JP2019216549A - Coil, motor stator, motor, and electric actuator - Google Patents

Abstract

To reduce the size and cost of a motor having a sensor for measuring a temperature of a coil and the like.SOLUTION: A coil C includes an insulator 12 having a cylindrical portion 12a, a winding 13 wound around the outer periphery of the cylindrical portion 12a of the insulator 12, and a sensor 15 arranged on the inner periphery of the winding 13.SELECTED DRAWING: Figure 2

Description

  The present invention relates to a motor, and more particularly to a motor that is used as a drive source of an electric actuator and has a sensor that measures a temperature of a coil of a motor stator.

  2. Description of the Related Art In recent years, electrification for the purpose of saving power and reducing fuel consumption of vehicles and the like has been progressing. For example, a system for operating an automatic transmission, a brake, a steering, and the like of an automobile by using an electric motor has been developed. Has been turned on. As an actuator used for such an application, a motion conversion mechanism (for converting a rotary motion of a rotary member (for example, a screw shaft) driven by a motor into a linear motion of a linear motion member (for example, a nut) screwed with the motor). An electric actuator having a ball screw mechanism and a sliding screw mechanism) is known.

  In such an electric actuator, for example, when the linear motion member abuts on another member and its linear motion is restricted, if the motor is continuously driven in that state, the temperature of the motor coil increases, and the coil may be damaged. There is. A motor provided with a temperature sensor for detecting the temperature of the coil has been known in order to avoid such damage caused by the temperature rise of the coil.

  For example, Patent Document 1 discloses a motor in which a temperature sensor (thermistor element) is inserted between adjacent coils. By arranging the temperature sensor in the dead space between the coils as described above, the layout of other members around the coil can be easily performed, and the size of the motor can be reduced.

Japanese Patent No. 5,672,984

  However, the space factor (apparent volume) of the coil varies depending on the wire diameter and the number of windings, and the gap between adjacent coils varies accordingly. Therefore, when the gap between the coils is small, it is necessary to use a small (small diameter) temperature sensor to be inserted into the gap. In this case, it is necessary to prepare a plurality of types of temperature sensors according to the specifications of the coil, which leads to an increase in cost.

  Accordingly, an object of the present invention is to reduce the size and cost of a motor having a sensor for measuring the temperature of a coil and the like.

  In order to solve the above-described problems, the present invention includes an insulator having a tubular portion, a winding wound around the outer periphery of the tubular portion of the insulator, and a sensor arranged on an inner periphery of the winding. Provide coils.

  By arranging the sensor on the inner periphery of the winding as described above, the size of the coil can be reduced as compared with the case where the sensor is arranged around the winding. In addition, by disposing the sensor on the inner circumference of the winding, a fixed space for disposing the sensor can be secured regardless of the space factor of the winding. In this case, the same type (size) of sensor can be used irrespective of the specification of the coil, so that the cost of the motor can be reduced.

  In the above-described coil, it is preferable that a sensor housing portion for housing the sensor is formed in the cylindrical portion of the insulator. The sensor accommodating portion can be formed, for example, by a concave portion provided in the cylindrical portion. If this concave portion is opened on the outer peripheral surface of the cylindrical portion, the sensor disposed in the concave portion and the winding wound on the outer peripheral portion of the cylindrical portion can directly face each other without interposing the insulator, so that the sensor Detection ability is improved. In this case, since the winding is not supported from the inner peripheral side in the region where the concave portion is formed, the shape of the winding may be lost. Therefore, if the above-described concave portion is formed in a flat portion on the outer peripheral surface of the cylindrical portion which originally does not substantially support the winding, it is possible to avoid a situation in which the shape of the winding is broken due to the formation of the concave portion.

  In the above-described coil, it is preferable that the sensor be housed in the sensor housing via a gap. In this case, the sensor can be inserted into the sensor accommodating portion even after winding the winding around the insulator.

  Depending on the use of the motor, the location (phase) of the coil that is likely to be high in temperature may be roughly determined. In this case, it is preferable to dispose the sensor on the inner periphery of the winding of the coil that is likely to be heated to a high temperature. However, depending on the location of the sensor, it is difficult to route the lead wire drawn from the sensor, and there is a possibility that the assemblability may be deteriorated. Therefore, it is preferable to provide a sensor wiring substrate electrically connected to the sensor in the coil. In this case, it is possible to easily change the location (phase) of the sensor simply by changing the location of the connection between the sensor wiring substrate and the conductor extending from the sensor.

  If the above-described sensor wiring substrate is formed in a ring shape and fitted to a bus ring electrically connected to the winding, the mounting of the sensor wiring substrate is facilitated.

  As described above, by arranging the sensor on the inner periphery of the winding of the coil, the size and cost of the motor can be reduced.

It is sectional drawing of an electric actuator. It is an expanded sectional view of the motor of the above-mentioned electric actuator. (A) is a plan view of a stator sub-assembly (a stator core, an insulator, and a winding), and (B) is a BB cross-sectional view of FIG. It is a perspective view of an insulator. It is a sectional perspective view in the state where a winding was wound around an insulator. It is a perspective view of the state where the winding was wound around the insulator. It is an exploded perspective view of a stator. It is a perspective view of a stator. It is sectional drawing of the stator which concerns on another embodiment.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings.

  The electric actuator shown in FIG. 1 mainly includes a motor 1 according to an embodiment of the present invention, and a screw mechanism 2 as a motion conversion mechanism that converts a rotational motion of the motor 1 into a linear motion.

  The motor 1 includes a rotating shaft 1a, a motor stator (hereinafter, also simply referred to as "stator") 10, a motor rotor (hereinafter, also simply referred to as "rotor") 20, and a housing 30 for accommodating these on the inner periphery. Having.

  The housing 30 has a cylindrical main body 31 and a lid 32 for closing a rear opening of the main body 31. Stator 10 is fixed to the inner peripheral surface of main body 31 of housing 30. The cover 32 of the housing 30 is provided with a wiring port 32a for taking out the wirings P1 and P2 extending from the stator 10 to the outside. The rotating shaft 1a is rotatably attached to the housing 30 via bearings 41 and 42. The rotor 20 is fixed to the outer periphery of the rotating shaft 1a, and rotates integrally with the rotating shaft 1a.

  In the following description, the direction of the rotation axis of the motor 1 (the left-right direction in FIG. 1) is referred to as “axial direction”. In the axial direction, the side (right side in FIG. 1) where the rotating shaft 1a protrudes from the housing 30 of the motor 1 is referred to as “front”, and the opposite side (left side in FIG. 1) is referred to as “rear”.

  The screw mechanism 2 includes a screw shaft 2a having an external thread 2a1 formed on the outer circumference, and a nut 2b having an internal thread 2b1 formed on the inner circumference. The screw shaft 2a is connected to the rotation shaft 1a of the motor 1, and is rotatably supported by a bearing (not shown). The rotation of the nut 2b is restricted by rotation restriction means (not shown). Rotational movement of the screw shaft 2a driven by the motor 1 is converted to linear movement (axial movement) of the nut 2b. The screw mechanism 2 may be a sliding screw mechanism in which the male screw 2a1 of the screw shaft 2a and the female screw 2b1 of the nut 2b are directly screwed, or a ball screw mechanism in which these are screwed through a large number of balls. Is also good.

  Hereinafter, the detailed structure of the motor 1 will be described focusing on the configuration of the stator 10.

  As shown in FIG. 2, the rotor 20 includes a cylindrical rotor core 21 formed of a plurality of steel sheets (for example, electromagnetic steel sheets) stacked in an axial direction, and a plurality of magnets 22 attached to the outer peripheral surface of the rotor core 21. And a cover 23 for holding the magnet 22 from the outer periphery.

  The stator 10 mainly includes a stator core 11, a coil C, a bus ring 14, and a sensor wiring substrate 16. The coil C has an insulator 12, a winding 13, and a sensor 15.

  Stator core 11 is formed of a plurality of steel sheets (for example, electromagnetic steel sheets) stacked in the axial direction. As shown in FIGS. 3A and 3B, the stator core 11 has an annular portion 11a and a plurality of teeth 11b protruding from the annular portion 11a in the radial direction. The plurality of teeth 11b are provided at equal intervals in the circumferential direction.

  The insulator 12 is integrally formed of an insulating material such as a resin, and has a cylindrical portion 12a and flange portions 12b and 12c provided at both open ends of the cylindrical portion 12a as shown in FIG. The teeth 11b of the stator core 11 are inserted into the inner periphery of the cylindrical portion 12a (see FIG. 3). When the insulator 12 is attached to the teeth 11b of the stator core 11, one flange portion 12b is arranged on the outer diameter side, and the other flange portion 12c is arranged on the inner diameter side. The outer peripheral surface of the cylindrical portion 12a has a flat portion 12a1 provided on the long side, a flat portion 12a2 provided on the short side, and a curved surface portion 12a3 which smoothly connects the flat portions 12a1 and 12a2 (FIG. 4). reference).

  A concave portion 12a4 is formed in the cylindrical portion 12a. In the present embodiment, as shown in FIG. 5, the concave portion 12a4 is provided at one open end of the cylindrical portion 12a (the end on the outer diameter side of the motor 1). In the illustrated example, the concave portion 12a4 opens in a region of the insulator 12 that is not covered from the outer periphery by the annular portion 11a of the stator core 11 (see FIG. 7). The recess 12a4 does not open at the other open end of the insulator 12 (the end on the inner diameter side of the motor 1), and is closed by the bottom surface 12a5 (see FIG. 5).

  In the present embodiment, as shown in FIGS. 4 and 5, the concave portion 12a4 is opened on the outer peripheral surface and the inner peripheral surface of the cylindrical portion 12a. In the illustrated example, the concave portion 12a4 opens to the flat portion 12a2 provided on the short side of the outer peripheral surface of the cylindrical portion 12a, and does not substantially open to the curved surface portion 12a3. Thereby, the shape of the winding 13 does not collapse due to the concave portion 12a4. Specifically, as shown in FIG. 5, the inner diameter of a portion of the winding 13 disposed on the outer diameter side of the recess 12a4 and the inner diameter of a portion disposed on the outer diameter side of the flat portion 12a2 are substantially equal. Are equal.

  The winding 13 is made of a metal wire, for example, a copper wire, is wound around the outer periphery of the cylindrical portion 12a of the insulator 12, and is housed in a space surrounded by the cylindrical portion 12a and the two flange portions 12b and 12c (FIG. 5 and FIG. 5). See FIG. 6). One end 13a and the other end 13b of the winding 13 are pulled out of the coil C and connected to the bus ring 14 (see FIG. 7).

  The bus ring 14 is formed in an annular shape coaxial with the stator core 11 (see FIG. 7). In the present embodiment, as shown in FIG. 2, the bus ring 14 is provided behind the stator core 11. The bus ring 14 has a U-phase ring 14a, a V-phase ring 14b, a W-phase ring 14c, and an earth ring 14d made of metal. An insulating ring 14e made of resin is provided behind the U-phase ring 14a (left side in the figure), between the rings 14a, 14b, 14c, 14d, and in front of the earth ring 14d (right side in the figure). A cylindrical portion 14f made of resin is provided on the inner circumference of each of the rings 14a to 14e. In the illustrated example, the cylindrical portion 14f is provided integrally with the insulating ring 14e at the front end. The cylindrical portion 14f protrudes rearward from the insulating ring 14e at the rear end. A plurality of positioning pins 14g for positioning the sensor wiring substrate 16 are provided on the insulating ring 14e at the rear end (see FIG. 7). The bus ring 14 is provided with a mounting portion 14h for mounting to the insulator 12 (see FIG. 2). The attachment portion 14h has, for example, a fitting surface 14h1 that fits with the inner peripheral surface of the insulator 12, and a locking surface 14h2 that contacts the end portion (the inner-diameter-side flange portion 12c) of the insulator 12. In the illustrated example, the mounting portion 14h is provided integrally with the insulating ring 14e at the front end.

  As shown in FIG. 8, one end 13a of the winding 13 extracted from each coil C is connected to the terminal 14d1 of the earth ring 14d, and the other end 13b is connected to the terminal 14a1 of the U-phase ring 14a and the V-phase ring 14b. Connected to either terminal 14b1 or terminal 14c1 of W-phase ring 14c. The U-phase ring 14a, the V-phase ring 14b, and the W-phase ring 14c are connected to a wiring P1 for flowing current therethrough. The wiring P1 is drawn out from the wiring port 32a of the lid 32 of the housing 30 (see FIG. 1).

  The sensor 15 is a temperature sensor for measuring a temperature. As shown in FIG. 2, the sensor 15 is disposed on the inner circumference of the winding 13 of the coil C, for example, between the winding 13 and the teeth 11 b of the stator core 11. In the present embodiment, the sensor 15 is provided in a sensor housing section S provided in the cylindrical portion 12a of the insulator 12. In the illustrated example, the sensor accommodating portion S is formed by the concave portion 12a4 of the cylindrical portion 12a of the insulator 12, and specifically, the concave portion 12a4 of the insulator 12, the inner peripheral surface of the winding 13, and the end surface of the stator core 11. It is formed. The sensor 15 is fixed to the insulator 12 by filling the sensor housing S with an adhesive (indicated by dotted lines in FIG. 2) in a state where the sensor 15 is arranged in the sensor housing S. It is preferable to use an adhesive having excellent thermal conductivity.

  Thus, by arranging the sensor 15 on the inner circumference of the winding 13 of the coil C, it is not necessary to secure a space for disposing the sensor 15 on the outer circumference of the winding 13. Further, a constant space can always be secured on the inner periphery of the winding 13 irrespective of the space factor of the winding 13, so that even when coils having different space factors of the winding are used, the same type ( (Size) sensor 15 can be used.

  Further, by disposing the sensor 15 in the sensor housing portion S formed by the concave portion 12a4 of the insulator 12, the sensor 15 can be directly fixed to the insulator 12 by the adhesive filled in the sensor housing portion S. This eliminates the need for a holder or the like that holds the sensor 15 and simplifies the mounting structure of the sensor 15.

  Further, since the concave portion 12a4 of the insulator 12 is opened on the outer peripheral surface of the cylindrical portion 12a, the sensor 15 and the winding 13 of the coil C face each other without the insulator 12, so that the detection accuracy of the sensor 15 is improved. Can be In particular, if an adhesive having excellent thermal conductivity (thermally conductive adhesive) is used, the detection accuracy of the sensor 15 can be further enhanced.

  As shown in FIG. 8, the sensor 15 includes a U-phase coil C (U) connected to the U-phase ring 14a of the bus ring 14, a V-phase coil C (V) connected to the V-phase ring, and a W-phase coil. It is provided for each of the W-phase coils C (W) connected to the ring. In the illustrated example, a sensor 15 is provided for each of the coils C (U), C (V), and C (W) constituting each phase. In addition, the sensor 15 may be provided in a plurality of coils C among the coils C constituting each phase. Further, the sensor 15 does not necessarily need to be provided for the coils C of all phases, and may be provided for any two or one phase C of the U phase, the V phase, and the W phase. However, by providing the sensors 15 for the coils C of all phases as in the present embodiment, the temperatures of the coils C (U), C (V), and C (W) of each phase can be individually monitored. it can.

  The sensor wiring substrate 16 is formed in an annular shape coaxial with the bus ring 14, and more specifically, in an annular shape (annular plate shape) having substantially the same diameter as the bus ring 14 (see FIG. 7). In the present embodiment, as shown in FIG. 2, the sensor wiring substrate 16 is provided behind the bus ring 14 and overlaps the bus ring 14 in the axial direction. The wiring pattern (not shown) is provided on the surface of the sensor wiring substrate 16. Specifically, a wiring pattern for U phase, a wiring pattern for V phase, a wiring pattern for W phase, and a wiring pattern for ground are formed on the surface of the sensor wiring substrate 16. The sensor 15 provided on the U-phase coil C (U) is connected to the U-phase wiring pattern and the ground wiring pattern. The sensor 15 provided on the V-phase coil C (V) is connected to a V-phase wiring pattern and a ground wiring pattern. The sensor 15 provided on the W-phase coil C (W) is connected to a W-phase wiring pattern and a ground wiring pattern. A wiring P2 for connecting to an external measuring instrument (not shown) is connected to each wiring pattern. The wiring P2 is drawn out from the wiring port 32a of the lid 32 of the housing 30 (see FIG. 1).

  A plurality of positioning holes 16a are provided in the sensor wiring substrate 16 (see FIG. 7). The positioning pins 14g of the bus ring 14 are inserted into the positioning holes 16a of the sensor wiring board 16 (see FIG. 8). The inner peripheral surface of the sensor wiring substrate 16 is fitted with the outer peripheral surface of the cylindrical portion 14f of the bus ring 14 (see FIG. 2).

  The stator 10 having the above configuration can be assembled in the following procedure. First, the winding 13 is wound around the outer periphery of the cylindrical portion 12a of the insulator 12 (see FIG. 6). The integral product of the winding 13 and the insulator 12 is attached to each tooth 11b of the stator core 11 (see FIG. 3). Specifically, the teeth 11b of the stator core 11 are inserted into the inner periphery of the cylindrical portion 12a of the insulator 12. Hereinafter, an integrated product of the winding 13, the insulator 12, and the stator core 11 is referred to as "stator sub-assembly A".

  Next, the bus ring 14 (see FIG. 7) in which the rings 14a to 14e are integrated is attached to the stator sub-assembly A. In the present embodiment, as shown in FIG. 2, the bus ring 14 is attached to the insulator 12 of the stator sub-assembly A. Specifically, the fitting surface 14h1 of the mounting portion 14h of the bus ring 14 and the inner peripheral surface of the insulator 12 are fitted together, and the locking surface 14h2 of the mounting portion 14h is axially contacted with the end of the insulator 12. Contact As a result, the bus ring 14 is positioned in the axial direction and the circumferential direction with respect to the stator sub-assembly A, and in this state, the bus ring 14 is fixed to the stator sub-assembly A by appropriate means.

  Thus, each coil C is connected to the bus ring 14 attached to the stator sub-assembly A. Specifically, as shown in FIG. 8, one end 13a of the winding 13 of each coil C is connected to the terminal 14d1 of the earth ring 14d of the bus ring 14, and the other end 13b of the winding 13 of each coil C is connected. To the terminal 14a1 of the U-phase ring 14a of the bus ring 14, the terminal 14b1 of the V-phase ring 14b, or the terminal 14c1 of the W-phase ring 14c.

  Next, the sensor wiring substrate 16 to which the sensor 15 is connected (see FIG. 7) is attached to the bus ring 14. Specifically, while fitting the inner peripheral surface of the sensor wiring substrate 16 to the outer peripheral surface of the cylindrical portion 14f of the bus ring 14, the positioning pin 14g of the bus ring 14 is inserted into the positioning hole 16a of the sensor wiring substrate 16. (See FIG. 8). Thereby, the sensor wiring substrate 16 is positioned with respect to the bus ring 14, and in this state, the sensor wiring substrate 16 is fixed to the bus ring 14 by an appropriate means such as bonding or screwing.

  Then, the three sensors 15 connected to the sensor wiring substrate 16 via the conductive wires are attached to the coils C (U), C (V), and C (W) of each phase, respectively. Specifically, each sensor 15 is inserted into the inner periphery of each coil C. Specifically, each sensor 15 is inserted from the outer diameter side into the sensor accommodating portion S formed by the concave portion 12a4 of the cylindrical portion 12a of the insulator 12. In the present embodiment, as shown in FIG. 2, the sensor 15 is provided with a gap in the sensor housing portion S formed by the recess 12 a 4 of the insulator 12, the inner peripheral surface of the winding 13, and the end surface of the teeth 11 b of the stator core 11. Is inserted through. That is, the axial dimension L of the sensor housing S is larger than the outer diameter D of the sensor 15. Thus, after assembling the stator sub-assembly A including the stator core 11, the insulator 12, and the winding 13, the sensor 15 can be inserted into the sensor housing S and disposed on the inner periphery of the winding 13. In this state, the sensor 15 is fixed to the inner periphery of the winding 13 by injecting an adhesive into the sensor accommodating portion S and curing the adhesive. Thus, the stator 10 shown in FIG. 8 is completed.

  In the electric actuator having the above configuration (see FIG. 1), when the winding 13 of the coil C of the stator 10 of the motor 1 is energized to rotate the rotor 20 in the forward direction, the rotation shaft 1a of the motor 1 and the screw are integrally formed. The screw shaft 2a of the mechanism 2 rotates in the forward direction, whereby the nut 2b moves forward. On the other hand, when the rotor 20 is rotated in the reverse direction, the screw shaft 2a rotates in the reverse direction integrally therewith, whereby the nut 2b moves rearward.

  The present invention is not limited to the above embodiment. For example, in the above-described embodiment, the concave portion 12a4 formed in the cylindrical portion 12a of the insulator 12 is opened on both the outer peripheral surface and the inner peripheral surface of the cylindrical portion 12a, but is not limited thereto. For example, as shown in FIG. 9, the concave portion 12a4 may be opened only on the outer peripheral surface of the cylindrical portion 12a. In this case, since the volume of the sensor housing portion S is smaller than that in the above-described embodiment, the amount of the adhesive filling the space can be reduced. Conversely, the concave portion 12a4 may be opened only on the inner peripheral surface of the cylindrical portion 12a (not shown).

  Further, in the above-described embodiment, the case where the rotating member of the screw mechanism 2 is the screw shaft 2a and the linearly moving member is the nut 2b has been described, but conversely, the nut is the rotating member and the screw shaft is the linearly moving member. It may be.

1 motor 2 screw mechanism (motion conversion mechanism)
2a Screw shaft 2b Nut 10 Motor stator 11 Stator core 11b Teeth 12 Insulator 12a Cylindrical part 12a4 Concave parts 12b, 12c Flange part 13 Winding 14 Bus ring 15 Sensor 16 Sensor wiring board 20 Rotor 30 Housing A Stator subassembly C Coil S Sensor housing Department

Claims (10)

  A coil comprising: an insulator having a cylindrical portion; a winding wound around an outer periphery of the cylindrical portion of the insulator; and a sensor arranged on an inner periphery of the winding.   The coil according to claim 1, wherein a sensor housing portion for housing the sensor is provided in a cylindrical portion of the insulator.   The coil according to claim 2, wherein the sensor accommodating portion is formed by a concave portion provided in the cylindrical portion.   The coil according to claim 3, wherein the concave portion is opened on an outer peripheral surface of the cylindrical portion.   The coil according to claim 4, wherein the concave portion is opened in a flat portion on an outer peripheral surface of the cylindrical portion.   The coil according to any one of claims 2 to 5, wherein the sensor is housed in the sensor housing via a gap.   A motor stator comprising: the coil according to any one of claims 1 to 6; and a stator core having teeth inserted into an inner periphery of a cylindrical portion of an insulator of the coil.   8. The motor stator according to claim 7, wherein the sensor is disposed between a winding of the coil and a tooth of the stator core. 9.   A motor comprising the motor stator according to claim 7 and a motor rotor having a magnet.   An electric actuator comprising: the motor according to claim 9; and a motion conversion mechanism that converts a rotational motion of the motor into a linear motion.

Images