JPH0141940Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a rotary damper for damping transmitted rotational force.

Conventionally, a disk fixed to the tip of a shaft through which rotational force is transmitted by gears, etc. is housed in a housing filled with oil such as silicone grease, and the disk is rotated in oil, and the rotational force is transmitted by the viscous resistance of the oil. Damping oil rotary dampers are known. However, as the ambient temperature rises, the oil expands and leaks out from the gap between the case and the cap that make up the housing, and the gap between the gear shaft and the hole in the case that it passes through. In addition, it is necessary to incorporate a device in the housing to absorb the volumetric expansion of the oil in order to prevent the damper effect from decreasing due to the decrease in the amount of oil in the housing when the ambient temperature drops. The number of parts inevitably increases.

Therefore, the present invention does not use oil, and in addition to the disk, a spring washer is fitted on the shaft to press the disk against the inner bottom surface of the case, and the through hole in the cap through which the shaft passes is designed to prevent the shaft from slipping out. A clamping piece is provided that tightens the shaft from around the shaft, and the rotational force is mainly damped by the clamping force of the clamping piece and the frictional force of the spring washer pressing the disc against the inner bottom surface of the cap, which eliminates the drawbacks of the oil type. The present invention will now be described with reference to an embodiment shown in the drawings.

1 is a shaft to which rotational force is transmitted by gear 1', etc., 2
numerals 3 and 4 denote a case and a cap for forming the housing, and numerals 3 and 4 denote a case and a cap for composing the housing, and numerals 3 and 4 denote a case and a cap that fit into the square shaft portion 1a at its tip, for example, through a central square hole, and rotate together with the shaft. The cap is molded from plastic. 4' is a mounting arm integrally provided with the cap. When the case and cap face each other and are pushed in, continuous or discontinuous protrusions 5 are formed on the inner periphery of one side and the outer periphery of the other side.
The housing is assembled by snapping together the grooves 5' with snaps.

The cap has a cylindrical part 6 at the center with an inner diameter equal to or slightly larger than the outer diameter of the shaft in order to pass the shaft 1 through it, and the wall of the cylindrical part becomes thinner at one end and curves inward. A tightening piece 7 is formed. It is preferable that the tightening piece 7 is annularly continuous like the cylindrical part 6 as in this embodiment, but in some cases it may have one or more notches in the circumferential direction, and may be discontinuous at the notches. It may be separated. And axis 1
has an annular groove 8 which prevents the tip of the tightening piece 7 from protruding and the shaft from coming out of the cap when assembled.
Form and place.

Reference numeral 9 denotes a spring washer punched and machined from a thin stainless steel plate. For example, it may be a disc spring, but here it has an annular portion 9a that is loosely fitted around the shaft 1, and an annular portion that extends radially at equal intervals from the outer periphery of the annular portion. A plurality of arms 9b are folded back and bent into a V shape on one side of the portion 9a...
has.

Therefore, to assemble the shaft 1, the shaft 1 is pushed into the cylindrical portion 6 of the cap from the tip 1a so that it protrudes onto the inner surface of the cap, and the tightening piece 7 at the tip of the cylindrical portion is engaged with the annular groove 8 of the shaft. Tighten the annular groove from around the
To prevent the shaft from coming off in the opposite direction from the cylindrical part 6 of the cap.

Then, after fitting the spring washer 9 to the shaft from the tip, the disk 2 is fitted to the square shaft portion, the disk 2 is brought into contact with the inner bottom surface of the case, and the cap is pushed into the case and engaged with the snap to assemble the housing. As a result, the spring washer 9 is compressed in the axial direction, and the disk 2
Press it against the inner bottom of the case with elastic force. If necessary, an oil film may be provided between the inner bottom surface of the case and the end surface of the disk 2 pressed against it, or a thin slippery sheet may be provided in place of the oil film to smooth the sliding of the disk.

Therefore, when rotational force is transmitted to the shaft 1 through the gear 1' or the like, the clamping force of the clamping piece 7 that tightens the annular groove 8 of the shaft 1 from around the shaft 1 and the disc 2 rotating integrally with the shaft 1 are applied to the spring washer. The rotational force transmitted to the shaft can be effectively braked by the frictional force pressed against the inner bottom surface of the case at 9.

As described above, the rotary damper of the present invention consists of a few parts including the shaft 1, the disk 2, the case 3, the cap 4, and the spring washer 9. engages the annular groove,
The tightening piece 7 that tightens the annular groove from the circumference serves to prevent the shaft 1 from coming off in the opposite direction from the cylindrical portion 6 of the cap, and to dampen the rotational force transmitted to the shaft 1.

Therefore, the shaft 1 is passed through the cylindrical portion 6 of the cap 4, and the annular groove 8 and the tightening piece 7 prevent the shaft from coming out of the cylindrical portion in the opposite direction.
The housing is completed by fitting the disk 2 and fixing the case 3 and the cap 4 by snap fitting, so that no labor is required for manufacturing and assembly. Furthermore, in the assembled state, the rotational force is transmitted to the shaft 1 by the tightening force of the tightening piece 7 tightening the annular groove 8 of the shaft from around it, and the frictional force of the disk 2 pressed against the inner bottom surface of the case by the spring washer 9. The braking effect is also great.

In this embodiment, the inner end surface 2' of the disk 2
A groove 10 for receiving an arm 9b for each spring washer is formed between the ridges 10', 10' so that the spring washer also rotates together with the disk 2 and shaft 1.
This is because the spring washer used in this embodiment has an arm 9b, so if the spring washer and the disk 2 are allowed to rotate relative to each other, the arm may damage the inner end surface 2' of the disk, and the frictional force-generating portion is dispersed, causing torque. This is because it is difficult to determine. However, when a disc spring without an arm is used as a spring washer, there is no such problem, so it is not necessary to rotate the spring washer all at once.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, in which Fig. 1 is a sectional view in an assembled state, Fig. 2 is an exploded perspective view, and Fig. 3 is an exploded perspective view.
The figure is a sectional view of the cap, Figure 4 is a front view of the disk, Figure 5 is a front view of the spring washer, and Figure 6 is a sectional view of the same. In the figure, 1 is the shaft, 2 is the disk, and 3 is the case. , 4 is a cap, 7 is a tightening piece, 8 is an annular groove,
9 indicates a spring washer.

Claims (1)

[Scope of claim for utility model registration] A housing that is assembled with a cap and a case, and a housing that penetrates the cap and enters the housing.
It has a shaft through which rotational force is transmitted, and a disk attached to the tip of the shaft that protrudes into the housing so that it can be moved in the axial direction but rotates together. At the same time, a spring washer is fitted to press the disc against the inner bottom surface of the case, and an annular groove is provided in the cap.One end of the cylindrical part through which the shaft passes is bent inward and inserted into the annular groove, and the shaft is tightened from around it. A rotary braking damper characterized by being provided with a tightening piece.