JP2011030351A - Structure of motor housing - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a positioning structure that does not have an effect on a flux passage, to provide a key structure capable of reducing the thickness of a motor housing so as to make a water jacket approach a motor (particularly stator external periphery), and to provide a water jacket structure capable of improving efficiency of cooling in the motor. <P>SOLUTION: In the structure of the motor housing which fittingly fixes a stator of the motor having the stator and a rotor into the motor housing, the structure of the motor housing is characterized by having a guide groove formed at the external peripheral surface of the stator of the motor and a female screw located in a proper position of the motor housing which is externally engaged with the stator, and by positioning the stator and the motor housing by screwing a male screw into the female screw. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a motor housing structure, and more particularly to a key structure for positioning and fixing a stator of a motor so as not to be relatively rotatable with respect to the motor housing, and suitable for a motor housing provided with a water jacket or the like. The present invention relates to a motor housing structure.

  Hybrid vehicles such as EV, HEV, PHEV, and FCV are equipped with a driving motor (electric motor) or a generator (generator). The motor includes a stator and a rotor, the stator is fitted and fixed inside the motor housing, and the rotor is rotatably supported with respect to the stator.

  In a motor housing structure in which a stator of a motor is fitted and fixed inside the motor housing, a parallel key is generally used in the past when determining the position between the stator and the motor housing. This parallel key also serves as a rotation stopper for the stator.

Japanese Patent No. 3591354 Japanese Utility Model Publication No. 55-94950

However, since the parallel key is long in the axial direction and protrudes in the radial direction, a water-cooled motor must avoid the key groove of the parallel key when installing a water jacket on the motor housing, which greatly restricts the structure. there were. Therefore, in the motor housing structure using the parallel key, the water jacket cannot be provided closer to the stator, and there is a problem that the cooling efficiency is deteriorated and the motor housing is increased in size and weight. The same applies to the motor housing structure of a motor in which the stator and the motor housing are bolted. Furthermore, the use of a parallel key requires that a key groove be provided also on the motor housing side, and there is a problem that may cause an increase in cost depending on the process and processing accuracy.
In a key structure provided in a general rotating body, the positioning accuracy is determined by the dimensional accuracy of each of the key and the two key grooves, and the accuracy is lowered due to accumulation of individual gaps both in the circumferential direction and in the radial direction. Therefore, processing with extremely high dimensional accuracy is required. Therefore, for example, a key structure provided with a set screw has been proposed, and a structure that improves the accuracy during assembly while eliminating the need for high machining accuracy has been proposed.
However, the formation position of the key groove is determined by selecting an arbitrary position that can be easily processed regardless of the circumferential direction or the axial direction. In addition, in a rotating body such as a pulley or a gear, there is no capacity space that is a non-structural body such as a water jacket, and sufficient consideration is not given for its formation.
Further, in order to receive a circumferential load applied to the key, it is necessary to increase the thickness of the portion where the key groove is provided so as to withstand the load. Since the depth of the key groove is also required, there is a problem that the thick part necessary for the key structure becomes large.
Furthermore, when a water jacket is provided in the motor housing, it is necessary to avoid the key structure, so it is necessary to meander to form a complicated shape or to enlarge in a radial direction. There is an inconvenience.
By the way, when press-fitting is involved in fixing the stator of the motor to the motor housing, the circumferential load applied to the key can be reduced. For this reason, in the case of a motor housing structure that involves press-fitting for fixing, it is conceivable that the function as a rotation stopper of the key structure is lowered, the key groove depth is reduced, and the function as positioning is emphasized.

  The present invention provides a positioning structure that does not affect the magnetic flux path, provides a key structure that can reduce the wall thickness of the motor housing so that the water jacket is close to the motor (especially the outer periphery of the stator), and cools the motor. An object is to provide a water jacket structure that increases efficiency.

  The present invention relates to a motor housing structure in which the stator of a motor having a stator and a rotor is fitted and fixed inside the motor housing, a guide groove provided on an outer peripheral surface of the stator of the motor, and the motor that is externally fitted to the stator. A female screw portion positioned at a proper position of the housing is provided, and a male screw is fastened to the female screw portion to position the stator and the motor housing.

  According to the motor housing structure of the present invention, the depth of the guide groove of the stator guided by the male screw can be made shallow enough not to affect the magnetic flux path. For this reason, this motor housing structure can suppress the thickness required for the positioning structure of the motor housing, and can reduce the weight.

It is a side view of a motor housing. (Example) It is sectional drawing by the II-II line of FIG. (Example) It is an expanded sectional view of the arrow III site | part of FIG. (Example) It is sectional drawing by the IV-IV line of FIG. (Example)

According to the present invention, the stator and the motor housing are positioned by a guide groove provided on the outer peripheral surface of the stator and a male screw fastened to a female screw portion positioned at an appropriate position of the motor housing externally fitted to the stator.
Embodiments of the present invention will be described below with reference to the drawings.

1 to 4 show an embodiment of the present invention. In FIG. 1 and FIG. 2, 1 is a motor mounted on, for example, a hybrid vehicle, 2 is a stator, 3 is a rotor, and 4 is a motor housing. The motor 1 includes a stator 2 and a rotor 3 disposed on the inner peripheral side of the stator 2. As shown in FIGS. 2 and 4, the stator 2 includes a cylindrical core 5 and a coil 8 wound around a groove 7 extending in the axial direction on the inner peripheral surface 6 from both axial ends of the core 5. The rotor 3 is rotatably supported on the inner peripheral side of the stator 2 by a rotating shaft 9.
As shown in FIG. 4, the motor housing 4 includes a cylindrical peripheral wall portion 10 disposed on the outer peripheral side of the core 5, and annular portions 11 and 12 provided at both axial ends of the peripheral wall portion 10. The annular portions 11 and 12 have a shape that protrudes outward in the radial direction from the peripheral wall portion 10. The annular portion 11 at one end in the axial direction is open. The annular portion 12 at the other end in the axial direction includes a partition wall portion 13 extending inward in the radial direction, and a shaft support hole 14 for supporting the rotating shaft 9 of the rotor 3 is provided at the center. As shown in FIG. 2, the stator 2 has the outer peripheral surface 15 of the core 5 fitted and fixed to the inner peripheral surface 16 of the peripheral wall portion 10 of the motor housing 4.
As shown in FIGS. 3 and 4, a guide groove 17 extending in the axial direction is provided on the outer peripheral surface 15 of the core 5 of the stator 2 of the motor 1. The depth of the guide groove 17 is made shallow so as not to affect the magnetic flux path generated by the stator 2. The motor housing 4 that is externally fitted to the core 5 of the stator 2 is provided with female screw portions 18 and 19 on the peripheral wall portion 10. The two female screw portions 18 and 19 are provided on the peripheral wall portion 10 so as to be disposed near both ends in the axial direction of the core 5 of the stator 2. Positioning male screws 20 and 21 are fastened to the female screw portions 18 and 19, respectively. The male screws 20 and 21 are formed in a screw shaft shape without a head or a seat, and are provided with tool holes 22 and 23 into which tools such as a screwdriver are inserted at the rear end.
The motor 1 is fastened by screwing positioning male screws 20 and 21 into female screw portions 18 and 19 that are opened in a straight line in the axial direction with respect to the motor housing 4. By engaging the guide groove 17 provided in the outer peripheral surface 15 of the core 5 of the second core 5 and fitting the core 5 of the stator 2 to the motor housing 4 with the guide groove 17 as a guide by the male screws 20 and 21, the stator 2 and Positioning with the motor housing 4 and mutual rotation prevention are performed.

As described above, in this motor housing structure, the depth of the guide groove 17 of the stator 2 guided by the male screws 20 and 21 can be made shallow enough not to affect the magnetic flux path. For this reason, this motor housing structure can suppress the wall thickness required for the positioning structure of the motor housing 4, and can be reduced in weight.
This motor housing structure uses a relatively small screw by pressing the outer peripheral surface 15 of the stator 2 against the inner peripheral surface 16 of the motor housing 4 by utilizing the high rigidity that maintains the respective self-shapes of the stator 2 and the motor housing 4. Even if it is the axial force, a large fixing force can be exerted by friction.
Since the male screws 20 and 21 are not structured to receive a shearing force on the surface forming the thread, the groove depth of the guide groove 17 provided on the outer peripheral surface 15 of the stator 2 of the motor 1 can be reduced. The pitch is smaller than 21 pitches. Thereby, the motor housing 4 can be reduced in thickness and weight.
By providing the female screw portions 18 and 19 near both ends of the axial dimension of the stator 2, the load sharing of each screw can be reduced. The male screws 20 and 21 can reduce the diameter of each screw front end surface, and thus can reduce the width of the guide groove 17 provided on the outer peripheral surface 15 of the stator 2.
In the female screw portions 18 and 19 for fastening the male screws 20 and 21 of the key-use bolts, the female screw forming range is radially outward with respect to the fitting surface (inner peripheral surface 16) for fitting the stator 2 to the motor housing 4. It is provided at the position (expanded position). The female screw portions 18 and 19 keep the female screw forming range small. The positioning male screws 20 and 21 use special bolts having no head or seat. The male screws 20 and 21 may have a shape in which a tip portion entering the guide groove 17 is matched to the groove shape. Further, the male screws 20 and 21 may be fastened by adding a nut for preventing loosening to the rear end side.

As shown in FIG. 4, the motor housing 4 includes a water jacket 24 on the peripheral wall portion 10 located outside the periphery of the stator 2. The water jacket 24 includes an inner peripheral wall 25 on the inner peripheral side of the peripheral wall portion 10 of the motor housing 4, end walls 26 and 27 that rise radially outward from both axial ends of the inner peripheral wall 25, and a peripheral wall portion of the stator 2. The outer peripheral wall 10 is surrounded by the outer peripheral wall 28 that is continuous with the outer peripheral edges of the both end walls 26 and 27. The female screw portions 18 and 19 are provided on both end walls 26 and 27 of the peripheral wall portion 10 forming the water jacket 24.
Thus, in this motor housing structure, it is not necessary to meander the water jacket 24 in order to avoid the female screw portions 18 and 19, and the water jacket 24 can be formed so as not to be complicated in shape. For this reason, this motor housing structure can significantly reduce the water-cooled motor housing 4. When the water channel shape of the water jacket 24 is configured so as to surround the circumference of the core 5 of the stator 2 once, the diameter of the water channel (based on the center of the motor shaft indicated by the one-dot chain line in FIG. 4) can be reduced. As a result, the weight of the motor housing 4 can be reduced in kilograms.
Further, since the female screw portions 18 and 19 are disposed near both ends of the stator 2 in the axial direction, the width of the water jacket 24 can be increased without being obstructed by the female screw portions 18 and 19. That is, as shown in FIG. 4, the width of the water jacket 24 can be increased so as to approach the width w1 of the core 5 of the stator 2, and the width of the water jacket 24 is also close to the width w2 even in the portion where the female screw portions 18 and 19 are provided. w3 can be secured. For this reason, this motor housing structure can improve the drive efficiency of the motor 1 by cooling, or can ensure durability.
The motor housing 4 is provided with female screw portions 18 and 19 for fastening male screws 20 and 21 (positioning screws) also serving as keys inside the peripheral wall portion 10 forming the water jacket 24. Out of the peripheral wall 10 that forms a water jacket 24 that extends in the form of a belt around the stator 2, both end walls 26 and 27 along the radial direction at both ends in the axial direction of the motor housing 4 are separated in the axial direction of the stator 2. The two end walls 26 and 27 are respectively provided with female screw portions 18 and 19 for fastening the male screws 20 and 21 serving as keys. The female screw portions 18 and 19 and the both end walls 26 and 27 have the same width as the width w1 (axial dimension) of the core 5 of the stator 2 with the width w2 of the cross-sectional area of the water jacket 24 being secured by the same thickness. As large as possible.
The water jacket 24 of the motor housing 4 is formed in a band-like water channel shape so as to have an annular shape when viewed from the axial direction of the motor 1 and to have a flat cross section. As shown in FIGS. 1 and 2, the water jacket 24 includes a lower inlet portion 29 and an upper outlet portion 30 that are arranged so as to be separated from each other at positions opposite to each other in the radial direction across the rotating shaft 9 of the motor 1. Then, cooling water is introduced and discharged respectively. The cooling water that has entered from the inlet 29 on the relatively lower side is divided into two in the circumferential direction as soon as it enters the water jacket 24, and heat exchange is performed while flowing in a semicircular manner. The cooling water is warmed by the heat exchange, and the motor housing 4 is cooled. The cooling water whose temperature has increased is merged immediately before the outlet portion 30 at a relatively higher position, and is discharged from the outlet portion 30.
The water jacket 24 formed in a substantially band shape can efficiently exchange heat by increasing the surface area while having a simple cross-sectional shape. Since the water jacket 24 has a simple cross-sectional shape, the flow rate can be increased and the cooling efficiency per unit time can be increased. By this heat exchange, the heat generation of the motor 1 can be suppressed and the driving efficiency of the motor 1 can be increased.

As shown in FIG. 1, a plurality of reinforcing ribs 32 extending along the axial direction of the motor 1 are provided on the outer peripheral surface 31 of the motor housing 4. The reinforcing rib 32 is provided so as to connect two annular portions 11 and 12 formed as outer peripheral portions at both ends in the axial direction of the motor housing 4 formed in a substantially cylindrical shape. The motor housing 4 provided with the reinforcing ribs 32 can reduce the distance between the cooling water channel of the water jacket 24 and the reinforcing ribs 32 because the thickness of the housing can be reduced while ensuring rigidity. For this reason, the thickness of the motor housing 4 increases the heat conduction inside and the capacity of the wall is small, so that the heat radiation effect from the surface of the motor housing 4 including the reinforcing ribs 32 serving as air cooling fins to the outside air is achieved. Can be increased. The annular portions 11 and 12 form joint surfaces (seal surfaces) 33 and 34 with other casings.
The female screw portions 18 and 19 are provided by using an outer peripheral wall 28 of a water jacket 24 that is sandwiched between the plurality of reinforcing ribs 32 and extends so as to connect the plurality of reinforcing ribs 32. is there. The reinforcing rib 32 can avoid deformation of the cross-sectional shape of the water jacket 24, and can minimize the increase in weight by co-walling with the outer peripheral wall 28. As shown in FIG. The thickness (height) t2 of the water jacket 24 can be increased with respect to the thickness t1 of the peripheral wall 10. The upper surfaces of the female screw portions 19 and 20 are formed at positions lower than a virtual plane connecting the ridge lines of the plurality of reinforcing ribs 33.
In addition, the outer peripheral wall 28 between the plurality of reinforcing ribs 32 is provided with a thick boss portion 35 at a position facing the water jacket 24 together with the female screw portions 18 and 19. The thick-walled boss portion 35 is a processing hole for removing a core necessary for forming the water jacket 24 and is closed by fitting a blind plug 36. The boss portion 35 can increase the rigidity, and at the same time, can make the machining direction of the female screw portions 18 and 19 the same angle, thereby improving workability.
In addition, although the water channel shape of the water jacket 24 was formed in the strip | belt-shaped water channel shape so that an annular | circular shape and a cross section may become flat, it can also be made into a spiral shape. Even when the water channel shape of the water jacket 24 is formed in a spiral shape with respect to the core 5 of the stator 2, the diameter of the water channel (based on the center of the motor shaft indicated by the one-dot chain line in FIG. 4) can be reduced. The weight of the motor housing 4 can be reduced.

  In the present invention, the stator and the motor housing are positioned by a guide groove provided on the outer peripheral surface of the stator and a male screw fastened to a female screw portion of the motor housing that is externally fitted to the stator. Applicable to body key structure.

DESCRIPTION OF SYMBOLS 1 Motor 2 Stator 3 Rotor 4 Motor housing 5 Core 8 Coil 9 Rotating shaft 10 Peripheral wall part 11/12 Annular part 15 Outer peripheral face 16 Inner peripheral face 17 Guide groove 18/19 Female thread part 20/21 Male thread 24 Water jacket 25 Inner peripheral wall 26 27 end wall 28 outer peripheral wall 29 inlet part 30 outlet part 32 reinforcing rib 35 boss part 36 blind plug

Claims (3)

In a motor housing structure in which the stator of a motor having a stator and a rotor is fitted and fixed inside the motor housing,
A guide groove provided on the outer peripheral surface of the stator of the motor, and a female screw portion positioned at an appropriate position of the motor housing externally fitted to the stator;
A motor housing structure in which a male screw is fastened to the female screw portion to position the stator and the motor housing. The motor housing includes a water jacket located outside the periphery of the stator,
The motor housing structure according to claim 1, wherein the female screw portions are provided on both end walls of the water jacket.   3. The motor housing structure according to claim 1, wherein the female screw portion is disposed in the vicinity of both ends in the axial direction of the stator. 4.

Images