described above, the retaining structure in the case where the bonded magnet 8 is embedded in the rotor 5 made of laminated steel has been described. However, the same applies to the stator 6 made of laminated steel as shown in FIG. The retaining structure can be applied.

  In the present invention, within the scope of the invention, any combination of the embodiments, or any modification of any component in each embodiment, or omission of any component in each embodiment is possible. .

  DESCRIPTION OF SYMBOLS 1 Case, 2 Housing, 3 Bearing, 4 Shaft, 5 Rotor, 5-1-5-n Steel plate, 6 Stator, 7, 7-1 to 7-n Slot, 8 Bond magnet, 9 Coil wire, 10 Bobbin, 11 connector, 12 terminal, 13 sensor board, 14 sensor, 15 sensor magnet, 20 steps, 100 rivets, 101 cover, 102 latching part, 103 recess.

Claims (5)

An embedded magnet type motor in which a bonded magnet is filled by injection molding into an axial slot provided in a rotor or stator made of laminated steel sheet,
In the inside of the slot, provided with a stepped portion that engages with the bond magnet to prevent the axial disconnection ,
The steel plate on one end side in the axial direction forming the rotor or the stator is provided with a gate hole for injection molding of the bond magnet, which is smaller than the slot, and the steel plate on the other end side in the axial direction. Is provided with an air vent hole for injection molding smaller than the slot,
The stepped portion, wherein said gate hole, and the air vent hole, the Rukoto is constituted by said groove holes provided sandwiched between steel plates between the steel sheet of the one end steel plate and the other end of the An embedded magnet type motor.   The step portion is constituted by the slot having different shapes provided in the steel plates at both ends constituting the rotor or the stator and at least one of the steel plates sandwiched therebetween. The interior magnet type motor according to claim 1. The slot provided in at least one or more of the steel plates sandwiched between the steel plates at both ends or between the steel plates at both ends has a concavo-convex shape at a peripheral portion thereof. interior permanent magnet motor 2 according.   2. The embedded magnet according to claim 1, wherein the stepped portion is formed in a multi-stage shape by alternately stacking one or more steel plates each having the groove having a different size or shape. Type motor.   2. The interior magnet type motor according to claim 1, wherein the step portion is configured by laminating steel plates while shifting the position of the slot in the circumferential direction.

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