Rotor structure

Abstract

To provide a rotor structure.SOLUTION: A rotor structure includes a core sheet, two ring covers, and a hollow shaft. The core sheet has a plurality of reduction holes that are arranged at equal angular intervals in a horizontal side surface. Each of the ring covers has a horizontal inner surface that is in contact with the horizontal side surface on the outermost side of the core sheet, and the horizontal side surface of the ring cover has guide chunks corresponding to the reduction holes. A guide groove is formed in an end surface of each guide chunk. An oil path inlet of the ring cover is located in an inner ring surface of the ring cover, and an oil path outlet is located on an outer ring surface of the ring cover. The core sheet and the two ring covers are covered with the hollow shaft, and the oil path inlets of the ring covers are fluidly connected to oil supply holes of the hollow shaft. The guide chunks reduce a flow speed which is split to the oil path due to a centrifugal force such that the supply oil amount and the discharge oil amount are maintained to be equal to each other.SELECTED DRAWING: Figure 6

Description

Technical Field

[0001] The present invention relates to a rotor structure, and more particularly to a rotor structure having a flow path structure capable of improving the temperature distribution on both side surfaces.

Background Art

[0002] When the rotor of a motor rotates at high speed, high temperature is generated, so it was necessary to install a cooling oil passage inside to assist heat dissipation. By installing a rotor oil passage, coolant is injected from the hollow axis of the rotor. A plurality of through holes are formed in the rotor core, and an axial cooling oil passage is formed in the through hole itself, or an axial cooling oil passage is formed by inserting an oil pipe into the through hole. The oil supply hole of the cooling oil passage is fluidly connected to the hollow axis, and the oil drain hole of the cooling oil passage is located in the outermost core (or end caps on both sides). The internal oil passage of the core can be installed at any position of the core. For example, the cooling oil passage may be adjacent to the periphery of the permanent magnet inside the core, or the coolant may be flowed so as to directly contact the permanent magnet.

Summary of the Invention

Problems to be Solved by the Invention

[0003] Due to the centrifugal force of the rotor, the coolant is introduced radially from the axial center into the core, and then radially led out from both sides of the core to the oil drain holes. However, if there are tolerances in the combination of cores, or if tolerances occur after combination due to differences in the materials of the cores and the end caps on both sides, gaps will occur on the adhering surfaces between the cores or between the core and the end cap. Due to the action of inertia during rotation, the fluid led out from the hollow axial center to the core is separated along the tangential direction and flows out from the gaps between the adhering surfaces, making it impossible to surely enter the inside of the rotor. This means that the amounts of oil contained in the plurality of axial flow paths are all different within the same time. Also, if the coolant does not completely enter the oil path, the internal oil amount distribution will become non-uniform, differences will occur in the flow velocities of different flow paths inside the rotor, affecting the heat exchange rate, and particularly affecting the temperature distribution at the positions of the end caps on both sides.

[0004] Therefore, as a result of intensive studies by the inventors, it has been found that the above object can be achieved by adopting the following configuration, and the present invention has been completed.

[0005] The present invention has been made by the intensive research of the inventors in view of the above problems, and its object is to provide a rotor structure.

Means for Solving the Problems

[0006] In order to solve the above problems, a rotor structure according to an aspect of the present invention includes at least one core sheet, two ring covers, and a hollow shaft. At least one core sheet has a horizontal side surface and a plurality of through holes. The plurality of through holes are mainly composed of a plurality of relief holes and a plurality of magnet mounting holes. The contours of the relief holes are the same and are arranged equiangularly at equal distances from the center of the circle. The ring cover has a horizontal inner surface that contacts the outermost horizontal side surface of the core sheet, and the horizontal inner surface has a plurality of guides With protrusions having, the guide With protrusionsA part of the guide groove is formed on each end face thereof. Flow path inlets located on the inner ring surface of the ring cover are formed in other parts of some of the guide grooves, and flow path outlets located on the outer ring surface of the ring cover are formed in other parts of some other guide grooves. The flow path inlets and the flow path outlets are provided so as to be staggered along the circumferential direction. The core sheet and the two ring covers are covered outside the hollow shaft, and the flow path inlet of the ring cover is fluidly connected to the oil supply hole of the hollow shaft. Guide With protrusions enters the inside of the relief hole with respect to the horizontal inner surface.

[0007] Guide With protrusions prevents the coolant from leaking from the adhered surface, decelerates the flow rate of the coolant entering the flow path of the core sheet from the ring covers on both sides, increases the residence time of the coolant at the axis, and enables sufficient heat exchange with the axis.

[0008] Preferably, an oil pipe having a plurality of oil holes distributed along the axial direction is installed inside the hollow shaft, and the coolant inside the hollow shaft has directivity and its flow rate is limited.

[0009] Preferably, Guide With protrusions has a rounded corner at the boundary between the side surface and the end face. When the coolant is guided from the core to the ring cover, it flows easily and smoothly along the boundary.

[0010] Preferably, Guide With protrusions further has the function of guiding the leaked coolant to the axial cooling flow path by having a space between the outer contour of Guide With protrusions and the contour of the relief hole, and stabilizes the internal oil quantity.

[0011] Preferably, radial guide grooves recessed with respect to the horizontal inner surface are formed in other parts of the guide groove and are used to maintain a stable flow rate.

[0012] Preferably, the radial guide groove and Guide With protrusionsThe boundary with the guide groove formed therein is an arc-shaped guide groove, which further decelerates the flow velocity of the coolant flowing into / out of the radial guide groove from the radial direction.

[0013] Preferably, a part of the side surface of the guide With protrusions is directed towards the hollow shaft, and the partial side surface has an arc surface extending in the circumferential direction, minimizing the coolant dispersed outside the flow path.

[0014] Preferably, the number of core sheets is plural and they are offset along the circumferential direction.

Brief Description of the Drawings

[0015]

Figure 1

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

Modes for Carrying Out the Invention

[0016] Hereinafter, the present invention will be described through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims. Also, not all combinations of features described in the embodiments are essential for the solution means of the invention.

[0017] First, with reference to FIGS. 1 to 7, an embodiment of the rotor structure according to the present invention will be described.

[0018] The rotor structure includes a rotor core 20, ring covers 40A and 40B, and a hollow shaft 50. The rotor core 20 includes at least one core sheet 21. The hollow shaft 50 has an outwardly expanding base 55 and an outer ring surface 56 located on the side surface.

[0019] The ring cover 40A, the rotor core 20, and the ring cover 40B are sequentially covered on the outer ring surface 56 of the hollow shaft 50, and the inner ring surface of the ring cover 40A is restricted inside the base 55. The outer ring surface 56 conforms to the structure of the inner ring surface of the core sheet 21, and the core sheet 21 rotates synchronously with the hollow shaft 50. The above-mentioned structural conformity means that, for example, the inner ring surface for positioning the core sheet 21 has bumps 215 fitted into the axial grooves 561 of the outer ring surface 56 and is also used for assisting in positioning. The end lock member 10 is locked from the other side surface of the hollow shaft 50, sandwiches the ring cover 40B, and forms a cooling oil passage inside the rotor.

[0020] The core sheets 21 are located on both sides and are horizontal, and have core side surfaces 211 and 212 that are parallel to each other and a plurality of through holes penetrating the core side surfaces 211 and 212. The through holes include a plurality of relief holes 23 and a plurality of magnet mounting holes 24. The contours of each of the relief holes 23 are the same and are arranged equiangularly at an equal distance from the center of the circle. In addition to reducing the weight of the rotor, the relief holes 23 are also used to define an axial flow passage inside the core. The plurality of magnet mounting holes 24 are spaced from the center of the circle with respect to the relief holes 23 and are used to accommodate the permanent magnets 30.

[0021] A relief hole (a hollow channel is formed) and a flow path hole (a flow path is formed) are separately formed inside the core. In this embodiment, the relief hole is directly adopted to form the flow path, and the size of the flow path and the oil storage amount of the relief hole are increased. At the same injection speed of the coolant, the flow rate of the coolant is decelerated so that sufficient heat exchange can be performed inside the core. In a preferred embodiment, the relief hole 23 is made as close as possible to the magnet mounting hole 24 so that the coolant can take away the high temperature of the permanent magnet 30.

[0022] Compared with the prior art, a flow path hole communicating with the magnet mounting hole is opened around the magnet mounting hole, and the coolant directly contacts the permanent magnet to achieve a cooling effect. However, if the flow resistance of the coolant becomes too large due to the size of the flow path hole, the coolant will be directly introduced into the flow path hole with a small size or it will be difficult to be led out at the junction of the radial flow path and the axial flow path due to the centrifugal force of rotation. The flow rates of all the cooling oil paths become non-uniform, affecting the temperature distribution of the entire rotor. In the prior art, since there are gaps on the adhering surfaces of adjacent members, actually less coolant enters the cooling oil path. When the rotor stops, the coolant will no longer flow out from the oil drain holes on both sides of the core, and the coolant accumulates inside, and the accumulated coolant enters the oil supply hole of the core. Therefore, when the coolant is not continuous during operation, the heat exchange effect is clearly limited.

[0023] In this embodiment, the structures of the ring covers 40A and 40B are the same. Taking the ring cover 40A as an example, it has a horizontal inner surface 401 and an outer surface 402. The inner surface 401 contacts the core side surface 212 which is the outermost of the rotor core 20, and the outer surface 402 is spaced apart from the rotor core 20 and is directed outward. On the horizontal inner surface 401 of the ring cover 40A, there are a plurality of guides With protrusions 41 which correspond one by one to the quantity and position of the plurality of relief holes 23. When the assembly of the rotor is completed, the guide With protrusions 41 enters into the relief hole 23 with respect to the horizontal inner surface 401. That is, the guide With protrusions41 is located within the inner ring wall 231 formed inside the core sheet 21 of the relief hole 23, and rotates the ring cover 40A and the core sheet 21 (hollow shaft 50) synchronously.

[0024] Guide With protrusions Each of the 41 has a side surface 411 and an end surface 412, and several guides With protrusions A part of the oil supply guide groove 451 is formed in the 41, and several other guides With protrusions A part of the oil discharge guide groove 452 is formed in the 41. The oil supply guide groove 451 is recessed inward along the end surface 412 and the side surface 411 of the guide With protrusions 41 to form a bent flow path. The guide With protrusions 41 extends toward the axis along the side surface 411, and a straight radial guide groove 461 is formed to be recessed in the inner side surface 401 of the ring cover 40A. Next, a flow path inlet 45A is formed in the inner ring surface 403 of the ring cover 40A. The oil discharge guide groove 452 is recessed inward along the end surface 412 and the side surface 411 of the guide With protrusions 41 to form a bent flow path. The guide With protrusions 41 extends outward along the side surface 411, and a straight radial guide groove 462 is formed to be recessed in the inner side surface 401 of the ring cover 40A. Next, a flow path outlet 45B is formed in the outer ring surface 404 of the ring cover 40A.

[0025] Specifically, the direction of the cooling oil path according to this embodiment is that the rotor cooling oil path is injected from the axis of the hollow shaft 50 and flows into the flow path inlet 45A of the ring cover 40A (40B) from the oil supply holes 511 and 512 on both sides of the hollow shaft 50. Next, it enters the inside of the rotor core 20 and is led out to the outside of the rotor from the flow path outlet 45B of the other ring cover 40B (40A).

[0026] As shown in FIGS. 6 and 7, taking the ring cover 40A as an example in the same way, the side surface 411 of the ring cover 40A contacts the core side surface 212 that is the outermost, the fuel supply guide groove 451, the oil discharge guide groove 452, and the radial guide grooves 461 and 462 are closed, and the flow path inlet 45A of the remaining inner ring surface 403 is joined to the fuel supply hole 511 (see FIG. 3), and the flow path outlet 45B of the outer side surface 402 is directed outward. The flow path inlet 45A and the flow path outlet 45B of the ring cover 40A are installed so as to intersect along the circumferential direction, the flow path inlet 45A of the ring cover 40A and the flow path outlet 45B of the ring cover 40B are fluidly connected to the cooling oil path in the same axial direction, and the flow path inlet 45A of the ring cover 40B and the flow path outlet 45B of the ring cover 40A are fluidly connected to the cooling oil path in the same axial direction. The flow path inlet 45A of the ring cover 40A is aligned with the fuel supply hole 511, the flow path inlet 45A of the ring cover 40B is aligned with the fuel supply hole 512 (see FIG. 3), the flow directions of the adjacent flow paths winding around the rotor core 20 intersect along the circumferential direction, and the temperature distribution of all the rotor cores 20 becomes more uniform.

[0027] guide With protrusions The fuel supply guide groove 451 and the oil discharge guide groove 452 formed on the surface of 41 are guide With protrusions Since 41 protrudes from the horizontal inner surface 401, a plurality of guide With protrusions 41 are arranged at equal angles along the circumference, and guide With protrusions The remaining surface (side surface 411) of 41 prevents the coolant from entering from the horizontal adhering surface (401, 212) between the core sheet 21 and the ring cover 40A, reduces the coolant dispersed outside the flow path, allows the coolant to accumulate only on the horizontal adhering surface in front of the side surface 411, enables the coolant to enter the flow path inlet 45A more easily, and stabilizes the amount of oil inside.

[0028] Also, based on Bernoulli's theorem, velocity and pressure are inversely proportional. When the rotor rotates, when the high-speed liquid collides with the side surface 411 or the fuel supply guide groove 451 of the guide With protrusions 41 of the ring cover 40A, the instantaneous velocity of the liquid decreases, the pressure of the liquid increases, the time for the liquid to stay at the axis also increases, the heat exchange amount between the liquid and the axis sufficiently increases, and the amount of oil inside the flow path stabilizes.

[0029] As shown in FIG. 5, in addition to the above-described structure, in a preferred embodiment, the guide With protrusions 41 and the contour of the relief hole 23 correspond to each other, and the guide With protrusions A part of the side surface 411 of 41 is directed toward the hollow shaft 50. The side surface 411 of the part has arc surfaces 413 distributed in the circumferential direction, which minimizes the coolant that disperses outside the flow path. When the above-described contours correspond to each other, it means that the sizes of the contours of the guide With protrusions 41 and the relief hole 23 are exactly the same, or the shapes of the contours are the same but the sizes are different.

[0030] In addition to the above structure, in other embodiments, in the example of FIG. 2, an oil pipe 53 is installed inside the hollow shaft 50. The oil pipe 53 has a plurality of oil holes 531 distributed along the axial direction. By doing so, the coolant inside the hollow shaft 50 has directivity, the flow rate is restricted, the instantaneous rotational speed generated by the rotation of the rotor is decelerated, and the speed of the fluid to be supplied with oil is modified.

[0031] In addition to the above structure, in other embodiments, the guide With protrusions 41 further has a rounded corner 414 at the boundary between the side surface 411 and the end surface 412. By doing so, when the coolant is guided from the rotor core 20 to the ring cover 40A (40B), it flows more smoothly along the rounded corner 414 at the boundary.

[0032] In addition to the above structure, in other embodiments, the guide With protrusions There is further a gap G between the outer contour formed on the side surface 411 of 41 and the contour of the relief hole 23. The related specific structure is shown in FIGS. 5 and 7. The entering coolant is blocked by the side surface 411 of the guide With protrusions 41 and drawn back into the relief hole 23, the amount of oil inside the flow path is stabilized, the pressures at the flow path outlets 45B on both sides are made consistent, the amount of oil discharged from both sides is improved, and the temperatures on both sides of the rotor become uniform.

[0033] In addition to the above structure, in other embodiments, the radial guide groove 461 and the guide With protrusions 41 is formed with an oil supply guide groove 451 (or the radial guide groove 462 and the guide With protrusions 41 is formed with an oil discharge guide groove 452), and the boundary therebetween further presents an arc guide groove 471 recessed inward, further reducing the flow velocity of the coolant flowing in and out in the radial direction in the radial guide groove 461 (radial guide groove 462), further extending the residence time of the coolant in the relief hole 23, and enabling sufficient heat exchange to be performed.

[0034] In the embodiment shown in FIG. 1, the number of core sheets 21 of the rotor core 20 is plural, and the plural core sheets 21 are laminated and positioned along the axial groove 561 on the outer circumferential surface of the hollow shaft 50, and the corresponding relief holes 23 are deposited along the axial direction, and the relief holes 23 of the core sheets 21 in different layers form a plurality of flow paths that do not intersect inside the rotor. However, the structure according to the above-described embodiment may also be a rotor core 20 composed of one core sheet 21, and the horizontal inner surfaces 401 of the two ring covers 40A and 40B are respectively adhered to the front core side surface 211 and the rear core side surface 212 of the core sheet 21.

[0035] In addition to the above structure, in other embodiments, the core sheets 21 in different layers are offset at equal angles along the circumferential direction, and the relief holes 23 of the core sheets 21 are also offset along the circumferential direction, and inclined flow paths may be formed in the axial cooling oil passage.

[0036] In this embodiment, the radial guide groove 461 of the ring cover 40A and the radial guide groove 462 of the ring cover 40B communicating with the same axial cooling oil passage are not on the same straight line. However, in other embodiments, the radial guide groove 461 of the ring cover 40A (of the oil supply guide groove 451) communicating with the same axial cooling oil passage is aligned with the radial guide groove 462 of the ring cover 40B (of the oil discharge guide groove 452).

[0037] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The scope of the present invention is shown not by the above description but by the claims, and it is intended that all modifications within the meaning and scope equivalent to the claims be included.

Explanation of Signs

[0038] 10 End lock member 20 Rotor core 21 Core sheet 211 Core side surface 212 Core side surface 215 Bump 23 Relief hole 231 Inner ring wall 24 Magnet mounting hole 30 Permanent magnet 40A Ring cover 40B Ring cover 401 Inner side surface 402 Outer side surface 403 Inner ring surface 404 Outer ring surface 41 Guide With protrusions 411 Side surface 412 End surface 413 Arc surface 414 Rounded corner 45A Flow path inlet 45B Flow path outlet 451 Oil supply guide groove 452 Oil discharge guide groove 461 Radial guide groove 462 Radial guide groove 463 Arc guide groove 50 Hollow shaft 511 Oil supply hole 512 Oil supply hole 53 Oil pipe 531 Oil hole 55 Base 56 Outer ring surface 561 Axial groove G Gap

Claims

1. At least one core sheet having a horizontal side surface and a plurality of through holes, wherein these through holes are constituted by a plurality of relief holes and a plurality of magnet mounting holes, the contours of these relief holes are the same, and at least one core sheet arranged equiangularly at equal distances from the center of the circle; Two ring covers, each of the ring covers having a horizontal inner surface that contacts the outermost horizontal side surface of the core sheet, the horizontal inner surface having a plurality of guide chunks that correspond one by one to these relief holes, a part of a guide groove being formed at each end surface of these guide chunks, a flow path inlet located on the inner ring surface of these ring covers being formed in other parts of some of these guide grooves, and a flow path outlet located on the outer ring surface of these ring covers being formed in other parts of some of these guide grooves, the flow path inlet and the flow path outlet being provided so as to intersect along the circumferential direction; two ring covers; A hollow shaft with the core sheet and the two ring covers covered on the outside, the flow path inlet of the ring cover being fluidly connected to the oil supply hole of the hollow shaft; a hollow shaft, comprising: These guide chunks enter the interior of these relief holes with respect to the horizontal inner surface, a rotor structure characterized by this.

2. An oil pipe having a plurality of oil holes distributed along the axial direction is installed inside the hollow shaft, the rotor structure according to claim 1, characterized by this.

3. The boundary between the side surface and the end surface of the guide chunk has a rounded corner, the rotor structure according to claim 1, characterized by this.

4. The outer contour of the guide chunk is spaced from the contour of the relief hole, the rotor structure according to claim 1, characterized by this.

5. In other parts of the guide groove, a radial guide groove recessed with respect to the horizontal inner surface is formed, the rotor structure according to claim 1, characterized by this.

6. The boundary between the radial guide groove and the guide groove formed in the guide chunk is an arc guide groove, the rotor structure according to claim 5, characterized by this.

7. The rotor structure according to claim 1, wherein a part of the side surface of the guide chunk is directed toward the hollow shaft, and the side surface of the part has an arc surface extending in the circumferential direction.

8. The rotor structure according to claim 1, wherein the number of the core sheets is plural, and these core sheets are offset along the circumferential direction.

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