JPH0628342U - Magnetic fluid bearing device - Google Patents

Abstract

(57) [Abstract] [Purpose] To obtain a small bearing with small friction loss. [Structure] A non-magnetic bearing member (5) provided inside the end of the frame (1) and having a hole larger than the outer diameter of the rotating shaft (2) in the center, and provided on the surface of the rotating shaft (2). , A radial bearing portion (4) having a radial bearing magnet (41) in which the permanent magnet of the rotor (3) is extended to the bearing portion and magnetized in multiple poles, and fixed to the rotating shaft (2) near the bearing portion The inner peripheral portion of the bearing member (5) and the radial member, each of which has a thrust bearing magnet (62) in which a surface facing the side surface of the bearing member (5) is multipolarly magnetized and a thrust disc (61). A radial bearing (4) filled with a magnetic fluid (7) between the bearing magnet (41) and a magnetic fluid (between the rotor-side side surface of the bearing member and the thrust disc (61)). And a thrust bearing portion (6) filled with 7).

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a bearing for a micro motor, and more particularly to a bearing using magnetic fluid.

[0002]

[Prior art]

 Conventionally, for example, there is a sliding bearing using a ruby as a bearing structure of a micro motor having an outer diameter of about 1 mm. Also, many bearings using magnetic fluid have been disclosed (for example, JP-A-64-83920).

[0003]

[Problems to be solved by the device]

 However, with the conventional slide bearing, the friction loss is large and the output efficiency of the motor is low. Further, the bearing using the magnetic fluid has a problem that the structure is complicated and the size becomes large because the fixed side is provided with the magnet. Therefore, an object of the present invention is to provide a small bearing having a small friction loss and a high motor output efficiency.

[0004]

[Means for Solving the Problems]

 In order to solve the above problems, the present invention provides a non-magnetic bearing member provided inside the frame end and having a hole in the center portion larger than the outer diameter of the rotating shaft, and a non-magnetic bearing member provided on the surface of the rotating shaft, and Multi-pole magnets for radial bearings with magnets extended to the bearings and magnets for thrust bearings that are fixed to the rotating shaft near the bearings and have their faces facing the side surfaces of the bearings multi-pole magnetized. A radial bearing portion in which a magnetic fluid is filled between an inner peripheral portion of the bearing member and the radial bearing magnet, a rotor-side side surface of the bearing member, and the thrust disc. And a thrust bearing portion filled with magnetic fluid between the two.

[0005]

[Action]

 By the above means, the magnetic pole of the rotor is used as it is for the bearing portion, so that the magnetic fluid can be retained, good lubrication can be obtained, and the output efficiency of the motor is improved.

[0006]

【Example】

 Hereinafter, a specific embodiment of the present invention will be described with reference to the drawings. FIG. 1 shows an example in which the bearing device of the present invention is applied to a small motor. In the figure, 1 is a motor frame, 2 is a rotary shaft, 3 is a rotor, 4 is a radial bearing portion, 5 is a non-magnetic bearing member made of a copper alloy, 6 is a thrust bearing portion, and 7 is a magnetic fluid. The details of the bearing are shown in Fig. 2. The radial bearing portion 4 has a radial bearing magnet 41 in which magnetic poles of the rotor 3 are extended as they are, and a magnetic fluid 7 is filled in a gap between the radial bearing portion 4 and the bearing member 5. The thrust bearing portion 6 has a structure in which a thrust bearing magnet 62 is provided on the surface of the thrust disk 61 that faces the side surface of the bearing member 5, and the magnetic fluid 7 is filled in the gap between the bearing member 5 and the thrust bearing magnet 62. Is. Now, when the rotating shaft 2 is rotated, both the radial bearing magnet 41 and the thrust bearing magnet 62 attract the magnetic fluid 7, so that the rotor can be supported in a fluid lubricated state. As a result of measuring the friction coefficient, it was found that the conventional sliding bearing had a value of about 0.1, but in the present embodiment, it was as small as 0.01 order, and the output efficiency of the motor was significantly improved.

[0007]

[Effect of device]

 As described above, according to the present invention, the magnetic pole of the rotor of the motor is extended to the bearing portion and the magnetic fluid is used as the lubricant, so that the friction loss is small, and the small bearing with high output efficiency of the motor is used. There is an effect that can be provided.

[Brief description of drawings]

FIG. 1 is a sectional view of a small motor using a bearing of the present invention.

FIG. 2 is a sectional view showing a bearing portion of the present invention.

[Explanation of symbols]

 1 frame 2 rotating shaft 3 rotor 4 radial bearing 41 radial bearing magnet 5 bearing member 6 thrust bearing 61 thrust disk 62 thrust bearing magnet 7 magnetic fluid

Claims (1)

[Scope of utility model registration request] 1. A non-magnetic bearing member provided inside a frame end and having a hole at its center portion larger than the outer diameter of a rotating shaft, and a permanent magnet of a rotor provided on the surface of the rotating shaft up to the bearing portion. A radial bearing magnet that is extended and multi-pole magnetized, and a thrust disk having a thrust bearing magnet that is fixed to a rotating shaft in the vicinity of the bearing portion and that has a multi-pole magnetized surface facing the side surface of the bearing member, A radial bearing portion filled with magnetic fluid between the inner peripheral portion of the bearing member and the radial bearing magnet, and magnetic fluid filled between the rotor-side side surface of the bearing member and the thrust disc. A magnetic fluid bearing device comprising: a thrust bearing portion.