JPH06335217A - Commutatorless motor - Google Patents

Abstract

(57) [Abstract] [Purpose] An inexpensive and highly reliable commutator motor that suppresses vibration noise generated in the gap between the shaft and the sliding bearing in a commutator motor used in various electric and electronic devices. provide. [Structure] An attracting member 18 made of a magnetic material is provided on a circuit board 14 facing a rotor of a permanent magnet. As a result, the permanent magnet 1 rotor is attracted toward the attraction member 18, so that the shaft 3 can rotate at a stable position without vibrating in the gap between the sliding bearings 9 and 10.
A commutatorless motor with less vibration can be realized by using an inexpensive sliding bearing.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a motor structure of a commutatorless motor.

[0002]

2. Description of the Related Art In recent years, the reliability of various electric and electronic devices has increased, and highly reliable non-commutator motors have been widely used as the power for these devices.

A conventional non-commutator motor will be described below. FIG. 4 shows the structure of a non-commutator motor used in a conventional fan motor for cooling equipment. In FIG. 4, 1 is a permanent magnet, 2 is a frame, 3 is a shaft, and these constitute a rotor. Around the rotor, a load portion 4 to which a fan motor blade 5 is attached is attached by a method such as press fitting. Reference numeral 6 denotes a stator, which is composed of a plurality of core plates having a plurality of protrusions and is installed so as to face the inner peripheral surface of the permanent magnet 1, and a winding 7 is wound around the protrusions. Reference numeral 8 is a bearing portion composed of two sliding bearings 9 and 10 and several sliding plates 11, and holds the shaft of 3. A stopper 12 is attached to the end of the shaft 3.
Is attached.

A magnetic sensor 13 for detecting the position of the rotor is installed on the circuit board 14 in the vicinity of the end face of the permanent magnet 1 together with the current control circuit of the winding 7.
Reference numeral 15 is a case of a fan motor that surrounds the blades 5 and holds the bearing portion 8. Shaft 3 has 1 oil drain
6 is attached for the purpose of preventing oil from scattering from the bearing portion 8. Further, 17 is also a member for the purpose of preventing oil leakage from the bearing portion 8 and is a cap.

The operation of the non-commutator motor having the above structure will be described below.

First, the magnetic sensor 13 detects the end face magnetic flux of the permanent magnet 1 of the rotor and sends a signal corresponding to the magnetic flux to the control circuit section. The control circuit section applies an appropriate current to the winding 7 in order to rotate the rotor in the correct direction in response to this signal. The rotor rotates accordingly. Since the magnetic sensor 13 constantly monitors the movement of the rotor, the rotation of the rotor continues without stopping.

[0007]

However, since there is a gap between the shaft 3 and the bearings 9 and 10 in the above-described conventional structure, the shaft is subjected to lateral pressure in a specific direction like a fan motor. If not, the shaft moves through the gap during the rotation of the motor to generate vibration. Since this vibration also changes the generated frequency according to the change in the moving state of the shaft, it is difficult to take measures against the vibration of the motor, which is a factor that hinders the adoption of a sliding bearing for the fan motor.

The present invention solves the above-mentioned conventional problems, and an object thereof is to provide an inexpensive commutatorless motor with less vibration.

[0009]

In order to achieve this object, the commutatorless motor of the present invention has a member made of a magnetic material, which is installed on the circuit board at a position facing the permanent magnet rotor.

[0010]

With this construction, the permanent magnet rotor is attracted toward the magnetic material member, and the shaft movement is suppressed and the shaft can rotate in a stable position. Therefore, vibration of the motor can be reduced even if the bearing is used as a sliding bearing. be able to.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, 1 is a permanent magnet, 2 is a frame, and 3 is a shaft, which form a rotor. Reference numeral 4 is a load portion having blades 5 attached to its outer periphery, and 8 is a bearing portion, which is composed of sliding bearings 9 and 10 for supporting the shaft 3 and several sliding plates 11.
Reference numeral 13 denotes a sensor that detects the position of the rotor, which is installed on the circuit board 14.

A member 18 made of a magnetic material is provided on the circuit board 14 so as to face the permanent magnet 1.
Reference numeral 6 denotes a stator in which a plurality of core plates having a plurality of protrusions are laminated, and a winding 7 is wound around the protrusion. Reference numeral 15 is a case of a fan motor that surrounds the blades 5 and holds the bearing portion 8. The inside of the case 15 serves as a wind tunnel to form a box-shaped cooling fan.

An oil drainer 16 is attached to the shaft 3 for the purpose of preventing oil from scattering from the bearing portion 8. Also, 1
7 is also a member for the purpose of preventing oil leakage from the bearing portion 8 and is a cap. A retaining member 12 is attached to the tip of the shaft 3.

FIG. 2 is a view of the positional relationship between the stator 6 of the fan motor of FIG. 1, the circuit board 14 and the suction member 18 made of a magnetic material, as viewed from above. FIG. 3 is a detailed view of the attraction member 18, where 19 is a surface facing the permanent magnet, the attraction surface of the permanent magnet, and 20 is a mounting foot portion for mounting on the circuit board.

According to the present embodiment constructed as described above, since the permanent magnet 1 of the rotor is always attracted by the attraction member 18 made of a magnetic material, the shaft 3 which is the center of rotation of the rotor is the sliding bearing 9. , 10 can be rotated in a stable position without moving at intervals, and vibration of the rotor can be suppressed small.

[0017]

As described above, the present invention can provide a low-vibration motor by having the magnetic material attracting member installed at a position facing the permanent magnet rotor on the circuit board.

[Brief description of drawings]

FIG. 1 is a sectional view of a commutatorless motor according to an embodiment of the present invention.

FIG. 2 is a top view of a stator portion of a commutatorless motor according to an embodiment of the present invention.

FIG. 3 is a detailed view of a suction member made of a magnetic material according to an embodiment of the present invention.

FIG. 4 is a sectional view of a conventional commutatorless motor.

[Explanation of symbols]

 1 Permanent Magnet 2 Frame 3 Shaft 4 Load Part 5 Blade 6 Stator 7 Winding 8 Bearing Part 9, 10 Sliding Bearing 11 Sliding Plate 12 Lockout 13 Magnetic Sensor 14 Circuit Board 15 Case 16 Oil Drain 17 Cap 18 From Magnetic Material Suction member 19 made of magnetic material Suction surface of suction member made of magnetic material 20 Attachment foot of suction member made of magnetic material

Claims (2)

[Claims] 1. A ring-shaped permanent magnet radially magnetized from an inner diameter to an outer diameter, a frame surrounding the outer circumference of the permanent magnet to form a magnetic path, and a rotation center of a rotor at one axial end of the frame. An annular rotor composed of a portion having a mechanism for holding a shaft forming a shaft, and a plurality of core plates having a plurality of protrusions inside the rotor and having a plurality of protrusions toward the rotor, stacked in the axial direction. Is
A stator that consists of a winding wound around each protrusion of this laminated core so as to generate a magnetic flux, and a sensor that detects the position of the rotor by the end face magnetic flux of the permanent magnet or the inner leakage flux. A non-commutator motor consisting of a circuit board including a control circuit that allows a current to flow according to the signal of this sensor, and a bearing section having at least one sintered oil-impregnated sliding bearing that is installed in the center of the stator and holds the rotor shaft. The non-commutator motor according to claim 1, wherein a member made of a magnetic material that attracts the permanent magnet rotor is installed at a position facing the permanent magnet rotor on the circuit board. 2. The non-commutator motor according to claim 1, wherein a plurality of blades are provided on an outer peripheral portion of the rotor, and an annular wind tunnel portion surrounds the blades to form a box-shaped cooling fan.