JPH08242569A - Commutatorless motor - Google Patents

Abstract

(57) [Abstract] [Purpose] It is difficult to maintain the reliability of a non-commutator motor if the bearing is a sliding bearing, and if the bearing is a rolling bearing, the motor is expensive. Was. An object of the present invention is to solve these problems and provide an inexpensive and highly reliable non-commutator motor. A magnetizing pattern of a permanent magnet 1 of a rotor is axially divided into two parts, a drive part facing a laminated core and generating a torque, and a position detecting part giving a position signal magnetic flux to the magnetic sensor, and a boundary part thereof. Is provided with a non-magnetized portion 19. As a result, the rotor is attracted in the direction of the circuit board 14 by a strong magnetic attraction force, so that the rotor can be rotated at a stable position without sliding on the end surface of the slide bearing 10 as in the conventional case, and thus reliability is improved. A high commutatorless motor can be realized by using inexpensive plain bearings.

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. 5 shows the structure of a non-commutator motor used in a conventional fan motor for cooling equipment. In FIG. 5, 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 composed of a plurality of core plates, which is installed so as to face the inner peripheral surface of the permanent magnet 1, and a winding 7 is wound around the protrusion thereof. 8
Is a bearing portion composed of two slide bearings 9 and 10 and several slide plates 11, and holds three shafts. A retainer 12 is attached to the end of the shaft. Also,
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 portion of the permanent magnet 1 together with the current control circuit portion 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. An oil drainer 16 is attached to the shaft 3 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.

FIG. 6 is a development view of a permanent magnet of the motor shown in FIG. The operation of the non-commutator motor configured as described above 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 causes the rotor 7 to rotate in the correct direction in response to this signal, so that an appropriate current is supplied to the winding 7. The rotor rotates accordingly. Since the magnetic sensor 13 constantly monitors the movement of the rotor, the rotation of the rotor continues without stopping.

[0006]

However, in the above-mentioned conventional structure, the magnetic sensor 13 has to be placed at a position apart from the laminated core to some extent because the winding 7 exists, and the magnetic flux of the permanent magnet is detected. Therefore, it is necessary to extend the end of the permanent magnet 1 of the rotor to the vicinity of the magnetic sensor 13. Since the magnetic flux of the rotor is uniform in the axial direction, the magnetic attraction force of the rotor naturally goes in the direction opposite to that of the circuit board. Therefore, in order to rotate the rotor at a stable position, it is necessary to limit the movement of the rotor at the end surface of the slide bearing 10. Since the plain bearing is generally weak against sliding on the end face, the life of the motor is shortened. Further, in order to prevent this, there is a problem that the bearing needs to be an expensive rolling bearing.

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

[0008]

To achieve this object, a commutatorless motor according to the present invention comprises a drive section for generating torque by facing a laminated core with a magnetized pattern of a permanent magnet of a rotor. The position detecting section that gives a position signal magnetic flux to the magnetic sensor is divided into two parts in the axial direction, and a non-magnetized part is provided at the boundary part.

[0009]

With this configuration, since the magnetic attraction force of the rotor is in the direction of the circuit board, even if the bearing is a sliding bearing, it is not necessary to limit the movement of the rotor at its end face, and the rotor can be placed at a stable position. Can be rotated.

[0010]

【Example】

(Embodiment 1) 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 part having blades 5 attached to its outer circumference. Reference numeral 8 is a bearing portion, and slide bearings 9 and 10 that support the shaft 3.
And an end face receiving plate 18 of the shaft 3. Thirteen
Is a sensor for detecting the position of the rotor, and the circuit board 1
It is installed in 4. A stator 6 has a winding 7 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. Shaft 3
An oil drainer 16 is attached to the bearing 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. This cap 17
Holds an end face receiving plate 18. Reference numeral 19 is a non-magnetized portion of the permanent magnet 1.

FIG. 2 is a developed view of the permanent magnet shown in FIG. As described above, according to this embodiment, even if the end portion of the permanent magnet 1 of the rotor is extended to the vicinity of the circuit board 14, the magnetic flux of the permanent magnet 1 is unbalanced.
Since a large magnetic attraction force in the direction of 4 is generated, the end face of the plain bearing 10 can regulate the movement of the rotor without limiting the movement of the rotor, and the reliability of the plain bearing 10 is not impaired. .

(Second Embodiment) A second embodiment of the present invention will be described below with reference to the drawings.

FIG. 3 shows only the bearing portion of another embodiment in which the structure of the bearing portion of FIG. 1 is changed. This is an example of a bearing portion in which the rotor side of the bearing member is a rolling bearing and the other one is a sliding bearing. 20 is a rolling bearing, 10 is a sliding bearing,
Reference numeral 21 is a spacer for allowing the inner ring of the rolling bearing 20 to receive the load of the rotor. 3 is a shaft and 2 is a frame. In this case, since the rolling bearing 20 regulates the movement of the rotor, the end face receiving plate is not necessary. Further, since the preload required when using the rolling bearing can be obtained by the strong magnetic attraction force of the rotor toward the circuit board, it is not necessary to use two expensive rolling bearings.

(Embodiment 3) A third embodiment of the present invention will be described below with reference to the drawings.

FIG. 4 shows another embodiment of the magnetization pattern of the permanent magnet of FIG. In this case, since the drive unit and the position detection unit are magnetized with different polarities, as a result, a non-magnetized portion is formed at the boundary between the drive unit and the position detection unit, and the same effect as the permanent magnet of FIG. 2 can be expected. .

[0017]

As described above, according to the present invention, there are provided a drive unit for generating a torque by facing a magnetized pattern of a permanent magnet of a rotor to a laminated core, and a position detection unit for giving a position signal magnetic flux to the magnetic sensor. Since it is divided into two parts in the axial direction and has a non-magnetized part at the boundary part, it is possible to obtain a large magnetic attraction force to the circuit board side. A commutator motor can be realized.

[Brief description of drawings]

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

FIG. 2 is a development view of a permanent magnet of a commutatorless motor according to the first embodiment of the present invention.

FIG. 3 is a sectional view of a bearing portion of a commutatorless motor according to a second embodiment of the present invention.

FIG. 4 is a development view of a permanent magnet of a commutatorless motor according to a third embodiment of the present invention.

FIG. 5 is a sectional view of a conventional commutatorless motor.

FIG. 6 is a development view of a permanent magnet of a conventional commutatorless motor.

[Explanation of symbols]

 DESCRIPTION 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 End face receiving plate 19 Non-magnetized part of permanent magnet 20 Rolling bearing 21 Spacer

Claims (8)

[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. And a ring-shaped rotor comprising a member having a mechanism for holding 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. In order to rotate the rotor in a fixed direction by passing a current through the stator winding, and a stator consisting of a winding wound around the protrusion so as to generate a magnetic flux on each protrusion of the laminated core, A sensor that detects the position of the rotor installed away from the side holding the shaft of the rotor by the end face magnetic flux of the permanent magnet or the leakage magnetic flux on the inner face, and a sensor that responds to the signal from the sensor. Control circuit that passes current A drive unit that includes a circuit board including the same and a bearing unit that is installed at the center of the stator and that configures the center of rotation of the rotor, wherein the annular permanent magnet magnetization pattern of the rotor faces the laminated core to generate torque. And the magnetic field is divided into two parts in the axial direction by the position detecting part that gives the position signal magnetic flux to the magnetic sensor, and the number of each magnetic pole is the same as a multiple of 2, and the driving part and the position detecting part facing each other in the axial direction are divided. The magnetic poles are magnetized to the same polarity, and by having a non-magnetized portion at the boundary between the drive section and the position detection section, a non-commutator in which the magnetic force of attracting the rotor toward the circuit board is greatly increased motor. 2. A 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. 3. The bearing according to claim 1, wherein the bearing portion is composed of two bearing members, the bearing member on the shaft holding mechanism side of the rotor is a rolling bearing, and the other one is a sliding bearing. No commutator motor. 4. The non-commutator motor according to claim 1, wherein the bearing portion comprises a slide bearing for receiving the outer circumference of the shaft and a slide bearing portion for receiving the tip of the shaft. 5. An annular permanent magnet radially magnetized from the inner diameter to the outer diameter, a frame surrounding the outer periphery of the permanent magnet to form a magnetic path, and a rotation center of a rotor at one axial end of the frame. And a ring-shaped rotor comprising a member having a mechanism for holding 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. In order to rotate the rotor in a fixed direction by passing a current through the stator winding, and a stator consisting of a winding wound around the protrusion so as to generate a magnetic flux on each protrusion of the laminated core, A sensor that detects the position of the rotor installed away from the side holding the shaft of the rotor by the end face magnetic flux of the permanent magnet or the leakage magnetic flux on the inner face, and a sensor that responds to the signal from the sensor. Control circuit that passes current A drive unit that includes a circuit board including the same and a bearing unit that is installed at the center of the stator and that configures the center of rotation of the rotor, wherein the annular permanent magnet magnetization pattern of the rotor faces the laminated core to generate torque. And the magnetic field is divided into two parts in the axial direction by the position detecting part that gives the position signal magnetic flux to the magnetic sensor, and the number of each magnetic pole is the same as a multiple of 2, and the driving part and the position detecting part facing each other in the axial direction are divided. Since the magnetic poles are magnetized differently, a region where the magnetic poles are reversed is formed at the boundary between the drive unit and the position detection unit, and the magnetic force that attracts the rotor toward the circuit board is greatly increased. Child motor. 6. The non-commutator motor according to claim 5, wherein a plurality of blades are provided on an outer peripheral portion of the rotor, and an annular wind tunnel portion surrounds the rotor to form a box-shaped cooling fan. 7. The bearing according to claim 5, wherein the bearing portion is composed of two bearing members, the bearing member on the shaft holding mechanism side of the rotor is a rolling bearing, and the other one is a slide bearing. No commutator motor. 8. The non-commutator motor according to claim 5, wherein the bearing portion comprises a slide bearing for receiving the outer circumference of the shaft and a slide bearing portion for receiving the tip of the shaft.