JPS6118254Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a mounting device for a rotating body, such as an idler or rotating gear of a tape recorder, which transmits a predetermined driving force to a driven body.

Conventionally, a rotating body such as an idler of a tape recorder has been mounted in a structure as shown in FIG. 1, for example.

That is, a shaft body 2 is installed on a chassis 1, and an annular groove 4 into which an E-ring 3, which is a stopper, is fitted is provided on the outer periphery of the tip end of the shaft body 2. An idler 8, which has a rubber body 6 fitted around the outer periphery of a ring body 5 made of synthetic resin and has a through hole 7 at its axis, is inserted into the shaft body 2 through the through hole 7, and By fitting the E-ring 3 into the annular groove 4, it is rotatably attached to the shaft body 2.

As mentioned above, in the case of the conventional type, a stopper such as an E-ring is required to fix the idler, so the installation work is extremely inefficient. especially,
For fasteners such as E-rings, the free end on the opening side must be pushed out with a jig or the like to fit onto the shaft, which is not only difficult but requires manual labor, and automatic It is becoming difficult to achieve automation using machines.

Therefore, the present invention makes it possible to attach a rotating body such as a tape recorder idler or rotating gear to a shaft body without using a stopper such as an E-ring as described above, thereby streamlining the installation work. It is an object of the present invention to provide a mounting device that can achieve automation as well as achieve automation.

Hereinafter, specific embodiments of the present invention will be described with reference to the drawings. This embodiment will be explained using an example in which it is applied to an idler of a tape recorder.

In the mounting device according to this invention, as shown in FIGS. 2 and 3, a shaft mounting hole 12 bored in the chassis 11 into which the mechanical part of the tape recorder is assembled is provided with a shaft mounting hole 12 having a diameter smaller than that of the shaft body 13. It has a shaft body 15 which is attached by caulking after inserting the formed one end flap 14. An annular recess 16 is provided on the outer periphery of the tip end side of the shaft body 15, which is formed so as to reduce the diameter of the shaft body 13.

As shown in FIGS. 2 and 3, the idler 17 rotatably attached to the shaft body 15 includes an idler body 18 made of flexible synthetic resin, and an outer periphery of the idler body 18. It is composed of a rubber body 19 which is elastically deformable and fitted into the body. A through hole 20 to be inserted into the shaft body 15 is provided in the axial center portion of the idler body 18 of the idler 17.
An extra gap 21 is provided concentrically with 0.
A portion surrounded by the through hole 20 and the free gap 21 constitutes a cylindrical portion 22. Note that the above-mentioned free gap 21 is the idler body 1.
8 is formed so as to have a concave cross section.

As mentioned above, the idler body 18 has an idle clearance 2.
1, the end surface of the cylindrical portion 22 integrally formed with the idler body 18 is provided with an annular engagement recess 16 of the shaft body 15 such that its tip protrudes and faces the through hole 20. A substantially L-shaped engagement protrusion 25 that engages with is integrally formed to protrude. A pair of slits 23, 23 are cut in parallel to the through hole 20 from the end surface of the cylindrical portion 22 on both sides where the engaging protrusion 25 is provided, and the end surface of the cylindrical portion 22 has a small arc-shaped portion. 22a and a large arcuate portion 22b. That is, the small arcuate portion 22a having the engagement protrusion 25 is formed to be smaller than 1/2 of the circumference of the end face of the cylindrical portion 22. and,
The engagement protrusion 25 is provided so as to protrude from the end face of a small arcuate portion 22a that is a part of the cylindrical portion 22 separated from the outer circumferential portion 26 of the idler body 18 via the free gap 21. The outer periphery of the idler body 18,
As a result, the rubber body 19 fitted around the outer periphery of the idler body 18 can be elastically deformed without affecting it.

When the idler 17 configured as described above is inserted into the shaft body 15 through the through hole 20, the engaging protrusion 25 engages with the shaft body 15 as shown in FIG.
The free gap 21 is elastically deformed. When the idler 17 is further inserted into the shaft body 15, the engagement protrusion 25, which had been elastically deformed toward the free gap 21 side, elastically returns to engage with the annular engagement recess 16 of the shaft body 15, and the idler 17 As shown in FIGS. 4 and 5, it is rotatably attached to the shaft body 15.

The idler 17 installed in this manner engages the engagement protrusion 25 provided on the cylindrical portion 22 separated from the outer peripheral portion 26 by the free gap 21 with the annular engagement recess 16 of the shaft body 15. Therefore, even if the engagement protrusion 25 strongly contacts the outer circumferential surface of the annular engagement recess 16 and is elastically deformed, the deformation is absorbed by the free gap 21 and no damage is caused to the rubber body 19 on the outer periphery of the idler 17. Therefore, the driven body driven by the idler 17 is not affected by a rotating ram or the like.

According to the device of the present invention as described above, a rotating body such as an idler can be installed only by inserting it into the shaft body, which not only improves the efficiency of the installation work but also allows automatic assembly by an automatic machine. is also possible.

In addition, the device of the present invention can be attached to the shaft of a rotating body such as an idler only by engaging the annular engagement recess of the elastically deformable engagement protrusion. It can be easily removed by inserting a tool and deflecting the engagement protrusion outward to deflect the annular engagement protrusion outward and release the engagement with the annular engagement recess.

Furthermore, in the device of the present invention, even if the engaging protrusion provided on a rotating body such as an idler is notched, the small arc-shaped portion is notched or deformed together with the engaging protrusion.
More than half the circumference of the cylindrical portion, ie, the large arc-shaped portion, remains as it is without being cut or deformed. Therefore, the idler etc. can be reattached to the shaft body using a fastener such as an E-ring by utilizing the large arc-shaped portion that is the remaining portion extending over half the circumference or more.

Furthermore, according to the device of the present invention, deformation that occurs at the contact portion with the shaft body due to the action of the free gap provided in the rotating body such as the idler does not affect the outer periphery, so that the rotating ram etc. Therefore, it is possible to provide a highly reliable mounting device for a rotating body that does not cause damage.

In the above-mentioned embodiment, an example in which the present invention is applied to an idler of a tape recorder has been described, but the present invention can also be widely applied to other rotating bodies such as rotating gears that transmit a predetermined driving force to a driven body.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing a conventional example. FIG. 2 is an exploded perspective view showing one embodiment of the present invention;
The figure is a sectional view thereof, FIG. 4 is a perspective view showing the attached state, and FIG. 5 is a sectional view thereof. DESCRIPTION OF SYMBOLS 11... Chassis, 15... Shaft body, 16... Annular engagement recess, 17... Idler, 20... Through hole of idler, 21... Free gap, 23, 24...
Slit, 25...engaging protrusion.

Claims (1)

[Scope of utility model registration request] It consists of a shaft that is fixed to the chassis and has an annular engagement recess formed on its outer periphery, and a flexible rotating body that has a through hole that is inserted through the shaft. A cylindrical part is formed with a concentric free gap, and an engaging protrusion whose tip protrudes toward the through hole and engages with the annular engaging recess is integrally provided on the end surface of the cylindrical part. ,
The through hole is formed on both sides of the engaging protrusion from the end face of the cylindrical part so that the length of the circular arc portion on the side having the engaging protrusion on the end face of the cylindrical part is less than 1/2 of the circumference of the end face. A mounting device for a rotating body that has a pair of slits parallel to the slits.