JP2023007636A - Driving device - Google Patents

Abstract

To provide a driving device capable of protecting a control circuit from an extraneous noise.SOLUTION: A driving device integrally comprises a motor and a control unit 40 that controls the motor. The control unit 40 includes: a substrate 41 that is arranged on a rotational shaft O of the motor; a motor driving element 55 that performs power conduction to the motor; a power wiring pattern 56 that is connected to the motor driving element 55 to supply power; and a control circuit 61 that transmits a control signal to the motor driving element 55. The control circuit 61 is arranged on a substrate center part 45. The power wiring pattern 56 is arranged on an outer side of a radial direction as compared to the motor driving element 55 in a substrate outer peripheral part 46 to surround the motor driving element 55 and the control circuit 61 in a half circumference or more, and is formed so as to be extended along an outer edge 44 of the substrate 41.SELECTED DRAWING: Figure 2

Description

The present invention relates to a driving device.

Conventionally, as a control unit including a board provided with a plurality of electronic components and a power wiring pattern for supplying power to them, for example, one described in Patent Document 1 is known. In Patent Document 1, the board is a multi-layer board, and the power wiring patterns are arranged on the outer periphery of a predetermined layer, and the power wiring patterns are arranged to face each other between the layers. The power wiring patterns facing each other between the layers serve as capacitors using the dielectric constant of the substrate, reduce the impedance of the power source, and act to absorb power source noise. By suppressing the emission of power supply noise, it is intended to prevent malfunction of peripheral devices.

JP-A-2002-94246

By the way, in the control unit, it is desired to protect the control circuit from external noise, and there is room for improvement in this respect.

SUMMARY OF THE INVENTION An object of the present invention is to provide a driving device capable of protecting a control circuit from external noise.

The driving device of the present invention integrally includes a motor (20) and a control unit (40) for controlling the motor. The control unit includes a substrate (41) arranged on the rotation axis (O) of the motor, a motor driving element (55) for energizing the motor, and a power wiring pattern for supplying power by being connected to the motor driving element. (56) and a control circuit (61) for sending control signals to the motor drive elements.

A portion of the substrate within a predetermined distance from the center of rotation and closer to the center of rotation than the outer edge of the substrate is defined as a central portion (45) of the substrate. A portion of the substrate other than the central portion of the substrate is defined as a substrate peripheral portion (46).

A control circuit is arranged in the central part of the substrate. The power wiring pattern is arranged radially outside of the motor driving element on the outer periphery of the substrate, surrounds the motor driving element and the control circuit by more than half the circumference, and extends along the outer edge of the substrate.

As a result, the power wiring pattern has sufficient conductor capacity to allow a large current to flow, so that the motor driving element and the control circuit are shielded by surrounding them with conductors of relatively low impedance. Therefore, the control circuit can be protected from external noise.

1 is a longitudinal sectional view of a drive device according to one embodiment; FIG. The figure which looked at the board|substrate of FIG. 1, an electronic component, and a screw from the arrow II direction. III partial enlarged view of FIG.

Embodiments of the driving device will be described below with reference to the drawings.

[One embodiment]
As shown in FIG. 1, the driving device 10 integrally includes a motor 20 and a control unit 40 for controlling it. The control unit 40 controls the motor 20 to generate a desired torque based on externally input information and information such as motor current detected inside the control unit 40 . Torque of the motor 20 is output from the output end of the rotary shaft 26 to the outside.

The motor 20 is a three-phase brushless motor and includes a stator 21, a rotor 25, and a housing 31 that accommodates them. Stator 21 has stator core 22 fixed to housing 31 and three-phase winding set 23 assembled to stator core 22 . The three-phase winding set 23 is connected to the control unit 40 via lead wires (not shown).

The rotor 25 has a rotating shaft 26 supported by a rear bearing 35 and a front bearing 36, and a rotor core 27 in which the rotating shaft 26 is fitted. The rotor 25 is provided inside the stator 21 and is rotatable relative to the stator 21 . A permanent magnet 37 is provided at one end of the rotating shaft 26 .

The housing 31 has a tubular case 32 , a front frame end 33 provided at one end of the case 32 , and a rear frame end 34 provided at the other end of the case 32 . The front frame end 33 and the rear frame end 34 are fastened together by bolts (not shown). Front frame end 33 also serves as a heat sink for control unit 40 . Hereinafter, when the function of the front frame end 33 as a heat sink is described, the term "heat sink 33" is used as appropriate.

As shown in FIGS. 1 and 2, the control unit 40 includes a heat sink 33 and a substrate 41 arranged on the rotation axis O of the motor 20, a screw 51 as a fixing member for fixing the substrate 41, and a , a power wiring pattern 56 connected to the motor drive element 55 to supply power, a control circuit 61 for sending a control signal to the motor drive element 55, and a rotation angle detection of the rotation shaft 26. and a rotation angle sensor 62 that rotates.

The substrate 41 is arranged on the side opposite to the stator 21 with respect to the heat sink 33 . In one embodiment, there is one substrate 41, but in other embodiments there may be two or more substrates. The screw 51 is inserted through the through hole 42 of the substrate 41 . The motor driving element 55 is composed of, for example, a switching element such as a MOSFET, and performs a switching operation in response to a control signal from the control circuit 61 to switch the conduction state of the three-phase winding set 23 . The control circuit 61 performs calculations based on information from the outside, the rotation angle sensor 62, etc., and generates a signal for instructing the motor driving element 55, etc. FIG.

The control unit 40 further has a cover 64 arranged to cover the board 41 and the electronic components mounted thereon, and a connector 66 for connecting the control unit 40 to the outside.

The cover 64 protects the control unit 40 from external shocks and prevents dust, water, and the like from entering the control unit 40 . 1 and 2, illustration of electronic components other than the motor driving element 55 and the control circuit 61 is omitted. The connector 66 is fixed to the connector connection portion 43 of the board 41 by a screw 63 and extends out of the cover 64 through the opening 65 .

A portion of the substrate 41 within a predetermined distance from the rotation axis O and closer to the rotation axis O than the outer edge 44 of the substrate 41 is defined as a substrate central portion 45 . A portion of the substrate 41 other than the substrate central portion 45 is defined as a substrate peripheral portion 46 .

The control circuit 61 is arranged in the substrate central portion 45 . Particularly, in one embodiment, the control circuit 61 is arranged on the rotation axis O and substantially at the center of the substrate central portion 45 .

The screws 51 are arranged on the outer peripheral portion 46 of the substrate to secure the mounting area and fix the substrate 41 to the heat sink 33 . In one embodiment, three screws 51 are provided circumferentially around the rotation axis O at intervals.

The power wiring pattern 56 and the motor drive element 55 are arranged on the substrate outer peripheral portion 46 . The power wiring pattern 56 is arranged radially outside (that is, closer to the outer edge 44 ) than the motor drive element 55 , surrounds the motor drive element 55 and the control circuit 61 more than half the circumference, and extends along the outer edge 44 . ing. In particular, in one embodiment, the power wiring pattern 56 is formed over the entire area of the substrate outer peripheral portion 46 other than the connector connection portion 43 .

The mounting surface of the substrate 41 opposite to the heat sink 33 is defined as a first mounting surface 47 . The mounting surface of the substrate 41 on the side of the heat sink 33 is defined as a second mounting surface 48 .

The motor driving element 55 is arranged on the first mounting surface 47 . That is, the motor drive element 55 is arranged on the opposite side of the heat sink 33 with the substrate 41 interposed therebetween.

The power wiring pattern 56 is arranged on the first mounting surface 47 and is connected to the high potential side of the motor driving element 55 to supply power. and a ground pattern 58 connected to the potential side. A power supply pattern 57 and a ground pattern 58 are arranged facing each other between the substrates 41 . The ground pattern 58 is electrically connected by contacting the heat sink 33 .

The ground pattern 58 is formed up to the edge of the through hole 42 and contacts the screw 51 . The ground pattern 58 is directly connected to the heat sink 33 and also indirectly connected to the heat sink 33 via the screw 51 .

(effect)
As described above, in one embodiment, the control circuit 61 is located in the substrate central portion 45 . The power wiring pattern 56 is arranged radially outside of the motor driving element 55 in the substrate outer peripheral portion 46 , surrounds the motor driving element 55 and the control circuit 61 by more than half the circumference, and extends along the outer edge 44 of the substrate 41 . formed. As a result, the power wiring pattern 56 has sufficient conductor capacity to allow a large current to flow, so that the motor drive element 55 and the control circuit 61 are shielded by surrounding them with conductors of relatively low impedance. Therefore, the control circuit 61 can be protected from external noise.

Also in one embodiment, the motor drive element 55 is located on the first mounting surface 47 . The power wiring pattern 56 is arranged on the first mounting surface 47 and is connected to the high potential side of the motor driving element 55 to supply power. and a ground pattern 58 connected to the potential side. The ground pattern 58 is electrically connected by contacting the heat sink 33 . By electrically connecting the ground pattern 58 to the heat sink 33 in this way, the impedance of the power wiring pattern 56 is further lowered, and the shielding effect of the power wiring pattern 56 can be further enhanced.

Further, in one embodiment, the power wiring pattern 56 is formed over the entire area of the substrate outer peripheral portion 46 other than the connector connecting portion 43 . As a result, substantially the entire circumference of the substrate 41 can be surrounded and effectively shielded.

[Other embodiments]
In another embodiment, the power wiring pattern may be formed to surround the entire perimeter of the substrate.

The present invention is not limited to the above-described embodiments, and can be embodied in various forms without departing from the scope of the invention.

REFERENCE SIGNS LIST 10 drive device 20 motor 33 heat sink 40 control unit 41 substrate 44 outer edge 45 substrate central portion 46 substrate outer peripheral portion 51 screw (fixing member) 55 motor drive element 56 power wiring pattern 61 control circuit , O rotation axis.

Claims (3)

A driving device integrally comprising a motor (20) and a control unit (40) for controlling the motor,
The control unit includes a substrate (41) arranged on the rotation axis (O) of the motor, a motor drive element (55) for energizing the motor, and a power supply connected to the motor drive element (55). and a control circuit (61) for sending a control signal to the motor driving element,
A portion of the substrate within a predetermined distance from the rotation axis and closer to the rotation axis than the outer edge (44) of the substrate is defined as a substrate central portion (45). If the portion other than the central portion of the substrate is defined as the peripheral portion (46) of the substrate,
The control circuit is arranged in the central portion of the substrate,
The power wiring pattern is arranged radially outside of the motor driving element at the outer peripheral portion of the substrate, surrounds the motor driving element and the control circuit by more than half the circumference, and extends along the outer edge. There is a drive. When the mounting surface of the substrate opposite to the heat sink is defined as a first mounting surface (47), and the mounting surface of the substrate on the heat sink side is defined as a second mounting surface (48). ,
the motor driving element is disposed on the first mounting surface;
The power wiring pattern is arranged on the first mounting surface and is connected to the high potential side of the motor driving element to supply power, and the power wiring pattern is arranged on the second mounting surface and is connected to the motor driving element. a ground pattern (58) connected to the low potential side of
2. The driving device according to claim 1, wherein said ground pattern is electrically connected by contacting said heat sink. The control unit further has a connector (66) for connecting the control unit to the outside,
The substrate peripheral portion has a connector connection portion (43) connected to the connector,
3. The driving device according to claim 1, wherein said power wiring pattern is formed on the entire peripheral portion of said substrate other than said connector connecting portion.

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