JP3427222B2 - motor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor incorporating a drive circuit. Conventionally, a molded brushless motor or the like has a built-in PC board provided with a drive circuit inside the mold. [0003] In the case of a motor incorporating this drive circuit, electrical insulation from the outside of the motor becomes a problem. For example, if there is a conductive object around the motor, there will be stray capacitance between the drive circuit and the object. There is no problem when the stray capacitance is small, but when the stray capacitance is a certain value or more, a voltage difference occurs between the drive circuit and the object due to disturbance or the like. This sometimes causes a malfunction or breakage of the drive circuit. [0004] In view of the above problems, the present invention provides a motor that can prevent malfunction and destruction of a drive circuit. [0005] The motor of the present invention is a PC
The board has a base layer and a ground pattern layer for noise suppression.
A structure having a conductive layer in order, the mounting parts of the motor drive circuit of the conductive layer <br/> of the PC board, the upper surface of the stator toward the PC board, the conductive layer on the stator side Or it is attached to the lower surface. [Work] The PC board has a base layer and a ground for noise suppression.
This structure has a pattern layer and a conductive layer in order.
In addition, since the conductive layer of the PC board on which the components are provided is disposed inside the motor, the floating capacitance between the PC board and the conductive material outside the motor is reduced. An embodiment of the present invention will be described below with reference to FIGS. The motor of the present embodiment is a brushless motor 10 in which a stator is covered with a mold resin. Reference numeral 12 denotes a stator. A protrusion 14 is provided on the upper surface of the stator 12. Reference numeral 16 denotes a PC board disposed on the projecting piece 14 of the stator 12. The PC board 16 has a four-layer structure as shown in FIG. 3, the first layer 16a is a conductive layer, the second layer 16b and the third layer 16c are ground patterns for noise suppression, and Four layers 16d are the base. Then, components 18 constituting a driving circuit such as transistors and resistors are arranged on the first layer 16a. The PC board 16 is attached to the protruding piece 14 such that the first layer 16a is disposed on the stator 12 side, whereby the component 18 is located on the stator 12 side. Reference numeral 20 denotes a mold resin that covers the stator 12, the PC board 16, and the component 18. The casing of the motor 10 is constituted by the mold resin 20. Reference numeral 22 denotes a rotor arranged on the inner peripheral side of the stator 12. Reference numeral 24 denotes a rotor 22 which is
4 shows a bracket to be attached to 4. In the motor 10 having the above-described structure, the component 18 constituting the drive circuit is located inside the motor 10, that is,
The motor 1 is mounted facing the stator 12 side.
The stray capacitance between the conductive circuit outside the zero and the conductive object is reduced, so that the driving circuit does not malfunction or be destroyed. Further, the PC board 16 has a four-layer structure, and two layers of the PC board 16 are ground patterns for noise suppression, so that a malfunction does not occur with respect to noise. As described above, according to the motor of the present invention,
The PC board is the base layer and the ground pattern for noise suppression.
A structure having a layer and a conductive layer in order, also, since the attachment toward the conductive layer of the PC board mounted components on the stator side, the stray capacitance between the conductive material outside of the motor The size of the driving circuit is small, and the driving circuit does not malfunction or be destroyed.

[Brief description of the drawings] FIG. 1 is a longitudinal sectional view of a motor. FIG. 2 is a plan view of a motor. FIG. 3 is an enlarged vertical sectional view of a main part of the PC board. [Explanation of symbols] 10 Motor 12 Stator 16 PC board 18 Parts 20 Mold resin 22 Rotor 24 Bracket

Claims (1)

(57) [Claims] [Claim 1] The PC board is provided with a base layer and an arm for noise suppression.
A structure having layers and the conductive layers of the scan pattern sequentially, the mounting parts of the driving circuit of the motor to the conductive layer of the PC board, the PC plate, the stator toward the conductive layer on the stator side A motor mounted on the upper or lower surface.