JPH0226213Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Field of Application of the Invention] The present invention relates to a brush holder used in a DC machine, especially a small DC machine. A brush, a spring that presses the brush so that it can slide up and down, and a terminal provided at the open end of the box-like body are fixedly supported on the side of the box-like body by a bracket integrated with the rear cover of the DC machine. This brush holder has a structure in which a pigtail that electrically connects the plate and the brush is held inside a box-shaped body. After the rear cover is fixedly attached to the DC machine case, a through hole is formed in the cylindrical part of the rear cover. By inserting the brush holder in the radial direction of the rotor shaft through the brush holder, the brush holder can be attached to the rear cover bracket.

[Background of the idea]

The prior art and its problems will be explained with reference to FIG. Figure 1 a shows a cross-sectional area showing an example of a conventional structure, and b shows an X
FIG. 3 is a cross-sectional view of the −X′ section viewed in the axial direction. In FIG. 1, a brush holder 1 is made into a box-like body with its upper and lower sides open, and inside this box-like body is a brush 3 whose one end surface is in sliding contact with the outer peripheral surface of a commutator 2.
and a spring 4 that presses the other end of this brush 3.
It holds a pigtail 6 that electrically connects a terminal plate 5 provided at the upper open end of the brush holder 1 and the brush 3. 7 is a rear cover, and the brush holder 1 is fixedly attached to the rear cover 7. A ball bearing 8 is held at the center of the rear cover 7 and rotatably supports the rotor shaft 9. 10 is an armature integral with the rotor shaft 9; 11 is a magnet arranged to face the outer peripheral surface of the armature 10 with a small gap in between; 12 is the magnet 1;
1 is fixed to the DC machine case, and 13 is an oil receiver provided between the commutator 2 and the ball bearing 8.

To assemble the DC machine, attach the armature 10 to the rotor shaft 9,
Attach the commutator 2, oil receiver 13, and ball bearing 8 in this order, and assemble the ball bearing 8 so that the outer periphery of the ball bearing 8 is held at the center of the end surface of the rear cover 7 where the brush holder is attached.
The DC machine case 12 with the mark and the rear cover 7 are combined. Finally, the terminal plate 5 is connected to the brush 3 via the brush 3, the spring 4, and the pigtail 6.
is inserted into the interior through a through hole 7' formed in the rear cover 7, and the brush 3 is installed in the brush holder 1.

However, the conventional structure described above has the following problems. That is, the assembly order was to attach the ball bearing 8 to the rotor shaft 9, on the other hand, to attach the brush holder 1 to the rear cover 7, and then to hold the ball bearing 8 in the center of the rear cover 7. The outer diameter of 8 needs to be smaller than the inner distance between the two brush holders 1 and 1' arranged above and below with the rotor shaft 9 in between.As a result, ball bearings with a large outer diameter are used for strength reasons. If this is the case, move the mounting positions of the two brush holders 1 and 1' in the outer circumferential direction accordingly, make the commutator 2 larger than necessary, and make the outer end of the brush holder 1 smaller than the case outer diameter. There was a problem in that it was necessary to adopt a structure that would allow it to protrude to the outside.

[Purpose of invention]

The purpose of the present invention is to solve the above-mentioned problems in the prior art, and to provide a brush holder for a DC machine with a structure in which the outer diameter of the ball bearing can be freely selected regardless of the inner distance between the two brush holders. Our goal is to provide the following.

[Summary of the idea]

The features of this invention are, in order to achieve the above objectives,
The brush holder is made of an electrically insulating material, and a through hole is formed in the cylindrical part of the rear cover large enough to allow the brush holder and its attached parts to be freely inserted and removed in the radial direction of the rotor shaft. An elastic arm, one end of which is fixed to the upper end of the brush holder, extends downward on one of the two sides, and the tip of this elastic arm is designed to prevent the brush holder from coming out against the bracket of the rear cover when inserted. A hook-shaped claw for locking the brush holder is provided facing outward, and the other side has a vertical dimension shorter than the vertical dimension of the elastic arm, and the tip thereof comes into contact with the bracket when the brush holder is inserted. The brush holder has a structure in which an elastic plate that functions to restrict the stopping position of the brush holder with respect to the bracket extends downward.

[Example of idea]

An embodiment of the present invention will be described below with reference to FIGS. 2, 3, and 4. Figure 2 shows an overall view of a small electric motor to which the present invention is applied, where a is a side view seen from the right side in the axial direction, b is a top view of the rear cover, and c is a
It is an XY cross-sectional view of the figure. As shown in FIG. 2b, in the present invention, a through hole 14 is formed in the cylindrical portion of the rear cover 7 and is large enough to allow the brush holder 1 to be freely inserted and removed in the radial direction of the rotor shaft. After the rear cover 7 is integrally fastened to the DC machine case and the front cover with bolts and nuts, the brush holder 1 can be attached to the bracket of the rear cover 7 through the through hole 14.

Before going into the explanation of the embodiment in which the brush holder 1 is attached to the bracket of the rear cover 7 through the through hole 14, first, referring to FIGS. 3a and 3b, the brush 3
A structure that allows the terminal board 5 with the attached terminal board 5 to be assembled into the brush holder 1 by simply inserting the terminal board 5 will be described. The brush holder 1 is made of an electrically insulating material such as synthetic resin, and one end of a pigtail 6 is connected to one end of the brush 3.
The other end of this pigtail 6 is connected to the lower surface of the terminal board 5. Further, a spring 4 is disposed between the upper end surface of the brush 3 and the lower surface of the terminal plate 5 to press the brush 3 toward the commutator (2 in FIG. 1). Hook-shaped claws 1' and 1' (one 1' is not visible in the illustration) are provided on two opposing sides of the brush holder 1 so as to project outward. The terminal plate 5 is made of an elastic metal plate so as to sandwich the two opposing sides of the brush holder 1 in a U-shape, and has the two hook-shaped claws 1',
1' and locks the terminal plate 5 to the brush holder 1 by simply inserting the terminal plate 5.
1,52 is open. Note that 15 is a notch provided at the upper end of the brush holder 1, and when removing the terminal plate 5 from the brush holder 1, this notch 15
The terminal board 5 can be removed by inserting the tip of the screwdriver into the section and turning the screwdriver. In this case, the hook-shaped claws 1', 1' protruding from both sides of the brush holder 1 are
As shown in Figure b, the lower part is shaped to stand up at right angles to the side surface, and the upper part is shaped to be gently sloped, so that the terminal plate 5 can be inserted simply by inserting it along the side surface of the brush holder 1. The terminal plate 5 can be assembled into the brush holder 1 so as to be prevented from coming off. In addition, the terminal plate 5 equipped with the engagement holes 51 and 52 that engage with the hook-shaped claws 1' and 1' is manufactured by cutting a single elastic metal plate into a rectangular shape as shown in Figure a. When doing this, the engagement hole 5 is formed by cutting a U-shaped parting line from the top surface of the plate to the bottom surface of the plate at both ends at the same time, and simply bending these U-shaped parts.
1, 52 can be used as the terminal board 5.

Next, as shown in FIG. 4, the brush holder 1 with the terminal plate 5 assembled therein as described above is inserted radially through the through hole 14 made in the cylindrical portion of the rear cover 7 and pulled out into the bracket of the rear cover 7. An embodiment structure for fixably locking and attaching will be explained with reference to FIG. 4.

FIG. 4a is a top view, b is a front side view, c is a side view seen from the left side, and d is a side view seen from the right side. In addition, in Figure 4, in order to simplify the drawing,
The illustration of the terminal board 5 and its attachments is omitted.
In FIG. 4, 1 is a brush holder, 16
is attached to one of the two opposing sides of the brush holder 1 (the two sides to which the hook-shaped claws 1', 1' are not attached), and extends downward from the upper end of the brush holder 1. It is an elastic arm having a hook-shaped claw 17 at its extended tip that functions to lock the brush holder in a manner that prevents it from being removed from the bracket when the brush holder is inserted. It is attached to the other of the two side surfaces, extends downward from the upper end of the brush holder 1, has a vertical dimension shorter than that of the elastic arm, and comes into contact with the bracket when the brush holder is inserted. This is an elastic plate that functions to regulate the stopping position of the brush holder relative to the bracket.

When the brush holder 1 to which the elastic arm 16 and elastic plate 18 are attached is inserted in the radial direction from the through hole 14 formed in the rear cover 7, the tip end surface of the elastic plate 18 will be inserted into the rear cover 7. When the brush holder 1 comes into contact with the upper end surface of the bracket, the insertion movement of the brush holder 1 is stopped, and at the same time, the hook-shaped claw 17 (the upper flat part) at the tip of the elastic arm 16 touches the upper end surface of another bracket of the front cover 7. By engaging with the lower end surface, the brush holder 1 is eventually locked in a predetermined position determined by the mounting position of the bracket so as to be prevented from coming off.

In the above explanation, before the brush holder 1 is inserted into the through hole 14, the terminal plate 5 with the brush 3, pigtail 6, etc. is assembled into the brush holder 1. 16, elastic plate 1
As is clear from the structure of 8, it is not always necessary to follow the above procedure; first, the brush holder 1 is locked and attached to the bracket, and then the terminal plate 5 with the brush 3 etc. attached is inserted through the through hole 14. It is also possible to assemble them into the brush holder 1 in the order in which they are assembled, which is convenient when replacing brushes for maintenance and inspection.

With the above, the brush 3 and brush holder 1 are
After the rear cover 7 is fastened to the DC machine case, it can be inserted in the radial direction through the through hole 14 provided in the rear cover 7 and fixedly attached to the bracket of the rear cover 7. To further stabilize the installation state, as shown in FIGS. 2a and 2c, the ends of the power supply lead wires 19 are connected to the terminal board 5 on the upper surface of the terminal board 5, and the rear cover 7 is
If the structure is such that the elastic plate 20 made of an insulator is attached to the rear cover 7 by inserting its both ends into grooves previously provided in the through-hole portion of the terminal plate 20, and presses the upper surface of the terminal plate 5 via the lead wire 19. good.

[Effect of idea]

As explained above, according to the present invention, after fastening the brush holder to the DC machine case,
Because it has a structure that allows it to be fixedly attached to the rear cover by inserting it through a through hole drilled in the cylindrical part of the rear cover, the outer diameter of the ball bearing is smaller than the spacing between the brush holders as in the case of the conventional structure. There is no need to do this, and the size of the ball bearing can be freely selected.Therefore, there is no need to make the commutator's outer diameter larger than necessary.
The brush holder can also be easily accommodated within the DC machine case.

[Brief explanation of drawings]

Fig. 1 is an explanatory diagram of a conventional structure, a is a sectional view, b is a sectional view taken along the line X-X', and Fig. 2 is an overall structural diagram for explaining an embodiment of the present invention, a is a side view, and b is a rear cover. 3 is a perspective view of the structure for locking the terminal plate to the brush holder, a is a terminal plate and its attachments, and b is a diagram showing the brush holder. FIG. 4 is a diagram showing the structure for attaching the brush holder according to the present invention to the rear cover, in which a is a top view, b is a front side view, and c is a side view seen from the left side.
d is a side view seen from the right side. Explanation of symbols, 1...Brush holder, 2...Commitator, 3...Brush, 4...Spring, 5...Terminal board, 6...Pigtail, 7...Rear cover, 8...
Ball bearing, 9... Rotor shaft, 10... Armature, 11... Magnet, 12... DC machine case, 13... Oil receiver, 14... Through hole, 15
... Notch, 16 ... Elastic arm, 17 ... Hook-shaped claw, 18 ... Elastic plate, 19 ... Lead wire, 20 ...
...Elastic board.

Claims (1)

[Scope of utility model registration request] It is made into a box-like body with the upper and lower two sides open, and is supported on the side by the bracket of the rear cover of the DC machine, and includes a brush, a spring that presses the brush so that it can slide vertically, and one side of the box-like body that is open. In a brush holder for a DC machine that holds inside a pigtail that electrically connects a terminal plate provided at the end and a brush, the brush holder is made of an electrically insulating material, and the brush holder and its accessories are attached to the cylindrical part of the rear cover. A through hole is made large enough to allow the brush holder to be freely inserted and removed in the radial direction of the rotor shaft, and an elastic arm with one end fixed to the upper end of the brush holder is attached to one of the two opposing sides of the brush holder. A hook-shaped claw that extends downward and locks the brush holder against the rear cover bracket when the brush holder is inserted so as to prevent it from being removed is provided at the tip of the elastic arm facing outward. is an elastic plate whose vertical dimension is shorter than the vertical dimension of the elastic arm, and whose distal end comes into contact with the bracket when the brush holder is inserted, and which functions to regulate the stopping position of the brush holder relative to the bracket. A brush holder for a DC machine characterized by an extended brush holder.