JP2015159655A - Cooling device of slip ring for rotary electric machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cooling device of a slip ring which enables liquid cooling of slide parts while preventing a coolant from adhering to the slide parts of conductive rings and conductive brushes.SOLUTION: A rotary shaft 30 of a rotary electric machine is inserted through conductive rings 36A to 36C. In the rotary shaft 30, a first coolant passage 50 extending in an axial direction is formed and branch paths 52 allowing the first coolant passage 50 and an outer peripheral surface to communicate with each other are also formed. Second coolant passages 56 are formed in the conductive rings 36A to 36C. Further, a cooling device 10 includes connection pipes 54, each of which connects the branch path 52 with the second coolant passage 56.

Description

  The present invention relates to a cooling device that cools a slip ring that transmits and receives power between a stationary side and a rotating armature in a rotating electric machine.

  Conventionally, a slip ring is known in which a conductive brush is provided on the stationary side, a conductive ring is provided on the rotating armature side, and power is transferred between the stationary side and the rotating armature by sliding both of them.

  When the rotary armature has a plurality of phases such as three phases, the conductive rings are provided for the number of phases. In order to avoid interphase conduction, the conductive rings are arranged on the rotary armature side, for example, the shaft of the rotary electric machine, in a state of being insulated from each other.

  As the conductive ring and the conductive brush slide, wear powder is generated from the sliding portion. When the wear powder accumulates around the conductive ring, adjacent conductive rings may become conductive. Here, it is empirically known that the amount of generated wear powder increases as the temperature of the sliding portion increases. In order to suppress the generation amount of wear powder, conventionally, a cooling device for cooling the sliding portion has been used.

  Examples of the cooling means for the sliding portion include an air cooling method in which a cooling gas is blown onto the sliding portion and a liquid cooling method in which a cooling liquid is supplied to the sliding portion. Among them, it is preferable to use the latter cooling means from the viewpoint of preventing the abrasion powder from scattering. For example, in Patent Document 1, a conductive ring and a conductive brush are housed in a case, and a cooling liquid is fed into the case to immerse the conductive ring and the conductive brush in the cooling liquid, thereby cooling the sliding portion.

JP 2013-183559 A

  By the way, if the cooling liquid adheres to the sliding portions of the conductive ring and the conductive brush, the contact resistance may fluctuate, and power transfer between the stationary side and the rotating armature may become unstable. Therefore, an object of the present invention is to provide a slip ring cooling device capable of cooling the sliding portion while avoiding the adhesion of the cooling liquid to the sliding portion.

  The present invention provides a slip ring for a rotating electrical machine in which a conductive brush is provided on the stationary side, a conductive ring is provided on the rotating armature side, and power is transferred between the stationary side and the rotating armature by sliding both of them. The present invention relates to a cooling device. The conductive ring is fitted into a rotating shaft of a rotating electrical machine, and the rotating shaft has a first coolant channel extending in an axial direction therein, and the first coolant flow A branch path communicating from the path to the outer peripheral surface is formed, and a second coolant flow path is formed inside the conductive ring. Furthermore, the cooling device includes a connection pipe that connects the branch path and the second coolant flow path.

  In the above invention, it is preferable that the connecting pipe is provided integrally with a bus bar that extends from the conductive ring toward the rotating armature and electrically connects the two.

  Moreover, in the said invention, it is suitable for the said connection pipe to be formed from the material of higher rigidity than the material of the said bus-bar.

  In the above invention, it is preferable that the second coolant channel is formed so that the coolant flow in the channel is bent.

  In the above invention, it is preferable that the second coolant channel is branched into a plurality of channels.

  In the above invention, the rotating armature is provided with a plurality of phases of windings, the conductive ring is provided in the number of phases of the rotating armature, and the plurality of conductive rings are separated from each other and insulated. It is preferable that the connecting pipe is inserted into the rotating shaft via a member, and the connecting pipe includes an extending portion made of an insulating material while extending from the bus bar to the branch path.

  Further, in the above invention, a plurality of the conductive rings are provided so as to be separated along the axial direction of the rotating shaft, and among the plurality of the conductive rings, a conductive ring that is relatively close to the rotating armature includes: It is preferable that an opening for passing the bus bar from the conductive ring relatively far from the rotary armature is formed.

  Moreover, in the said invention, it is suitable that the insulating member is provided between the said opening and the bus-bar which passes the said opening.

  In the above invention, the conductive ring is formed by joining two divided bodies in the axial direction, and one diameter of the divided body is formed to be larger than the other diameter. It is preferable that the two divided bodies are joined so that the one divided body covers the other divided body.

  According to the present invention, it is possible to cool the sliding portion while avoiding the adhesion of the cooling liquid to the sliding portion between the conductive ring and the conductive brush.

It is a side view which illustrates the drive mechanism containing the cooling device concerning this embodiment. FIG. 2 is an AA cross-sectional perspective view of FIG. 1, and an enlarged perspective view around a rotating shaft. It is a figure explaining the arrangement | sequence of a conductive ring. It is a figure explaining the channel pattern of the 2nd coolant channel. It is a figure explaining the channel pattern of the 2nd coolant channel. It is a figure explaining the channel pattern of the 2nd coolant channel. It is a figure explaining assembly of a conductive ring. It is a figure explaining assembly of a conductive ring.

  FIG. 1 illustrates a drive mechanism 12 including a cooling device 10 according to the present embodiment. The drive mechanism 12 is used as a drive source of a hybrid vehicle, for example. The drive mechanism 12 is provided, for example, between an internal combustion engine (denoted as E / G in FIG. 1) and a transmission (denoted as T / M in FIG. 1), and transmits drive force from the internal combustion engine to the transmission. To communicate. The drive mechanism 12 drives the transmission in cooperation with or independently of the internal combustion engine. A driving force is transmitted to wheels (not shown) via this transmission.

  The drive mechanism 12 includes a rotary electric machine 14, a fixed armature side inverter 16, a rotary armature side inverter 18, a power storage device 20, a slip ring 22, and a cooling device 10.

  The rotating electrical machine 14 includes a rotating armature 24, a rotating field element 26, and a fixed armature 28. The rotating armature 24 is fitted and fixed to the rotating shaft 30 to which the driving force is transmitted from the internal combustion engine, and rotates together with the rotating shaft 30. A plurality of phases (for example, three phases) are wound around the rotary armature 24.

  The rotating field element 26 is a substantially cylindrical field element that is disposed on the outer peripheral side of the rotating armature 24 so as to be separated from the armature 24. The rotating field element 26 is provided with a permanent magnet 32, whereby the rotating field element 26 is electromagnetically coupled to the rotating armature 24 and the fixed armature 28. The rotating field element 26 transmits a driving force to the transmission via the clutch 34. When the clutch 34 is released, the rotating field element 26 can rotate relative to the rotating armature 24. When the clutch 34 is engaged, the rotating field element 26 rotates synchronously with the rotating armature 24.

  The fixed armature 28 is a substantially cylindrical armature disposed on the outer peripheral side of the rotating field element 26 and spaced from the field element 26. As with the rotary armature 24, a plurality of (for example, three-phase) windings are wound around the fixed armature 28.

  The rotary armature side inverter 18 is an orthogonal converter provided between the power storage device 20 and the rotary armature 24. Further, the fixed armature side inverter 16 is an orthogonal converter provided between the power storage device 20 and the fixed armature 28. The power storage device 20 is configured by a chargeable / dischargeable secondary battery such as a battery.

  A driving force from the internal combustion engine (E / G) is transmitted to the rotating armature 24 via the rotating shaft 30. This driving force is transmitted to the rotating field element 26 by electromagnetic coupling between the winding of the rotating armature 24 and the permanent magnet 32 of the rotating field element 26. Thereby, the driving force of the internal combustion engine can be transmitted to the transmission (T / M) and the wheels ahead thereof.

  In addition, power can be transferred between the power storage device 20 and the winding of the rotary armature 24 via the slip ring 22 and the rotary armature side inverter 18. From this, by controlling the electric power of the winding of the rotary armature 24 by the rotary armature-side inverter 18, it is possible to control the driving force and the rotational speed output to the transmission.

  For example, when the rotation speed of the rotating armature 24 is higher than the rotation speed of the rotating field element 26, the generated power of the winding of the rotating armature 24 is supplied to the power storage device 20 side via the rotating armature side inverter 18. Is done. When the rotation speed of the rotary armature 24 is lower than the rotation speed of the rotary field element 26, the electric power of the power storage device 20 is supplied to the windings of the rotary armature 24 via the rotary armature side inverter 18. .

  Further, the winding of the fixed armature 28 and the permanent magnet 32 of the rotating field element 26 are electromagnetically coupled. From this, by supplying electric power from the power storage device 20 side to the winding of the fixed armature 28 via the fixed armature side inverter 16, it is possible to generate a driving force in the rotating field element 26. That is, the torque transmitted to the transmission can be controlled by controlling the power supply to the windings of the fixed armature 28 by the fixed armature-side inverter 16.

  The slip ring 22 exchanges power between the stationary side and the rotary armature 24. The slip ring 22 includes a conductive ring 36 and a conductive brush 38. The conductive brush 38 is provided on the stationary side. The stationary side refers to the side that is stationary with respect to the rotation of the rotary armature 24, for example, the side that is fixed to the frame (not shown) of the drive mechanism 12 together with the fixed armature 28. The conductive brush 38 is made of a conductive material such as carbon.

  The conductive ring 36 is a substantially annular member provided on the rotary armature 24 side. As shown in FIG. 2, the conductive ring 36 is fitted and fixed to the rotary shaft 30. When the conductive ring 36 and the conductive brush 38 slide, power can be exchanged between the stationary side and the rotary armature 24. The conductive ring 36 is made of a conductive member such as copper.

  For example, as shown in FIG. 2, three conductive rings 36 are provided. When the plurality of conductive rings 36 </ b> A to 36 </ b> C are inserted into the rotating shaft 30, the conductive rings 36 </ b> A to 36 </ b> C are inserted into the rotating shaft 30 in a state of being separated and insulated in order to avoid mutual conduction. For example, each of the plurality of conductive rings 36 </ b> A to 36 </ b> C is spaced along the axial direction of the rotating shaft 30 and is fitted into the rotating shaft 30 via a collar 40 that is a cylindrical member made of an insulating material.

  In addition, each of the conductive rings 36 </ b> A to 36 </ b> C is connected to a winding of each phase of the rotary armature 24. For example, bus bars 42A to 42C are provided in the conductive rings 36A to 36C, respectively. The bus bars 42A to 42C are rod-shaped conductive members that extend from the conductive rings 36A to 36C toward the rotary armature 24 and electrically connect them.

  The bus bars 42 </ b> A to 42 </ b> C extend, for example, along the axial direction of the rotary shaft 30. The bus bars 42A to 42C are arranged so as not to interfere with each other. For example, the bus bars 42A to 42C are arranged at intervals around the circumference of the conductive rings 36A to 36C. For example, the bus bars 42A to 42C are arranged around the circumference of the conductive rings 36A to 36C at intervals of 120 °.

  FIG. 3 illustrates a view in which the conductive rings 36A to 36C and the bus bars 42A to 42C are extracted from FIG. In order to avoid that the bus bar of the conductive ring relatively far from the rotating electrical machine 14 comes into contact with the conductive ring relatively close to the rotating electrical machine 14 in the middle of the extension, the conductive ring 36A, 36B includes a bus bar. It is preferable that an opening 44 through which 42B and 42C pass is formed. For example, the opening 44 may be a notch formed in the inner periphery of the conductive rings 36A and 36B. The opening 44 may be formed so as to be larger than the bus bar 42. In order to avoid electrical contact between the bus bar 42 and the conductive ring 36, an insulating member may be sandwiched between the opening 44 and the bus bar 42 passing through the opening 44.

  The ends of the bus bars 42 </ b> A to 42 </ b> C on the rotary armature 24 side may not be in contact with the rotary armature 24. For example, the end portions of the bus bars 42 </ b> A to 42 </ b> C on the rotary armature 24 side may be sandwiched by clamps (not shown), and cables extended from the clamps may be connected to the respective phase windings of the rotary armature 24.

  Returning to FIG. 2, the cooling device 10 cools the slip ring 22. The cooling device 10 includes a coolant tank 46, a liquid feed pump 48, a first coolant channel 50, a branch channel 52, a connecting pipe 54, and a second coolant channel 56 (see FIG. 4).

  The coolant tank 46 is provided, for example, outside the drive mechanism 12 and stores the coolant. The coolant may be, for example, automatic transmission fluid (ATF). The coolant stored in the coolant tank 46 is sent to the first coolant channel 50 by the liquid feed pump 48.

  The first coolant channel 50 extends inside the rotary shaft 30 along the axial direction. For example, a hollow cylindrical member is used as the rotating shaft 30, and this hollow portion is used as the first cooling channel 50. The first coolant channel 50 may penetrate to the axial end surface of the rotary shaft 30, and in this case, the first coolant channel from the liquid feed pump 48 through the axial end opening of the rotary shaft 30. 50 is supplied with coolant.

  In addition to the first coolant flow path 50, a branch path 52 that communicates from the flow path 50 to the outer peripheral surface of the shaft is also formed in the rotary shaft 30. The number of the branch paths 52 may be provided as many as the extending portions 64 described later. For example, three branch paths 52 may be provided in accordance with the coolant supply lines of the conductive rings 36A to 36C. Moreover, the branch path 52 may be provided in the axial direction edge part of the rotating shaft 30, and may be provided in the axial direction intermediate part as shown in FIG.

  The second coolant channel 56 is provided inside the conductive rings 36A to 36C. FIG. 4 illustrates a cross-sectional plan view of the conductive ring 36A. The second coolant channel 56 extends from the inlet 58 extending to the outside of the conductive rings 36A to 36C to the outlet 60 along the circumferential direction of the conductive rings 36A to 36C.

  The second coolant channel 56 is preferably formed such that the coolant flow in the channel is bent. By doing in this way, it becomes possible to increase a heat exchange area and to generate a turbulent flow, and to improve cooling efficiency. For example, as shown in FIG. 4, the second coolant channel 56 may be formed so as to meander along the circumferential direction of the conductive rings 36 </ b> A to 36 </ b> C. Further, as shown in FIG. 5, a protrusion may be provided in the second coolant channel 56.

  Furthermore, as shown in FIG. 6, the second coolant channel 56 may be branched into a plurality of channels. By doing in this way, a heat exchange area can be increased and a cooling efficiency can be improved.

  In addition, in order to form the 2nd cooling fluid flow path 56 inside the conductive rings 36A-36C, you may comprise the conductive rings 36A-36C from the division body which consists of several parts. For example, as shown in FIG. 7, the conductive rings 36 </ b> A to 36 </ b> C may be configured by overlapping two parts divided in the axial direction. A second coolant channel 56 is formed on the opposing surface of the divided body, and the second coolant channel 56 is accommodated in the conductive rings 36A to 36C by overlapping the divided bodies.

  When the two divided bodies are formed so as to have the same diameter, a slit 62 is formed on the side surfaces of the conductive rings 36A to 36C when the divided bodies are overlapped. By forming the slit 62, abnormal wear may occur between the conductive brushes 38 that are in sliding contact with the side surfaces of the conductive rings 36A to 36C.

  Therefore, as shown in FIG. 8, even if one of the divided members of the conductive rings 36 </ b> A to 36 </ b> C has a larger diameter than the other and one covers the other (covers one over the other), Good. By doing in this way, it can prevent that a slit is formed in the side surface of electroconductive rings 36A-36C.

  Returning to FIG. 2, the connecting pipe 54 connects the branch path 52 of the rotating shaft 30 and the second coolant flow path 56. For example, two (a pair) of the connection pipes 54 are provided for each of the conductive rings 36 </ b> A to 36 </ b> C so as to be connected to the inlet 58 and the outlet 60 of the second coolant channel 56.

  The connection pipe 54 extends along the axial direction of the rotary shaft 30. As shown in FIG. 3, the connecting pipe 54 may be provided integrally with the bus bar 42 that is also extended along the axial direction of the rotating shaft 30. For example, the connection pipe 54 is embedded in the bus bars 42A to 42C. In this way, the structure around the conductive rings 36A to 36C can be simplified. Further, it is possible to save the trouble of providing the opening 44 different from the bus bars 42A to 42C in the conductive rings 36A to 36C.

  Further, as described above, the bus bars 42 </ b> A to 42 </ b> C are sandwiched between clamps at the end portions. In order to prevent the connecting pipe 54 from being crushed by this pinching, it is preferable that the connecting pipe 54 is made of a material having higher rigidity than the material of the bus bar. For example, it is preferable to use a material with relatively high crushing rigidity for the connecting pipe 54 when a pipe material having the same diameter as the pipe material made of the constituent materials of the bus bars 42A to 42C is formed. Moreover, in order to suppress the electrical conductivity fall of bus-bar 42A-42C which is an electric power supply path, it is suitable for the connecting pipe 54 to be comprised from the electrically-conductive material. For example, the connecting pipe 54 is made of a steel pipe material that is a conductive material having high crushing rigidity.

  Returning to FIG. 2, as described above, the connection pipe 54 connects the second coolant flow path 56 and the branch path 52 of the rotary shaft 30. In this case, in order to prevent interphase conduction between the conductive rings 36 </ b> A to 36 </ b> C via the rotary shaft 30, it is preferable that at least a part of the connection pipe 54 is made of an insulating material. For example, the extending portion 64 extending from the bus bar 42 to the branch path 52 may be made of an insulating material such as a resin material.

  The path of the coolant in the cooling device 10 according to the present embodiment is as follows. The coolant sent out from the liquid feed pump 48 flows into the first coolant flow path 50. Thereafter, the coolant flows into the branch path 52 and reaches the second coolant channel 56 via the extending portion 64 and the connecting pipe 54. Thereby, the conductive ring 36 is cooled. The coolant flowing through the conductive ring 36 flows into the connection pipe 54 (the connection pipe not connected to the branch path 52) from the outlet 60 (see FIG. 4) of the second coolant flow path 56, and finally. Is discharged to the outside in the radial direction of the rotary shaft 30.

DESCRIPTION OF SYMBOLS 10 Cooling device, 12 Drive mechanism, 14 Rotating electric machine, 22 Slip ring, 24 Rotating armature, 30 Rotating shaft, 36A-36C Conductive ring, 38 Conductive brush, 42A-42C Bus bar, 44 Opening, 50 1st coolant flow path 52 branch pipe, 54 connecting pipe, 56 second coolant flow path, 64 extension part.

Claims (9)

A cooling device for a slip ring for a rotating electrical machine,
The conductive ring is inserted into the rotating shaft of the rotating electrical machine,
The rotary shaft is formed with a first coolant flow path extending in the axial direction therein, and a branch path communicating from the first coolant flow path to the outer peripheral surface is formed.
A second coolant flow path is formed inside the conductive ring,
A cooling device for a slip ring for a rotating electrical machine, comprising a connection pipe connecting the branch path and the second coolant flow path. A cooling device for a slip ring for a rotating electrical machine according to claim 1,
The cooling apparatus for a slip ring for a rotating electrical machine, wherein the connecting pipe is provided integrally with a bus bar that extends from the conductive ring toward the rotating armature and electrically connects both. A cooling device for a slip ring for a rotating electrical machine according to claim 2,
The cooling device for a slip ring for a rotating electrical machine, wherein the connection pipe is formed of a material having rigidity higher than that of the bus bar. A cooling device for a slip ring for a rotating electrical machine according to any one of claims 1 to 3,
The cooling device for a slip ring for a rotating electrical machine, wherein the second coolant channel is formed so that a coolant flow in the channel is bent. A cooling device for a slip ring for a rotating electrical machine according to any one of claims 1 to 4,
The cooling apparatus for a slip ring for a rotating electrical machine, wherein the second coolant channel is branched into a plurality of channels. A cooling device for a slip ring for a rotating electrical machine according to any one of claims 2 to 5,
The rotating armature is provided with a plurality of phase windings,
The conductive ring is provided for the number of phases of the rotating armature,
The plurality of conductive rings are respectively spaced apart and inserted into the rotating shaft via an insulating member,
The said connecting pipe is provided with the extending part which consists of an insulating material while extending from the said bus bar to the said branch path, The cooling device of the slip ring for rotary electric machines characterized by the above-mentioned. A cooling device for a slip ring for a rotating electrical machine according to any one of claims 2 to 6,
A plurality of the conductive rings are provided so as to be separated along the axial direction of the rotating shaft,
Among the plurality of conductive rings, the conductive ring relatively close to the rotary armature is formed with an opening for allowing the bus bar from the conductive ring relatively far from the rotary armature to pass therethrough. A cooling device for a slip ring for a rotating electrical machine. The cooling device for a slip ring for a rotating electrical machine according to claim 7,
An insulating member is provided between the opening and the bus bar that passes through the opening. A cooling device for a slip ring for a rotating electrical machine according to any one of claims 1 to 8,
The conductive ring is formed by joining two divided parts in the axial direction,
One diameter of the divided body is formed to be larger than the other diameter, and the two divided bodies are joined so as to cover the other divided body, Cooling device for slip rings for rotating electrical machines.

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