JP2014193006A - Rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a rotary electric machine which securely fixes a stator to a housing even when the stator having uneven thickness is used.SOLUTION: A generator motor serving as a rotary electric machine includes: a housing 15; a stator 10 fixed to the interior of the housing 15 by multiple bolts 22 which are arranged spaced away from each other; and a rotor rotatably disposed in the stator 10. The housing 15 includes: bolt threaded holes 33 with which the multiple bolts 22 are threadedly engaged; multiple stator contact surfaces 38 provided with the bolt threaded holes 33 and with which the stator 10 contacts; and recessed parts 39, each of which is provided between the adjacent stator contact surfaces 38 recessed from the stator contact surfaces 38.

Description

  The present invention relates to a rotating electrical machine, and more specifically, to an improvement in a fixing structure for fixing a stator constituting a generator or an electric motor to a housing.

  Conventionally, in a hydraulic excavator configured as a hybrid construction machine, it is known to drive a generator by the output of an engine and to drive an electric motor for turning a revolving body with electric energy generated by the generator. (For example, Patent Document 1).

  The generator used here includes a rotatable rotor coupled to the output shaft of the engine and an annular stator disposed on the outer peripheral side of the rotor. Of these, the stator has a structure in which a large number of electromagnetic steel sheets or the like are laminated, and is fixed in the housing of the generator by a plurality of bolts that penetrate a yoke that is a laminated portion on the outer peripheral side. The stator is provided with a plurality of teeth along the circumferential direction protruding radially inward from the yoke portion. A coil is wound around each tooth.

  By the way, in the generator, all the coils are covered with varnish so that the insulation performance is not deteriorated by vibration after being incorporated in the construction machine. As such a varnish treatment, for example, first, the entire stator provided with a coil is immersed in a varnish tank. Next, the entire stator is pulled up from the varnish tank and left for a predetermined time, whereby excess varnish is dropped and removed, and then dried. In the varnish treatment, as in the case of fixing the stator to the housing, the stator is attached to the immersion jig with a plurality of bolts penetrating the yoke portion, and the entire stator is immersed in the varnish tank together with the immersion jig.

JP 2012-313275 A

  However, since the stator of the generator has a structure in which a large number of steel plates are laminated, the varnish penetrates between the steel plates when immersed in the varnish tank. At this time, since the stator is fixed to the immersion jig by bolts used at intervals in the circumferential direction during the varnish treatment, the varnish is difficult to penetrate in the portion tightened with the bolts. Soak in the part between. For this reason, if the varnish that has soaked in is hardened without being completely removed, as the stator, a portion where the thickness in the axial direction hardly changes and a portion where the thickness increases greatly appear alternately along the circumferential direction. And the fixed surface will wave. As a result, as shown in FIG. 5, when the stator is fixed to the housing with a bolt, the stator does not come into good contact with the contact surface of the housing, and the stator is bolted in the raised state. The bolt may loosen gradually.

  An object of the present invention is to provide a rotating electrical machine that can securely fix a stator to a housing even when a stator having a non-uniform thickness is used.

  A rotating electrical machine according to a first aspect of the present invention includes a housing, a stator fixed in the housing by a plurality of bolts arranged at intervals in the circumferential direction, and a rotor arranged rotatably inside the stator. The housing includes a bolt screw hole into which the plurality of bolts are screwed, a plurality of stator contact surfaces with which the stator is in contact with the bolt screw holes, and the adjacent stator contacts. It has a concave part provided so that it was depressed rather than the said stator contact surface between contact surfaces, It is characterized by the above-mentioned.

  In the rotating electrical machine according to the second invention, the stator has a bolt insertion part through which the bolt is inserted, and an intermediate part provided between the adjacent bolt insertion parts, and the thickness of the intermediate part is: It is desirable that the thickness of the concave portion is greater than the thickness of the bolt insertion portion, corresponding to the intermediate portion.

In the rotating electrical machine according to a third aspect of the present invention, the stator is configured by laminating a plurality of steel plates, and the thickness of the intermediate portion is determined by the varnish soaked between the steel plates during the varnish treatment of the stator. It may be thicker than the thickness.
The rotating electrical machine according to the fourth aspect of the invention is preferably mounted on a construction machine.
The rotating electrical machine according to the fifth aspect of the invention is preferably used as a generator in which the rotor is driven by the output of the engine.

  A rotating electrical machine according to a sixth aspect of the present invention is a rotating electrical machine that is mounted on a construction machine and functions as a generator motor. The rotating electrical machine is formed by laminating a housing and a plurality of electromagnetic steel plates, and is spaced apart in the circumferential direction. An annular stator fixed in the housing by a plurality of arranged bolts, and a rotor rotatably arranged inside the stator and connected to an output shaft of an engine installed in the construction machine The housing includes a bolt screw hole into which the plurality of bolts are screwed, a plurality of stator contact surfaces with which the stator is in contact with the bolt screw holes, and the adjacent stator contacts. A concave portion provided between the contact surfaces that is recessed from the stator contact surface, and the stator includes a bolt insertion portion through which the bolt is inserted and the adjacent bolt. An intermediate portion provided between the through portions, and the thickness of the intermediate portion is thicker than the thickness of the bolt insertion portion by a varnish that has penetrated between the electromagnetic steel sheets during the varnish treatment of the stator. The concave portion is provided corresponding to the intermediate portion.

  According to the first aspect of the present invention, the housing to which the stator is bolted is provided with a plurality of stator contact surfaces corresponding to the bolt screw holes individually in an island shape, and a concave portion between adjacent stator contact surfaces. Therefore, the stator may be arranged so that the thick portion of the stator corresponds to the concave portion and bolted to the housing. By doing so, the bolt can be fixed in a state where the stator is securely in contact with the stator contact surface of the housing, and can be prevented from being bolted in a state where the stator is lifted. Therefore, while the rotating electrical machine is used over time, such a gap is not clogged and the bolt is not loosened, and the fixed state of the stator can be maintained well.

According to the second aspect, since the bolt insertion part and the intermediate part having different thicknesses are clearly provided on the stator side, the effect of the present invention can be exhibited more remarkably.
According to the third invention, even when the varnish treatment of the stator is performed by a method of immersing the stator together with the varnish tank, the stator after the varnish treatment can be appropriately fixed to the housing.
In particular, as in the fourth to sixth inventions, when the rotating electrical machine is mounted on a construction machine or driven by an engine as a generator, it can withstand a large vibration generated in the construction machine. In addition, it can withstand vibrations from the engine that are constantly generated while the engine is being driven, and a highly reliable construction machine and generator can be provided.

The disassembled perspective view which shows the rotary electric machine which concerns on one Embodiment of this invention. The inside view which shows the inner side of the housing which comprises a rotary electric machine. It is sectional drawing which shows the principal part of a housing, and is the III-III sectional view taken on the line of FIG. Sectional drawing which shows the fixing | fixed part of the stator and housing of a rotary electric machine. Sectional drawing for demonstrating the subject of this invention.

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.
FIG. 1 is an exploded perspective view showing a generator motor 1 as a rotating electrical machine of the present embodiment.
In FIG. 1, a generator motor 1 is mounted on an upper swing body of a hybrid construction machine (hydraulic excavator) and is disposed so as to be sandwiched between an engine (not shown) and a hydraulic pump.

[General configuration of hydraulic excavator]
A hybrid hydraulic excavator includes a traveling body and a revolving body provided on the traveling body so as to be able to swivel. The swivel body includes a work machine, a cab, a counterweight, and an engine room. The swivel body is driven by a swivel electric motor that operates by electric energy from the generator motor 1 or the capacitor. The swing electric motor generates power by regeneration during deceleration of the swing body, and the electric energy obtained by the power generation is stored in the capacitor.

[Configuration of generator motor]
The generator motor 1 has a rotor shaft 14A connected directly or indirectly to the output shaft of the engine and the input shaft of the hydraulic pump, and generates power by the rotational driving force of the output shaft of the engine. The generator motor 1 is connected to a capacitor via an inverter. When increasing the rotation of the engine, the generator motor 1 is used as an electric motor by the electric energy stored in the capacitor as needed to assist the rotation of the engine. When the engine is in an idling state, the generator motor 1 generates power by receiving the rotational driving force of the engine, and the electric energy generated by the power generation is stored in the capacitor.

  The generator motor 1 in the present embodiment is a generator motor having a three-phase, twelve-pole switched reluctance (hereinafter abbreviated as SR) motor structure, and includes an annular stator 10 and an engine side. A first housing 11, a flywheel 12, a coupling 13, a rotor 14, a second housing 15 on the hydraulic pump side as a housing, and a flange 16 are provided.

The stator 10 is provided in a space in the first and second housings 11 and 15 constituting the outer shell of the generator motor 1. The stator 10 includes an annular stator core 20 and a plurality of coils 21.
The stator core 20 is configured by laminating a plurality of electromagnetic steel plates. The outer peripheral side of the stator core 20 is an annular yoke. The yoke is provided with a plurality of teeth protruding inward in the radial direction at equal intervals along the circumferential direction. A coil 21 is wound around each tooth. In the present embodiment, the stator core 20 having a total of 36 teeth is used to form the 36-pole stator 10.
Such a stator 10 is bolted to the second housing 15 by 16 bolts 22 (only one is shown in FIG. 1) penetrating the yoke portion from the engine side.

  The first housing 11 is a cast iron member, and is joined to the second housing 15 to form a space in which the stator 10, the rotor 14 and the like are housed. In the lower part of the storage space, an oil reservoir portion 23 is formed that promotes lubrication of the rotor shaft 14A and the bearing portion and stores cooling oil for cooling a heat generating portion (coil 21 and the like) of the stator 10.

  The flywheel 12 is fixed to the output shaft of the engine in the first and second housings 11 and 15. The flywheel 12 is connected to the rotor 14 via the coupling 13 and rotates in the first and second housings 11 and 15.

  The coupling 13 is a substantially annular member and is bolted to the flywheel 12. In this coupling 13, an internal spline formed on the inner diameter portion meshes with an external spline formed on the outer diameter portion on the engine side of the rotor shaft 14A, and is splined to each other. As a result, the flywheel 12, the coupling 13, and the rotor 14 having the rotor shaft 14A rotate together and are driven by the engine.

  The rotor 14 is disposed in a space on the inner peripheral side of the stator 10 in the first and second housings 11 and 15. A support space 14B in which the rotor shaft 14A is bolted is formed in the center of the rotor 14. A cylindrical support portion 16A provided at the center of the flange 16 enters the support space 14B. The rotor 14 is rotatably supported around the support portion 16A of the flange 16 by disposing the bearing between the inner peripheral surface of the support space 14B and the outer peripheral surface of the support portion 16A.

  On the other hand, the hydraulic pump side portion of the rotor shaft 14 </ b> A of the rotor 14 is inserted into the support portion 16 </ b> A of the flange 16. In the rotor shaft 14A of the rotor 14, an internal spline is formed on the inner diameter side of the portion inserted into the support portion 16A. The internal spline and the external spline provided on the input shaft of the hydraulic pump are splined. As a result, the hydraulic pump is driven by the engine via the rotor 14.

  The second housing 15 is a cast iron member, and is provided on the hydraulic pump side (the right side in FIG. 1) of the generator motor 1. The second housing 15 forms a storage space for storing the stator 10, flywheel 12, coupling 13, and rotor 14 together with the first housing 11 that is bolt-fixed.

  An electric box 17 having an internal space communicating with the accommodation space is attached to the shoulder portion of the second housing 15. A terminal for connecting a power line from the coil 21 is disposed in the internal space of the electric box 17. Such a terminal is connected to a connector of a power cable fixed to the electric box 17. That is, the electric energy generated by the generator motor 1 is transmitted from the electric box 17 to the inverter through the power cable.

  The flange 16 is a member that closes the storage space formed by the first and second housings 11 and 15 on the second housing 15 side. Therefore, the flange 16 is bolted to the second housing 15 from the hydraulic pump side. An insertion hole 16B is provided in the center of the flange 16 coaxially with the support portion 16A, and the input shaft of the hydraulic pump inserted through the insertion hole 16B is coupled to the rotor shaft 14A of the rotor 14 as described above. .

[Static varnish treatment]
Here, the varnish treatment of the stator 10 constituting the generator motor 1 will be described.
The coil 21 provided in the stator 10 is covered with varnish in order to suppress deterioration over time. In this case, the varnish treatment includes a pre-process for attaching the stator 10 provided with the coil 21 to the immersion jig with bolts 22, an immersion process in which the entire stator 10 is immersed in the varnish tank together with the immersion jig, The varnish dropping step of dropping the excess varnish and removing it, and a drying step after which the varnish is dried.

  As a result of such varnish treatment, the stator 10 has a portion where the varnish penetrates between the laminated steel plates and a portion where the varnish hardly penetrates. And in the part into which the varnish penetrated, the phenomenon that the thickness of an axial direction changes arises.

  That is, in the stator 10 fixed to the immersion jig using the bolt 22, a tightening force acts on a portion through which the bolt 22 is inserted. Therefore, the amount of penetration of the varnish between the steel plates in this portion is as follows. There is little change in thickness. On the other hand, since the tightening force that acts between the adjacent bolts 22 becomes weak at the portion between the adjacent bolts 22, the amount of varnish that penetrates between the steel plates is large. The thickness in the direction increases.

  For this reason, in the circumferential direction of the stator 10, the portion between the adjacent bolts 22 swells with respect to the tightening position of the bolts 22, and the stator 10 is fixed so that the fixing surface with the second housing 15 undulates. (See FIG. 4). Conventionally, the bolt 22 is loosened after the stator 10 is fixed to the second housing 15 by this phenomenon.

[Structure of second housing]
FIG. 2 is an interior view showing the inside of the second housing 15. FIG. 3 is a cross-sectional view of a main part of the second housing 15, and is a cross-sectional view taken along line III-III in FIG.

  2 and 3, the second housing 15 has a housing opening 30 that is largely open on the first housing 11 (FIG. 1) side. On the outer peripheral side of the accommodation opening 30 of the second housing 15, a joining surface 31 to which the first housing 11 is joined by a bolt is provided. A substantially annular stator fixing portion 32 to which the stator 10 (FIG. 1) is fixed is provided at a position closer to the center on the inner side than the joint surface 31. The stator fixing portion 32 is provided with a plurality (16 in this embodiment) of bolt screw holes 33 at equal intervals in the circumferential direction. The 16 bolts 22 arranged in an annular shape are screwed into the bolt screw holes 33 through the yoke portion of the stator 10, so that the stator 10 is bolted to the stator fixing portion 32.

  At a portion closer to the center of the stator fixing portion 32, a substantially annular flange fixing portion 34 that is thinner is provided. The flange 16 is bolted to a flange contact surface 35 provided on the side of the hydraulic pump of the flange fixing portion 34 (the lower side in FIG. 3). As described above, the stator fixing portion 32 is configured as a step portion provided between the outer peripheral joint surface 31 and the inner peripheral flange fixing portion 34.

  A first inner wall portion 36 that is orthogonal to the stator fixing portion 32 is provided on the outer side of the stator fixing portion 32. The outline of the first inner wall portion 36 forms the opening shape of the accommodation opening 30. A space between the flange fixing portion 34 and the stator fixing portion 32 is a second inner wall portion 37 orthogonal to these.

  The stator fixing portion 32 is provided with a plurality of independent stator contact surfaces 38 in an island shape. The bolt screw hole 33 described above is provided in the approximate center of each stator contact surface 38. As shown in FIG. 3, a concave portion 39 that is recessed toward the hydraulic pump side from the stator contact surface 38 is formed between the adjacent stator contact surfaces 38.

  The surfaces of the concave portion 39 and the first and second inner wall portions 36 and 37 are the casting surface of the second housing 15 to be cast. On the other hand, the joint surface 31, the flange contact surface 35, and the island-shaped stator contact surface 38 are finished surfaces machined to a predetermined surface roughness.

[Fixing of second housing and stator]
As shown in FIG. 4, the stator 10 in contact with each stator contact surface 38 is fixed to the second housing 15 with bolts 22.
Here, a portion of the stator 10 where the insertion hole 40 through which the bolt 22 is inserted is a bolt insertion portion 41 having an axial thickness T1. Moreover, the part between the volt | bolts 22 (insertion hole 40) has become the intermediate part 42 expanded substantially equally to the both sides of an axial direction because the varnish permeates. For this reason, the thickness T2 of the intermediate part 42 is thicker than the thickness T1.

  The second housing 15 is provided with a recessed portion 39 that is recessed corresponding to the intermediate portion 42 of the stator 10, so that the intermediate portion 42 does not come into contact with the stator fixing portion 32. Thus, the fixed surface 43 of the stator 10 can be reliably brought into contact with the stator contact surface 38, and the lift from the stator contact surface 38 can be prevented. Therefore, such lifting does not clog the stator contact surface 38 side during use, and the bolt 22 once tightened can be prevented from loosening.

[Modification]
It should be noted that the present invention is not limited to the above-described embodiments, and modifications, improvements, and the like within the scope that can achieve the object of the present invention are included in the present invention.
For example, in the above embodiment, the surface of the concave portion 39 of the second housing 15 is a cast surface, but the entire surface of the stator fixing portion 32 including the concave portion 39 and the stator contact surface 38 is You may finish by machining.

In the said embodiment, although the stator 10 was demonstrated on the assumption that it was varnished by being immersed in a varnish tank, even if it is a stator varnished by other methods, it can be used as a rotating electrical machine of the present invention. Can do.
That is, the housing according to the present invention is provided as a recess between the island-shaped stator contact surface with which the stator is contacted, the bolt screw hole provided in the stator contact surface, and the adjacent stator contact surface. Any method may be used for the varnish treatment of the stator. It does not matter whether the stator has the bolt insertion part 41 and the intermediate part 42 having different thicknesses as in the above embodiment.
For example, a stator with a uniform thickness was initially used, but as a result of mass production of a stator that has undergone a varnish bath immersion process due to a change in the manufacturing process, a stator with a non-uniform thickness accompanying maintenance It may be necessary to change to. Therefore, assuming such a case, it is consistent with the object of the present invention to use a housing provided with a concave portion in advance regardless of the method of varnishing the stator.

In the above embodiment, the generator motor 1 has been described as an example of the rotating electrical machine of the present invention. However, the rotating electrical machine of the present invention may have only a power generation function, and may have a motor (electric motor) function. It may be a case having only. That is, the present invention is applicable to both a generator and an electric motor.
In the embodiment, the hybrid construction machine has been described as the vehicle on which the rotating electrical machine of the present invention is mounted. However, in addition to the hybrid construction machine, a hybrid automobile, an electric construction machine, an electric automobile, or the like The present invention may be applied to. Further, the construction machine is not limited to a hydraulic excavator, and the present invention may be applied to an arbitrary construction machine such as a wheel loader.

  The present invention can be used not only for a hybrid construction machine but also for a hybrid automobile, an electric automobile, and an electric construction machine.

  DESCRIPTION OF SYMBOLS 1 ... Generator motor which is a rotary electric machine, 10 ... Stator, 14 ... Rotor, 15 ... 2nd housing which is a housing, 21 ... Coil, 22 ... Bolt, 33 ... Bolt screwing hole, 38 ... Stator contact surface, 39 ... concave part, 41 ... bolt insertion part, 42 ... intermediate part, T1, T2 ... thickness.

Claims (6)

A housing;
A stator fixed in the housing by a plurality of bolts spaced apart in the circumferential direction;
A rotor disposed rotatably inside the stator,
The housing is
A bolt screwing hole into which the plurality of bolts are screwed;
A plurality of stator contact surfaces provided with the bolt screw holes and with which the stator contacts;
A dynamo-electric machine comprising: a recessed portion provided between the adjacent stator contact surfaces that is recessed from the stator contact surface. In the rotating electrical machine according to claim 1,
The stator is
A bolt insertion part through which the bolt is inserted;
An intermediate portion provided between the adjacent bolt insertion portions,
The intermediate portion is thicker than the bolt insertion portion,
The rotating electrical machine, wherein the concave portion is provided corresponding to the intermediate portion. The rotating electrical machine according to claim 2,
The stator is configured by laminating a plurality of steel plates,
The rotating electric machine according to claim 1, wherein the thickness of the intermediate portion is larger than the thickness of the bolt insertion portion by a varnish that has penetrated between the steel plates during the varnish treatment of the stator. The rotating electrical machine according to any one of claims 1 to 3,
A rotating electrical machine that is mounted on a construction machine. The rotating electrical machine according to any one of claims 1 to 4,
The rotating electrical machine is used as a generator in which the rotor is driven by engine output. A rotating electric machine mounted on a construction machine and functioning as a generator motor;
A housing;
An annular stator that is formed by laminating a plurality of electromagnetic steel plates and is fixed in the housing by a plurality of bolts arranged at intervals in the circumferential direction,
A rotor that is rotatably arranged inside the stator and that is coupled to an output shaft of an engine installed in the construction machine;
The housing is
A bolt screwing hole into which the plurality of bolts are screwed;
A plurality of stator contact surfaces provided with the bolt screw holes and with which the stator contacts;
A concave portion provided below the stator contact surface between the adjacent stator contact surfaces;
The stator is
A bolt insertion part through which the bolt is inserted;
An intermediate portion provided between the adjacent bolt insertion portions,
The thickness of the intermediate portion is thicker than the thickness of the bolt insertion portion by the varnish soaked between the electromagnetic steel sheets during the varnish treatment of the stator,
The rotating electrical machine, wherein the concave portion is provided corresponding to the intermediate portion.

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