JP2018019511A - Bus bar unit and switched reluctance motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a bus bar unit capable of suppressing increase in an axial/radial dimension of a motor while making supply currents to phases equal in an SR motor comprising a three-phase independent circuit.SOLUTION: A bus bar unit 14 is used for an SR motor 1 which includes a three-phase excitation coil 8 and to which a current is supplied by an independent power supply circuit 21, and comprises an annular bus bar 9. The bus bar 9 consists of an outer bus bar 9a and an inner bus bar 9b of different diameters, and two bus bars are arranged in parallel in a radial direction and disposed while being overlapped in an axial direction. In the bus bar unit 14, positive electrode side bus bars 9U+, 9V+ and 9W+ are disposed outsides and negative electrode side bus bars 9U-, 9V- and 9W- are disposed insides. The positive/negative electrode side bus bars 9U+ and 9U- or the like of the same phase are disposed in the same layer. The positive electrode side bus bar 9U+ or the like and the negative electrode side bus bar 9U- or the like have an equal electroresistance value and the bus bars 9 of each phase consisting of a pair of positive and negative side bus bars have an equal resistance value.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a bus bar unit for supplying power to a motor, and more particularly to a bus bar unit suitable for an SR motor (Switched Reluctance Motor).

  In general, SR motors and brushless motors are energized and driven by a plurality of phases of current, and conventionally, a metal bus bar is used for energizing an exciting coil wound around a stator. In that case, normally, a plurality of bus bars are required for energizing each phase. For example, in the bus bar device of Patent Document 1, four bus bars for U, V, W phases and neutral points are used. Each bus bar is used so as to overlap in the axial direction of the motor. Further, in the bus bar unit of Patent Document 2, three bus bars are used for each of U, V, and W, and each bus bar is arranged side by side in the radial direction of the motor.

JP 2014-193025 A JP 2011-82512 A

  On the other hand, in the SR motor having a three-phase independent circuit, when bus bars are used for energization, six bus bars of 2 × 3 phases (U, V, W) on the + side and − side are required. However, when the bus bars are formed in an annular shape so that the supply current to each coil is equal, and they are stacked in the axial direction of the motor as in Patent Document 1, the bus bar unit has a thickness equivalent to six stacked bus bars. As a result, there is a problem that the axial dimension becomes large. On the other hand, when the bus bar is arranged in the radial direction as in Patent Document 2, there is a problem that the radial dimension of the motor is increased, although the axial dimension is suppressed.

  An object of the present invention is to provide a bus bar unit capable of suppressing an increase in axial and radial dimensions of a motor in an SR motor having a three-phase independent circuit.

  The bus bar unit of the present invention includes a multi-phase excitation coil, and is used in a motor to which current is supplied to the excitation coil by an independent circuit, and electrically connects the excitation coils of the same phase to the excitation coil. A bus bar unit for supplying current to the bus bar unit, wherein the bus bar unit includes a plurality of bus bars formed in an annular shape, and the bus bar includes an outer bus bar and an inner bus bar having different diameters, and The outer bus bar and the inner bus bar are arranged concentrically along the radial direction, and the outer bus bar and the inner bus bar are respectively stacked and arranged along the axial direction. To do.

  Another bus bar unit of the present invention is used in a motor that includes a plurality of phases of excitation coils and is supplied with current by an independent circuit to the excitation coils, and electrically connects the excitation coils of the same phase. A bus bar unit for supplying a current to the coil, wherein the bus bar unit has a plurality of bus bars formed in an annular shape, and the bus bar is a positive electrode electrically connected to a positive electrode side of the exciting coil. Side bus bar and a negative side bus bar electrically connected to the negative side of the exciting coil, and the positive side bus bar and the negative side bus bar are arranged concentrically along the radial direction. In addition, one of the bus bars arranged radially outside and one of the bus bars arranged radially inside are stacked in the axial direction, respectively. And wherein the Rukoto.

  In the present invention, the annular bus bars are arranged in parallel in the radial direction, and the radially outer and inner bus bars are arranged in a plurality of layers. Thereby, the thickness of the bus bar unit can be reduced as compared with the case where a plurality of bus bars are arranged in series in the axial direction. Therefore, the motor using the bus bar unit is also reduced in size accordingly.

  In the bus bar, the positive electrode bus bar and the negative electrode bus bar having the same phase may be arranged in the same layer. Thereby, the coil connection terminal and the end of the exciting coil are connected at the same position for each phase, the length of the coil end can be made uniform for each phase, and workability can be improved.

  Furthermore, the bus bars may be laminated so that the same-polarity bus bars are adjacent in the axial direction. Thereby, the polarities of the inner and outer bus bars are aligned, the device configuration is easily understood, and wiring and connection are also facilitated.

  In the bus bar unit, the plurality of positive electrode bus bars all have the same electric resistance value, and the plurality of negative electrode bus bars all have the same electric resistance value, and is composed of a pair of the positive electrode bus bar and the negative electrode bus bar. The bus bar of each phase may have the same resistance value. As a result, the current values flowing through the excitation coils of each phase are equalized, and distortion of the current waveform due to non-uniformity of the currents of each phase and the occurrence of abnormal noise associated therewith are suppressed.

  Also, the bus bar is provided with a coil connection terminal electrically connected to the exciting coil, and the bus bar arranged radially outside of the bus bar protrudes radially outward, and the bus bar Of these, the coil connection terminal may be provided so as to protrude radially inward in the case of being arranged radially inward. Thereby, a coil connection terminal can be arrange | positioned in the position corresponding to the winding start and winding end of an exciting coil, and the layout property is improved.

  On the other hand, the switched reluctance motor of the present invention is characterized by having the bus bar unit as described above. In the switched reluctance motor, the bus bar unit is downsized, so that the entire motor can be downsized.

  According to the bus bar unit of the present invention, an annular bus bar is arranged in parallel in the radial direction in a bus bar unit that is used in a motor that includes a plurality of excitation coils and is supplied with current by an independent circuit to the excitation coils. Since they are arranged in a plurality of layers, the thickness of the bus bar unit can be reduced as compared with the case where a plurality of bus bars are simply arranged in the axial direction. Further, the motor using the bus bar unit can be reduced in size accordingly.

It is explanatory drawing which shows the structure of SR motor using the bus-bar unit which is one embodiment of this invention. It is explanatory drawing which shows the arrangement | positioning state of the bus-bar in the bus-bar unit which is one embodiment of this invention. It is explanatory drawing which shows the attachment state of the bus-bar unit of FIG. It is explanatory drawing which shows the circuit structure of the exciting coil in SR motor of FIG.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is an explanatory diagram showing a configuration of an SR motor using a bus bar unit according to an embodiment of the present invention. The SR motor 1 of FIG. 1 has an inner rotor type configuration, and includes a stator 3 fixed in the housings 2 a and 2 b and a rotor 4 that is rotatably arranged in the stator 3. The stator 3 includes a stator core 5 in which a large number of thin electromagnetic steel plates are laminated. The stator core 5 is provided with a ring-shaped yoke portion 6 and a radial projection from the yoke portion 6 toward the radially inner side (center direction). The salient pole 7 is provided. An exciting coil 8 (hereinafter abbreviated as “coil 8”) is wound around the outer periphery of the salient pole 7. The coil 8 is composed of a plurality of phase coils (here, U-phase, V-phase, and W-phase), and each phase coil 8 forms an independent circuit. A current is supplied to the coil 8 via a bus bar 9 formed of a conductive member (for example, a metal such as copper).

  A rotor 4 is inserted inside the stator 3. The rotor 4 includes a rotating shaft 11 and a rotor core 12 fixed to the rotating shaft 11. The rotor core 12 is also formed by laminating a large number of thin electromagnetic steel plates. On the outer periphery of the rotor core 12, salient poles 13 project in the radial direction (see FIG. 3). In the SR motor 1, the rotation angle of the rotor 4 is detected by a resolver (not shown), and the coils 8 of each phase are sequentially excited according to the angular position of the rotor 4. The salient poles 7 around which the excited coils 8 are wound sequentially become magnetic poles, and a three-phase (U phase, V phase, W phase) rotating magnetic field is formed in the stator 3. The salient pole 13 of the rotor 4 is attracted to the magnetized salient pole 7, whereby the rotor 4 rotates in the stator 3 and the SR motor 1 operates.

  On the other hand, in the SR motor 1, the bus bar unit 14 is disposed adjacent to one end side (left end side in the drawing) of the stator core 5 in the axial direction. A plurality of bus bars 9 are embedded in the bus bar unit 14 while being insulated from each other. FIG. 2 is an explanatory view showing an arrangement state of a plurality of bus bars 9 in the bus bar unit, and FIG. 3 is an explanatory view showing an attachment state of the bus bar unit 14. The bus bar unit 14 has a configuration in which a plurality of bus bars 9 formed in an annular shape are insert-molded in a resin in a main body portion 15 formed of a synthetic resin.

  As shown in FIG. 2, in the bus bar unit 14, the plurality of bus bars 9 include two outer bus bars 9 a and inner bus bars 9 b having different diameters arranged concentrically along the radial direction. Further, the outer bus bar 9a and the inner bus bar 9b are respectively arranged in three layers in the vertical direction (axial direction in the motor) in FIG. In-phase bus bars 9a and 9b are arranged in the same layer, and a positive electrode (positive electrode) is arranged on the outer side and a negative electrode (negative electrode) bus bar 9 is arranged on the inner side. That is, the bus bars 9 on the positive and negative sides are laminated so that the bus bars 9 with the same polarity are adjacent to each other along the axial direction. Therefore, in FIG. 2, the U-phase, V-phase, and W-phase positive and negative bus bars 9U +, 9U−, 9V +, 9V−, 9W +, and 9W− are arranged in parallel and in three layers in order from the top. ing.

  As described above, when the plurality of bus bars 9 are arranged in parallel in the radial direction and are arranged in a plurality of layers, the bus bar unit 14 is greatly compared with the case where the plurality of bus bars 9 are arranged in the axial direction. Can be reduced in thickness. For example, when six bus bars 9 are required as in the case of the SR motor 1, when the thickness of the bus bars is 1 mm and the clearance between the bus bars is 1 mm, if six bus bars are arranged in an overlapping manner, the thickness direction of the bus bars The arrangement dimension is 1 mm × 6 (plate thickness) +1 mm × 5 (clearance) = 11 mm. On the other hand, in the configuration of the present invention, the arrangement dimension for the six bus bars is 1 mm × 3 (plate thickness) +1 mm × 2 (clearance) = 5 mm. That is, according to the present invention, the arrangement dimension in the thickness direction of the bus bar 9 can be reduced to half or less, and the thickness of the bus bar unit 14 is reduced and the size is reduced. Therefore, the SR motor 1 using the bus bar unit 14 is also downsized accordingly. In addition, by arranging the bus bars 9 in the radial direction, two bus bars can be simultaneously manufactured by press working, and the manufacturing cost can be reduced.

  The plurality of bus bars 9 are provided with a coil connection terminal 16 connected to the coil 8 and a power connection terminal connected to the power supply side. In the plurality of bus bars 9, from the outer side bus bar 9a (positive side bus bar 9U +, 9V +, 9W +), from the coil connection terminal 16a and the inner side bus bar 9b (negative side bus bar 9U-, 9V-, 9W-) toward the radially outer side. The coil connection terminals 16b protrude from the inner side in the radial direction. The power connection terminal is connected to the motor driver 17 (see FIG. 4). As shown in FIG. 3, each of the coil connection terminals 16a and 16b has an end portion 18 (hereinafter referred to as a coil end portion, 18a: winding start end (+ side), 18b: winding end) of each corresponding phase coil 8. End (− side)), and thereby the bus bar 9 and the coil 8 are electrically connected.

  As described above, the outer bus bar 9a arranged radially outwardly protrudes the coil connection terminal 16 toward the radially outer side, and the inner bus bar 9b arranged radially innerward places the coil connection terminal 16 radially inward. By projecting toward the end, the coil connection terminal 16 can be disposed at a position corresponding to the start and end of winding of the coil 8, thereby improving the layout. Moreover, in the bus bar unit 14, since the positive / negative in-phase bus bars 9 are arranged for each layer, the coil connection terminal 16 and the coil end 18 are connected at the same position for each phase. For this reason, in the said SR motor 1, the length of the coil end part 18 can be arrange | equalized for every phase, and workability | operativity is improved.

  FIG. 4 is an explanatory diagram showing a circuit configuration of the coil 8 in the SR motor 1. As shown in FIG. 4, in the SR motor 1, the coils 8 </ b> U, 8 </ b> V, 8 </ b> W of the respective phases constitute independent circuits, and a plurality of bus bars 9 are arranged before and after the coils 8. A current is supplied to the coil 8 from the motor driver 17 and the power source 22 through the power supply circuit 21 (21U, 21V, 21W). At that time, in the bus bar unit 14, the + side bus bars 9U +, 9V +, 9W + are arranged on the outside, and the − side bus bars 9U-, 9V-, 9W- are arranged on the inside (in the figure, the bus bar unit is represented by a resistor). ). Since the extended distances of the plurality of bus bars 9 are different between the outer side and the inner side, the electric resistance values of the respective bus bars 9 themselves are different on the + side and the − side. However, in the bus bar unit 14, since the bus bar 9 of each phase is one set inside and outside, the resistance value for each phase is the same as each other as a whole. For this reason, the current values flowing through the respective phase coils 8U, 8V, 8W are also equal, and the distortion of the current waveform due to the non-uniformity of the respective phase currents and the occurrence of abnormal noise associated therewith can be suppressed.

It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention.
For example, in the above-described embodiment, the outer bus bar is the positive pole and the inner bus bar is the negative pole. However, the polarity may be reversed (the outside is-and the inside is +), and each layer has a polarity. May be arranged differently (first layer: outer + / inner-, second layer: outer- / inner +, third layer: outer + / inner-, etc.). However, if the polarities of the inner and outer bus bars are aligned, it is easier to understand in terms of configuration, and wiring and connection are also easier. In addition, the plurality of bus bars is not limited to the structure in which the resin is insert-molded with the resin, but may be in a state of being insulated from each other in the bus bar unit. Also good.

  Furthermore, the arrangement of each phase bus bar is not necessarily arranged in the same layer in the same layer. For example, the U phase + may be arranged in the first layer and the U phase-may be arranged in the third layer. Is possible. However, in this case as well, it is easier to understand in terms of structure that the first layer is the U phase both inside and outside, and the length of the coil end 18 is also aligned for each phase as described above. . In addition, from the relationship of resistance value (refer FIG. 4), it is preferable to make the + pole and-pole of the same phase into the combination of the outer side and the inner side even when the layers are different.

  In addition, in the above-described embodiment, an example in which the bus bar unit according to the present invention is used for a three-phase driving SR motor is shown. However, the number of driving phases of the motor is not limited to three, and the bus bar unit of the present invention is It can be used as appropriate for a motor having two or more phases and a plurality of phases.

  The bus bar unit according to the present invention can be applied to a brushless motor driven by a plurality of phases in addition to the SR motor.

DESCRIPTION OF SYMBOLS 1 SR motor 2a, 2b Housing 3 Stator 4 Rotor 5 Stator core 6 Yoke part 7 Salient pole 8 Excitation coil 9 Bus bar 9a Outer bus bar 9b Inner bus bar 9U +, 9V +, 9W + Positive side bus bar 9U-, 9V-, 9W- Negative side bus bar 11 Rotating shaft 12 Rotor core 13 Salient pole 14 Bus bar unit 15 Body 16 Coil connection terminals 16a and 16b Coil connection terminals 17 Motor driver 18 Coil ends 18a and 18b Coil connection terminals 21 Feed circuit 22 Power supply

Claims (7)

A bus bar unit that is used in a motor that includes a plurality of phases of excitation coils and that is supplied with current by an independent circuit to the excitation coils, and that electrically connects the excitation coils of the same phase and supplies current to the excitation coils Because
The bus bar unit has a plurality of bus bars formed in an annular shape,
The bus bar comprises an outer bus bar and an inner bus bar having different diameters from each other,
The outer bus bar and the inner bus bar are arranged concentrically along the radial direction,
Each of the outer bus bar and the inner bus bar is laminated and arranged along the axial direction. A bus bar unit that is used in a motor that includes a plurality of phases of excitation coils and that is supplied with current by an independent circuit to the excitation coils, and that electrically connects the excitation coils of the same phase and supplies current to the excitation coils Because
The bus bar is composed of a positive side bus bar electrically connected to the positive side of the excitation coil and a negative side bus bar electrically connected to the negative side of the excitation coil.
The positive side bus bar and the negative side bus bar are arranged concentrically along the radial direction,
One of the bus bars arranged radially outside and one of the bus bars arranged radially inside are stacked and arranged along the axial direction, respectively. The bus bar unit according to claim 2,
The bus bar unit, wherein the positive electrode bus bar and the negative electrode bus bar in the same phase are arranged in the same layer. In the bus bar unit according to claim 2 or 3,
The bus bar unit is characterized in that the bus bars are stacked so that the same-polarity bus bars are adjacent in the axial direction. In the bus bar unit according to any one of claims 2 to 4,
The positive side bus bar has the same electrical resistance value, and the negative side bus bar also has the same electrical resistance value,
The bus bar unit having the same resistance value for each phase of the bus bar composed of the positive bus bar and the negative bus bar. In the bus bar unit according to any one of claims 1 to 5,
The bus bar has a coil connection terminal electrically connected to the excitation coil,
The coil connection terminal protrudes radially outward when the bus bar is arranged radially outside, and protrudes radially inward when the bus bar is arranged radially inside. Busbar unit characterized by being made.   A switched reluctance motor comprising the bus bar unit according to claim 1.

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