JP5257038B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine, and more particularly to a technique for reducing vibration and noise of a rotating electrical machine caused by vibration of a stator.

The vibration of the stator is positioned as a main source of vibration and noise in the rotating electrical machine. In a hybrid vehicle in which a drive source is configured by combining an internal combustion engine and a rotating electric machine, noise from the rotating electric machine causes a loss of silence, which is one of the greatest advantages. Here, as a technique for reducing the vibration and noise of the rotating electrical machine, there is a technique in which the stator core is divided into a plurality of blocks, and the fixing portions of the respective blocks with respect to the case are shifted in the circumferential direction between these blocks. (Patent Document 1). Specifically, in a rotating electrical machine including a stator core configured by laminating a plurality of electromagnetic steel plates, the stator core is divided into three blocks each made of a plurality of electromagnetic steel plates, and each block is 180 ° circumferentially. An ear metal part, which is a fixed part, is formed at an axially symmetric position with an interval of. Then, each block is rotated by 120 ° relative to each other so that the metal ears are arranged at equal intervals of 60 ° in the circumferential direction between these blocks. Each block is fixed to the case by the stator bolt inserted.
JP 2007-159332 A (paragraph number 0018)

  However, in the technique described in the above-mentioned Patent Document 1, each block is arranged so that their ear metal parts are arranged at equal intervals in the circumferential direction. There is a problem that it cannot be effectively suppressed. Annular vibration of the stator refers to in-plane vibration of a stator core that is an annular (ring-shaped) member, and its low-order deformation mode, particularly secondary or tertiary deformation mode, with respect to vibration and noise of a rotating electrical machine. It is known that the influence of is significant. Here, since the stator (stator core) is restrained at the fixed portion with respect to the case, each subsequent deformation mode of the ring vibration is a deformation based on these fixed portions. For example, in a rotating electrical machine in which a stator is fastened to a case with three fixed portions (at intervals of 120 °), the secondary deformation mode in annular vibration is 30 depending on the position of the fixed portion serving as a deformation base point. Appears every °. Similarly, in the rotating electrical machine in which the stator is fastened at four fixed portions (90 ° intervals), the secondary deformation mode appears every 45 °. Here, according to the technique described in the above literature, the position of the vibration antinode overlaps between the upper and lower blocks stacked, and there is a concern that the vibration energy concentrates on this antinode position and the amplitude increases. It can be said that there is still room for improvement in terms of suppressing the ring vibration of the stator with respect to reducing vibration and noise of the rotating electrical machine.

  In view of the above problems, an object of the present invention is to reduce vibration and noise of a rotating electrical machine by effectively suppressing annular vibration of a stator.

  A rotating electrical machine according to the present invention includes an annular stator, a rotor disposed so as to be rotatable relative to the stator, and a case that houses the stator and the rotor, and includes a stator core member (stator core). The first and second blocks having end faces intersecting the central axis of the stator are stacked in the axial direction. Here, the first block is fixed to the case at a first fixing portion provided at every predetermined angle θ in the circumferential direction, and the second block is set at every angle equal to the predetermined angle θ in the circumferential direction. It fixes to a case in the provided 2nd fixing | fixed part. In the present invention, the second block is shifted from the first block in the circumferential direction with a predetermined phase difference. When the odd number of first fixing portions are provided in the first block, the second block has a phase difference (θ / 4, θ that is larger than 0 and smaller than θ with respect to the first block). / 2 and 3θ / 4 are excluded), and when the even number of first fixing portions are provided in the first block, the second block is compared to the first block. The phase is shifted in the circumferential direction with a phase difference larger than 0 and smaller than θ (excluding θ / 3, θ / 2, and 2θ / 3).

  According to the present invention, in a rotating electrical machine including an annular stator, the stator core is divided into a plurality of blocks, and the second block is shifted with respect to the first block in the circumferential direction with the predetermined phase difference. By fixing to the case, it is avoided that the position of the vibration antinode overlaps between the first and second blocks in the secondary or tertiary deformation mode in the circular vibration. As a result, the vibration energy is distributed between the first and second blocks with respect to the low-order deformation mode in which the influence on the vibration and noise of the rotating electrical machine becomes significant. Thus, vibration and noise of the rotating electrical machine can be reduced.

  Embodiments of the present invention will be described below with reference to the drawings.

  FIG. 1 shows the configuration of the motor generator 1 according to the first embodiment of the present invention in a cross section including the rotation center axis of the motor generator 1 (indicated by the xx line in FIG. 2B). . The motor generator 1 according to the present embodiment is a three-phase alternating current type rotating electric machine, and can function not only as an electric motor but also as a generator by driving a rotor shaft 111 described later. The motor generator 1 can be combined with an internal combustion engine (not shown) to constitute a drive source for a hybrid vehicle. The motor generator 1 can also constitute a drive source for an electric vehicle such as a fuel cell vehicle. In the following, a case where the motor generator 1 having both the functions of an electric motor and a generator is adopted as the rotating electric machine will be described as an example. However, the present invention is not limited to this, and an electric motor mounted for the purpose of powering only, It is also possible to apply to a generator mounted only for the purpose of power generation (including the case where it is performed as regeneration of braking energy of a vehicle).

  The motor generator 1 includes a rotor 101 and a stator 201, and the rotor 101 and the stator 201 are accommodated in a case 301. The rotor 101 includes a plurality of permanent magnets 131 arranged side by side in the circumferential direction, and is held rotatably inward in the radial direction of the stator 201 by a bearing (not shown). When the motor generator 1 constitutes a drive source for a vehicle such as a hybrid vehicle, the rotor 101 is connected to the drive wheel via a gear set to a predetermined reduction ratio. On the other hand, the stator 201 has a coil 221 and is fixed to the case 301 by stator bolts 231a and 231b described later.

  The rotor 101 includes a rotor shaft 111 serving as an output shaft of the motor generator 1, and a rotor core 121 and an end plate 141 attached to the rotor shaft 111. The rotor core 121 is configured by laminating a plurality of electromagnetic steel plates such as silicon steel plates. When the electromagnetic steel plates are referred to as the axial direction of the rotor shaft 111 (hereinafter simply referred to as “axial direction”) with respect to the rotor shaft 111, (Referred to as the axial direction of the rotor shaft 111). A plurality of magnet accommodation holes penetrating the rotor core 121 in the axial direction are formed in the outer circumferential portion of the rotor core 121 in the circumferential direction, and permanent magnets 131 are embedded in the respective magnet accommodation holes. The end plate 141 is arranged in contact with the end surface on each axial side of the rotor core 121, and the rotor core 121 is sandwiched between the pair of end plates 141 and 141 so as to sandwich the rotor core 121 from both sides in the axial direction. It is held at a fixed position on the shaft 111.

  The stator 201 includes a stator core 211 and a coil 221 and is formed in an annular shape as a whole. The stator core 211 is configured by laminating a plurality of electromagnetic steel plates in the same manner as the rotor core 121. The stator core 211 is concentric with the rotor core 121 by the stator bolts 231a and 231b in a state in which these electromagnetic steel plates are continuous in the axial direction with respect to the case 301. It is fixed to. The stator core 211 is provided with a plurality of tooth-like protrusions (teeth) protruding radially inward in the circumferential direction, and a coil slot is formed between adjacent teeth. A conductive wire is wound around these teeth, so that a three-phase coil 221 accommodated in the coil slot is formed. A part of the coil 221 is located outside the slot to form a coil end.

  In this embodiment, the core member (stator core 211) of the stator 201 is divided into a plurality of blocks 211a and 211b each made of a plurality of electromagnetic steel plates, and each of these blocks 211a and 211b is a case. 301 is tightened by separate stator bolts 231a and 231b. Specifically, the stator core 211 is divided into two blocks (a first block 211a and a second block 211b) made of an equal number of electromagnetic steel plates, and the stator bolts 231a and 231b are inserted through the blocks 211a and 211b. The plurality of ear metal parts 212a and 212b to be formed are formed at predetermined equal angles θ. The first and second blocks 211a and 211b are stacked in a state shifted in the circumferential direction with respect to each other with a predetermined phase difference δ, coupled to each other by caulking, and the first and second blocks 211a and 211b It is reinforced by welding applied to the outer peripheral surface of the stator core 211 over both sides. Caulking can be achieved by forming a protruding portion on one of the joint surfaces of the first and second blocks 211a and 211b and forming a concave portion on the other joint surface, and fitting these portions together. It is. In this way, the coil 221 is formed on the stator core 211 to which the first and second blocks 211a and 211b are coupled, and the stator 201 is fixed to the case 301 by the stator bolts 231a and 231b in the subsequent assembly process. . In the present embodiment, pedestal portions 311a and 311b that receive the stator 201 are formed by projecting portions of the inner wall of the case 301 that are located outside the first and second ear metal portions 212a and 212b radially inward. And the screw holes of the stator bolts 231a and 231b are formed in the pedestal portions 311a and 311b. Of the pedestal portions 311a and 311b, the end surface forming the seating surface of the stator 201 is set at a position near the end surfaces of the first and second ear metal portions 212a and 212b, and the first and second blocks 211a and 211b By interposing the buffer material 241 between the pedestal portions 311a and 311b corresponding to each block, the ear metal portions 212a and 212b and the pedestal portions 311a and 311b are brought into contact with each other via the buffer material 241. .

  In the present embodiment, the ear metal part 212a provided in the first block 211a corresponds to the “first fixing part”, and the stator bolt 231a inserted into the bolt boss of the metal ear part 212a is the “first fixing part”. Corresponds to "Bolt". On the other hand, the ear metal part 212b provided in the second block 211b corresponds to the “second fixing part”, and the stator bolt 231b inserted into the bolt boss of the metal ear part 212b corresponds to the “second bolt”. .

  FIG. 2 shows the relative positional relationship of the first and second blocks 211a and 211b after assembly to the case 301. 2A shows the first block 211a, and FIG. 2B shows the second block 211b.

  In the present embodiment, in each of the first and second blocks 211a and 211b, three ear metal portions 212a and 212b are formed as fixed portions at every predetermined angle θ (= 120 °) in the circumferential direction. . As already described, the bolt bosses B1 and B2 for inserting the stator bolts 231a and 231b are formed in the respective ear metal portions 212a and 212b. The first and second blocks 211 a and 211 b are coupled by caulking or the like while being shifted in the circumferential direction with a predetermined phase difference δ and assembled to the case 301. In the present embodiment, the predetermined phase difference δ is set to δ = θ / 8 (= 15 °), where θ is the interval (angle) between the ear metal parts 212a and 212b.

  3 and 4 schematically show a low-order deformation mode in the ring vibration of the stator 201 according to the present embodiment, FIG. 3 shows a secondary deformation mode, and FIG. The deformation mode is shown. In each of FIGS. 3 and 4, a first block 211a is representatively shown. Hereinafter, with reference to FIGS. 3 and 4, the phase difference δ between the first and second blocks 211 a and 211 b will be described, and effects obtained by the present embodiment will be described together with this.

  In the present embodiment, the first and second blocks 211a and 211b are fixed while being shifted in the circumferential direction with a predetermined phase difference δ (= θ / 8). 2nd order and 3rd order deformation mode vibrations, which are considered to have a significant influence on vibration and noise, are suppressed. It is generally known to those skilled in the art that the deformation of the annular stator core 211 approaching an ellipse is called a secondary mode (FIG. 3), and the deformation approaching a triangle is called a tertiary mode (FIG. 4). Here, since the stator 201 is restrained with respect to the case 301 by the first and second metal parts 212a and 212b, each deformation mode of the ring vibration is determined by these metal parts 212a, The deformation is based on 212b. In the present embodiment, the first and second blocks 211a and 211b are fixed by three ear metal parts 212a and 212b provided at intervals of θ = 120 °, respectively. As shown in FIGS. 3A to 3C, the mode appears at every θ / 4 (= 30 °) according to the position of the ear metal part 212a that is the base point of deformation. Specifically, FIG. 3A shows a deformation mode in the case where the upper metal bar portion 212a becomes the base point toward the drawing, and FIG. 3B shows the left metal wire portion 212a. (C) further shows the deformation mode when the right-side ear metal part 212a is the base point. On the other hand, the third-order deformation mode in the ring vibration appears every θ / 2 (= 60 °) as shown in FIG.

  Thus, in the circular vibration of the stator 201, the second deformation mode appears every θ / 4 and the third deformation mode appears every θ / 2. Therefore, the second deformation mode appears for the first block 211a. The block 211b of the first block 211a is shifted in the circumferential direction and fixed with a phase difference δ excluding θ / 4, 2θ / 4 (= θ / 2) and 3θ / 4. The position of the vibration antinode and the position of the antinode of the second and third order vibrations in the second block 211b can be shifted in the circumferential direction. In the present embodiment, by providing a phase difference of δ = θ / 8 between the first and second blocks 211a and 211b, the first and second blocks 211a and 211b are in these deformation modes. By avoiding overlapping positions of vibration antinodes, vibration energy can be distributed between the blocks 211a and 211b. Thus, according to the present embodiment, it is possible to effectively suppress the ring vibration of the stator 201 and reduce the vibration and noise of the motor generator 1.

  The above description regarding the phase difference δ between the first and second blocks 211a and 211b, and the effect of fixing the blocks 211a and 211b with the phase difference δ is as follows. This is the case for the entire phase difference δ represented by the following equation (1), where n is a natural number of 1 to 4 when the fixing portions (ear metal portions 212a and 212b) are provided.

  δ = (2n−1) θ / 8 (1)

  In the present embodiment, since the phase difference δ is provided between the first and second blocks 211a and 211b, the ear metal parts 212a and 212b are shifted in the circumferential direction between the blocks 211a and 211b. Will be placed. This shortens the fastening length l (FIG. 1) of the stator bolts 231a and 231b for fixing one block to the case 301, thereby increasing the fastening strength of the blocks by the stator bolts 231a and 231b. It is possible to further suppress the vibration of the motor generator 1 by suppressing the amplitude in the bending or torsion mode vibration of the stator 201 and suppressing the vibration input to the case 301.

  Furthermore, since the thickness of the stator core 201 (block) fastened by one stator bolt 231a, 231b is reduced, the thickness of each block 211a, 211b caused by crushed varnish interposed between adjacent electromagnetic steel sheets is reduced. The cost can be reduced, and the inclination or falling of the stator 201 at the time of assembly can be prevented, so that the assembly accuracy of the stator 201 and thus the output performance of the motor generator 1 can be increased.

  Further, the cushioning material 241 is interposed between the first and second blocks 211a and 211b and the case 301, so that gaps generated between the respective blocks 211a and 211b and the case 301 at the time of assembling are filled. The assembly stability of 201 can be improved, and the transmission of vibration from the stator 201 to the case 301 can be suppressed. Note that the cushioning material 241 is not necessarily provided for both the blocks 211a and 211b, and may be provided between one of the blocks 211a and 211b and the case 301 as required.

  Hereinafter, other embodiments of the present invention will be described.

  FIG. 5 shows the relative positional relationship after the first and second blocks 211a and 211b are assembled in the second embodiment of the present invention. As in FIG. 2, FIG. 5A shows the first block 211a, and FIG. 5B shows the second block 211b.

  In the present embodiment, in each of the first and second blocks 211a and 211b, four ear metal parts 212a and 212b are formed in the circumferential direction for each predetermined angle θ (= 90 °). Stator bolts 231a and 231b are inserted into the bolt bosses B1 and B2 provided on the respective ear metal parts 212a and 212b. In the present embodiment, the first and second blocks 211a and 211b have a phase difference of δ = 5θ / 12 (= 37.5 °) set in accordance with the arrangement of the ear metal parts 212a and 212b which are fixed parts. They are coupled in a state shifted in the circumferential direction and assembled to the case 301.

  6 and 7 show a low-order deformation mode in the circular vibration of the stator 201 as a representative of the first block 211a. FIG. 6 shows a secondary deformation mode, and FIG. The deformation mode is shown.

  In the present embodiment, the first and second blocks 211a and 211b are fixed by four ear metal portions 212a and 212b provided at an interval of θ = 90 °, respectively. The mode appears every θ / 2 (= 45 °) as shown in FIGS. 6 (a) and 6 (b). On the other hand, the third-order deformation mode appears every θ / 3 (= 30 °) as shown in FIGS. 7 (a) and 7 (b).

  Thus, in the annular vibration of the stator 201 having the four ear metal portions 212a and 212b, the second-order deformation mode appears every θ / 2 and the third-order deformation mode appears every θ / 3. Similar to the first embodiment, the second block 211b is shifted and fixed in the circumferential direction with a phase difference δ excluding θ / 3, θ / 2 and 2θ / 3 with respect to the first block 211a. It can be avoided that the positions of antinodes of vibration in the secondary and tertiary modes overlap between the first and second blocks 211a and 211b. Thereby, vibration energy can be disperse | distributed between the 1st and 2nd blocks 211a and 211b, and the annular vibration of the stator 201 can be suppressed effectively.

  From the above description, when an even number of fixing parts (ear metal parts 212a and 212b) are provided in each of the first and second blocks 211a and 211b, a preferable phase difference is provided between these blocks 211a and 211b. An example of δ can be expressed by the following equation (2), where n is a natural number of 1 to 6.

  δ = (2n−1) θ / 12 (2)

  In the above description, the case where the stator core 211 is configured by laminating a plurality of electromagnetic steel plates has been described. However, the present invention is not limited to the rotating electrical machine including the steel plate laminated stator 201, and is formed by powder metallurgy or the like. The present invention can also be applied to a rotating electrical machine in which a stator core is configured by stacking the first and second blocks. In such a rotating electrical machine, the first and second blocks are shifted in the circumferential direction with a predetermined phase difference δ according to the arrangement of each fixing portion, and fixed to the case, so that between these blocks By avoiding overlapping positions of vibration antinodes, it is possible to suppress the ring vibration of the stator.

  Moreover, although the case where the stator core 211 is divided into two blocks 211a and 211b has been described above, the number of blocks to be divided is not limited to two, and may be three or more. By establishing a relationship having a predetermined phase difference δ between a pair of blocks among a plurality of divided blocks, the effects described above with respect to the pair of blocks are obtained, and noise of the rotating electrical machine is reduced. be able to.

  Further, the ear metal part 212a (first fixing part) of the first block 211a and the metal part 212b (second fixing part) of the second block 211b are at different intervals (angles θ1, θ2). It may be provided. As yet another third embodiment, the number and interval of the ear metal parts 212a and 212b are different between the two blocks 211a and 211b, and the second block 211b is placed at a predetermined position with respect to the first block 211a. The phase difference δ is shifted in the circumferential direction. By setting the phase difference δ so that the position of the vibration antinode is shifted in the circumferential direction between the blocks 211a and 211b in the low-order deformation mode, the concentration of vibration energy is avoided, and the stator Circular vibration can be suppressed.

Sectional drawing which shows the structure of the motor generator which concerns on the 1st Embodiment of this invention. The top view which shows the relative arrangement | positioning of the 1st and 2nd block in the stator which concerns on embodiment same as the above. The top view which shows typically the deformation | transformation of the block of a secondary mode in the ring vibration of the stator which concerns on embodiment same as the above. The top view which shows typically the deformation | transformation of the block of the third-order mode in an annular vibration same as the above The top view which shows the relative arrangement | positioning of the 1st and 2nd block in the stator which concerns on the 2nd Embodiment of this invention. The top view which shows typically the deformation | transformation of the block of a secondary mode in the ring vibration of the stator which concerns on embodiment same as the above. The top view which shows typically the deformation | transformation of the block of the third-order mode in an annular vibration same as the above

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Motor generator as a "rotating electrical machine", 101 ... Rotor, 111 ... Rotor shaft, 121 ... Rotor core, 131 ... Permanent magnet, 141 ... End plate, 201 ... Stator, 211 ... Stator core, 211a ... First block, 211b ... second block, 212a ... ear metal part as "first fixing part", 212b ... ear metal part as "second fixing part", 221 ... coil, 231a ... as "first bolt" Stator bolts, 231b ... Stator bolts as "second bolts", 241 ... cushioning material, 301 ... case, 311a, 311b ... pedestal, B1, B2 ... bolt bosses.

Claims (9)

An annular stator;
A rotor arranged to be rotatable relative to the stator;
A case for accommodating the stator and the rotor;
Comprising
The stator includes a stator core configured by axially stacking first and second blocks having end faces intersecting with a central axis,
The first block is fixed to the case at an odd number of first fixing portions provided at predetermined angles θ in the circumferential direction,
The second block has a phase difference larger than 0 and smaller than θ with respect to the first block in a second fixing portion provided at an angle equal to the predetermined angle θ in the circumferential direction. A rotating electrical machine fixed to the case by shifting in the circumferential direction (excluding θ / 4, θ / 2, and 3θ / 4).   2. The rotating electrical machine according to claim 1, wherein the second fixed portion is arranged with a phase difference of (2n−1) θ / 8, where n is a natural number of 1 to 4, with respect to the first fixed portion. . An annular stator;
A rotor arranged to be rotatable relative to the stator;
A case for accommodating the stator and the rotor;
Comprising
The stator includes a stator core configured by axially stacking first and second blocks having end faces intersecting with a central axis,
The first block is fixed to the case at an even number of first fixing portions provided at predetermined angles θ in the circumferential direction,
The second block has a phase difference larger than 0 and smaller than θ with respect to the first block in a second fixing portion provided at an angle equal to the predetermined angle θ in the circumferential direction. A rotating electrical machine fixed to the case by shifting in the circumferential direction (excluding θ / 3, θ / 2, and 2θ / 3).   4. The rotating electrical machine according to claim 3, wherein the second fixed portion is arranged with a phase difference of (2n−1) θ / 12, where n is a natural number of 1 to 6, with respect to the first fixed portion. .   The rotating electrical machine according to any one of claims 1 to 4, wherein the stator has a welded portion that connects the first and second blocks. The rotating electric machine according to any one of claims 1 to 5, wherein the stator is formed by joining the first and second blocks by caulking. The first block has a bolt boss in the first fixing portion, and is fixed to the case by a first bolt inserted through the bolt boss.
The second block has a bolt boss in the second fixing portion, and is fixed to the case by a second bolt inserted through the bolt boss.
The case has a pedestal portion in which a screw hole for each of the first and second bolts is formed.
The pedestal section than said radially outer ends of the first and second of said stator determined according to each of the placement of the fixed portion extends inwardly, the first of said first bolt fixing portion An end surface opposite to an end surface forming the seating surface of the head portion or an end surface opposite to an end surface forming the seating surface of the second bolt of the second fixing portion is brought into contact. The rotary electric machine in any one of 1-6.   The rotating electrical machine according to claim 7, further comprising a cushioning material interposed between at least one of the first and second fixing portions and the pedestal portion. A rotating electric machine having an annular stator,
The stator has a core member formed by being divided into a plurality of blocks each having an end surface intersecting a central axis.
The first block among the plurality of blocks is fixed to the case of the rotating electrical machine in the plurality of first fixing portions provided at intervals in the circumferential direction,
At least one second block other than the first block has a plurality of second fixing portions provided in a circumferentially shifted manner with respect to the first fixing portion, and the shaft is relative to the first block. Fixed to the case in a stacked state,
Each of the second fixed portions is deformed with respect to the vibration antinode of the first block determined according to the arrangement of the first fixed portions with respect to the second-order or third-order deformation mode of annular vibration. A rotating electrical machine set at a position where an antinode of vibration of the second block determined with respect to a mode is shifted in the circumferential direction.

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