JP2009213218A - Cooling structure for rotating electrical machines and manufacturing method therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a cooling structure for rotating electrical machines suitable for maintaining the water-tightness of a coolant passage and a manufacturing method for the structure. <P>SOLUTION: In a stator 5, a coil 5A is housed in each slot and is wound on each tooth. The stator includes: a fitting area 21 where its outer circumferential portion is fit in the inner surface of an inner circumferential wall 11 positioned on the inner circumferential side of an annular space 6 for coolant passage of a housing 2 by press fit or interference shrink fit; and a diameter expansion area 22 where an opening in the annular space 6 is closed with its side face and its outer circumferential surface is opposed to the inner circumferential surface of an outer circumferential wall 10 positioned on the outer circumferential side of the annular space 6. The area between the side face of the diameter expansion area 22 of the stator 5 and the end face of the inner circumferential wall 11 and the area between the outer circumferential surface of the diameter expansion area 22 and the inner surface of the outer circumferential wall 10 are respectively closed with sealing means 12, 23. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a rotating electrical machine cooling structure and a manufacturing method thereof, and more particularly to a rotating electrical machine cooling structure and a manufacturing method thereof suitable for ensuring watertightness of a coolant passage.

  2. Description of the Related Art Conventionally, a cooling structure for an electric motor having a coolant passage in a peripheral wall portion of a housing on the outer periphery of the stator is known in order to cool the heat generation of the stator coil due to energization and the heat generation of the stator core due to the influence of internal magnetic flux (see Patent Document 1). .

The cooling fluid passage is formed by an annular space opened to the side of the peripheral wall of the housing in consideration of mold removal during casting of the housing, and the inner and outer peripheral surfaces on the open end side of the annular space are machined in a later step. It is processed and closed with a plug having a ring shape and a sealing material such as an O-ring on the inner and outer surfaces to ensure watertightness of the coolant passage. In addition, the stator of the electric motor is fixed in the housing by shrink fitting and the plug body is formed integrally with a front cover that functions as a lid body of the housing.
JP 2003-74679 A

  By the way, as a material of the housing, for example, a light metal such as an aluminum-based metal having a linear expansion coefficient larger than that of the stator is generally used. Even when the temperature rises due to operation of the motor, the stator outer peripheral surface and the housing inner periphery are used. In order to hold the stator securely while maintaining contact with the surface, it is necessary to shrink fit with a large interference between the stator outer periphery and the housing inner periphery.

  However, when shrink fitting is performed with a large interference between the outer periphery of the stator and the inner periphery of the housing, a large hoop stress is applied to the peripheral wall of the housing, particularly to the inner peripheral side portion of the annular space constituting the coolant passage. When this occurs, the portion is deformed, the dimensional accuracy of the seal surface facing the inner peripheral side of the plug body is lowered, and the water tightness of the seal member disposed therebetween may be lowered. If the seal surface is processed after shrink-fitting of the stator, the dimensional accuracy of the seal surface can be ensured. However, the processing is performed during the assembly, and the housing is highly accurate while protecting the coil wound around the stator. Machining requires a complicated work process and increases the cost.

  Accordingly, the present invention has been made in view of the above problems, and an object of the present invention is to provide a cooling structure for a rotating electrical machine suitable for ensuring the water tightness of a coolant passage and a method for manufacturing the same.

  The present invention provides a peripheral wall portion that surrounds the outer periphery of the stator with an annular space between the outer peripheral wall and the outer peripheral wall so as to form an annular space for the coolant passage by opening the axial side to the inner space. A housing provided with an inner peripheral wall located in the slot, and a coil accommodated in each slot and wound around each tooth portion, and the outer peripheral portion is fitted to the inner surface of the inner peripheral wall of the housing by press-fitting or shrink fitting And an enlarged diameter region that closes the opening of the annular space with a side surface so that the outer peripheral surface faces the inner peripheral surface of the outer peripheral wall, and between the side surface of the enlarged diameter region and the end surface of the inner peripheral wall and And a stator that is closed by sealing means between the outer peripheral surface and the inner surface of the outer peripheral wall.

  Therefore, in the present invention, the coil is accommodated in each slot and wound around each tooth portion, and the outer peripheral portion is press-fitted or fired on the inner surface of the inner peripheral wall located on the inner peripheral side of the annular space for the coolant passage of the housing. A fitting region that is fitted by fitting, and a diameter-enlarging region that closes the opening of the annular space with a side surface and faces the outer peripheral surface to the inner peripheral surface of the outer peripheral wall positioned on the outer peripheral side of the annular space. A plug body that closes the opening of the coolant passage is provided between the side surface of the enlarged diameter region of the stator and the end surface of the inner peripheral wall and between the outer peripheral surface of the enlarged diameter region and the inner surface of the outer peripheral wall. This eliminates the need for separate parts for ensuring the water tightness of the product, reducing the number of parts and reducing the cost. The expanded area can be formed by simply punching a yoke steel plate having a large outer diameter with a press, and the conventional process can be used as it is when it is laminated and formed into a stator, requiring a special process. Does not affect the cost increase.

  Hereinafter, an embodiment of a cooling structure for a rotating electrical machine and a manufacturing method thereof according to the present invention will be described with reference to FIGS. FIG. 1 is a sectional view of a rotating electrical machine showing a first embodiment of a cooling structure of a rotating electrical machine (motor, generator, or motor / generator) to which the present invention is applied, and FIG. It is.

  In FIG. 1, a housing 2 of a rotating electrical machine 1 is fitted into an opening of a substantially cylindrical peripheral wall 2A that is open on one side, a side wall 2B that is integral with the peripheral wall 2A and closes one end in the axial direction, and an opening in the peripheral wall 2A. The side plate 2C closes the other end in the axial direction. The peripheral wall 2A of the housing 2 is further extended in the axial direction from the portion where the side plate 2C is fitted, and a flange 2D serving as a connecting portion with other housings (not shown) is provided at the tip thereof. A cylindrical rotor 3 is accommodated in the housing 2. The rotor 3 has both ends of the rotating shaft 3A supported by the side wall 2B and the side plate 2C via bearings 4, respectively, and is rotatable about the rotating shaft 3A. A cylindrical stator 5 is disposed on the inner peripheral surface of the peripheral wall 2 </ b> A of the housing 2 so as to surround the outer periphery of the rotor 3. A predetermined gap is provided between the inner peripheral surface of the stator 5 and the outer peripheral surface of the rotor 3.

  The peripheral wall 2A of the housing 2 located on the outer periphery of the stator 5 is a cooling formed by an annular space 6 that is open to the inner space of the peripheral wall 2A of the housing 2 in consideration of mold removal during casting of the housing 2. A liquid passage is formed, and the peripheral wall 2A is formed with an inner peripheral wall 11 connected to the outer peripheral wall 10 at the abutting end (bottom) of the annular space 6 by the annular space 6 constituting the coolant passage. The tip of the inner peripheral wall 11 is formed into an annular flat surface by machining, and an annular groove 11A is formed in the annular flat surface, and a heat-resistant seal material 12 such as an O-ring is accommodated. The Moreover, the inner peripheral surface which faces the opening part of the said annular space 6 of the said surrounding wall 2A (outer peripheral wall 10) is formed in the cylindrical sealing surface 13 by machining. Note that machining of the inner and outer peripheral surfaces on the open end side of the annular space 6 is not required.

  The stator 5 is formed by stacking yoke steel plates, and is formed by winding a stator coil 5A around a tooth portion (not shown) in a state of being accommodated in a slot (not shown). It is press-fitted into the inner surface of the inner peripheral wall 11 of the housing 2 whose temperature has been raised, and after the press-fitting, the housing 2 is cooled and fixed by shrinkage fitting. The stator 5 has a fitting region 21 that fits on the inner peripheral surface of the inner peripheral wall 11 by shrink fitting, and a seal that is provided on the inner peripheral surface of the outer peripheral wall 10 with a predetermined length continuously to the fitting region 21. The stator coil 5 </ b> A is wound across the fitting region 21 and the diameter-enlarged region 22, and is formed by a flange-shaped diameter-enlarged region 22 having an outer peripheral surface facing the surface 13. An annular circumferential groove 22A is formed on the outer periphery of the enlarged diameter region 22, and a sealing material 23 such as a heat-resistant O-ring is accommodated.

  In addition, the outer peripheral part of the said enlarged diameter area | region 22 is coated with an adhesive so that the clearance gap between yoke steel plates may be filled, for example, a cooling liquid may be between yoke steel plates by heating and pressurizing after lamination | stacking. It is configured not to penetrate into the gap. In addition, the predetermined length of the diameter-enlarged region 22 is set to a thickness that can form the circumferential groove 22A capable of holding the sealing material 23 or the O-ring.

  The rotating electrical machine 1 composed of the above components includes an inner peripheral surface and a seal surface 13 into which the side plate 2C of the outer peripheral wall 10 of the housing 2 is fitted, and an annular groove 11A that accommodates the inner peripheral surface of the inner peripheral wall 11 and the sealing material 12. In addition, the stator 5 around which the coil 5A is wound in the state in which the tip end face is completely machined and heated for shrink fitting, the temperature is increased, and the sealing material 12 is disposed in the annular groove 11A. In a state where the sealing material 23 is disposed in the circumferential groove 22 </ b> A of the enlarged diameter region 22, it is press-fitted into the inner peripheral surface of the inner peripheral wall 11 of the housing 2 from the end of the fitting region 21 of the stator 5.

  The sealing material 23 provided on the outer periphery of the diameter-enlarged region 22 of the stator 5 is fitted to the seal surface 13 provided on the inner surface of the outer peripheral wall 10 of the housing 2, and the end surface of the diameter-enlarged region 22 is the tip of the inner peripheral wall 11 of the housing 2. The press-fit is completed when the seal material 12 arranged in the annular groove 11 </ b> A comes into contact, and then the tip of the fitting region 21 comes into contact with the inner surface machining end of the inner peripheral wall 11 in the housing 2.

  In this state, the sealing material 12 disposed in the tip annular groove 11 </ b> A of the inner peripheral wall 11 of the housing 2 is in watertight contact with the end surface of the diameter-enlarged region 22 of the stator 5 and is disposed on the outer periphery of the diameter-enlarged region 22. The sealing material 23 is in contact with the sealing surface 13 provided on the inner surface of the outer peripheral wall 10 of the housing 2. In this state, the housing 2 is cooled, the housing 2 contracts, and the fitting region 21 of the stator 5 is firmly shrink-fitted to the inner peripheral surface of the inner peripheral wall 11 of the housing 2. Further, the sealing material 23 disposed on the outer periphery of the enlarged diameter region 22 comes into watertight contact with the sealing surface 13 of the housing 2 due to the contraction of the housing 2.

  The seal surface 13 provided on the inner surface of the outer peripheral wall 10 of the housing 2 is a portion that is not deformed by shrinkage fitting of the stator 5, and ensures good water tightness with the outer peripheral side of the enlarged diameter region 22 in the stator 5. Can do. Further, the sealing material 12 disposed in the tip annular groove 11A of the inner peripheral wall 11 of the housing 2 is in watertight contact with the end face of the diameter-enlarged region 22 of the stator 5, and the inner peripheral wall 11 is greatly deformed in the radial direction by shrink fitting. Is also an end face seal structure disposed between the faces facing each other in the axial direction, and maintains water tightness. Thereafter, the rotating electrical machine 1 is assembled by sequentially assembling the bearing 4 and the rotor 3 fixed to the rotating shaft 3A and assembling the side plates 2C.

  In the cooling structure of the rotating electric machine 1 described above, the coolant is supplied to the coolant passage 7 from a coolant inlet (not shown) provided on the outer peripheral wall 102A and is discharged from the coolant outlet (not shown). Is circulated. The coolant circulating through the coolant passage absorbs heat from the stator 5 fitted to the inner periphery via the inner peripheral wall 11 and the coil 5A wound around the stator 5 to cool them. Further, the coolant is directly brought into contact with the diameter-enlarged region 22 of the stator 5, and heat is absorbed from the stator 5 and the coil 5 </ b> A wound around the stator 5 from the diameter-enlarged region 22 to cool them.

  In the above embodiment, as a means for ensuring watertightness on the inner peripheral side of the coolant passage, an annular groove 11A is provided on the end surface of the inner peripheral wall 11 on the housing 2 side to hold the sealing material 12, and the diameter-enlarged region of the stator 5 Although the sealing material 12 is sandwiched between the side surfaces of 22 to ensure watertightness, as shown in FIG. 3, the annular groove 22 </ b> B formed on the side surface of the enlarged diameter region 22 of the stator 5 as shown in FIG. 3. The sealing material 12 may be sandwiched between the front end surface of the inner peripheral wall 11 of the housing 2 and the water tightness may be ensured.

  With such a configuration, when the stator 5 is shrink-fitted into the inner periphery of the housing 2, the seal material 12 is held by the stator 5, so that the seal material 12 can be prevented from being directly heated. The heat resistance performance of 12 can be relaxed.

  In the above-described embodiment, the seal materials 12 and 23 have been described as using heat-resistant O-rings or the like. However, although not illustrated, the side surface and the peripheral surface of the diameter-enlarged region 22 of the stator 5 and the housing 2. Is not a sliding contact portion, and may be a heat-resistant sealing material such as a gasket. In that case, the groove for accommodating the sealing material is not necessarily used.

  In the rotating electrical machine 1 having the above configuration, the enlarged diameter region 22 having a cover function (plug body function) is formed on one end surface side of the stator 5, the side surface of the enlarged diameter region 22 and the coolant passage are configured, and the stator 5 and sealing material 12, 23 such as an O-ring disposed between the outer peripheral surface of the enlarged diameter region 22 and the inner peripheral side sealing surface 13 of the housing 2, respectively. As a result, the water tightness of the coolant passage can be ensured, so that a separate part for securing the water tightness such as a plug that closes the opening of the coolant passage becomes unnecessary, the number of parts can be reduced, and the cost can be reduced. Moreover, the said enlarged diameter area | region 22 can be formed only by punching a yoke steel plate with a large outer periphery diameter by a press, and also when forming in the stator 5 by laminating, a conventional process can be used as it is, and a special process can be used. Since it is not necessary, it does not affect the cost increase.

  Further, an inner peripheral side sealing means (12) for the coolant passage is disposed between the end surface of the inner peripheral wall 11 of the housing 2 that deforms in the radial direction during shrink fitting and the side surface of the enlarged diameter region 22 of the stator 5. Therefore, even if the inner peripheral wall 11 of the housing 2 is greatly deformed in the radial direction during shrink fitting, it has an end face seal structure disposed between the faces facing each other in the axial direction. The watertightness can be ensured without affecting the dimensional change in the radial direction.

  In the present embodiment, the following effects can be achieved.

  (A) The annular space 6 is sandwiched between the outer peripheral wall 10 and the outer peripheral wall 10 so as to form an annular space 6 for the coolant passage by opening the axial side to the inner space in the peripheral wall portion surrounding the outer periphery of the stator 5. The housing 2 having the inner peripheral wall 11 located on the inner peripheral side, and the coil 5A is accommodated in each slot and wound around each tooth portion, and the outer peripheral portion is press-fitted into the inner surface of the inner peripheral wall 11 of the housing 2 or A fitting region 21 to be fitted by shrink fitting, and an enlarged region 22 that closes the opening of the annular space 6 with a side surface and faces the outer peripheral surface to the inner peripheral surface of the outer peripheral wall 10. The stator 5 is closed between the side surface and the end surface of the inner peripheral wall 11 and between the outer peripheral surface of the enlarged diameter region 22 and the inner surface of the outer peripheral wall 10 by sealing means 12 and 23, respectively.

  In other words, the coil 5A is accommodated in each slot and wound around each tooth portion, and the outer peripheral portion is press-fitted into the inner surface of the inner peripheral wall 11 located on the inner peripheral side of the annular space 6 for the coolant passage of the housing 2. Alternatively, the fitting region 21 to be fitted by shrink fitting and the opening of the annular space 6 are closed by side surfaces, and the diameter of the outer peripheral surface of the outer peripheral wall 10 located on the outer peripheral side of the annular space 6 is increased. Region 22 is provided in the stator 5, and sealing means 12, between the side surface of the enlarged diameter region 22 of the stator 5 and the end surface of the inner peripheral wall 11 and between the outer peripheral surface of the enlarged diameter region 22 and the inner surface of the outer peripheral wall 10, respectively. Therefore, a separate part for ensuring watertightness such as a plug that closes the opening of the coolant passage is unnecessary, the number of parts can be reduced, and the cost can be reduced. Moreover, the said enlarged diameter area | region 22 can be formed only by punching a yoke steel plate with a large outer periphery diameter by a press, and also when forming in the stator 5 by laminating, a conventional process can be used as it is, and a special process can be used. Since it is not necessary, it does not affect the cost increase.

  (A) The sealing means 12 disposed between the side surface of the enlarged diameter region 22 and the end surface of the inner peripheral wall 11 is the sealing material 12 held on either the side surface of the enlarged diameter region 22 or the end surface of the inner peripheral wall 11. Even if the inner peripheral wall 11 of the housing 2 is deformed greatly in the radial direction during shrink fitting, it is formed by contact with the other side of the side surface of the enlarged diameter region 22 and the end surface of the inner peripheral wall 11. The end face seal structure is disposed between the faces facing each other in the axial direction, and water tightness can be ensured without affecting the dimensional change in the radial direction.

  (C) As shown in FIG. 3, the sealing means disposed between the side surface of the diameter-enlarged region 22 and the end surface of the inner peripheral wall 11 includes the sealing material 12 held on the side surface of the diameter-enlarged region 22 and the inner peripheral wall 11. If the stator 5 is formed by contact with the end face of the housing 2, the seal material 12 is held by the stator 5 when the stator 5 is shrink-fitted to the inner periphery of the housing 2, so that the seal material 12 is directly heated. The heat resistance performance of the sealing material 12 can be relaxed.

  (D) The annular space 6 is sandwiched between the outer peripheral wall 10 and the outer peripheral wall 10 so as to form an annular space 6 for the coolant passage by opening the axial side to the inner space in the peripheral wall portion surrounding the outer periphery of the stator 5. The inner peripheral wall 11 located on the inner peripheral side is formed in the housing 2, and the fitting space 21 in which the outer peripheral portion is fitted to the inner surface of the inner peripheral wall 11 of the housing 2 by press-fitting or shrink fitting and the annular space 6. A coil 5A is accommodated in each slot of the stator 5 that is integrally formed with a diameter-enlarged region 22 that closes the opening with a side surface and faces the outer peripheral surface to the inner peripheral surface of the outer peripheral wall 10 and winds it around each tooth portion. And press fitting or shrink fitting the inner surface of the inner peripheral wall 11 of the housing 2 between the side surface of the enlarged diameter region 22 and the end surface of the inner peripheral wall 11 and the outer peripheral surface of the enlarged diameter region 22. Between the outer wall 10 and the inner surface of the outer peripheral wall 10 By closing the annular space 6 of the housing 2 with the sealing means 12 and 23, the stator 5 is shrink-fitted and press-fitted into the housing 2 in a state where the sealing means 12 and 23 are arranged. Can be secured.

Sectional drawing of the cooling structure of the rotary electric machine which shows one Embodiment of this invention. Sectional drawing which expanded the principal part similarly. Sectional drawing of the modification which expanded the principal part similarly.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Rotating electrical machine 2 Housing 3 Rotor 4 Bearing 5 Stator 6 Annular space 10 Outer peripheral wall 11 Inner peripheral wall 12, 23 Seal material as sealing means 21 Fitting region 22 Expanded region

Claims (4)

An inner wall located on the inner circumferential side of the outer circumferential wall and the outer circumferential wall with the annular space sandwiched between the outer circumferential wall and the outer circumferential wall so as to form an annular space for the coolant passage by opening the axial side to the inner space around the outer circumferential portion of the stator. A housing comprising a peripheral wall;
A coil is accommodated in each slot and wound around each tooth portion, and a fitting region in which the outer peripheral portion is fitted to the inner surface of the inner peripheral wall of the housing by press-fitting or shrink fitting, and the opening of the annular space is formed by the side surface. A diameter-enlarging region that causes the outer peripheral surface to face the inner peripheral surface of the closing outer peripheral wall, and between the side surface of the enlarged-diameter region and the end surface of the inner peripheral wall and between the outer peripheral surface of the enlarged-diameter region and the inner surface of the outer peripheral wall, respectively A cooling structure for a rotating electrical machine, comprising: a stator closed by a sealing means.   The sealing means disposed between the side surface of the diameter-enlarged region and the end surface of the inner peripheral wall includes a sealing material held on one of the side surface of the diameter-enlarged region and the end surface of the inner peripheral wall, and the side surface of the diameter-enlarged region. 2. The cooling structure for a rotating electrical machine according to claim 1, wherein the cooling structure is formed by contact with any one of the end surfaces of the inner peripheral wall.   The sealing means disposed between the side surface of the enlarged diameter region and the end surface of the inner peripheral wall is formed by contact between the sealing material held on the side surface of the enlarged diameter region and the end surface of the inner peripheral wall. The cooling structure for a rotating electrical machine according to claim 1. An inner wall located on the inner circumferential side of the outer circumferential wall and the outer circumferential wall with the annular space sandwiched between the outer circumferential wall and the outer circumferential wall so as to form an annular space for the coolant passage by opening the axial side to the inner space around the outer circumferential portion of the stator. A peripheral wall and a housing,
A fitting region in which an outer peripheral portion is fitted to the inner surface of the inner peripheral wall of the housing by press-fitting or shrink fitting, and a diameter-enlarged region in which the opening of the annular space is closed with a side surface and the outer peripheral surface faces the inner peripheral surface of the outer peripheral wall; A coil is accommodated in each slot of the stator formed integrally and wound around each tooth portion,
The fitting region is press-fitted or shrink-fitted into the inner surface of the inner peripheral wall of the housing, thereby being arranged between the side surface of the enlarged diameter region and the end surface of the inner peripheral wall and between the outer peripheral surface of the enlarged diameter region and the inner surface of the outer peripheral wall. A method of manufacturing a rotating electrical machine, wherein the annular space of the housing is closed by the sealing means.

Images