An embodiment disclosed therein relates to a rotating electric machine.
An AC motor having a stator core mounted onto an inner surface of a tubular frame is known.
According to one aspect of the disclosure, there is provided a rotating electric machine including a tubular frame and a stator core. The frame includes a bulged linear part on an inner peripheral surface. The bulged linear part has a shape extended linearly in an axial direction and bulged toward the inner periphery side. The stator core is fixed onto an inner periphery of the frame. The stator core includes a groove part fitted to the bulged linear part on an outer peripheral surface.
In the following, the embodiment of the present disclosure will be described with reference to the drawings.
First, a configuration of a rotating electric machine 1 in relation to the present embodiment will be described using
Assembling holes 31 are formed through each of the frame 22 and the two brackets 21, 25 along the axial direction on the two corners on a diagonal line viewed in an axially orthogonal section thereof. While the assembling bolt holes 31 in the load-side bracket 25 and the frame 22 are simple through holes, taps are formed on inner peripheries of the assembling bolt holes 31 in the opposite load-side bracket 21. The assembling bolts 26 pass through the assembling bolt holes 31 in the load-side bracket 25 and the frame 22 and are fastened to the taps of the assembling bolt holes 31 in the load-side bracket 21, and thereby the entire rotating electric machine 1 is fixed as one assembly. The rotating electric machine 1 so configured of the present embodiment is an inner-rotor type motor in which the above-mentioned two brackets 21, 25, the frame 22 and the stator core 23 are integrated to configure a stator and the rotor 24 is rotatably provided therein.
In the assembly of the rotating electric machine 1, the shaft on the front side in the drawing (the side that the rotor 24 projects from the load-side bracket 25) in the two shafts on the both ends of the rotor 24 acts as an output shaft to be coupled to the load-side of the object to be driven. In addition, the shaft on the back side (the side that the rotor 24 projects from the opposite load-side bracket 21) acts as a shaft to be coupled to a not shown encoder or the like. In the entire rotating electric machine 1, an end face of the opposite load-side bracket 21 is fixed to a device main body (illustration thereof is omitted) that is the driven object. For this purpose, mounting bolt holes 35 are formed through two corners other than those for the above-mentioned assembling bolt holes 31 viewed in the axially orthogonal section of the opposite load-side bracket 21, and the entire rotating electric machine 1 concerned is fixed to the device main body by making mounting bolts 28 respectively pass through the mounting bolt holes 35 and fastening tip ends thereof to the above-mentioned device main body.
In addition, in a case where the rotating electric machine 1 concerned is rotationally driving the rotor, it is necessary to suppress rotation of the stator caused by reaction torque thereof. For this purpose, in a case of a small-sized motor, the entire stator is formed by an approximately square pole that is approximate to a regular tetragon in its axially orthogonal section such that the rotation thereof may be readily suppressed by nipping and holding the stator by mutually facing two flat plates and so forth. Then, the recessed parts 32 adapted to avoid interference with the mounting bolts 28 are formed in the two corners of the frame 22 corresponding to the assembling bolt holes 31 in the above-described opposite load-side bracket 21 along the entire axial direction of the frame 22 concerned.
An inner structure of the rotating electric machine 1 concerned will be described with reference to
The stator core 23 that is fitted into the bore of the frame 22 has an approximately cylindrical laminated iron core body 5 that faces an outer peripheral surface of the rotor 24 in a radial direction with the gap interposed, an approximately cylindrical yoke part 6 that is located between the outer periphery side of this laminated iron core body 5 and the inner peripheral surface of the frame 22 and has been divided from the laminated iron core body 5 in the radial direction, a bobbin 7 that is mounted onto the laminated iron core body 5, and a coil wire 8 that is wound around the bobbin 7. The bobbin 7 is made of an insulating material in order to electrically insulate the laminated iron core body 5 from the coil wire 8. The laminated iron core body 5 includes a plurality of projected teeth parts 5a which has inner peripheral-side cylindrical tip end parts coupled together and which radially projects outward in the radial direction. The respective teeth parts 5a are disposed in a circumferential direction at equal intervals and the bobbins 7 with the coil wires 8 wound therearound are mounted onto the teeth parts 5a. A resin is injected into spaces between the bobbins 7 and between the coil wires 8 located between the respective teeth parts 5a and thereby the entire stator core 23 is mold-fixed.
Incidentally, the assembling bolt 26 corresponds to an example of fixing bolt described in each claim, the mounting bolt 28 corresponds to an example of mounting bolt described in each claim, the assembling bolt hole 31 corresponds to an example of bolt hole for the fixing bolt described in each claim, and the coil wires 8 corresponds to an example of stator coil described in each claim.
The recessed parts 32 corresponds to an example of means for avoiding interference between the frame and a mounting bolt described in claims, and the bulged linear parts 33 and the groove parts 34 corresponds to an example of means for engaging of the frame with the stator core to prevent the stator core from idling in the frame.
In the stator core 23 so configured, when a current is made to flow through the coil wire 8 of each bobbin 7, the corresponding teeth part 5a is magnetized and works as a magnetic pole. The polarities and field system intensities of the magnetic poles of the respective teeth parts 5a are sequentially switched to impart circumferential attractive force and repulsive force to a magnetic pole that has been magnetized to the permanent magnet 24b on the outer periphery of the rotor 24, thereby generating rotating torque in the rotor 24 consequently. In the rotating electric machine 1 of the present embodiment, the adjacent three teeth parts 5a are respectively connected to a three-phase AC source to function as an AC motor all together. Therefore, the teeth parts 5a to be disposed on the stator core 23 are disposed by the number of a multiple of 3.
In contrast, in the rotating electric machine 1 of the present embodiment, as shown in
In addition, the frame 22 of the rotating electric machine 1 that is generally used as the motor is made of a material of quality that is high in thermal conductivity in order to increase heat dissipation and is a non-magnetic body in order not to leak lines of magnetic force, for example, aluminum. On the other hand, the laminated iron core body 5 and the yoke part 6 of the stator core 23 are made of iron that is a magnetic body. Since aluminum is lower in rigidity than iron that is the material of the stator core 23, it is necessary to make the outer diameter of the stator core 23 as large as possible relative to the frame 22 as a design technique for increasing the rigidity of the entire rotating electric machine 1. In contrast, in the configuration shown in
In contrast, in the rotating electric machine 1 of the present embodiment, as shown in
In addition, in the rotating electric machine 1 of the present embodiment, the groove part 34 in the stator core 23 is formed at the circumferential position corresponding to each teeth part 5a on the outer peripheral surface of the yoke part 6. As shown in
As described above, the bulged linear part 33 and the groove part 34 are required to be formed at the circumferential positions respectively corresponding to the assembling bolt hole 31 or the recessed part 32 on the outer periphery side thereof and the teeth part 5a on the inner periphery side thereof. Then, since the frame 22 is formed into the approximately regular tetragon in its axially orthogonal section as described above, it is common that the assembling bolt holes 31 to be formed in two places or the recessed parts 32 to be formed in two places are mutually arranged on the diagonal line of the above-mentioned approximately regular tetragon. Therefore, it is preferable that the bulged linear parts 33 and the groove parts 34 be formed at intervals of 180 degrees or at intervals of 90 degrees in the circumferential direction so as to make their positions correspond to the circumferential positions of the assembling bolt holes 31 or the recessed parts 32 on the outer periphery side.
In the rotating electric machine 1 of the present embodiment, as shown in
Then, in the rotating electric machine 1 of the present embodiment, also an arrangement configuration of the teeth parts 5a on the inner peripheral side is modified by making the positions of the teeth parts 5a correspond to the circumferential positions of the above-mentioned assembling bolt holes 31 and recessed parts 32. As described above, in a case where the rotating electric machine 1 concerned is to be used as the AC three-phase motor, the number of slots of the stator core 23 (that is, the number of the teeth parts 5a) amounts to a multiple of 3 and it is necessary to arrange the teeth parts 5a at equal intervals in the circumferential direction. On the other hand, in a case where the bulged linear parts 33 and the groove parts 34 are to be arranged at intervals of 180 degrees, it is necessary to set the number of slots to a multiple of 2 and in a case where the bulged linear parts 33 and the groove parts 34 are to be arranged at intervals of 90 degrees, it is necessary to set the number of slots to a multiple of 4. Therefore, it becomes possible to arrange the bulged linear parts 33 and the groove parts 34 to be formed at the circumferential positions corresponding to the teeth parts 5a at intervals of 180 degrees by setting the number of slot to a multiple of 6 (=3×2), and it becomes possible to arrange the bulged linear parts 33 and the groove parts 34 at intervals of 90 degrees by setting the number of slots to a multiple of 12 (=3×4).
It is possible to functionally arrange the bulged linear parts 33 and the groove parts 34 by applying the present disclosure to the form of 10P12S such as the example of the present embodiment shown in
According to the above-mentioned embodiment of the present disclosure, such advantageous effects as follows are obtained. That is, the bulged linear parts 33 of the shape that linearly extends in the axial direction and bulges toward the inner periphery side are formed on the inner peripheral surface of the frame 22 and the groove parts 34 that come into fitting on the bulged linear parts 33 are formed on the outer peripheral surface of the stator core 23. It is possible to readily attain whirl stopping of the frame 22 and the stator core 23 by fitting of the bulged linear parts 33 into the groove parts 34. As a result, since the pin is no longer needed and the drilled hole machining and the pin press-fitting process are no longer needed, it is possible to improve the productivity of the rotating electric machine 1.
In addition, by arranging these bulged linear parts 33 and groove parts 34 at the positions corresponding to the assembling bolt holes 31 and the recessed parts 32, it becomes possible to assure the thickness of the frame 22 in the assembling bolt holes 31 and the recessed parts 32 owing to fitting of the bulged linear parts 33 into the groove parts 34, even in a case where the outer diameter of the stator core 23 is made large to such an extent that it interferes with the assembling bolt holes 31 and the recessed parts 32. As a result, since it become possible to make the outer diameter of the stator core 23 larger relative to the frame 22, it is possible to increase the rigidity of the rotating electric machine 1.
In addition, in the present embodiment, in particular, it is possible to arrange the bulged linear parts 33 and the groove parts 34 at the positions corresponding to the assembling bolt holes 31 and the recessed parts 32, by forming the bulged linear parts 33 and the groove parts 34 in the rotation direction respectively on the inner peripheral surface of the frame 22 and the outer peripheral surface of the stator core 23 at intervals of 180 degrees or at intervals of 90 degrees.
In addition, in the present embodiment, in particular, since the bulged linear parts 33 and the groove parts 34 are formed at the positions corresponding to the recessed parts 32, it is possible to assure the thickness of the frame 22 in the recessed parts 32 owing to fitting of the bulged linear parts 33 into the groove parts 34 even in a case where the outer diameter of the stator core 23 is made large to such an extent that it interferes with the recessed parts 32. Therefore, since it becomes possible to make the outer diameter of the stator core 23 larger relative to the frame 22, it is possible to increase the rigidity of the rotating electric machine 1.
In addition, in the present embodiment, in particular, since the bulged linear parts 33 and the groove parts 34 are formed at the positions corresponding to the assembling bolt holes 31, it is possible to assure the thickness of the frame 22 in the assembling bolt holes 31 owing to fitting of the bulged linear parts 33 into the groove parts 34 even in a case where the outer diameter of the stator core 23 is made large to such an extent that it interferes with the assembling bolt holes 31. Therefore, since it becomes possible to make the outer diameter of the stator core 23 larger relative to the frame 22, it is possible to increase the rigidity of the rotating electric machine 1.
In addition, in the present embodiment, in particular, it is possible to reduce the influence on the magnetic flux and to suppress a reduction in motor characteristic, by forming the groove parts 34 in the stator core 23 at the positions corresponding to the teeth parts 5a on the outer peripheral surface of the yoke part 6.
In addition, in the present embodiment, in particular, it becomes possible to arrange the bulged linear parts 33 and the groove parts 34 to be formed at the positions corresponding to the teeth parts 5a at intervals of 180 degrees, by setting the number of slots to a multiple of 6 (=3×2), and it becomes possible to arrange the bulged linear parts 33 and the groove parts 34 at intervals of 90 degrees, by setting the number of slots to a multiple of 12 (=3×4). As a result, it becomes possible to arrange the bulged linear parts 33 and the groove parts 34 at the positions corresponding to the assembling bolt holes 31 and the recessed parts 32.
In addition, although the stator core configured to divide the cylindrical yoke from the teeth that are disposed to project toward the inner periphery side of the yoke concerned and the tip ends of which are coupled has been illustrated, the present disclosure is not limited to this and even the stator core of a configuration that the yoke and the teeth are coupled together and the yoke is divided in the circumferential direction may be used.
Although, in the foregoing, the case where the rotating electric machine is the motor has been described by way of example, the present embodiment is also applicable to a case where the rotating electric machine is a generator.
In addition, the techniques brought about by the above-mentioned embodiment and respective modified examples may be utilized by appropriately combining them in addition to the already described configurations.
Besides, though not illustrated one by one, the present embodiment is to be implemented by being modified in a variety of ways within a range not deviating from the gist thereof.
This is a continuation application PCT/JP2012/069839, filed Aug. 3, 2012, which was published under PCT article 21(2) in English.
Number | Date | Country | |
---|---|---|---|
Parent | PCT/JP2012/069839 | Aug 2012 | US |
Child | 14609431 | US |