The present invention relates to a driving apparatus in which a position of a rotating shaft of an electric motor in an axis direction is determined.
Conventionally, a driving apparatus for use in a wiper apparatus of a vehicle has been known and disclosed in Japanese Patent Application Laid-Open Publication No. 2011-234453. The driving apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2011-234453 comprises: a cylindrical yoke, a gear case to which the yoke is fixed, a cover for covering an opening of the gear case, and an electric motor disposed inside and over the yoke and the gear case. The electric motor comprises: a permanent magnet fixed to an inner surface of the yoke and an armature rotatably installed inside the yoke. The armature is formed by winding an energizing coil around it, and an armature shaft installed in the therein is rotated together with the armature. The armature shaft is disposed inside and over the yoke and the gear case. To the armature shaft, a commutator for energizing the coil is attached.
In the armature shaft, a worm is formed on an outer periphery of a portion disposed inside the gear case. A worm wheel is formed inside the gear case, and a gear formed on the outer periphery of the worm wheel is meshed with the worm. A terminal holder is formed in the gear case, and the terminal connected to the commutator is supported by the terminal holder. A positioning member is attached to the gear case, and the position of the armature shaft is determined in an axis direction by the positioning member.
However, in the driving apparatus described in Japanese Patent Application Laid-Open Publication No. 2011-234453, the terminal holder and the positioning member are disposed side by side in the axis direction. For this reason, the driving apparatus tends to be increased in size in the axis direction.
An object of the present invention is to provide a driving apparatus capable of being suppressed in size in the axis direction of the rotating shaft.
According to one aspect of the present invention, there is provided a driving apparatus in which a position of a rotating shaft of an electric motor in an axis direction is determined, the driving apparatus comprising: a positioning member which determines a position of the rotating shaft in the axis direction, and a terminal holder which holds a first terminal for supplying an electric current to the electric motor, wherein a layout region of the positioning member in the axis direction and a layout region of the terminal holder in the axis direction are overlapped with each other.
In another aspect of the present invention, the electric motor comprises: a stator having a coil connected to the first terminal; and a rotor attached to the rotating shaft, and forming a rotating magnetic field together with the stator.
In another aspect of the present invention, the driving apparatus further comprises: a gear case in which the rotating shaft is housed; and a bearing disposed inside the gear case, the bearing rotatably supporting the rotating shaft, wherein the positioning member is made in contact with the bearing and the gear case to determine the position of the rotating shaft in the axis direction.
In another aspect of the present invention, the driving apparatus further comprises: a worm formed on the rotating shaft; and a worm wheel rotatably disposed in the gear case, the worm wheel having a worm gear which is meshed with the worm.
In another aspect of the present invention, the driving apparatus further comprises: a cover which covers an opening of the gear case, a control board supported by the cover, the control board having installed thereon electric parts which control the electric motor, and a second terminal attached to the control board and connected to the first terminal.
In another aspect of the present invention, a load receiving mechanism is installed inside the gear case, and receives a load which is applied to the terminal holder when the first terminal and the second terminal are connected to each other.
In another aspect of the present invention, the load receiving mechanism is a mount which protrudes from an inner surface of the gear case.
In another aspect of the present invention, the load receiving mechanism is the positioning member.
In another aspect of the present invention, the second terminal protrudes in the axis direction from an edge of the control board, and a sensor for detecting a rotation phase of the rotating shaft is installed on the control board.
In another aspect of the present invention, the driving apparatus further comprises: an output shaft which is connected to a wiper arm, and rotated with the worm wheel.
In another aspect of the present invention, the electric motor is a brushless motor.
According to the present invention, in the axis direction, since the layout region of the terminal holder and the layout region of the positioning member are overlapped with each other, it is possible to suppress the size of the driving apparatus in the axis direction.
Hereinafter, embodiments of the driving apparatus will be described in detail with reference to the drawings.
The motor case 11 and the gear case 12 form a first housing chamber A1, and the gear case 12 and the cover 13 form a second housing chamber A2. In other words, the first housing chamber A1 and the second housing chamber A2 are formed in the casing 10A. In the gear case 12, a wall 12B is formed so as to partition an inner space into the first housing chamber A1 and the second housing chamber A2. A shaft hole 12C extends in such a way as to penetrate the wall 12B. The first housing chamber A1 and the second housing chamber A2 communicate with each other through the shaft hole 12C.
The driving apparatus 10 includes an electric motor 16 and a speed-reducing mechanism 73. The electric motor 16 is disposed in the first housing chamber A1. The speed-reducing mechanism 73 is disposed in the second housing chamber A2.
The motor case 11 includes a cylindrical portion 17 and a wall 18 closing a first end of the cylindrical portion 17, the first end being one end in a direction along an axis B1. The motor case 11 is molded integrally out of insulating material such as synthetic resin. The material of the motor case 11 is not limited to the synthetic resin. Other materials, such as iron, may be used to make the motor case 11 such that an iron sheet is stamped by a press machine to form the motor case 11. An opening 34 is formed on a second end of the cylindrical portion 17. The gear case 12 includes a body 22 having a recession 21, and a cylindrical connecting portion 23 continuous with the body 22. The connecting portion 23 is fixed to the cylindrical portion 17, using a screw 14. The gear case 12 is integrally molded out of conductive material such as iron and aluminum. The wall 12B is formed on the inner surface of the connecting portion 23 along its entire circumference.
The electric motor 16 has a stator 25 and a rotor 26. The stator 25 is disposed in the first housing chamber A1, and does not rotate relative to the motor case 11 and the gear case 12. The stator 25 has a stator core and a plurality of coils 88 wound around the stator core. The coils 88 include three coils, i.e., “U-phase coil”, “V-phase coil”, and “W-phase coil”.
The rotor 26 has a rotor core 26a and a permanent magnet 28 fixed to the outer periphery of the rotor core 26a. The rotor 26 is disposed in such a way as to extend from the housing chamber A1 to the housing chamber A2. A rotating shaft 27 is disposed in such a way as to extend from the housing chamber A1 to the housing chamber A2, and fitted with two bearings, i.e., bearings 29 and 30 which rotatably support the rotating shaft 27. The rotating shaft 27 is fitted in an inner ring of the bearing 30, and the bearing 30 is fixed to the rotating shaft 27 in a direction of an axis B1. The rotor 26 is fixed to the outer periphery of the rotating shaft 27. The rotor core 26a and the rotating shaft 27 are integrally rotated around the axis B1.
As shown in
A stopper 77 is installed between the bearing support portion 75 and the wall portion 12B, and the position of the stopper 77 is determined in the direction of the axis B1. Furthermore, an annular end face 75A is formed on the inner peripheral portion of the bearing support portion 75, and perpendicular to the axis B1.
The stopper 77 is formed by press working on a metal material, and as shown in
The bearing 30 is disposed between the stopper 77 and the end face 75A in the direction of the axis B1. The stopper 77 and the end face 75A determine the position of the rotating shaft 27 in the direction of the axis B1 relative to the gear case 12 together with the bearing 30. Each surface of two leg portions 77A of the stopper 77 has a concavo/convex shape in the direction of the axis B1. The stopper 77 is pressed onto the bearing 30 and the wall portion 12B by an elastic force of the stopper 77. One portion of the rotating shaft 27 in a length direction thereof is disposed in the shaft hole 12c.
Furthermore, as shown in
In the rotating shaft 27, a worm 40 is fitted to an outer periphery of a portion which is disposed in a recessed portion 21 of the gear case 12, or a portion which is housed in the second housing chamber A2. A permanent magnet 47 is fitted to the outer periphery of the portion disposed in a recessed portion 21 of the gear case 12, in the rotating shaft 27. The permanent magnet 47 is used as a sensor magnet, and has magnetic poles alternately arranged in a rotation direction of the rotating shaft 27.
Furthermore, as shown in
In
On the other hand, as shown in
As shown in
As shown in
Furthermore, a terminal 44 is provided in the terminal holding slot 37, a terminal 45 is provided in the terminal holding slot 38, and a terminal 46 is provided in the terminal holding slot 39. The terminals 44, 45, and 46 are respectively connected to three coils 88, that is, the U-phase coil, V-phase coil, and W-phase coil. In other words, the terminals 44, 45, and 46 are arranged in the second housing chamber A2.
As shown in
The control board 49 is disposed between the cover 13 and the board cover 48 in a direction along the axis C1. In
The control board 49 is molded out of insulating material, and carries an electric circuit as well as various electric components. The electric components mounted on the control board 49 include a controller chip 53, capacitors 54 and 55, an inductor 56, an inverter chip 57 having a plurality of switching elements, terminals 58, 59, and 60, terminals 61 to 65, a ground terminal 66, and three magnetic sensors 68. The three magnetic sensors 68 are Hall ICs, and disposed along an edge 49a of the control board 49. The edge 49a extends in a direction substantially perpendicular to the axis B1, when seen in the bottom view of the gear case 12. The layout region of the three magnetic sensors 68 is overlapped with the layout region of the permanent magnet 47. The three magnetic sensors 68 detect the intensity of the magnetic field and switching of the magnetic field formed by the permanent magnet 47, and output electric signals.
As shown in
The terminal 59 has leg portions 59a and 59b and a connecting portion 59c connecting the leg portion 59a to the leg portion 59b. The leg portion 59a has an end fixed to the control board 49, and an end (the other end) connected to the connecting portion 59c. The terminal 60 has leg portions 60a and 60b and a connecting portion 60c connecting the leg portion 60a to the leg portion 60b. The leg portion 60a has an end fixed to the control board 49, and an end (the other end) connected to the connecting portion 60c. All of the leg portions 58a, 58b, 59a, 59b, 60a , and 60b extend in a thickness direction of the control board 49, that is, extend in a direction along the axis C1.
Furthermore, in
As shown in
Next, operations and controls of the driving apparatus 10 will be described in detail. Power of an external power supply is supplied to the electric circuits of the control board 49 through the terminals 61 to 65. Furthermore, electric power is supplied from the external power supply, so that currents flow through the three coils 88 through the terminals 58, 59 and 60 as well as the terminals 44, 45 and 46. The switching elements of the inverter chip 57 are switched ON/OFF so that currents successively flow through the three coils 88 to form a rotating magnetic field, thereby allowing the rotor 26 to integrally rotate. The controller chip 53 detects the actual rotation phase and the actual rotation speed of the rotating shaft 27 by signals from the magnetic sensors 68, and by controlling the ON/OF timing and the ON ratio of the switching elements, it controls a target rotation number and a target rotation speed of the rotor 26.
In this manner, the electric motor 16 has a configuration for allowing electric currents to flow through the coils 88 of the stator 25, a rotating magnetic field is formed by cooperative functions between the rotor core 26a and the permanent magnet 28. The electric motor 16 is not provided with energizing brushes and a commutator with which the brushes are made in contact. That is, the electric motor 16 is a brushless motor. A torque of the rotating shaft 27 is transmitted to the worm wheel 41 through the worm 40 so that the output shaft 74 rotates and the wiper arm 83 is operated.
As shown in
Furthermore, since the layout region of the stopper 77 and the layout region of the protruding portion 33 are overlapped with each other in the axis direction of the rotating shaft 27 corresponding to the direction of the axis B1, the amount of each protrusion of the terminals 58, 59 and 60 from the edge 49a of the control board 49 in the axis direction of the rotating shaft 27 corresponding to the direction of the axis B1 can be reduced as much as possible.
Next, an assembling method for the driving apparatus 10 will be described in detail. First, as shown in
After completion of the parallel movement of the rotor 26 into the gear case 12, the stopper 77 is inserted between the bearing support portion 75 of the gear case 12 and the wall portion 12B, and the position of the rotor 26 is determined relative to the gear case 12 in the axis direction of the rotating shaft 27 corresponding to the direction of the axis B1. The two leg portions 77A of the stopper 77 are disposed so as to across and straddle the rotating shaft 27. Then, the worm wheel 41 is disposed in the concave portion 21 of the gear case 12 so that the worm gear 42 and the worm 40 are meshed with each other.
Next, the terminal holder 31 is inserted into the connection portion 23, and the protruding portion 33 is also inserted into the through hole 36. Furthermore, the cylindrical portion 32 of the terminal holder 31 is allowed to proceed into the connection portion 23 so that as shown in
Furthermore, the cover 13, to which the substrate cover 48 and the control board 49 are attached, and the gear case 12 are made closer to each other in the axis direction of the output shaft 74, which corresponds to a direction along the axis C1. In this case, the leg portion 58b of the terminal 58 is allowed to proceed to the terminal holding groove 37 so that the leg portion 58b is connected to the terminal 44. In the same manner, the leg portion 59b of the terminal 59 is allowed to proceed to the terminal holding groove 38 so that the leg portion 59b is connected to the terminal 45, and the leg portion 60b of the terminal 60 is allowed to proceed to the terminal holding groove 39 so that the leg portion 60b is connected to the terminal 46. Furthermore, as shown in
In the above-mentioned assembling processes of the driving apparatus 10, when the terminals 58, 59 and 60 and the terminals 44, 45 and 46 are mutually connected to each other, the protruding portion 33 receives a pressing load or a press-inserting load. In this case, the seat surface of the mount 82 and the surface 77E are disposed at the same positions as each other in the axis direction of the output shaft 74, which corresponds to the direction of the axis C1, the load received by the protruding portion 33 is transmitted to the mount 82 and the stopper 77.
Furthermore, as shown in
In contrast, as shown in
In this manner, the load to be received by the protruding portion 33 can be received by the mount 82 so that insertion amounts of the terminals 58, 59 and 60 into the terminals 44, 45 and 46 need not be managed in detail. Therefore, it is possible to easily carry out connection works between the terminals 58, 59, 60 and the terminals 44, 45, and 46.
The electric motor 16 described in the embodiment corresponds to “electric motor”, the rotating shaft 27 corresponds to “rotating shaft”, the axis B1 corresponds to “axis”, the driving apparatus 10 corresponds to “driving apparatus”, the stopper 77 corresponds to “positioning member”, each of the terminals 44, 45, 46 correspond to “first terminals”, and the terminal holder 31 corresponds to “terminal holder”. The coil 88 corresponds to “coil”, the stator 25 corresponds to “stator”, the rotor 26 corresponds to “rotor”, the gear case 12 corresponds to “gear case”, the bearing 30 corresponds to “bearing”, the worm 40 corresponds to “worm”, the opening 12D corresponds to “opening”, and the cover 13 corresponds to “cover”.
The electric portions include a controller chip 53, capacitors 54 and 55, a inductor 56, an inverter chip 57 having a plurality of switching elements, terminals 58, 59 and 60, terminals 61 to 65, an earth terminal 66, and a magnetic sensor 68. The control board 49 corresponds to “control board”, and each of the terminals 58, 59 and 60 correspond to “second terminals”. At least, either one of the mount 82 and the plate portion 77B of the stopper 77 corresponds to “load receiving mechanism”, and the mount 82 corresponds to “mount”. Furthermore, the magnetic sensor 68 corresponds to “sensor”, the electric motor 16 corresponds to “brushless motor”, the worm wheel 41 corresponds to “worm wheel”, and the output shaft 74 corresponds to “output shaft”.
The present invention is not to be limited to the described embodiment. Alternations and/or modifications of the illustrated and/or described embodiments are contemplated as being alternative forms of the invention as far as they do not depart from the scope of the present invention, which is defined by the appended claims. Each number of the first and second terminals is not limited to three, and for example, two, four or more terminals are provided as each of the first and second terminals.
Furthermore, the electric motor is not limited by the brushless motor, and may include a motor with brushes. The motor with brushes is provided with a commutator fixed to the rotating shaft, a brush holder attached to the motor case, and brushes which are supported by the brush holder and made in contact with the commutator. In this case, the terminal holder is installed as an integral unit of the brush holder or a separated unit therefrom. The first terminals attached to the terminal holder are connected to the brushes. Furthermore, the driving apparatus includes a structure which allows the brushes to be made in contact with the commutator when the brush holder is attached to the gear case in assembling processes for the motor with brushes.
The layout region of the positioning member and the terminal holder includes meaning of the layout length in the axis direction or the layout range in the axis direction.
The driving apparatus can be used as a power source of an operating apparatus to be mounted on for example a vehicle, such as for example, a wiper apparatus for operating a wiper arm, a power window apparatus for operating a window incorporated in a door, a slide door apparatus for operating a slide door provided on either/both sides of the vehicle body.
While the present disclosure has been illustrated and described with respect to a particular embodiment thereof, it should be appreciated by those of ordinary skill in the art that various modifications to this disclosure may be made without departing from the spirit and scope of the present disclosure.
Number | Date | Country | Kind |
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2015-007698 | Jan 2015 | JP | national |
This application is a National Stage application of International Patent Application No. PCT/JP2016/050536, filed on Jan. 8, 2016, which claims priority to Japanese Patent Application No. 2015-007698, filed on Jan. 19, 2015, each of which is hereby incorporated by reference in its entirety.
Filing Document | Filing Date | Country | Kind |
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PCT/JP2016/050536 | 1/8/2016 | WO | 00 |