JP5239772B2 - Rotating electric machine - Google Patents

Description

  The present invention relates to a rotating electrical machine, and more particularly, to a rotating electrical machine including a conductive slip ring provided on a rotating shaft and a brush that is pressed against and electrically contacts the slip ring.

  As a method for energizing a coil of a rotating electrical machine, there is a method using a slip ring called a commutator provided on a rotating shaft and a brush provided on a fixed side. In this case, since the rotating slip ring and the brush are electrically connected by frictional contact, the brush and the slip ring are worn as the rotating shaft rotates. For example, when a slip ring is made of a metal such as copper and a brush is made of a material containing carbon, the brush is worn mainly with the operation of the rotating electrical machine.

  For example, in Patent Document 1, in a brush holder device of a DC motor, a brush held by a holder is pressed against a commutator inserted into a drive shaft by a spring, so that the brush contacts and slides on the commutator. It is stated that current flows from the brush to the armature through the commutator.

JP-A-5-300705

  As described above, since the slip ring and the brush are electrically connected by contact, it is necessary to maintain stable contact when the slip ring rotates. That is, it is necessary to improve the followability of the brush with respect to the rotation of the slip ring. Further, since the reliability of electrical connection is lowered when the pressing force of the brush changes, it is necessary to prevent the pressing force from fluctuating even if the brush is worn.

  The objective of this invention is providing the rotary electric machine which makes it possible to make a brush contact stably with respect to a slip ring. Another object is to provide a rotating electrical machine that can ensure a stable pressing force even when a brush is worn. The following means contribute to at least one of these purposes.

A rotating electrical machine according to the present invention includes a conductive slip ring provided on a rotating shaft, a brush pressed against and electrically contacting the rotating slip ring, and a pressing force of the brush against the slip ring that is attached to the housing portion. A pressing mechanism that provides an intermediate member having a mass larger than the mass of the brush, an elastic body for pressing attached between the brush and the intermediate member, and one end attached to the intermediate member. An elastic body for buffering, which has a smaller elastic constant than that of the elastic body for pressing, and an origin position for the biasing force of the buffering elastic body attached to the other end of the buffering elastic body look including a an adjustment unit that adjusts the intermediate member, the other end in the rotation support part provided in the housing part is rotatably supported, one end along the circumferential direction of the casing brush It is a member extending in the direction and is an arm-like member in which the moment of inertia around the rotation support portion is larger than the moment of inertia around the rotation support portion of the brush, instead of the magnitude relationship of mass, and the elastic body for pressing is One end is connected to the top of the brush, and the other end is connected to a predetermined pressing elastic body mounting position on one end side of the arm-shaped member. It is connected to a preset shock absorber mounting position on the other end side of the member, the adjustment portion is provided in the housing portion, and the other end of the shock absorber elastic body is moved in the circumferential direction of the housing portion. It is a moving mechanism that adjusts the origin position of the urging force of the buffering elastic body .

  In the rotating electrical machine according to the present invention, the ratio between the length L from the rotation support portion of the intermediate member to the pressing elastic body mounting position and the length S from the rotation support portion to the buffering elastic body mounting position. Certain (S / L) is preferably (1/2) or less (1/20) or more.

  In the rotating electrical machine according to the present invention, it is preferable that the adjusting unit changes the origin position of the buffering elastic body in a direction in which the pressing force of the brush is reduced according to a predetermined operating state of the rotating electrical machine.

  With the above configuration, the rotating electrical machine is a pressing mechanism that gives the pressing force of the brush against the slip ring, an intermediate member having a mass larger than the mass of the brush, and an elastic body for pressing attached between the brush and the intermediate member, A buffer elastic body having an elastic constant smaller than the elastic constant of the pressing elastic body with one end attached to the intermediate member, and an origin for the biasing force of the buffer elastic body attached to the other end of the buffer elastic body And an adjustment unit for adjusting the position.

  Thus, in the structure connected in series with the brush-pressing elastic intermediate member-buffering elastic body adjusting unit, the mass of the intermediate member is larger than the mass of the brush, and moreover than the elastic constant of the pressing elastic body If the elastic constant of the buffering elastic body is small, the amount of movement is almost the amount of deformation of the buffering elastic body by moving the position of the adjusting portion, and the elastic force due to the amount of deformation is the elasticity of the pressing elastic body. Adjusted to power. Therefore, the pressing amount with respect to the brush can be varied. For example, when energization between the brush and the slip ring is necessary, the pressing force is increased to improve the electrical contact, and the energization is not necessary. Unnecessary wear of the brush can be suppressed by reducing the pressing force.

  Further, as in the above configuration, by setting the mass of the intermediate member larger than the mass of the brush and setting the elastic constant of the buffer elastic body to be smaller than the elastic constant of the elastic body for pressing, the brush and the pressing The natural frequency of the entire vibration system can be increased as compared with the configuration of only the elastic body. This makes it possible to improve the follow-up response of the brush to fluctuations in the sliding position due to the eccentricity of the slip ring and the unevenness of the sliding surface.

  Further, in the above configuration, when the brush is worn with the adjusting portion as a fixed position, the amount of wear of the brush is almost covered by the reduction of the deformation amount of the buffering elastic body. When the deformation amount of the buffering elastic body is reduced, the elastic force is reduced accordingly, and the pressing force against the brush is also reduced. The amount of decrease is close to a value obtained by multiplying the elastic constant of the buffering elastic body by the amount of wear of the brush. Since the elastic constant of the buffering elastic body is smaller than the elastic constant of the pressing elastic body, this value is considerably smaller than the original pressing force determined almost by the large elastic constant of the pressing elastic body. Therefore, according to the said structure, the change of pressing force by abrasion of a brush can be suppressed to a small range.

  Further, in the rotating electrical machine, the intermediate member is a member that is rotatably supported at the other end of the rotation support portion provided in the casing portion, and has one end extending in the brush direction along the circumferential direction of the casing portion. The pressing elastic body is attached to the one end side, the one end of the buffering elastic body is attached to the other end side, and the adjusting unit moves the other end of the buffering elastic body in the circumferential direction of the housing portion. . With such a configuration, the pressing mechanism is arranged in the circumferential direction of the brush casing, so that the pressing mechanism can be arranged within the range of the outer shape of the casing, and the space utilization efficiency of the arrangement is improved.

  In the rotating electrical machine, the ratio is between the length L from the rotation support portion of the intermediate member to the pressing elastic body mounting position and the length S from the rotation support portion to the buffer elastic body mounting position (S / L) is (1/2) or less (1/20) or more. Thus, when the brush is worn, even if there is a movement amount corresponding to the wear amount of the brush at the pressing elastic body mounting position of the intermediate member, the movement amount at the buffering elastic body mounting position. (S / L). Thus, the influence of the amount of wear of the brush on the buffering elastic body can be reduced.

  In the rotating electrical machine, the adjustment unit changes the origin position of the buffering elastic body in a direction in which the pressing force of the brush is reduced according to a predetermined operating state of the rotating electrical machine. Thereby, when the electric current path through a brush and a slip ring becomes unnecessary, the pressing force with respect to the slip ring of a brush can be made small, and the unnecessary wear of a brush can be suppressed.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. In the following, the rotating electrical machine includes a stator, a permanent magnet rotor, and a winding rotor, a clutch is provided between the permanent magnet and the winding rotor, and one side of the rotating shaft of the winding rotor is connected to the engine. The power transmission mechanism in which the permanent magnet rotor is connected to the transmission will be described. However, any structure other than this may be used as long as it is a rotating electrical machine that uses a slip ring and a brush. The materials, shapes, dimensions, and the like described below are examples for explanation, and can be appropriately changed so as to conform to the specifications of the rotating electrical machine.

  Below, the same code | symbol is attached | subjected to the same element in all the drawings, and the overlapping description is abbreviate | omitted. In the description in the text, the symbols described before are used as necessary.

  FIG. 1 is a diagram illustrating a configuration of a hybrid drive system 10 in which a slip ring and a brush are used. The hybrid drive system 10 is used for driving a vehicle, and a rotating electrical machine 20 as a power transmission mechanism is provided between an engine 12 and a transmission 14. The tip of the transmission 14 is connected to the wheel 16.

  The rotating electrical machine 20 operates with a three-phase signal, and rotates around the rotating shaft 22 with a rotating shaft 22, a winding rotor 24 around which the rotor winding 25 is wound and rotatable around the rotating shaft 22, and a permanent magnet. A possible permanent magnet rotor 26 and a stator 28 disposed on the outer peripheral side of the permanent magnet rotor 26 and fixed to the rotating electrical machine casing. A slip ring 30 is attached to the rotating shaft 22, and a brush portion 32 is provided so as to be pressed against the slip ring 30. The slip ring 30 and the brush portion 32 correspond to each of the three-phase signals and have a configuration having three electrically separated portions. Each of the three slip rings 30 corresponding to the three phases is connected to each of the three-phase windings in the rotor winding 25 that is the winding of the winding rotor 24.

  The hybrid drive system 10 includes, as a power supply circuit unit, a rectifier 60 that rectifies a three-phase signal extracted from the brush unit 32 into direct current, a DC / DC converter 62 that boosts the output of the rectifier 60, and a positive electrode of the DC / DC converter 62. A battery 64, an inverter 66, and a cranking inverter 68 are configured to have both terminals connected to the bus and the negative bus. Further, although not shown in FIG. 1, it includes a control unit that controls the operation of each element constituting the hybrid drive system 10 as a whole.

  The operation of such a hybrid drive system is as follows. In the configuration of FIG. 1, when the winding rotor 24 is rotationally driven through the rotating shaft 22 by the power of the engine 12, and the rotational speed of the winding rotor 24 becomes higher than the rotational speed of the permanent magnet rotor 26, the winding rotor 24. An induced electromotive force is generated in the rotor winding 25 which is the winding of the first. Here, by controlling the step-up ratio of the DC / DC converter 62 so that the output voltage of the DC / DC converter 62 becomes higher than the voltage of the battery 64, an induced current flows through the rotor winding 25, and the winding rotor 24. Torque is applied between the permanent magnet rotor 26 and the permanent magnet rotor 26 so that the permanent magnet rotor 26 is rotationally driven.

  Since this power transmission path is due to the mechanical power of the engine 12, it can be called a mechanical path. The torque acting between the winding rotor 24 and the permanent magnet rotor 26 can be controlled by the step-up ratio of the DC / DC converter 62, that is, the duty ratio of the switching elements constituting the DC / DC converter 62. With the above configuration, a difference in rotation between the winding rotor 24 and the permanent magnet rotor 26 can be allowed. Therefore, the engine 12 does not stall even when the rotation of the wheel 16 is stopped, and a function as a so-called torque converter can be realized.

  Further, the three-phase AC power generated in the rotor winding 25 is taken out via the slip ring 30 and the brush part 32. The extracted AC power is rectified to DC by the rectifier 60, and the rectified DC power is boosted by the DC / DC converter 62. The direct current power from the DC / DC converter 62 is converted again into three-phase alternating current by the inverter 66 and then supplied to the stator winding 29, which is the winding of the stator 28, whereby the stator 28 and the permanent magnet rotor 26 are connected. Torque acts between them. Since this power path is based on electric power, it can be called an electric path.

  In addition, the engine 12 generates power by controlling the switching operation of the inverter 66 so that power is supplied from the battery 64 to the stator winding 29 and applying torque between the stator 28 and the permanent magnet rotor 26. Even if not, the permanent magnet rotor 26 can be driven to rotate. That is, so-called EV (Electrical Vehicle) traveling can be performed.

  Further, a three-phase signal is generated by the cranking inverter 68 using the electric power from the battery 64, and the drive current is supplied to the rotor winding 25 of the winding rotor 24 through the brush portion 32 and the slip ring 30. it can. As a result, torque can be generated between the permanent magnet rotor 26 and the winding rotor 24 to start the engine 12. That is, a cranking function can be provided. Further, by disconnecting the clutch 18, it is possible to take out the electric power generated in the rotor winding 25 of the winding rotor 24. That is, it can have a function as a generator.

  As described above, the rotating electrical machine 20 described with reference to FIG. 1 has a function as a torque converter having a torque amplification function, an engine direct drive function, a function that enables hybrid travel and EV travel as a motor, and engine start-up performance. This is a multi-function power transmission mechanism that can selectively use a ranking function, a function as a generator, and the like according to the driving situation of the vehicle.

  Next, the details of the slip ring 30 and the brush portion 32 in the rotating electrical machine 20 will be described. FIG. 2 is a view showing the state of the slip ring 30 and the brush portion 32, and shows a front view and a side view.

  The slip ring 30 is a metal ring that is fixed to the rotating shaft 22 of the rotating electrical machine 20 and is rotated and integrally rotated with the rotating shaft 22. As shown in the side view of FIG. 2, three slip rings 30 are provided on the rotary shaft in parallel corresponding to the three-phase signal, and are partitioned by an annular member made of an insulating material. Each slip ring 30 is connected to each of the three-phase rotor windings 25 of the winding rotor 24 of the rotating electrical machine 20 by a lead wire (not shown).

  As the slip ring 30, for example, a ring made by processing a pure copper material can be used. In order to electrically insulate the three rings from each other and align them in parallel, a method of integrally molding with an insulating material can be used.

  The brush part 32 includes a brush 34, a pressing mechanism 40, and a brush housing part 36. As shown in the front view of FIG. 2, the brush housing portion 36 is an annular member, is fixedly attached to the housing of the rotating electrical machine 20, and has a function of holding the pressing mechanism 40 and the brush 34.

  The brush 34 is a conductive sliding member that is pressed against and electrically contacts the slip ring 30 that rotates together with the rotating shaft 22. The brushes 34 are electrically separated into three systems corresponding to the three slip rings 30. In FIG. 2, a state in which three brushes 34 are provided corresponding to each phase is shown, but of course one may be provided, two may be provided, or four or more may be provided. By arranging a plurality of brushes at equal intervals along the circumferential direction with respect to one slip ring 30, the sliding load on the slip ring 30 can be equalized.

  The plurality of brushes 34 are grouped for each phase using an appropriate leader line, and are connected to the rectifier 60 and the cranking inverter 68 as described with reference to FIG. As this brush 34, what was shape | molded into the predetermined shape using the metal mold | die etc., for example using carbon containing copper as a material can be used.

  Since the brush 34 is gradually worn by sliding with the slip ring 30, considering the design life of the rotating electrical machine 20, the initial height dimension is set so that the height is sufficient even at the end of the life. Is set. For example, when it is predicted that about 15 mm of wear is expected during the design life, the initial height is defined as a dimension along the radial direction around the rotation shaft 22 when contacting the slip ring 30 as a height dimension. The dimension can be about 20 mm.

  The pressing mechanism 40 is a mechanism that is attached to the brush housing portion 36 as described above and applies a pressing force of the brush 34 against the slip ring 30. The pressing force of the brush 34 is appropriately set according to the material of the slip ring 30 and the brush 34, the rotational speed of the rotating shaft 22 of the rotating electrical machine 20, and the like. Can be set to be about several N.

  The pressing mechanism 40 includes a pressing spring 42 that is a pressing elastic body, an intermediate member 44, a buffer spring 46 that is a buffering elastic body, and an adjustment unit 48. That is, the brush 34 is given a pressing force against the slip ring 30 through the structure of the pressing spring 42, the intermediate member 44, the buffer spring 46, and the adjusting portion 48. In FIG. 2, the pressing mechanism 40 is illustrated so as to be disposed so as to protrude from the brush casing 36, but the adjustment unit 48 is disposed to be fixed to a fixed element of the rotating electrical machine 20. One of the simplest arrangement methods is to project a part of the brush housing part 36 so that the adjusting part 48 can be attached.

  In the front view of FIG. 2, three brushes 34 are illustrated for one slip ring 30 corresponding to one of the three phases, but the pressing mechanism 40 includes one of the brushes 34. Only those for are shown. The pressing mechanism 40 having the same structure is provided for the other two brushes 34, and the same applies to the brushes 34 corresponding to the other phases.

  The pressing spring 42 is an elastic body for pressing, and here is a coil spring having one end attached to the brush 34 and the other end attached to the intermediate member 44. Here, K is a spring constant that is an elastic constant of the pressing spring 42.

  The intermediate member 44 is a member having a mass larger than that of the brush 34. When the mass of the brush 34 is m and the mass of the intermediate member 44 is M, M is larger than m. Preferably, M is 5 times or more of m, and more preferably, M is about 10 times m. As the intermediate member 44, a material having a specific mass larger than that of the material of the brush 34 and molded into an appropriate shape can be used.

  The buffer spring 46 is a buffer elastic body, and here is a coil spring having one end attached to the intermediate member 44 and the other end attached to the movable portion 56 of the adjustment unit 48. Here, if the spring constant that is the elastic constant of the buffer spring 46 is k, k is a smaller value than the spring constant K of the pressing spring 42 described above. In other words, K is greater than k. Preferably, K is 5 times or more of k, and more desirably K is about 10 times of k.

  The adjusting unit 48 is attached to the other end of the buffer spring 46 and has a function of adjusting the origin position of the biasing force of the buffer spring 46. Specifically, as shown in FIG. 2, the movable part 56 to which the other end of the buffer spring 46 is attached is movable in the guide groove between the ON position and the OFF position, and the movable part 56 is turned on. It has a function of moving between the position and the OFF position and holding at each position.

  Here, the ON position is a position set when the rotating electrical machine 20 is in a normal operation state. The normal operation state is an operation state in which energization is performed between the slip ring 30 and the brush 34. The OFF position is a position that is set when the rotating electrical machine 20 is in a predetermined operation state that is set in advance. The predetermined operation state is an operation state in which it is not necessary to energize between the slip ring 30 and the brush 34, but in the following, the rotor winding 25 of the rotating electrical machine 20 and the power circuit need to be connected. The description will be continued assuming that the operation state in the non-operation mode is a predetermined operation state.

  In the above description, the two positions of the ON position and the OFF position can be taken. Alternatively, the position of the movable portion 56 may be taken continuously between the two positions. In this case, in a predetermined operation state, the position of the movable portion 56 can be continuously changed according to the operation state. As this adjustment part 48, actuators, such as a small motor and a plunger, can be used. The plunger can have a simple configuration when it can take two positions, and the small motor can be used particularly effectively when it can assume continuous positions.

  The operation of the above configuration will be described with reference to FIGS. These drawings are schematic views showing only necessary elements. FIGS. 3 and 4 are diagrams respectively showing the case where the adjustment unit 48 sets the position of the movable unit 56 to the ON position and the OFF position when the wear of the brush 34 is small. FIG. 5 and FIG. 6 are diagrams respectively showing the case where the adjustment unit 48 sets the position of the movable unit 56 to the ON position and the OFF position when the wear of the brush 34 has progressed.

  FIG. 3 is a schematic diagram showing a state in which the brush 34 is less worn, for example, in an initial state, and when the ON position is selected by the adjustment unit 48. As described above, the ON position is selected when the rotating electrical machine 20 is in a normal operation state in which energization is performed between the slip ring 30 and the brush 34.

  In this case, since the mass M of the intermediate member 44 is set larger than the mass m of the brush 34 as described above, and the spring constant k of the buffer spring 46 is set smaller than the spring constant K of the pressing spring 42, the brush The magnitude of the pressing force of the 34 against the slip ring 30 can be determined by the amount of deformation of the buffer spring 46.

  The pressing spring 42, the intermediate member 44, the buffer spring 46, and the adjusting unit 48 are arranged in series, the adjusting unit 48 is fixed at the ON position, K is set larger than k, and M is set larger than m. The system can increase the natural frequency of the entire vibration system as compared with the configuration of only the brush 34 and the pressing spring 42. As a result, the follow-up response of the brush 34 with respect to the variation of the sliding position due to the eccentricity of the slip ring 30 or the unevenness of the sliding surface can be improved.

  FIG. 4 is a schematic diagram showing a state in which the brush 34 is less worn, for example, in an initial state, and when the OFF position is selected by the adjustment unit 48. As described above, the OFF position is selected when the rotating electrical machine 20 is in a predetermined operating state in which no current is supplied between the slip ring 30 and the brush 34.

  In this case, since the other end of the buffer spring 46 is moved from the ON position to the OFF position by the adjusting unit 48, the length of the buffer spring 46 becomes B longer than the length A in FIG. Since the spring constant K of the pressing spring 42 is sufficiently larger than the spring constant k of the buffer spring 42, the deformation amount of the pressing spring 42 is much smaller than the deformation amount of the buffer spring 46, and the change in the distance from the ON position to the OFF position is It is absorbed by the change (B-A) in the length of the buffer spring 46. Due to the change in the length of the buffer spring 46, the spring force, which is the elastic force of the buffer spring 46, changes. In the case of FIG. 4, the spring force is smaller than that in FIG. As a result, the overall spring force applied to the brush 34 by the pressing spring 42 and the buffer spring 46 becomes smaller than that in FIG. That is, by changing from the ON position to the OFF position, the origin position of the urging force of the buffer spring 46 is changed, but the pressing force of the brush 34 against the slip ring 30 is thereby reduced.

  In this way, in the OFF position, a pressing force that is less than the pressing force in the ON position can be applied to the brush 34. Accordingly, unnecessary wear of the brush 34 can be suppressed when the energization is not performed between the brush 34 and the slip ring 30.

  FIG. 5 shows a state in which the wear of the brush 34 has progressed, for example, the amount of wear is Δ, and the height dimension of the brush 34 is lower than the initial state by (−Δ), and the adjustment unit 48. It is a model diagram which shows a mode when an ON position is selected by. As described above, the ON position is selected when the rotating electrical machine 20 is in a normal operation state in which energization is performed between the slip ring 30 and the brush 34.

  In this case, since the distance length from the surface of the slip ring 30 to the other end of the buffer spring 46 is a position where the ON position is fixed from the surface of the slip ring 30, both the case of FIG. 3 and the case of FIG. It is. Here, since the height dimension of the brush 34 changes (−Δ), this change is absorbed by the pressing spring 42 and the buffer spring 46. As described above, since the spring constant k of the buffer spring 46 is set to be smaller than the spring constant K of the pressing spring 42, most changes in (−Δ) are borne by the buffer spring 46. Therefore, assuming that the length of the buffer spring 46 in FIG. 3 is A, the length of the buffer spring 46 is (A + Δ) in FIG.

  Thus, when the brush 34 is worn by Δ, the length of the buffer spring 46 is increased by Δ, and the pressing force of the brush 34 against the slip ring 30 is reduced by the amount of (kΔ) as the spring force. Since the original pressing force is almost determined by the deformation amount of the buffer spring 46, if the original deformation amount is set sufficiently large, the magnitude of (kΔ) is much smaller than the original pressing force. That is, by setting k to be appropriately smaller than K, variation in the pressing force due to wear of the brush 34 can be reduced.

  FIG. 6 shows a state where the wear of the brush 34 has progressed, for example, the amount of wear is Δ, and the height dimension of the brush 34 is lower than the initial state by (−Δ), and the adjustment unit 48. It is a model diagram which shows a mode when an OFF position is selected by. As described above, the OFF position is selected when the rotating electrical machine 20 is in a predetermined operating state in which no current is supplied between the slip ring 30 and the brush 34.

  In this case, as described with reference to FIG. 5, the length of the buffer spring 46 is (B + Δ) as compared with FIG. 4 in which the brush 34 is not worn. Since Δ is smaller than B, the content is the same as that described in FIG. In other words, in the OFF position, a pressing force that is less than the pressing force in the ON position can be applied to the brush 34. Accordingly, unnecessary wear of the brush 34 can be suppressed when the energization is not performed between the brush 34 and the slip ring 30.

  In the case of the configuration of FIG. 2, as already described, the pressing mechanism 40 is disposed so as to protrude beyond the original brush housing part 36, and for example, a part of the brush housing part 36 is projected, The size of the arrangement increases. Therefore, if the pressing mechanism is arranged along the circumferential direction of the brush housing portion 36, the space utilization efficiency of the arrangement can be improved and the size can be reduced. FIG. 7 shows an example of such a configuration.

  The pressing mechanism 40 shown in FIG. 7 includes a pressing spring 42, an intermediate member 45, a buffer spring 46, and an adjustment unit 48. The brush 34 includes a pressing spring 42, an intermediate member 45, a buffer spring 46, and an adjustment unit 48. The pressing force applied to the slip ring 30 through the structure is the same as the configuration of FIG. The difference is an arm-like member in which the intermediate member 45 is rotatably attached to the rotation center shaft 54 of the brush housing portion 36, and one end of the buffer spring 46 is attached to the intermediate member 45 near the rotation center shaft 54. Is to be. In the following, these differences will be mainly described, and detailed description of contents common to those in FIG. 2 will be omitted.

  The intermediate member 45 is a member having an arm shape as described above, and is supported at the other end thereof so as to be rotatable with respect to the brush housing part 36 on the rotation center shaft 54, and has one end in the circumferential direction of the brush housing part 36. , And a tip end portion of which can swing around the rotation center axis 54. Then, one end of the buffer spring 46 is attached at the attachment portion 52 provided near the rotation center shaft 54 at the other end and toward the one end, and is pressed at the attachment portion 50 provided at the distal end portion of the one end. A spring 42 is connected. As described above, the intermediate member 44 is a member disposed between the pressing spring 42 and the buffer spring 46.

  In FIG. 2, the mass M of the intermediate member 44 is set to be sufficiently larger than the mass m of the brush 34, but in FIG. 7, instead of this mass relationship, the rotation support portion of the intermediate member 45, that is, the intermediate member 45. The inertia moment I around the rotation center axis 54, which is the rotation support point, is set sufficiently larger than the inertia moment i around the rotation center axis 54 of the brush 34. Preferably, I is 5 times or more of i, and more preferably, I is 10 times or more of i.

  The buffer spring 46 is a coil spring that is attached between the intermediate member 45 and the adjustment portion 48, and has one end connected to the attachment portion 52 of the intermediate member 45 and the other end connected to the movable portion 56 of the adjustment portion 48. . As described above, the spring constant k of the buffer spring 46 is set so that the rigidity around the rotation support point is sufficiently small compared to the spring constant K of the pressing spring 42. That is, as described above, the rigidity around the rotation support point is set to 5 times or more, preferably 10 times or more.

  As described above, the mounting portion 52 of the buffer spring 46 is provided in the vicinity of the rotation center shaft 54 on the other end of the intermediate member 45 and on the side toward the one end. In FIG. 7, the distance between the attachment portion 52 and the rotation center shaft 54 is indicated as S.

  In the intermediate member 45, where L is the distance from the mounting portion 50 of the pressing spring 42 to the rotation center shaft 54, L / S is the lever ratio for the lever having the rotation center shaft 54 as the rotation center. That is, if the movement amount in the attachment portion 50 is Δ, the movement amount δ in the attachment portion 52 is Δ × (S / L). (S / L) is 1 or less, preferably (1/2) or less and (1/20) or more.

  The amount of wear of the brush 34 can be considered as the amount of movement in the mounting portion 50. Therefore, if the wear amount of the brush 34 is Δ, the influence of the wear amount Δ of the brush 34 on the mounting portion 52 is Δ × (S / L). The amount of movement of the mounting portion 52 is the amount of change in the overall length of the buffer spring 46. Therefore, by setting (S / L) as described above, the influence of the wear amount Δ of the brush 34 on the buffer spring 46 can be reduced.

  The operation of the above configuration will be described with reference to FIGS. These drawings are schematic views showing only necessary elements. FIGS. 8 and 9 are diagrams respectively showing the case where the adjustment unit 48 sets the position of the movable unit 56 to the ON position and the OFF position when the wear of the brush 34 is small. FIGS. 10 and 11 are diagrams respectively showing the case where the adjustment unit 48 sets the position of the movable unit 56 to the ON position and the OFF position when the wear of the brush 34 has progressed.

  In these drawings, the ON position and the OFF position with respect to the buffer spring 46 are opposite to those described with reference to FIGS. That is, in these drawings, since the intermediate member 45 is supported so as to be swingable around the rotation center shaft 54, the expansion and compression of the buffer spring 46 are reversed from those in the configurations of FIGS. 3 to 6. ing.

  FIG. 8 is a diagram corresponding to FIG. 3, and is a schematic diagram showing a state in which the brush 34 is less worn, for example, in an initial state and the ON position is selected by the adjustment unit 48.

  In this case, the inertia moment I of the intermediate member 45 is set larger than the inertia moment i of the brush 34 as described above, and the spring constant k of the buffer spring 46 is set smaller than the spring constant K of the pressing spring 42. The magnitude of the pressing force of the brush 34 against the slip ring 30 can be determined by the amount of deformation of the buffer spring 46.

  The pressing spring 42, the intermediate member 44, the buffer spring 46, and the adjusting unit 48 are arranged in series, the adjusting unit 48 is fixed at the ON position, K is set larger than k, and I is set larger than i. The system can increase the natural frequency of the entire vibration system as compared with the configuration of only the brush 34 and the pressing spring 42. As a result, the follow-up response of the brush 34 with respect to the variation of the sliding position due to the eccentricity of the slip ring 30 or the unevenness of the sliding surface can be improved.

  FIG. 9 is a diagram corresponding to FIG. 4, and is a schematic diagram showing a state in which the brush 34 is less worn, for example, in an initial state and the OFF position is selected by the adjustment unit 48.

  In this case, since the other end of the buffer spring 46 is moved from the ON position to the OFF position by the adjustment unit 48, the length of the buffer spring 46 becomes D shorter than the length C in FIG. Since the spring constant K of the pressing spring 42 is sufficiently larger than the spring constant k of the buffer spring 42, the deformation amount of the pressing spring 42 is much smaller than the deformation amount of the buffer spring 46, and the change in the distance from the ON position to the OFF position is It is absorbed by the change (DC) in the length of the buffer spring 46. The spring force, which is the elastic force of the buffer spring 46, changes due to the change in the length of the buffer spring length 46. In the case of FIG. 9, the force is smaller than that in FIG. Since the intermediate member 45 swings around the rotation center shaft 54, the total spring force by the pressing spring 42 and the buffer spring 46 applied to the brush 34 at the tip end portion is smaller than that in FIG. That is, by changing from the ON position to the OFF position, the origin position of the urging force of the buffer spring 46 is changed, but the pressing force of the brush 34 against the slip ring 30 is thereby reduced. That is, the same effect as in FIG. 4 can be obtained.

  In this way, in the OFF position, a pressing force that is less than the pressing force in the ON position can be applied to the brush 34. Accordingly, unnecessary wear of the brush 34 can be suppressed when the energization is not performed between the brush 34 and the slip ring 30.

  FIG. 10 shows a state in which the wear of the brush 34 has progressed, for example, the amount of wear becomes Δ, and the height dimension of the brush 34 is lower than the initial state by (−Δ), and the adjustment unit 48. It is a model diagram which shows a mode when an ON position is selected by.

  In this case, the position of the attachment portion 50 at the distal end portion of the intermediate member 45 changes by (−Δ). Since the intermediate member 45 swings around the rotation center axis 54, the change amount (−Δ) becomes a change in the position of the mounting portion 52, and the length of the buffer spring 46 changes. As described with reference to FIG. 7, the change in the position of the attachment portion 50 is multiplied by (S / L) and appears in the attachment portion 52. Therefore, the length of the buffer spring 46 is {C−Δ × (S / L)} where C is the length in FIG.

  As described above, when the brush 34 is worn by Δ, the length of the buffer spring 46 is shortened by {Δ × (S / L)}. Since this change is a small value compared to the deformation amount of the buffer spring 46 when the brush 34 is not worn, the change in the spring force of the buffer spring 46 is a small value. Therefore, the influence hardly affects the pressing force of the brush 34. That is, the same effect as in FIG. 5 can be obtained.

  FIG. 11 is a view corresponding to FIG. 6, and the wear of the brush 34 has progressed. For example, the wear amount is Δ, and the height dimension of the brush 34 is (−Δ) lower than the initial state. FIG. 5 is a schematic diagram showing a state when an OFF position is selected by the adjustment unit 48.

  In this case, as described with reference to FIG. 10, the length of the buffer spring 46 is {D−Δ × (S / L)} compared to FIG. 9 in which the brush 34 is not worn. As described above, {Δ × (S / L)} is a small value compared to the deformation amount, and therefore has the same content as described in FIG. In other words, in the OFF position, a pressing force that is less than the pressing force in the ON position can be applied to the brush 34. That is, the same effect as in FIG. 6 can be obtained.

It is a figure explaining the structure of the hybrid drive system to which the rotary electric machine using the slip ring and brush of embodiment which concerns on this invention is applied. It is the front view and side view which show the mode of the slip ring and brush part of embodiment which concern on this invention. In embodiment which concerns on this invention, when there is little abrasion of a brush, it is a figure which shows a mode when the position of the attaching part of a buffer spring is made into ON position by the adjustment part. In embodiment which concerns on this invention, when there is little abrasion of a brush, it is a figure which shows a mode when the position of the attaching part of a buffer spring is made into the OFF position by the adjustment part. In embodiment which concerns on this invention, when abrasion of a brush has progressed, it is a figure which shows a mode when the position of the attaching part of a buffer spring is made into ON position by the adjustment part. In embodiment which concerns on this invention, when abrasion of a brush has advanced, it is a figure which shows a mode when the position of the attaching part of a buffer spring is made into the OFF position by the adjustment part. It is the front view and side view which show the mode of the slip ring and brush part of other embodiment. FIG. 8 is a diagram illustrating a state where the position of the mounting portion of the buffer spring is set to the ON position by the adjusting portion when the brush wear is small in the embodiment of FIG. 7. FIG. 8 is a diagram illustrating a state where the position of the mounting portion of the buffer spring is set to the OFF position by the adjusting portion when the brush wear is small in the embodiment of FIG. 7. In the embodiment of FIG. 7, when the wear of the brush has progressed, it is a diagram showing a state when the position of the mounting portion of the buffer spring is set to the ON position by the adjusting portion. In the embodiment of FIG. 7, when the wear of the brush has progressed, it is a diagram showing a state when the position of the mounting portion of the buffer spring is set to the OFF position by the adjusting portion.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 10 Hybrid drive system, 12 Engine, 14 Transmission, 16 Wheel, 18 Clutch, 20 Rotating electrical machinery, 22 Rotating shaft, 24 Winding rotor, 25 Rotor winding, 26 Permanent magnet rotor, 28 Stator, 29 Stator winding, 30 Slip ring, 32 brush section, 34 brush, 36 brush housing section, 40 pressing mechanism, 42 pressing spring, 44, 45 intermediate member, 46 buffer spring, 48 adjusting section, 50, 52 mounting section, 54 rotation center shaft, 56 Movable part, 60 rectifier, 62 DC / DC converter, 64 battery, 66 inverter, 68 inverter for cranking.

Claims (3)

A conductive slip ring provided on the rotating shaft;
A brush that is pressed against the rotating slip ring and makes electrical contact;
A pressing mechanism that is attached to the housing and gives a pressing force of the brush against the slip ring;
With
The pressing mechanism is
An intermediate member having a mass larger than the mass of the brush;
An elastic body for pressing attached between the brush and the intermediate member;
A buffering elastic body having one end attached to the intermediate member, the buffering elastic body having a smaller elastic constant than the elastic constant of the pressing elastic body;
An adjustment unit that is attached to the other end of the buffering elastic body and adjusts the origin position of the biasing force of the buffering elastic body;
Only including,
The intermediate member is a member that is rotatably supported at the other end of the rotation support portion provided in the housing portion, and has one end extending in the direction of the brush along the circumferential direction of the housing portion. Instead of the arm-like member, the moment of inertia around the rotation support portion of the brush is larger than the moment of inertia around the rotation support portion of the brush,
The pressing elastic body has one end connected to the top of the brush and the other end connected to a predetermined pressing elastic body mounting position on one end side of the arm-shaped member,
The buffering elastic body has one end connected to a predetermined buffering elastic body mounting position on the other end side of the arm-shaped member,
The adjustment unit is a moving mechanism that is provided in the housing unit and moves the other end of the buffering elastic body in the circumferential direction of the housing unit to adjust the origin position of the urging force of the buffering elastic body. A rotating electric machine that is characterized. In the rotating electrical machine according to claim 1 ,
The ratio (S / L) between the length L from the rotation support portion of the intermediate member to the pressing elastic body mounting position and the length S from the rotation support portion to the buffering elastic body mounting position is (1 / L). / 2) A rotating electrical machine characterized by being equal to or less than (1/20) . In the rotating electrical machine according to claim 1 ,
The adjusting unit changes the origin position of the buffering elastic body in a direction in which the pressing force of the brush is reduced according to a predetermined operating state of the rotating electric machine.

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