JPS60241764A - Brushless motor - Google Patents

Abstract

PURPOSE:To reduce the cost by integrally constructing a rotor boss and a slip ring, thereby reducing components. CONSTITUTION:A rotor boss 22 made of a material having preferable conductivity and slidability is press-fitted or shrink-fitter to the inner periphery 21a of a turntable mounting base 21. The boss 22 is secured at the inner periphery 22a to a rotational shaft 1, and has a cylinder 22b projected along the shaft 1. One end of the slide of a brush 19 of a brush assembly IV slides on the flat portion 22c of the boss 22, the mounting terminal of the other end of the brush 19 is mounted through the mounting hole of a ring-shaped member 20 at a metl housing 7, and electrically connected.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a brushless motor used in a video disc turntable drive source.

Conventional technology Vl (D type video disc is a device that expresses the signal of the disc as a screen by detecting the capacitance. In order to detect the capacitance between the stylus tip and the disc, If the potential of the turntable in contact with it changes moment by moment, the image quality of the video disc will deteriorate.
generally known. Therefore, in order to solve problem M, it is necessary to maintain stable conduction between the turntable and the chassis (i.e., metal housing or bracket), but due to the lubricating oil interposed between the rotating shaft and the metal, , this problem cannot be solved without a special conduction device.

A conventional example will be explained below with reference to FIG.

In the figure, the rotor assembly I includes a rotation axis f+1, a turntable mount (2) or turntable a) having a rotor boss 2a fixed to the rotation axis (1), and a turntable mount (2). It is composed of a rotor yoke (3) fixed to the lower surface, a driven magnet (4) fixed to the inner peripheral surface of the rotor yoke (3), and a speed detection magnet (8) for speed detection. Stator assembly■
A stator core (5) and a stator winding Q2 are arranged facing each other with a predetermined gap in the radial direction from the driven magnet (4).
and is fixed to the bracket assembly I.

Bracket assembly I includes metals Q4 and α9 that rotatably support the rotating shaft (1), a metal housing (7) into which metals 64 and a9 are press-fitted, and a flange (9) for fixing the motor to the chassis. and a bottom plate t111 having a thrust bearing lea for supporting the rotating shaft +11. A C-ring (6) is installed on the metal I side to prevent the rotor assembly I from being pulled out, and the rotating shaft (+1
A slip ring ae is press-fitted into the bottom plate aυ, and a brush assembly +171 that slides on the surface of the slip ring Oe is fixed to the bottom plate aυ. Note that +1 (I is a printed circuit board for mounting a position detection element and detecting speed.

In the conventional configuration, the slip ring tJI19 is fixed to the rotating shaft (1) by press-fitting using a specified jig after the rotor assembly I is assembled into the bracket assembly (2). If force is applied or when attaching the fixed bottom plate at+ of the brush assembly + I7+ to the metal housing (7), the brush assembly Q? ) is inserted in a state in which it is opened in the radial direction beyond the outer diameter of slip ring Qf9,
At this time, there are problems in workability, such as having to take care not to adhere to the grease that has been applied to the thrust receiver 11a.Furthermore, the slip ring OQ is made of a hollow metal with good conductivity and sliding properties. It also has disadvantages in terms of cost because it needs to be manufactured into a cylindrical shape by cutting or the like.

FIG. 6 shows the configuration of a brushless motor according to another embodiment (application number 57-179583) that is an improvement over the conventional example shown in FIG. In addition, the same parts as the configuration in Figure 5,
Descriptions of those having the same configuration will be omitted.

In Fig. 6, the brush assembly ■ is a metal housing (7
), the slip ring α ladder is attached to the turntable mounting base (
2) is fixed. The above-mentioned brush assembly (2) consists of a brush a9 and a brush fixing body (support), and one end of the brush Q1 and the metal housing (7) are electrically connected.
The other end of the brush Q9 is configured to slide on the surface of a slip ring fixed to the turntable mounting base (2) by press-fitting or tightening.

However, in the above structure, the problems of the conventional example shown in FIG. 5, such as machining of metal I5α9 and resistance to grease adhesion, are solved. Since the component assemblies that are pre-assembled on the turntable mount (2) that make up I are divided into parts, the configuration has been improved to be simple, and the cost of each component has also been reduced. For example, improvements have been made by flattening the slip ring or unitizing the brush assembly, but these have had the following drawbacks.

That is, (1) The slip ring Qll is disadvantageous in terms of parts unit cost and assembly man-hours due to the use of slip ring parts.

(2) There is a high risk that abrasion powder caused by sliding between the brush Ql and the slip ring 08 will get between the metal shaft and the rotating shaft +11.

(3) When fixing the brush 0I, force is applied to the metal housing (7) due to press fitting or comparison, causing distortion.
! Affects the dimensions of 9. Further, there were other problems such as the shape of the fixed end of the brush 09 being complicated in order to ensure continuity between the metal housing (force and the a value of the brush).

Problems to be Solved by the Invention The present invention eliminates the drawbacks of the prior art, simplifies the components, and
The purpose is to ensure electrical conduction between the metal housing and the brush, thereby reducing costs (part unit costs and assembly man-hours) and improving reliability.

Structure of the Invention The present invention comprises a rotor boss of a turntable mounting base made of a material with good conductivity and slidability, a cylindrical portion protruding outwardly at the bottom of the rotor boss, and a cylindrical portion on the lower surface of the cylinder. , the brush of the brush assembly is configured to slide and serve as a rotor boss and a slip ring, and the brush assembly is attached to the metal housing via a resin ring member,
An oil drain member is directly screwed and fixed to the rotating shaft by press fit or adhesive between the cylindrical lower surface of the rotor boss and the ring member.

Function The present invention prevents brush sliding powder from entering into the sliding parts of the metal and the rotating shaft, and prevents the oil impregnated in the metal from scattering and evaporating, and prevents oil from adhering to the brush sliding parts. It is possible to reduce the amount of oil transmitted through the rotating shaft.

Embodiment FIG. 1 is a sectional view of an embodiment of the present invention, and FIG. 2 is a sectional view of a turntable mounting base of the present invention.

Descriptions of parts and structures that are the same as those shown in FIGS. 5 and 6 will be omitted.

In the figure, 69 is a brush assembly (■), 19a is a mounting terminal part, 19b is a mounting hole, 19c is a brush sliding part, (4) is a resin ring member, 20a is a mounting hole, and 20b is an annular upper protrusion. 20c is an annular lower protrusion, 00 is a turntable mounting base, 21a is an inner peripheral surface into which a rotor boss (described later) is inserted, which is bored in the center of the turntable mounting base, 21b is a turntable mounting annular edge, (2) is rota boss, 22
a is the inner circumferential surface of the rotating shaft (1) bored in the center of the rotor boss 4, 2213 is a cylindrical portion integrally formed with the rotor boss body and protrudes outward, 22c is the annular lower surface portion of the cylindrical portion 22b, ( (to) indicates a mounting screw, 24a indicates a ring-shaped oil cutting member, 24a indicates a downwardly protruding collar, and 24b indicates a space formed by the collar 24a.

The configuration of the plasticless motor of the present invention will be explained.

A rotor boss @ made of a material with good conductivity and slidability is fixed to the inner circumferential surface 21a of the turntable mount Ca1l by press-fitting or shrink fitting, thereby configuring the turntable mount member.

The rotor boss (2) has an inner circumferential surface 22a fixed to the rotating shaft f+1 by press fitting or shrink fitting, and the rotor boss (2) is fixed to the rotating shaft f+1 by press fitting or shrink fitting.
It has a cylindrical portion 22b that protrudes along. Brush assembly ■ (hereinafter simply referred to as the brush) O! One end of the sliding part 19c of the brush J is adapted to slide on the flat part 22c of the rotor boss (c), and the mounting terminal part 19a at the other end of the brush 09 is arranged to slide on the flat part 22c of the rotor boss (c). Mounting hole 19b and resin ring member (4) mounting hole 20
It is attached to the metal housing (forced) and electrically conductive by the mounting screws through the brush a.
A rotating shaft (
1) has an oil draining member (goods) having a collar 24a on the lower outer periphery by press fitting, etc., and the space 2 inside the collar 24a.
The oil draining member (goods) is attached to the rotating shaft (]) so that the upper protrusion part 20b of the ring member (toward) can fit in while keeping an appropriate gap between
Fixed. Furthermore, the lower protrusion 2 of the ring member ■
0o is fitted and fixed to the inner surface 7b of the metal housing (7).

The operation of the brushless morph of the present invention will be explained.

By fixing the rotor boss (2) made of a material with good conductivity and sliding properties to the turntable mounting base QO by press-fitting or shrink-fitting, it can serve as both a rotor boss and a slip ring. A boxwood 24 is placed between the sliding part 19c of the metal housing (7) and the metal housing (7).
An oil cutter member (goods) having a shape and a ring member (a) having a shape in which the protruding portion 201) enters the space 24b of the oil cutter (2).
The protrusion 20c of the ring member (2), which has an outer diameter smaller than the maximum outer diameter of the ring member, is attached to the housing (
7) so as to be fitted and fixed to the inner circumferential surface 7b. When compared with the conventional example shown in FIG. 6, the following effects are produced.

(1) By forming the rotor boss (2) in which the rotor boss 2a and the slip ring are integrated, the number of components can be reduced and costs can be reduced.

(2) Due to the structure of the oil draining member (goods) and the ring member (a), the abrasion powder generated by the sliding of the brush 09 and the sliding surface 22c of the rotor boss It can prevent intrusion into sliding parts and adhesion.

(3) By fitting the ring member into the metal housing (forcefully) with its protruding portion 20a, evaporation and scattering of oil from the metal α9 is prevented, and the oil draining member Q41
It is possible to prevent oil from entering the sliding portion of the brush Ql.

(4) By using resin for the ring member, the brush O
j can be easily positioned. [Due to rubbing, a complicated shape in which one end 19a fits can be easily obtained.

The present invention is not limited to the turntable mount QO, but also the turntable integrated with the turntable mount (QO).
(not shown). In addition, in the embodiment of the present invention, the brush Ql and the ring member - are fixed with screws (c), but by using conductive resin etc. for the ring member
Electrical continuity between the brush (7) and the housing (7) is established by fitting and fixing the protrusion 20c of the ring member (A) to the inner circumference 7b of the housing (force), and inserting the ring member into the mounting hole 19b of one end 19a of the brush Ql. This can be easily obtained by providing fitting protrusions and fusing and fixing the brush αl, and the screw (2) can be omitted.

Effect of the invention The present invention produces the following effects with the above configuration.

(1) Costs (part unit price and assembly man-hours) can be reduced by using both the rotor boss and slip ring.

(2) It is possible to prevent brush sliding powder from entering the sliding part between the metal and the rotating shaft, improving the reliability of the metal.

(3) Since the ring member covers the metal surface, it is possible to prevent the oil impregnated into the metal from scattering and evaporating, thereby reducing the risk of oil adhering to the brush sliding part.

(4) The oil draining member prevents the oil transmitted along the rotating shaft from reaching the rotor boss, which serves as a slip ring, thereby increasing the reliability of sliding between the brush and the rotor boss.

[Brief explanation of the drawing]

FIG. 1 is a sectional view showing a first embodiment of the brushless motor of the present invention, FIG. 2 is a sectional view of a turntable mounting base member of the embodiment of the present invention, and FIG. FIG. 4 is a sectional view showing the installed state of the oil draining member of the present invention, FIG. 5 is a sectional view of a first conventional brushless motor, and FIG. 6 is a sectional view of a second conventional brushless motor. show. 1: Rotating shaft 2, 21: Turntable mounting base 2a
+22+ Rotor boss 3: Rotor yoke 4: Driven magnet 5 Nicheeter micro: C ring 7: Metal housing 8: FG magnet 9: Flange LO niblint board 1]: Bottom plate 12: Stator winding 13, turntable 14, 15: Metal 16.18 Varnish spring 17: Brush assembly 19: Brush 20: Ring member 23
: Mounting screw 24: Oil drain member I: Rotor assembly 1'
Stator assembly ■Bracket assembly■: Brush assembly patent applicant Isao Abe, patent attorney for Matsushita Electric Industrial Co., Ltd.

Claims (1)

[Claims] 1) @Rotating shaft, a turntable mount or turntable fixed to the rotating shaft, a driven magnet magnetized in a direction perpendicular to the rotating shaft, and a hollow cylindrical rotor yoke to which the driven magnet is fixed. a stator assembly having a stator winding and a stator yoke, which are arranged opposite to the driven magnet with a predetermined gap in the radial direction; The turntable or the turntable mounting base has a conductive part on its inner periphery that is inserted into and fixed to the rotary shaft. and a rotor boss having a cylindrical portion protruding outward at the lower part made of a material with good sliding properties is fixed, and a resin is attached to the end surface of the metal housing electrically short-circuited to the chassis on the cylindrical lower surface of the rotor boss. The brush is fixed via a ring member made of aluminum and is electrically short-circuited with the metal housing, and is configured to slide, and is press-fitted or glued into the cylindrical lower part of the rotor boss and the rotating shaft between the reshiring member. A brushless motor with a fixed oil drain member.