JP3774862B2 - Rotating electric machine - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a rotating electrical machine.
[0002]
[Prior art and problems to be solved by the invention]
Conventionally, various liquid-cooled rotary electric machines and inverter-integrated rotary electric machines have been proposed. Japanese Laid-Open Patent Publication No. 5-292703 proposes a liquid-cooled inverter-integrated rotating electrical machine that cools both the inverter and the motor with a coolant. However, this liquid-cooled inverter-integrated rotating electrical machine employs a structure in which a liquid-cooled inverter (controller) is fixed to the motor end face via a heat sink, so that the device size and weight increase. And there was a fault that motor cooling performance was inferior.
[0003]
The present invention has been made in view of the above-described problems, and is excellent in cooling performance of both the controller (stator current control circuit device), in particular, the semiconductor switching element for stator current interruption and the motor, and suppresses an increase in physique and weight. The object is to provide a rotating electric machine that can be used.
[0004]
[Means for Solving the Problems]
The rotating electrical machine according to claim 1, wherein the stator is inserted into the slot having a cylindrical stator core having a slot in the inner periphery and fixed to the housing, and coil ends protruding from both end faces of the stator core. A stator current control circuit including a coil, a cooling member having a coolant passage therein and closely contacting the stator core, a semiconductor switching element fixed to a surface of the cooling member and controlling a current of the stator coil; In a rotating electrical machine comprising a rotor that rotates facing the inner peripheral surface of a stator core,
The cooling member is housed in a cylindrical space portion having a coolant passage therein and defined by an end surface of the stator core and an outer peripheral surface of the coil end, and is fixed to the end surface of the stator core. And a plate portion extending radially inward from the inner peripheral surface of the main body portion with a predetermined gap with respect to the outer end surface of the coil end.
[0005]
According to the present invention, cylindrical is partitioning the main body of the liquid cooling member for cooling the semiconductor switching element for controlling the stator currents by the outer peripheral surface of the end face of the stator core which has been idle space in the conventional coil end It is housed in a space (the thickness of the idle space in the radial direction is approximately equal to the thickness of the yoke portion of the stator core), and only the plate portion that forms the cooling fin and the heat sink of the heat generating circuit component extends from the main body portion in the radial direction. Therefore, an increase in the radial dimension and an increase in the axial dimension of the rotating electrical machine can be suppressed, and an increase in the size and weight of the rotating electrical machine can be minimized. Further, since the plate portion is provided, a wide circuit mountable area can be secured, and good mechanical protection can be given to the coil end by the main body portion and the plate portion.
[0006]
In addition, the cooling member mounts the semiconductor switching element and cools it satisfactorily, and since it closely contacts the end face of the stator core, the stator core and the stator coil which is a large heat generating member mounted on the stator core can be cooled well. In addition, compared with the case where the above-described liquid-cooled controller is brought into close contact with the end face of the motor through a heat sink, the end of the stator coil and the semiconductor switching element for controlling the stator current can be arranged close to each other. Loss and electromagnetic radiation noise can be reduced.
[0007]
It is also possible to fill a material having good heat conductivity between the surface of the cooling member and the surface of the coil end facing the cooling member by a method such as resin molding, in which case the cooling performance of the stator coil is further improved. can do.
[0008]
In the configuration according to claim 1 , in particular, the main body portion has an annular cylindrical portion in which the coolant passage is opened outward in the axial direction, and the plate portion is in close contact with an outer end surface of the cylindrical portion and the cooling is performed. Seal the agent passage.
[0009]
In this way, the plate portion can be brought into close contact with the cylindrical portion by the through bolt, and at the same time, the main body portion can be brought into close contact with the end surface of the stator core, improving the cooling effect of the stator core and easily completing the coolant passage. Can be made.
[0010]
The main body can be individually adhered to both end faces of the stator core, and even in this case, both the main body can be fixed to the stator core at once and satisfactorily by through bolts, and liquid leakage can be prevented well. it can.
[0011]
The coolant passage is preferably formed in a spiral shape, and the coolant enters and exits the spiral coolant passage through a hole provided in the plate portion and extending in the axial direction. is there.
[0012]
The main body portion can have a cylindrical stator core surrounding tube portion that is in close contact with the outer peripheral surface of the stator core. In this case, the cooling member can also serve as a housing that mechanically protects the stator core. At the same time, the stator core cooling effect can be further improved by additionally providing the stator core enclosing cylinder portion.
[0013]
According to a second aspect of the present invention, in the rotating electrical machine according to the first aspect, since the plate portion rotatably supports the shaft of the rotor via a bearing, the stator core is fixed and the rotor is rotatably supported. It can also serve as a housing as a mechanical member that surrounds and protects the stator core, the stator coil, and the rotor, so that the number of parts can be reduced and the weight can be greatly reduced.
[0014]
According to a third aspect of the present invention, in the rotating electric machine according to the first aspect, since the stator current control circuit is fixed to the outer end surface of the plate portion capable of securing a large plane area, the stator current control circuit is not limited to a coil end or a cooling unit. The semiconductor switching elements and circuit parts can be arranged in a plane while preventing an increase in the overall physique to a minimum without interfering with the agent passage, and wiring between the parts is facilitated.
[0015]
According to a fourth aspect of the present invention, in the rotating electric machine according to the third aspect , the plate portion has a through-hole through which an end portion of the stator coil protruding substantially axially outward from the coil end passes. As a result, the distance between wires having a large current and a large inductance can be shortened, so that it is possible to reduce resistance loss and electromagnetic radiation noise.
[0016]
According to a fifth aspect of the present invention, in the rotating electrical machine according to the fourth aspect , the magnetic core with a gap fitted into the through hole and a magnetoelectric conversion element disposed in the gap. As a result, it is possible to easily fix the current sensor that is not easily mounted without causing an increase in the length of the stator coil wiring.
[0017]
BEST MODE FOR CARRYING OUT THE INVENTION
Preferred embodiments of the rotating electrical machine of the present invention will be described below with reference to the drawings. This rotating electrical machine is a three-phase brushless DC motor, but of course, other types of rotating electrical machines may be used.
(Overall structure)
1 is a substantially ring-shaped front frame, 2 is a substantially ring-shaped end frame, 3 is a ring plate-shaped end plate, 4 is a stator core, 5 is a stator coil, 6 is a rotor, 7 is a rotating shaft, and 8 is a cooling fan. , 9 is a through bolt, 10 is a semiconductor switching element, and 11 is a resin cover. The front plate, the front frame 1, the end frame 2, and the end plate 3 are manufactured by aluminum die casting.
[0018]
Although not shown in FIG. 1, a front plate (not shown) is fixed in exactly the same manner as the joined state between the end frame 1 and the end plate 3. In this embodiment, the end frame 2 and the front frame 1 have the same shape, and the end plate 3 and the front plate (not shown) do not have a coolant passage or a through hole at the end of the stator coil. The controller has the same structure except that the controller is not mounted on the outer end surface.
[0019]
On the outer periphery of the rear end of the end frame 2 and the outer periphery of the end plate 3, flanges 11 and 12 having through holes (not shown) are provided on the outer side in the radial direction. A flange portion (not shown) having a through-hole (not shown) is provided on the outer peripheral portion and the outer peripheral portion of the front plate in the radial direction. Through bolts 9 penetrate through these through holes and are bolted. As a result, a front plate, a front frame 1, an end frame 2, a stator core 4 and an end plate 3 (not shown) are stacked in the axial direction and integrated with the through bolts 9. It has become.
[0020]
Bearings 13 are fitted on the inner peripheral surfaces of the front plate and the end plate 3, and the pair of bearings 13 (only one is shown) is rotatably supported by the rotating shaft 7. A rotor 6 is fitted and fixed to the rotating shaft 7, and the outer peripheral surface of the rotor 6 faces the inner peripheral surface of the stator core 4 with an electromagnetic gap interposed therebetween.
[0021]
The stator coil 5 is inserted into a slot 14 that extends in the axial direction on the inner peripheral portion of the stator core 4, and both axial ends of the stator coil 5 protrude from the stator core 4 to form a coil end 15. Although the stator coil 5 in FIG. 1 is schematically illustrated, the shape and structure of this type of stator coil 5 are already well-known matters, and further description is omitted.
[0022]
The cooling fan 8 is fixed to both end faces of the rotor 6 as in the prior art. In this embodiment, the cooling fan 8 is a centrifugal fan.
[0023]
The semiconductor switching element 10 is fixed to the outer end surface of the end plate 3. A controller for controlling the current of the stator coil 5 is mounted on the outer end surface of the end plate 3. The semiconductor switching element 10 constitutes a switching element of a three-phase inverter circuit that forms part of this controller. Since this type of controller, three-phase inverter circuit, and semiconductor switching element 10 are already known matters, further explanation is omitted.
[0024]
The resin cover 11 has a hooked ring plate shape and is fastened to the outer end surface of the end plate 3 to surround and protect the controller.
[0025]
Reference numeral 16 denotes a connector fixed to the outer end surface of the end plate 3, and this connector protrudes in the axial direction through a window provided in the resin cover 11. A DC power cable 17 and a cable (not shown) for communication with an external controller are attached to the connector 16, and the DC power cable 17 supplies DC power to the controller through the connector 16 and a bus bar (not shown).
[0026]
(Modification)
In the above embodiment, each member is fastened in the axial direction by the common through bolt 9. Further, only the bolt and nut for fastening only the front plate and the front frame 1, and only the end plate 3 and the end frame 2 are used. It is also preferable to add a bolt and a nut for fastening the nut. In this way, even when the through bolt 9 is loosened, no liquid leaks from a coolant passage which will be described later.
(Cooling structure)
Next, the cooling structure of the motor and the semiconductor switching element (or controller) constituting the characteristic configuration of this embodiment will be described. Since the cooling structure on the front side is exactly the same as that on the end side, only the cooling structure on the end side will be described.
[0027]
The end frame 2 has a cylindrical main body 21 accommodated in a cylindrical space portion defined by the end surface of the stator core 4 and the outer peripheral surface of the coil end 15, and a cylindrical shape protruding forward from the outer periphery of the main body 21 and the front end. And a cylindrical portion 22.
[0028]
A coolant passage 23 is formed in a spiral in the main body 21, and the coolant passages 23 are formed in quadruple in FIG. 1. The coolant passage 23 opens at the rear end surface of the main body portion 21, the rear end surface of the main body portion 21 is in close contact with the front end surface of the end plate 3, and the coolant passage 23 is sealed by the through bolt 9.
[0029]
A coolant passage 31 is also recessed in the front end surface of the end plate 3 at the same radial position as the coolant passage 23 of the end frame 2, and a coolant injection pipe 32 is provided at one end of the spiral coolant passage 31. A coolant discharge pipe 33 is formed integrally with the other end. Accordingly, the coolant is circulated by the external pump in the coolant passages 23 and 31 that are integrally formed with each other. Reference numeral 34 denotes an O-ring which is inserted into two ring grooves recessed in the front end surface of the end plate 3 to prevent liquid leakage.
[0030]
The front end surface of the main body portion 21 is pressure-bonded to the outer peripheral portion of the rear end surface of the stator core 4 by through bolts 9, and the inner peripheral surface of the cylindrical portion 22 is fitted to the outer peripheral surface of the stator core 4 via heat conductive grease. ing. Thereby, the stator core 4 can be satisfactorily cooled by the coolant.
[0031]
An annular gap is formed between the inner peripheral surface of the main body 21 and the outer peripheral surface of the coil end 15, whereby the centrifugal cooling air formed by the cooling fan 8 </ b> N penetrates the coil end 15. It cools by reaching the inner peripheral surface of the main body 21 while cooling it. Reference numeral 24 denotes cooling fins formed on the inner peripheral surface of the main body 21. The cooling fins 24 cool the centrifugal cooling air well. Thereafter, the centrifugal cooling air flows radially inward along the front end surface of the end plate 3, is cooled by the cooling fins 35 of the end plate 3, and returns to the cooling fan 8.
[0032]
Further, since the coolant favorably cools the end plate 3 that also serves as a heat sink of the semiconductor switching element 10, the semiconductor switching element 10 mounted on the outer end surface of the end plate 3 is favorably cooled, and the bearing 13 is prevented from overheating. Is done.
(Stator coil wiring extraction structure)
Next, a stator coil wiring take-out structure for drawing out the end conductor 50 of the stator coil 5 will be described below with reference to FIG.
[0033]
The end plate 3 is formed with three through holes 35 for taking out the three end conductors 50 at three locations. FIG. 2 shows one of the through holes 35. A substantially C-shaped ferrite core 36 with a part cut away is fixed to the through hole 35.
[0034]
A printed circuit board 37 is fixed to the outer end surface of the end plate 3, and a circuit component 38 for a control circuit is mounted on the printed circuit board 37. A current detector 40 incorporating a Hall element 39 is fixed to the back surface of the printed circuit board 37, and the current detector 40 is inserted into the notch 41 of the ferrite core 36.
[0035]
The end conductor 50 of the stator coil 5 passes through the ferrite core 36 and the printed circuit board 37 in the axial direction and is connected to the AC output terminal of the semiconductor switching element 10 through the bus bar 42.
[0036]
With this configuration, the ferrite core 36 can be easily attached, and the circuit element mounting surface of the printed circuit board 37 can be used effectively.
(Modification)
A modification of the above embodiment is shown in FIG.
[0037]
In this embodiment, the end frame 2 and the end plate 3 are integrated to form a cylindrical end frame 100 with a bottom. This end frame 100 has a ring groove 102 recessed from the outer peripheral surface side in a space defined by the rear end surface of the stator core 4 and the outer peripheral surface of the coil end 15, and a pipe through which coolant flows in the ring groove 102. 103 is wound. If it does in this way, the cooling effect similar to the above and the physique increase suppression effect can be acquired, and a number of parts can be reduced. Note that the coolant may be either liquid or gas.
[Brief description of the drawings]
FIG. 1 is a partial axial sectional view showing an embodiment of a rotating electrical machine of the present invention.
FIG. 2 is a partial enlarged axial sectional view of FIG. 1;
FIG. 3 is a partial axial sectional view showing a modification.
[Explanation of symbols]
2 End frame (cooling member)
3 End plate (cooling member)
4 Stator Core 5 Stator Coil 6 Rotor 7 Rotating Shaft 8 Cooling Fan 9 Through Bolt 10 Semiconductor Switching Element

Claims (5)

A cylindrical stator core having a slot in the inner periphery and fixed to the housing;
A stator coil having coil ends protruding from both end surfaces of the stator core and inserted into the slot;
A cooling member having a coolant passage therein and in close contact with the stator core;
A stator current control circuit including a semiconductor switching element fixed to the surface of the cooling member and controlling the current of the stator coil;
A rotor rotating to face an inner peripheral surface of the stator core;
In a rotating electrical machine comprising:
The cooling member is
A main body having a coolant passage therein and being accommodated in a cylindrical space portion defined by an end surface of the stator core and an outer peripheral surface of the coil end and fixed to the end surface of the stator core;
A plate portion having a predetermined gap with respect to the outer end surface of the coil end and extending radially inward from the inner peripheral surface of the main body portion;
Have a,
The main body is
The coolant passage has an annular cylindrical portion that opens outward in the axial direction;
The plate portion is
A rotating electrical machine, wherein the coolant passage is sealed in close contact with an outer end surface of the cylindrical portion. The rotating electrical machine according to claim 1, wherein
The plate portion is
A rotating electrical machine, wherein a shaft of the rotor is rotatably supported via a bearing. The rotating electrical machine according to claim 1, wherein
The stator current control circuit is
A rotating electrical machine characterized by being fixed to an outer end surface of the plate portion. In the rotating electrical machine according to claim 3 ,
The plate portion is
A rotating electrical machine comprising a through hole through which an end portion of a stator coil protruding substantially axially outward from the coil end passes. The rotating electrical machine according to claim 4 ,
A rotating electrical machine comprising: a magnetic core with a gap fitted into the through hole; and a magnetoelectric conversion element disposed in the gap.

Images