JP5818949B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine that can be suitably used as, for example, an electric motor or a generator.

  As a conventional rotating electric machine, a shaft disposed along an axis, a yoke fixed to the outer peripheral side of the shaft, a permanent magnet disposed on the yoke, and an axial end of the permanent magnet An end face plate that is arranged adjacently and restricts movement of the permanent magnet in the axial direction, and an annular inner peripheral face that is press-fitted into the cylindrical outer peripheral face of the shaft to fix the end face plate. A fixing member is provided, and the fixing member is substantially the same as the linear expansion coefficient of the shaft, and the end face plate includes a rotor formed of a nonmagnetic material having a larger linear expansion coefficient than the shaft. There is an electric motor (see, for example, Patent Document 1).

Japanese Patent No. 4837288 (pages 2 and 3, FIGS. 1 and 2)

  In the prior art as described above, the end plate that restricts the movement of the permanent magnet in the axial direction uses a stainless steel such as SUS304 or SUS305, or a non-magnetic material such as aluminum, so that the material cost is high. Furthermore, these non-magnetic materials have a problem that they are difficult to process as compared with steel plates such as SPCC, which is a magnetic material.

  The present invention has been made to solve the above-described problems, and an object thereof is to obtain a rotating electrical machine that can be easily processed and can be manufactured at low cost.

A rotating electrical machine according to the present invention includes a rotor core mounted on a shaft, a permanent magnet embedded in the rotor core and having an axial end portion exposed at an axial end surface portion of the rotor core, and an axial end surface of the rotor core A rotary electric machine having a rotor provided with an end plate disposed in a portion for restricting movement of the permanent magnet in the axial direction and a fixing member for fixing the end plate to the shaft, the axial direction of the rotor core At least one of the pair of end plates provided on both end surface portions of the base plate is from a bridge distance L in which the thickness T of the portion facing the permanent magnet is the shortest distance between the outer peripheral surface of the rotor core and the permanent magnet. In addition, the thickness of the fixing member corresponding to the end plate made of the magnetic material is greater than the thickness T of the end plate made of the magnetic material. Oite, said end plate and consists of mutually independent parts and the fixing member, the fixing member is made of the same material as the shaft, an end plate made of the magnetic body, the permanent magnet facing portion Irregularities are provided so as to form a space for reducing leakage of magnetic flux by the end plate .

In the present invention, at least one of the end plates is made of a magnetic material, and the thickness T of the portion of the end plate facing the permanent magnet is made thinner than the bridge distance L so that the thickness of the fixing member near the shaft. Is formed thicker than the thickness T of the end plate, so that both the fixing member and the end plate can be made in a simple shape, so that the manufacture is easy and the end plate is formed of a non-magnetic material. In addition, a space that reduces the leakage of magnetic flux by the end plate is formed by unevenness in the portion of the end plate that is made of a magnetic material facing the permanent magnet. Since the leakage can be reduced, the influence on the motor efficiency can be further reduced.

Sectional drawing which shows the motor as a rotary electric machine which concerns on Embodiment 1 of this invention. It is a figure which shows the rotor shown by FIG. 1 schematically, (a) is the figure seen from the front side, (b) is sectional drawing seen from the side surface side. FIG. 3 is a cross-sectional view taken along line AA in FIG. Sectional drawing which shows schematically the rotor of the rotary electric machine which concerns on Embodiment 2 of this invention. The arrow directional cross-sectional view in the BB line of FIG. It is a figure which shows schematically the rotor of the rotary electric machine which concerns on Embodiment 3 of this invention, (a) is the figure seen from the front side, (b) is sectional drawing seen from the side surface side. Sectional drawing seen from the side surface which shows roughly the rotor of the rotary electric machine which concerns on Embodiment 4 of this invention.

Embodiment 1 FIG.
FIG. 1 is a cross-sectional view showing a motor as a rotating electrical machine according to Embodiment 1 of the present invention. 2A and 2B are diagrams schematically showing the rotor shown in FIG. 1, where FIG. 2A is a view seen from the front side, and FIG. 2B is a cross-sectional view seen from the side side. FIG. 3 is a cross-sectional view taken along line AA in FIG. In the figure, a motor as a rotating electrical machine has a shaft 1 formed of a rotating shaft and a plurality of permanent magnets 2 (shown in FIG. 3) extending in the direction of the axis O embedded in a zigzag shape in the circumferential direction in this example. A rotor core 3 that is laminated and press-fitted and fixed to the outer periphery of the shaft 1, and a donut disk shape that is disposed at the end of the rotor core 3 in the axial direction (left-right direction in FIG. 1) and prevents the permanent magnet 2 from moving and scattering. The end plate 4 and the rotor 6 including a ring-shaped fixing member 5 that fixes the end plate 4 between the rotor core 3 in the axial direction and the rotor 6 are disposed so as to surround the rotor 6. 7, a frame 9 that holds the stator 8, a bracket 11 that is fixed to the frame 9 and supports the rotor 6 via a bearing 10, and the like.

  The permanent magnet 2 is fixed to the rotor core 3 using an adhesive (not shown). The end plate 4 is made of, for example, a magnetic material using a steel plate such as SPCC defined in JIS, and is thin in order to minimize leakage of magnetic flux. Specifically, the thickness T is the outer circumference of the rotor core 3. It is about 0.3 mm thinner than the bridge distance L (shown in FIG. 3) which is the shortest distance between the surface and the permanent magnet 2. The fixing member 5 is a magnetic body, and the outer diameter R is smaller than the minimum inner diameter of the portion where the permanent magnet 2 is disposed, and the plate thickness is larger than the thickness T of the end plate 4. It is fixed by press-fitting against. Note that the linear expansion coefficients of the fixing member 5 and the shaft 1 are substantially equal, and the fixing member 5 is maintained in a fixed state with respect to the shaft 1 within a range from a low temperature to a high temperature set as a design use temperature limit. Since other configurations are the same as those of the conventional one, description thereof is omitted.

  In the first embodiment configured as described above, a non-magnetic material such as stainless steel such as SUS304 or SUS305 or aluminum is not used, so that the material cost to be used can be reduced. Moreover, since both the fixing member 5 and the end plate 4 have simple shapes, they can be easily manufactured by pressing or the like, so that the work required for processing the fixing member 5 and the end plate 4 is simple, and the constituent members are inexpensive. Can be. Further, since the end plate 4 can be fixed to the rotor 6 simply by press-fitting the fixing member 5 to the shaft 1, the assembling work is easy and the product can be made inexpensive.

  The fixing member 5 made of a magnetic material having a thickness greater than the thickness T of the end plate 4 is present only on the inner diameter side of the portion where the permanent magnet 2 is disposed. Leakage can be minimized. In addition, since the member that restricts the movement of the permanent magnet 2 is divided into two parts, that is, an end plate 4 and a fixing member 5 that fixes the end plate 4, the shape of each member becomes simple and processing is possible. It is easy and leads to cost reduction. For example, the end plate 4 made of a thin ring disk can be processed by pressing, and the ring-shaped fixing member 5 can be easily manufactured by sheet metal pressing or steel pipe cutting.

Embodiment 2. FIG.
4 is a cross-sectional view schematically showing a rotor of a rotating electrical machine according to Embodiment 2 of the present invention, and FIG. 5 is a cross-sectional view taken along line BB in FIG. In the figure, the fixing member 5A has a portion corresponding to the permanent magnet 2 (see FIG. 3) whose outer diameter is the same as or slightly smaller than the outer diameter of the rotor core 3 and is exposed at the end face of the rotor core 3. A plurality of window holes 5 a penetrating in the axial direction and having a shape corresponding to the shape of the permanent magnet 2 are formed. As shown in FIG. 5, the end plate 4 is visible from the window hole 5a. Since other configurations including the material and thickness of the fixing member 5A and the material and thickness of the end plate 4 are the same as those in the first embodiment, description thereof will be omitted.

  In the second embodiment configured as described above, the thick fixing member 5A is only provided on the outer side in the axial direction of the permanent magnet 2 exposed at the end surface portion of the rotor core 3, and the thin fixing plate 5A. Is provided with a window hole 5a formed so as to follow the shape of the end face of the permanent magnet 2, so that the leakage of magnetic flux by the fixing member 5A hardly occurs and the characteristics of the rotor may be impaired as in the first embodiment. Minor. In the second embodiment, the outer diameter of the fixing member 5A is formed larger than that in the first embodiment, and the thick fixing member 5A exists on the outer peripheral side, so that the balance of the rotor 6 can be easily corrected. That is, it is possible to obtain a further effect that balance correction can be performed on the outer peripheral side of the magnet arrangement portion that is a portion close to the outer periphery. Furthermore, when the rotor core 3 is press-fitted into the shaft 1, the laminated portion of the rotor core 3 may be warped. However, since the fixing member 5 exists up to the outer peripheral portion, the effect of preventing the warpage of the rotor core 3 together with the end plate 4. Can be expected.

Embodiment 3 FIG.
6A and 6B are diagrams schematically showing a rotor of a rotary electric machine according to Embodiment 3 of the present invention, in which FIG. 6A is a view seen from the front side, and FIG. In the figure, end plate 4A made of the same material and thickness as in the first and second embodiments follows the shape of permanent magnet 2 so that a space is formed in the portion facing permanent magnet 2. Concavities and convexities formed of a plurality of concave portions 4a are formed as viewed from the motor front side or front side (left side in FIG. 6B). The recess 4a is formed only in a portion where the end plate 4A faces the permanent magnet 2, and is not formed in a portion facing or abutting the rotor core 3. The recess 4a can be easily formed by pressing. Note that the end plates 4 </ b> A on which the concave and convex portions formed by the concave portions 4 a are formed are disposed at both axial end portions of the rotor core 3. Since other configurations are the same as those of the first embodiment, description thereof is omitted.

In the third embodiment configured as described above, since the space formed by the concave portion 4a is provided in the contact portion of the end plate 4A made of a magnetic material with the permanent magnet 2, the case is more than in the case of the first embodiment. Since the leakage of magnetic flux can be reduced, the influence on the motor efficiency can be further reduced. Moreover, all members can be manufactured at a lower cost than manufacturing with a non-magnetic material.
In addition, about the function which regulates the movement to the axial direction of the permanent magnet 2 which is the original purpose of the end plate 4A, the size of the recessed part 4a is made smaller than the size of the end surface of the permanent magnet 2, for example. 2 and the end plate 4A can be easily secured by forming them so as to partially abut. For example, the concave portion 4a may be formed in a wave shape in the circumferential direction, or may be formed in a concentric limb shape with the axis O as the center.

Embodiment 4 FIG.
FIG. 7 is a cross-sectional view schematically showing a rotor of a rotating electrical machine according to Embodiment 4 of the present invention as seen from the side. In the figure, a flange 1a formed integrally with the shaft 1 is provided on the motor front side of the shaft 1A. The flange 1 a is configured to have the function of the fixing member 5, the axial position of the flange 1 a is the same as the fixing position of the fixing member 5, and the outer diameter of the flange 1 a is the same as the outer diameter of the fixing member 5. Is formed. The front end plate 4F is sandwiched and fixed between the flange 1a of the shaft 1 and the end surface of the rotor core 3. The end plate 4F is made of a nonmagnetic material and prevents leakage of magnetic flux. On the other hand, the end plate 4R on the rear side (right side in FIG. 7) is formed of a thin magnetic body having a plate thickness of about 0.3 mm in order to minimize leakage of magnetic flux, as in the first embodiment. Other configurations are the same as those of the first embodiment.

  In the fourth embodiment configured as described above, since the flange 1a provided on the shaft 1 has a function of a fixing member for fixing the end plate 4F, the fixing member 5 is one on the rear side. The number of parts can be reduced, leading to cost reduction. Further, since one end plate 4F of the pair of end plates is made of a non-magnetic material, the other end plate 4R is made of a magnetic material. Since leakage can be reduced, an effect that the reduction in motor performance is small compared to the case where both are end plates made of a magnetic material can be obtained.

  It should be noted that within the scope of the present invention, a part or all of each embodiment can be freely combined, or each embodiment can be appropriately modified or omitted. For example, the arrangement method and number of permanent magnets 2, the bridge distance L, the dimension (thickness T) of the end plate 4, etc. are not limited to the embodiment. Moreover, although both comprised the end plate 4 (4A, 4R) and the fixing member 5 (5A) which consist of magnetic bodies with two components, you may comprise in the form which united both as one component. Moreover, although it comprised as an electric motor in embodiment, it cannot be overemphasized that it can use similarly as a generator or a generator motor.

  1, 1A shaft, 1a rod, 2 permanent magnet, 3 rotor core, 4, 4A, 4R end plate (magnetic body), 4F end plate (non-magnetic body), 4a recess, 5, 5A fixing member, 5a window hole, 6 Rotor, 7 coils, 8 stator, 9 frame, 10 bearing, 11 bracket, L bridge distance, T thickness, O axis.

Claims (4)

A rotor core mounted on a shaft; a permanent magnet embedded in the rotor core and having an axial end portion exposed at an axial end surface portion of the rotor core; and the permanent magnet disposed on an axial end surface portion of the rotor core A rotary electric machine having a rotor including an end plate that restricts movement of the end plate in the axial direction and a fixing member that fixes the end plate to the shaft, and is provided at a pair of end surfaces in the axial direction of the rotor core. At least one of the end plates is made of a magnetic material having a thickness T of a portion facing the permanent magnet that is thinner than a bridge distance L that is the shortest distance between the outer peripheral surface of the rotor core and the permanent magnet. The fixing plate corresponding to the end plate made of the magnetic body is formed with a thickness in the vicinity of the shaft larger than the thickness T of the end plate made of the magnetic body. Consists mutually independent parts and members, the fixing member is made of the same material as the shaft, an end plate made of the magnetic body, reduce the leakage of magnetic flux due to the end plate to the permanent magnet facing portion A rotating electric machine characterized by being provided with irregularities so as to form a space to be formed.   One of the pair of end plates provided at both axial end surfaces of the rotor core has a thickness T of a portion facing the permanent magnet that is the shortest distance between the outer peripheral surface of the rotor core and the permanent magnet. 2. The rotating electrical machine according to claim 1, wherein the rotating electrical machine is configured by the magnetic material that is thinner than the bridge distance L, and the other end plate is configured by a non-magnetic material.   The thickness of the fixing member in the vicinity of the shaft corresponding to the end plate made of the magnetic material is continuous from the portion in contact with the shaft to the outer side in the radial direction and before the portion facing the permanent magnet. The rotating electrical machine according to claim 1 or 2, characterized in that   2. A flange projecting in a radial direction is provided on one side or the other side of the mounting portion of the rotor core in the outer peripheral portion of the shaft, and the collar is one of the fixing members. The rotating electrical machine according to claim 3.

Images