Rotating electric machine and vehicle drive system equipped therewith

Abstract

To cool a stator coil and magnets of a rotor according to the rotating speed of the rotor.SOLUTION: A rotary electric machine comprises a rotor 110 and a stator 140 arranged on an outer-diameter side of the rotor 110. A rotor shaft 111 is provided on an inner peripheral side of the rotor 110, and a shaft flow passage 120 is provided inside the rotor shaft 111. The rotor 110 has: a first flow passage 131a which extends outwards in a radial direction of the rotor shaft 111, and has a first discharge port made open radially outwards; and a second flow passage which extends radially outward after extending outward in a radial direction of the rotor shaft 111 to extend axially inside a rotor core 112, and has a second discharge port made open radially outwards. The first flow passage 131a and the second flow passage are connected to the shaft flow passage 120, and the second discharge port is arranged radially outside the first discharge port.SELECTED DRAWING: Figure 7

Description

Technical Field

[0001] The present invention relates to a rotating electric machine and a vehicle drive device including the same.

Background Art

[0002] As a technique for cooling a rotating electric machine, for example, there are techniques described in Patent Documents 1 to 3. In Patent Document 1, an oil hole is provided in the central portion of a shaft, and a supply hole extending to the outer peripheral side of the shaft penetrates the oil hole. The rotor incorporated in the shaft is provided with a cooling oil passage extending axially therethrough and a receiver that covers an opening of the cooling oil passage at an end of the cooling oil passage. When the rotor rotates, lubricating oil discharged by being opened to the atmosphere from the supply hole is received by the receiver, and the lubricating oil is caused to flow through the cooling oil passage to cool the rotor. Then, the lubricating oil is discharged from the cooling oil passage to cool the coil end of the stator.

[0003] In Patent Document 2, an oil passage penetrating axially is formed in a rotor core. An end plate having an oil supply hole communicating with the oil passage and an oil discharge hole protruding oil to a coil is provided at one end of the rotor core. The cross-sectional area of the oil passage is made larger on the downstream side than on the upstream side of the oil flow. An end plate having an oil discharge hole communicating with an oil passage having an enlarged cross-sectional area is provided at the other end of the rotor core. Then, the coil is cooled by the oil discharged from the oil discharge hole, and the rotor is cooled by the oil flowing through the oil passage.

[0004] Patent Document 3 describes a rotating shaft with a hole that penetrates radially outward and communicates with a shaft flow path. An end plate is provided at the axial end of the rotating core, and a groove is formed in this end plate, forming a refrigerant passage between the wall surface of the end plate and the end surface of the rotating core. This refrigerant passage communicates with the hole in the shaft. A first discharge hole is provided in the middle of the refrigerant passage, and a second discharge hole is provided at the end of the refrigerant passage. The oil that has flowed through the shaft flow path, hole, and refrigerant passage is discharged from the first and second discharge holes to cool the coil end. [Prior art documents] [Patent Documents]

[0005] [Patent Document 1] Japanese Patent Publication No. 2019-68622 [Patent Document 2] Japanese Patent Publication No. 2012-223075 [Patent Document 3] Japanese Patent Publication No. 2011-142788 [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] For example, in a rotating electric machine used for vehicle propulsion, when the rotor speed is low and a large torque is obtained, the current flowing through the stator coil becomes large, causing the stator coil to heat up, and therefore the stator coil needs to be cooled. On the other hand, when the rotor speed is high, eddy current losses increase in the rotor, causing heat, so the rotor on which the magnets are placed needs to be cooled.

[0007] In the technology described in Patent Document 1, the rotor rotates, and the lubricating oil discharged from the supply port by centrifugal force is received by a receiver. The lubricating oil is then flowed into a cooling oil passage to cool the rotor, and then the lubricating oil is discharged from the cooling oil passage to cool the coil end of the stator. However, since the lubricating oil discharged from the supply port is released into the atmosphere, even if the rotor rotation speed increases, it is not possible to increase the flow rate of lubricating oil flowing through the cooling oil passage using centrifugal force. For this reason, the technology described in Patent Document 1 has the problem that the magnets arranged on the rotor cannot be sufficiently cooled in proportion to the increase in the rotor rotation speed.

[0008] In the technology described in Patent Document 2, the cross-sectional area of ​​the oil passage is larger downstream than upstream. As a result, even when the rotor speed increases due to the open-air condition, it is not possible to increase the flow rate of oil through the oil passage by utilizing centrifugal force. Therefore, the technology described in Patent Document 2 has the problem that the magnets placed on the rotor cannot be sufficiently cooled in response to the increase in rotor speed.

[0009] In the technology described in Patent Document 3, since no flow path for the coolant to flow in the axial direction of the rotating core is formed, it was difficult to cool the magnets placed on the rotor.

[0010] The object of the present invention is to provide a rotating electric machine capable of cooling the stator coil and the magnets of the rotor according to the rotational speed of the rotor, and a vehicle drive system equipped therewith. [Means for solving the problem]

[0011] To achieve the above objective, the present invention provides a rotating electric machine comprising a rotor in which magnets are arranged within a rotor core, and a stator arranged on the outer diameter side of the rotor, A rotor shaft is provided on the inner circumference side of the rotor, and a shaft passage through which refrigerant flows is provided inside the rotor shaft, and the rotor is Inside the rotor,A first flow path having a first discharge port that extends radially outward from the rotor shaft and opens radially outward, Inside the rotor, The first and second flow channels extend radially outward from the rotor shaft, extend axially inside the rotor core, and then extend radially outward, and have a second discharge port that opens radially outward, wherein the first and second flow channels are the shaft flow channels. and Furthermore, the second discharge port is characterized by being positioned radially outward from the first discharge port. [Effects of the Invention]

[0012] According to the present invention, it is possible to provide a rotating electric machine capable of cooling the stator coil and the magnets of the rotor according to the rotational speed of the rotor, and a vehicle drive system equipped therewith. [Brief explanation of the drawing]

[0013] [Figure 1] This is a schematic diagram of an electric vehicle according to an embodiment of the present invention. [Figure 2] This is a schematic diagram of a system for cooling a vehicle drive unit according to an embodiment of the present invention. [Figure 3] This is an exploded perspective view of the rotor 110 as seen from the non-load side. [Figure 4] This is an exploded perspective view of the rotor 110 as seen from the load side. [Figure 5A] This is a plan view of the first and third end plates as seen from the side facing the second and fourth end plates. [Figure 5B] This is a plan view of the first and third end plates as seen from the side facing the rotor core. [Figure 6] This is a cross-sectional view of the rotor, cut in a direction perpendicular to the axial direction. [Figure 7] This is a cross-sectional perspective view of a rotor 110 according to Embodiment 1 of the present invention, cut along the axial direction. [Figure 8] This is a cross-sectional view of the upper half of the rotor 110, cut along the axial direction. [Figure 9]It is a diagram showing the relationship between the flow rates of the first flow path and the second flow path according to the change in the rotational speed. [Figure 10] It is a cross-sectional view of the rotor according to Example 2 of the present invention cut in a direction orthogonal to the axial direction. [Figure 11] It is an upper half cross-sectional view of the rotor 110 according to Example 3 of the present invention cut along the axial direction. [Figure 12] It is a cross-sectional perspective view of the rotor 110 according to Example 4 of the present invention cut along the axial direction. [Figure 13] It is a cross-sectional perspective view of the rotor 110 according to Example 5 of the present invention cut along the axial direction. [Figure 14] It is a cross-sectional perspective view of the rotor 110 according to Example 6 of the present invention cut along the axial direction.

Embodiments for Carrying Out the Invention

[0014] Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. The same reference numerals are given to the same components, and the same explanations will not be repeated.

[0015] The various components of the present invention do not necessarily have to exist independently individually. It is allowed that one component consists of a plurality of members, a plurality of components consist of one member, a certain component is a part of another component, or a part of a certain component overlaps with a part of another component, etc.

Examples

[0016] FIG. 1 is a schematic configuration diagram of an electric vehicle according to Example 1 of the present invention. In FIG. 1, a vehicle drive device 3 for driving the wheels 2 is mounted on the vehicle body 1. The vehicle drive device 3 is a drive unit in which devices such as a rotating electric machine and an inverter are integrated.

[0017] An oil cooler 4 is connected to the vehicle drive unit 3 via piping 7. Piping 7 is equipped with a refrigerant pump 8 that pumps the first refrigerant, supplying it to the equipment within the vehicle drive unit 3 to cool it. A chiller 6 is also connected to the oil cooler 4 via piping 5, and the second refrigerant flows through the oil cooler 4, piping 5, and chiller 6. Heat exchange takes place in the oil cooler 4, where the heated first refrigerant is cooled by the second refrigerant. The second refrigerant is pumped by a pump 9 in piping 5 and sent to the chiller 6. In the chiller 6, the heated second refrigerant is cooled by the airflow generated when the vehicle is running. The cooled refrigerant is then sent back to the oil cooler 4.

[0018] Figure 2 is a schematic diagram of a system for cooling a vehicle drive unit according to Embodiment 1 of the present invention.

[0019] In the diagram, as indicated by the arrows, the side on which the vehicle drive unit 3 transmits driving force is defined as the "load side," the opposite side as the "non-load side," the upward direction as the "upper / upper side," and the downward direction as the "lower / downward side." Furthermore, the direction along the shaft is defined as the "axial direction," the circumference of the rotor shaft as the "circumferential direction," the radial direction (dynamic direction) when the shaft is centered as the "radial direction," and the direction perpendicular to the horizontal line as the vertical direction.

[0020] The vehicle drive system 3 includes a rotating electric machine 100, a reduction gear 200 that transmits the driving force of the rotating electric machine 100, and an inverter (not shown).

[0021] The rotating electric machine 100 comprises a rotor 110 and a stator 140 positioned on the outer diameter side of the rotor 110. The rotor 110 and stator 140 are housed within a housing 101.

[0022] The rotor 110 has a rotor shaft 111 that is rotatably supported on its inner circumference by bearings 150, 151, and 152. The load side of the rotor shaft 111 has a drive gear 201 that constitutes the reduction gear 200, a driven gear 202 that meshes with the drive gear 201 and transmits driving force to the drive gear 201, a driven gear shaft 203 attached to the driven gear 202, and bearings 204 and 205 that support the driven gear shaft 203.

[0023] The stator 140 includes a plurality of starter coils 141 that are inserted into slots formed in the stator core.

[0024] The rotor shaft 111 is hollow inside, forming a shaft passage 120 through which the refrigerant flows. The refrigerant flowing through the shaft passage cools the stator coil 141 and rotor 110, and then falls into an oil pan 154 located at the bottom of the rotating electric machine 100. The refrigerant collected in the oil pan 154 is pumped by a refrigerant pump 8 and sent to the oil cooler 4 and the shaft passage 120. After cooling the stator coil 141 and rotor 110, it falls back into the oil pan 154. In this embodiment, the refrigerant is circulated in this way to cool the stator coil 141 and rotor 110.

[0025] Next, the detailed structure for cooling the stator coil 141 and rotor 110 will be described.

[0026] Figure 3 is an exploded perspective view of the rotor 110 as seen from the non-load side. Figure 4 is an exploded perspective view of the rotor 110 as seen from the load side. Figure 5A is a plan view of the first and third end plates as seen from the side facing the second and fourth end plates. Figure 5B is a plan view of the first and third end plates as seen from the side facing the rotor core. Figure 6 is a cross-sectional view of the rotor cut in a direction perpendicular to the axial direction.

[0027] The rotor 110 comprises a rotor core 112 formed by laminating multiple steel plates, a first end plate 113 positioned at one axial end (non-load side) of the rotor core 112, a second end plate 114 positioned on one axially outward side (non-load side) of the first end plate 113, a third end plate 115 positioned at the other axial end (load side) of the rotor core 112, and a fourth end plate 116 positioned on the other axially outward side (load side) of the third end plate 115. The first end plate 113 is positioned so as to be sandwiched between the second end plate 114 and the rotor core 112, and the third end plate 115 is positioned so as to be sandwiched between the fourth end plate 116 and the rotor core 112.

[0028] The outer circumferential surface of the rotor shaft 111 is provided with a first shaft flow path hole 121 that communicates with the shaft flow path 120, a second shaft flow path hole 122 that communicates with the shaft flow path 120 and is located adjacent to the first shaft flow path hole 121, a third shaft flow path hole 123 that communicates with the shaft flow path 120, and a fourth shaft flow path hole 124 that communicates with the shaft flow path 120 and is located adjacent to the third shaft flow path hole 123.

[0029] The first shaft flow path hole 121 and the second shaft flow path hole 122 are located at the same position in the circumferential direction of the rotor shaft 111, and the third shaft flow path hole 123 and the fourth shaft flow path hole 124 are located at the same position in the circumferential direction of the rotor shaft 111. The first shaft flow path hole 121 (second shaft flow path hole 122) and the third shaft flow path hole 123 (fourth shaft flow path hole 124) are offset from each other in the circumferential direction of the rotor shaft 111. In addition, there are multiple first to fourth shaft flow path holes 121 to 124 located in the circumferential direction of the rotor shaft 111.

[0030] An insertion hole 113a is formed in the center of the first end plate 113, which penetrates axially through which the rotor shaft 111 is inserted.

[0031] Multiple first grooves 131 are formed on the outer surface (second end plate 114 side) of the first end plate 113, extending radially outward from the insertion hole 113a.

[0032] Multiple second grooves 132 are formed on the inner surface (rotor core 112 side) of the first end plate 113, extending radially outward from the insertion hole 113a.

[0033] Furthermore, the first end plate 113 has a plurality of protrusions 113b that project radially outward. On the inner surface (rotor core 112 side) of the first end plate 113, a plurality of sixth grooves 136 are formed that extend radially outward.

[0034] The first end plate 113 is positioned to overlap with the first shaft flow path hole 121 and the second shaft flow path hole 122 formed in the rotor shaft 111. The first groove 131 communicates with the first shaft flow path hole 121, and the second groove 132 communicates with the second shaft flow path hole 122.

[0035] When the first end plate 113 comes into contact with the second end plate 114, the first groove 131 is covered, and a first flow path 131a through which the refrigerant flows is formed. That is, the first groove 131 is formed by being sandwiched between the first end plate 113 and the second end plate 114. The first flow path 131a is formed to penetrate radially from the insertion hole 113a to the radially outward side.

[0036] When the first end plate 113 comes into contact with the rotor core 112, the second groove 132 is covered, forming a non-load side second flow path 132a (second flow path) through which the refrigerant flows. Also, when the first end plate 113 comes into contact with the rotor core 112, the sixth groove 136 is covered, forming a non-load side fourth flow path 136a (fourth flow path) through which the refrigerant flows. In other words, the non-load side second flow path 132a, which is part of the second flow path, and the non-load side fourth flow path 136a, which is part of the fourth flow path, are formed by being sandwiched between the first end plate 113 and the rotor core 112.

[0037] The second channel 132a (second channel) on the non-load side has an inner radial end that penetrates the insertion hole 113a, but its outer radial end is blocked by a damming section 132s (Figure 5B). The outer radial end 132e of the second channel 132a (second channel) on the non-load side is connected to the rotor core channel 130. The fourth channel 136a (fourth channel) on the non-load side has an outer radial end that penetrates, but its inner radial end is blocked. The inner radial end 136e of the fourth channel 136a (fourth channel) on the non-load side is connected to the rotor core channel 130.

[0038] The second end plate 114 has an insertion hole 114a into which the rotor shaft 111 is inserted, a notch 114b which becomes the first discharge port of the first flow path 131a, and a protruding portion 113b which fits into it, as well as a fitting notch 114c which becomes the fourth discharge port.

[0039] In this embodiment, by combining the first end plate 113, the second end plate 114, and the rotor core 112, a first flow path 131a, a second flow path 132a (second flow path) on the non-load side, and a fourth flow path 136a (fourth flow path) on the non-load side are formed. By combining these with the rotor shaft 111, the first flow path 131a and the first shaft flow path hole 121 are connected, and the second flow path 132a (second flow path) on the non-load side and the second shaft flow path hole 122 are connected.

[0040] An insertion hole 115a is formed in the center of the third end plate 115, which penetrates axially through which the rotor shaft 111 is inserted.

[0041] Multiple third grooves 133 are formed on the outer surface (towards the fourth end plate 116) of the third end plate 115, extending radially outward from the insertion hole 115a.

[0042] Multiple fourth grooves 134 are formed on the inner surface (rotor core 112 side) of the third end plate 115, extending radially outward from the insertion hole 115a.

[0043] Furthermore, the third end plate 115 has a plurality of protrusions 115b that project radially outward. On the inner surface (rotor core 112 side) of the third end plate 115, the protrusions 115b have a plurality of fifth grooves 135 that extend radially outward.

[0044] The third end plate 115 is positioned to overlap with the third shaft flow hole 123 and the fourth shaft flow hole 124 formed in the rotor shaft 111. The third groove 133 communicates with the third shaft flow hole 123, and the fourth groove 134 communicates with the fourth shaft flow hole 124.

[0045] When the third end plate 115 comes into contact with the fourth end plate 116, the third groove 133 is covered, and a third flow path 133a through which the refrigerant flows is formed. That is, the third groove 133 is formed by being sandwiched between the third end plate 115 and the fourth end plate 116. The third flow path 133a is formed to penetrate radially from the insertion hole 113a to the radially outward side.

[0046] When the third end plate 115 comes into contact with the rotor core 112, the fourth groove 134 is covered, forming a load-side fourth flow path 134a (fourth flow path) through which the refrigerant flows. Also, when the third end plate 115 comes into contact with the rotor core 112, the fifth groove 135 is covered, forming a load-side second flow path 135a (second flow path) through which the refrigerant flows. In other words, the load-side fourth flow path 134a, which is part of the fourth flow path, and the load-side second flow path 135a, which is part of the second flow path, are formed by being sandwiched between the third end plate 115 and the rotor core 112.

[0047] The load-side fourth channel 134a (fourth channel) has an inner radial end that penetrates the insertion hole 115a, but its outer radial end is blocked by a damming section 134s (Figure 5B). The outer radial end 134e of the load-side fourth channel 134a (second channel) is connected to the rotor core channel 130. The load-side second channel 135a (second channel) has an outer radial end that penetrates, but its inner radial end is blocked. The inner radial end 135e of the load-side second channel 135a (second channel) is connected to the rotor core channel 130.

[0048] The fourth end plate 116 has an insertion hole 116a into which the rotor shaft 111 is inserted, a notch 116b which becomes the third discharge port of the third flow path 133a, and a fitting notch 116c which becomes the second discharge port, into which the protruding portion 115b fits.

[0049] In this embodiment, by combining the third end plate 115, the fourth end plate 116, and the rotor core 112, a third flow path 133a and a load-side fourth flow path 134a (fourth flow path) are formed. By combining these with the rotor shaft 111, the third flow path 133a and the third shaft flow path hole 123 are connected, and the load-side fourth flow path 134a (fourth flow path) and the fourth shaft flow path hole 124 are connected.

[0050] Furthermore, in this embodiment, the connection points between the first and second flow paths and the shaft flow path 120 are located on one side of the rotor shaft 111, while the connection points between the third and fourth flow paths and the shaft flow path 120 are located on the other side of the rotor shaft 111.

[0051] Next, the rotor core 112 will be explained using Figures 3 to 6. The rotor core 112 has multiple permanent magnets 117 (magnets) arranged on it. The permanent magnets 117 have alternating north and south poles in the circumferential direction. In addition, the permanent magnets 117 arranged at one pole are divided.

[0052] The rotor core 112 has an axially penetrating insertion hole 112a into which the rotor shaft 111 is inserted, and a plurality of axially penetrating rotor core channels 130 (rotor core channels 130a to 130h) that constitute part of the second and fourth channels through which the refrigerant flows. The plurality of rotor core channels 130a to 130h are arranged to maintain magnetic pole symmetry or magnetic pole pair symmetry. In this embodiment, the plurality of rotor core channels 130a to 130h are arranged at 45° intervals in the circumferential direction. According to this embodiment, since the plurality of rotor core channels 130a to 130h that constitute the second and fourth channels are arranged to maintain magnetic pole symmetry or magnetic pole pair symmetry, it is possible to suppress differences in motor characteristics between powering and regeneration.

[0053] Of the multiple rotor core flow paths 130, rotor core flow paths 130a to 130d each communicate with the anti-load side second flow path 132a (second flow path) at the position of the radially outer end 132e formed on the first end plate 113, and rotor core flow paths 130e to 130h each communicate with the anti-load side fourth flow path 136a (fourth flow path) at the position of the radially inner end 136e formed on the first end plate 113. In other words, rotor core flow paths 130a to 130d become the second flow path, and rotor core flow paths 130e to 130h become the fourth flow path. Furthermore, of the multiple rotor core flow paths 130, rotor core flow paths 130a to 130d each communicate with the load-side second flow path 135a (second flow path) at the position of the radially inner end 135e formed on the third end plate 115, and rotor core flow paths 130e to 130h each communicate with the load-side fourth flow path 134a (fourth flow path) at the position of the radially outer end 134e formed on the third end plate 115.

[0054] In this embodiment, the second flow path extends radially outward of the rotor shaft 111 via the anti-load side second flow path 132a and connects to the rotor core flow paths 130a to 130d. After extending axially inside the rotor core 112 via the rotor core flow paths 130a to 130d, it connects to the load side second flow path 135a and extends radially outward, and has a second discharge port that opens radially outward.

[0055] Similarly, the fourth flow path in this embodiment extends radially outward of the rotor shaft 111 via the load-side fourth flow path 134a and connects to the rotor core flow paths 130e to 130h, extends axially inside the rotor core 112 via the rotor core flow paths 130e to 130h, then connects to the non-load-side fourth flow path 136a and extends radially outward, and has a fourth discharge port that opens radially outward.

[0056] Next, the flow of refrigerant in the rotor 110 will be described. Figure 7 is a cross-sectional perspective view of the rotor 110 according to Embodiment 1 of the present invention, cut along the axial direction. Figure 8 is a cross-sectional view of the upper half of the rotor 110, cut along the axial direction.

[0057] The rotor shaft 111 has an open end (non-load side) in the axial direction and a solid end (load side) at the other end. A refrigerant pump 8 is connected to the opening at one end of the rotor shaft 111 via an oil cooler 4 (Figure 2). When the rotor 110 rotates, some of the refrigerant that flows into the shaft passage 120 is discharged from the first shaft passage hole 121 and the second shaft passage hole 122.

[0058] The refrigerant discharged radially outward from the first shaft flow path hole 121 passes through the first flow path 131a and is discharged from the notch 114b (first discharge port). The refrigerant discharged from the notch 114b hits the stator coil 141 and cools the stator coil 141.

[0059] The refrigerant discharged radially outward from the second shaft flow path hole 122 passes through the non-load side second flow path 132a, the rotor core flow path 130 (130a, 130c, 130e, 130g), and the load side second flow path 135a, which form the second flow path, and is discharged from the fitting notch 116c (second discharge port). The refrigerant discharged from the fitting notch 116c hits the stator coil 141 and cools the stator coil 141. In addition, the refrigerant flowing through the second flow path flows inside the rotor core 112, so it cools the permanent magnets 117 located in the rotor core 112.

[0060] Similarly, the refrigerant discharged radially outward from the third shaft flow path hole 123 passes through the third flow path 133a and is discharged from the notch 116b (third discharge port). The refrigerant discharged from the notch 116b hits the stator coil 141 and cools the stator coil 141.

[0061] The refrigerant discharged radially outward from the fourth shaft flow path hole 124 passes through the load-side fourth flow path 134a, the rotor core flow paths 130 (130b, 130d, 130f, 130h), and the non-load-side fourth flow path 136a, which form the fourth flow path, and is discharged from the fitting notch 114c (fourth discharge port). The refrigerant discharged from the fitting notch 114c hits the stator coil 141 and cools the stator coil 141. In addition, the refrigerant flowing through the fourth flow path flows inside the rotor core 112, and therefore cools the permanent magnets 117 located in the rotor core 112.

[0062] The flow in the rotor core channels 130a to 130d that form the second flow channel and the flow in the rotor core channels 130e to 130h that form the fourth flow channel are arranged so that their axial flows are opposite to each other and they are staggered in the circumferential direction.

[0063] The first and second channels, and the third and fourth channels, are each arranged in groups of four at equal intervals in the circumferential direction. Furthermore, the number of first and second channels is the same on both sides of the axial direction, and the number of third and fourth channels is the same on both sides of the axial direction.

[0064] Furthermore, in this embodiment, the first and third flow channels are arranged so as not to overlap when viewed from the axial direction, and are offset by 45° in the circumferential direction. Similarly, the second and fourth flow channels are arranged so as not to overlap when viewed from the axial direction, and are offset by 45° in the circumferential direction. By arranging them in this way, the circumferential weight balance of the rotor can be made uniform, and eccentricity during rotor rotation can be suppressed.

[0065] Rotating electric machines used for driving vehicles and the like have a rotational speed that changes depending on the load. At low rotational speeds, a large motor torque is required, so the current flowing through the stator coil increases, and the amount of heat generated by the stator coil increases. On the other hand, at high rotational speeds, eddy current losses increase, and the temperature of the permanent magnet rises. In other words, it is preferable to cool the stator coil mainly at low rotational speeds and the permanent magnet mainly at high rotational speeds.

[0066] In this embodiment, the fitting notch 116c (second discharge port), which serves as the discharge port for the second flow path, is positioned radially outward from the notch 114b (first discharge port), which serves as the discharge port for the first flow path. That is, the discharge position γ02 of the fitting notch 116c (second discharge port) is greater than the discharge position γ01 of the notch 114b (first discharge port) (γ02 > γ01).

[0067] In this embodiment, the fitting notch 116c (second discharge port) is positioned radially outward from the notch 114b (first discharge port), so the flow resistance of the second flow path is greater than that of the first flow path. When the rotor 110 rotates, the flow path is filled with refrigerant, and refrigerant is discharged from the notch 114b (first discharge port) and the fitting notch 116c (second discharge port). However, when the rotational speed of the rotor 110 is low (low-speed rotation), the centrifugal force due to the rotation of the rotor 110 is small, so the amount of refrigerant discharged from the notch 114b (first discharge port), which has less flow resistance, increases.

[0068] On the other hand, when the rotor 110 rotates at a high speed, the centrifugal force acting on the refrigerant at the fitting notch 116c (second discharge port), which is located radially outward from the notch 114b (first discharge port), becomes greater. As a result, the amount of refrigerant flowing through the second flow path (non-load side second flow path 132a, rotor core flow paths 130a to 130e, load side second flow path 135a) increases compared to the amount of refrigerant flowing through the first flow path.

[0069] Figure 9 shows the relationship between the flow rates of the first and second channels in response to changes in rotational speed. In Figure 9, the sum of the discharge rates of the first and second channels equals the total discharge rate. As shown in Figure 9, as the rotational speed increases, the discharge rate from the first channel decreases. On the other hand, as the rotational speed increases, the discharge rate from the second channel increases. Thus, in this embodiment, the discharge rates from the first and second channels change according to the rotational speed.

[0070] According to this embodiment, when the rotor rotation speed is low, the amount of refrigerant flowing through the first channel is increased, allowing the stator coil, which generates a large amount of heat, to be mainly cooled. When the rotor rotation speed is high, the amount of refrigerant flowing through the second channel is increased, allowing the permanent magnet, whose temperature rises due to increased eddy current losses, to be mainly cooled.

[0071] Furthermore, according to this embodiment, since the first and second flow paths are independently connected to the shaft flow path 120, the centrifugal pump effect due to the centrifugal force acting on the refrigerant in the second flow path acts only on the second flow path. Therefore, the increase in flow rate in the second flow path due to the centrifugal pump effect at high rotational speeds can be further improved.

[0072] Although the explanation will be omitted, the relationship between the notch (third discharge port) 116b and the fitting notch (fourth discharge port) 114c is the same as the relationship between the notch 114b (first discharge port) and the fitting notch 116c (second discharge port). [Examples]

[0073] Embodiment 2 of the present invention will be described with reference to Figure 10. Components common to Embodiment 1 are denoted by the same reference numerals, and their detailed descriptions are omitted. Figure 10 is a cross-sectional view of the rotor according to Embodiment 2 of the present invention, cut in a direction perpendicular to the axial direction.

[0074] In Example 1, multiple rotor core channels 130a to 130h were arranged to maintain magnetic pole symmetry or magnetic pole pair symmetry, but in Example 2, multiple rotor core channels 130a to 130h were arranged not to maintain magnetic pole symmetry or magnetic pole pair symmetry.

[0075] According to this embodiment, by arranging the rotor core channels 130a to 130d constituting the second channel and the rotor core channels 130e to 130h constituting the fourth channel so as not to maintain magnetic pole symmetry or magnetic pole pair symmetry, the amplitude of the annular vibration mode corresponding to the symmetry of the rotor shape can be reduced, thereby suppressing vibration and noise. [Examples]

[0076] Embodiment 3 of the present invention will be described with reference to Figure 11. Components common to Embodiment 1 are denoted by the same reference numerals, and their detailed descriptions are omitted. Figure 11 is a cross-sectional view of the upper half of the rotor 110 according to Embodiment 3 of the present invention, cut along the axial direction.

[0077] In Example 1, the first flow path and the non-load side second flow path 132a (second flow path) were independently connected to the shaft flow path 120, but in Example 3, the connection points of the first flow path and the non-load side second flow path 132a (second flow path) to the shaft flow path 120 are shared.

[0078] The outer circumferential surface of the rotor shaft 111 is provided with a second shaft flow path hole 122 that communicates with the shaft flow path 120, and a fourth shaft flow path hole 124 that communicates with the shaft flow path 120. The non-load side second flow path 132a (second flow path) and the second shaft flow path hole 122 are in communication.

[0079] One end of the branch channel 137 is connected to the second channel 132a (second channel) on the non-load side, and the other end of the branch channel 137 is connected to the first channel 131a.

[0080] The refrigerant discharged from the second shaft flow path hole 122 flows through the non-load side second flow path 132a (second flow path), and is also branched off by the branch flow path 137 to flow into the first flow path 131a. The subsequent flow of the refrigerant is the same as in Example 1, so the explanation is omitted.

[0081] According to this embodiment, the communication portion between the first and second flow channels and the shaft flow channel is shared, thus simplifying the flow channel structure.

[0082] Although the explanation will be omitted, the connection between the third and fourth flow channels to the shaft flow channel is similar, and the communication section to the shaft flow channel is shared. [Examples]

[0083] Embodiment 4 of the present invention will be described with reference to Figure 12. Components common to Embodiment 1 are denoted by the same reference numerals, and their detailed descriptions are omitted. Figure 12 is a cross-sectional perspective view of the rotor 110 according to Embodiment 4 of the present invention, cut along the axial direction.

[0084] In Example 4, the cross-sectional areas of the second flow path 132a on the non-load side and the second flow path 135a on the load side, which form the second flow path, are made different. The cross-sectional area of ​​the flow path of the second flow path 132a on the non-load side, which is located upstream of the second flow path (upstream flow path cross-sectional area S u ) is the cross-sectional area of ​​the flow path of the second flow path 135a on the load side located downstream (downstream flow path cross-sectional area S d ) or more.

[0085] According to this embodiment, by making the flow path cross-sectional area smaller on the downstream side than on the upstream side, it is possible to suppress the reduction in the pressure difference created by the centrifugal force acting on the refrigerant due to the intrusion of air from the discharge port into the flow path, thereby further improving the flow rate increase effect of the second flow path during high-speed rotation.

[0086] In this embodiment, the second channel has been described, but the first, third, and fourth channels may be configured in the same manner. [Examples]

[0087] Embodiment 5 of the present invention will be described with reference to Figure 13. Components common to Embodiment 1 are denoted by the same reference numerals, and their detailed descriptions are omitted. Figure 13 is a cross-sectional perspective view of the rotor 110 according to Embodiment 5 of the present invention, cut along the axial direction.

[0088] In Example 5, the cross-sectional areas of the first channel 131a and the anti-load side second channel 132a that forms the second channel are made different. The cross-sectional area S1 of the first channel 131a is set to be greater than or equal to the cross-sectional area of ​​the anti-load side second channel 132a (cross-sectional area S2 of the second channel) which is located upstream of the second channel.

[0089] According to this embodiment, by making the cross-sectional area of ​​the first flow path greater than or equal to the cross-sectional area of ​​the second flow path, the flow resistance of the first flow path can be reduced, and the flow rate ratio of the first flow path at low rotational speeds can be increased, thereby improving the cooling performance of the stator coil at low rotational speeds. [Examples]

[0090] Embodiment 6 of the present invention will be described with reference to Figure 14. Components common to Embodiment 1 are denoted by the same reference numerals, and their detailed descriptions are omitted. Figure 14 is a cross-sectional perspective view of the rotor 110 according to Embodiment 6 of the present invention, cut along the axial direction.

[0091] In Example 6, the cross-sectional areas of the first shaft flow path hole 121 and the second shaft flow path hole 122 are different. Cross-sectional area S of the first shaft flow path hole 121 i1 The cross-sectional area S of the second shaft flow path hole 122 is i2 The following applies:

[0092] According to this embodiment, by making the inlet cross-sectional area of ​​the first flow path smaller than the inlet cross-sectional area of ​​the second flow path, the inlet pressure loss, which is the main pressure loss during high-speed rotation, can be made smaller in the second flow path than in the first flow path, and thus the flow rate ratio of the second flow path can be increased during high-speed rotation.

[0093] It should be noted that the present invention is not limited to the embodiments described above, and includes various modifications. The embodiments described above are explained in detail for the purpose of clearly illustrating the present invention, and are not necessarily limited to those having all the configurations described. [Explanation of symbols]

[0094] 1...Body, 2...Wheels, 3...Vehicle drive system, 4...Oil cooler, 5...Piping, 6...Chiller, 7...Piping, 8...Refrigerant pump, 100...Rotating electric machine, 101...Housing, 110...Rotor, 111...Rotor shaft, 112...Rotor core, 113...First end plate, 113a...Insertion hole, 114...Second end plate, 114a...Insertion hole, 114b...Notch (First discharge port), 114c...Fitting notch (Fourth discharge port), 115...Third end plate, 115a...Insertion hole, 115b...Protrusion, 116...Fourth end plate, 116a...Insertion hole, 116b...Notch (Third discharge port), 116c...Fitting notch (Second discharge port) Outlet), 117…Permanent magnet, 120…Shaft channel, 121…First shaft channel hole, 122…Second shaft channel hole, 123…Third shaft channel hole, 124…Fourth shaft channel hole, 130, 130a~130h…Rotor core channel, 131…First groove, 131a…First channel, 132…Second groove, 132a…Non-load side second channel (second channel), 132s…Damming section, 132e…Radial outer end, 133…Third groove, 133a…Third channel, 134…Fourth groove, 134a…Load side fourth channel (fourth channel), 134s…Damming section, 134e…Radial outer end, 135…Fifth groove 135a...Load-side second passage (second passage), 135e...Radial inner end, 136...Sixth groove, 136a...Non-load-side fourth passage (fourth passage), 136e...Radial inner end, 137...Branch passage, 140...Stator, 141...Starter coil, 150, 151, 152...Bearings, 154...Oil pan, 200...Reduction gear, 201...Drive gear, 202...Driven gear, 203...Driven gear shaft, 204, 205...Bearings

Claims

1. A rotating electric machine comprising a rotor in which magnets are arranged within the rotor core, and a stator arranged on the outer diameter side of the rotor, A rotor shaft is provided on the inner circumference side of the rotor, and a shaft passage through which refrigerant flows is provided inside the rotor shaft. The rotor is The rotor has a first flow path that extends radially outward from the rotor shaft and has a first discharge port that opens radially outward, The rotor has a second flow path that extends radially outward from the rotor shaft, extends axially from the rotor core, and then extends radially outward from the rotor and has a second discharge port that opens radially outward, The first flow path and the second flow path are in communication with the shaft flow path. A rotating electric machine characterized in that the second discharge port is arranged radially outward from the first discharge port.

2. In claim 1, A rotating electric machine characterized in that the first flow path and the second flow path are each provided in multiple quantities at equal intervals in the circumferential direction.

3. In claim 1, A rotating electric machine characterized in that the number of the first flow path and the second flow path are the same.

4. In claim 1, The rotor is A third flow path having a third discharge port that extends radially outward from the rotor shaft and opens radially outward, The rotor core has a fourth flow path that extends axially inside the rotor core and then extends radially outward, and has a fourth discharge port that opens radially outward, The third and fourth flow paths are connected to the shaft flow path. The fourth discharge port is provided radially outward from the third discharge port, A rotating electric machine characterized in that the connection points of the first and second flow channels to the shaft flow channels are located on one side of the rotor shaft, and the connection points of the third and fourth flow channels to the shaft flow channels are located on the other side of the rotor shaft.

5. In claim 4, A rotating electric machine characterized in that the axial flow direction of the second flow channel and the axial flow direction of the fourth flow channel are opposite to each other.

6. In claim 1, The rotating electric machine is characterized in that the second flow channel is arranged to maintain magnetic pole symmetry or magnetic pole pair symmetry.

7. In claim 1, A rotating electric machine characterized in that the second flow channel is arranged in such a way that it does not maintain magnetic pole symmetry or magnetic pole pair symmetry.

8. In claim 1, A rotating electric machine characterized in that the first flow path and the second flow path each independently communicate with the shaft flow path.

9. In claim 1, A rotating electric machine characterized in that the first flow path and the second flow path share a connection portion with the shaft flow path.

10. A rotating electric machine comprising a rotor in which magnets are arranged within the rotor core, and a stator arranged on the outer diameter side of the rotor, A rotor shaft is provided on the inner circumference side of the rotor, and a shaft passage through which refrigerant flows is provided inside the rotor shaft. The rotor is A first flow path having a first discharge port that extends radially outward from the rotor shaft and opens radially outward, It has a second flow path that extends radially outward from the rotor shaft, extends axially inside the rotor core, and then extends radially outward and has a second discharge port that opens radially outward, The first flow path and the second flow path are connected to the shaft flow path, The second discharge port is positioned radially outward from the first discharge port. A rotating electric machine characterized in that the cross-sectional area of ​​the upstream channel of the second channel is greater than or equal to the cross-sectional area of ​​the downstream channel.

11. A rotating electric machine comprising a rotor in which magnets are arranged within a rotor core, and a stator arranged on the outer diameter side of the rotor, A rotor shaft is provided on the inner circumference side of the rotor, and a shaft passage through which refrigerant flows is provided inside the rotor shaft. The rotor is A first flow path having a first discharge port that extends radially outward from the rotor shaft and opens radially outward, It has a second flow path that extends radially outward from the rotor shaft, extends axially inside the rotor core, and then extends radially outward and has a second discharge port that opens radially outward, The first flow path and the second flow path are connected to the shaft flow path, The second discharge port is positioned radially outward from the first discharge port. A rotating electric machine characterized in that the cross-sectional area of ​​the first channel is greater than or equal to the cross-sectional area of ​​the second channel.

12. A rotating electric machine comprising a rotor in which magnets are arranged within the rotor core, and a stator arranged on the outer diameter side of the rotor, A rotor shaft is provided on the inner circumference side of the rotor, and a shaft passage through which refrigerant flows is provided inside the rotor shaft. The rotor is A first flow path having a first discharge port that extends radially outward from the rotor shaft and opens radially outward, It has a second flow path that extends radially outward from the rotor shaft, extends axially inside the rotor core, and then extends radially outward and has a second discharge port that opens radially outward, The first flow path and the second flow path are connected to the shaft flow path, The second discharge port is positioned radially outward from the first discharge port. The rotor shaft is provided with a first shaft flow path hole communicating with the first flow path and a second shaft flow path hole communicating with the second flow path. A rotating electric machine characterized in that the cross-sectional area of ​​the first shaft flow path hole is less than or equal to the cross-sectional area of ​​the second shaft flow path hole.

13. A rotating electric machine comprising a rotor in which magnets are arranged within the rotor core, and a stator arranged on the outer diameter side of the rotor, A rotor shaft is provided on the inner circumference side of the rotor, and a shaft passage through which refrigerant flows is provided inside the rotor shaft. The rotor is A first flow path having a first discharge port that extends radially outward from the rotor shaft and opens radially outward, It has a second flow path that extends radially outward from the rotor shaft, extends axially inside the rotor core, and then extends radially outward and has a second discharge port that opens radially outward, The first flow path and the second flow path are connected to the shaft flow path, The second discharge port is positioned radially outward from the first discharge port. The rotor core comprises a first end plate positioned axially outward on one side, and a second end plate positioned axially outward on one side of the first end plate. A rotating electric machine characterized in that a portion of the first flow path and the second flow path are formed by being sandwiched between the first end plate and the second end plate, and the first end plate and the rotor core.

14. In claim 1, The rotor shaft is characterized in that one end is open in the axial direction and the other end is solid.

15. In claim 14, A rotating electric machine characterized in that a refrigerant pump is connected to an opening at one end of the rotor shaft.

16. A vehicle drive system that drives a vehicle, A vehicle drive system characterized by comprising a rotating electric machine as described in any one of claims 1 to 15.

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