JPS5827392Y2 - Friction torque generator - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a friction torque generating device conventionally used in a drive mechanism of a magnetic recording/reproducing device.

FIG. 1 shows a longitudinal cross section of a typical example of this type of friction torque generating device that has been known in the past.

In the figure, 1 is a driving wheel that is driven by some means from a drive source and rotates, 2 is a rotatable rotating shaft that transmits rotational force to an external mechanism by some means, and 3 is a rotating shaft 2 that is press-fitted. A driven wheel 4, which rotates together with the rotating shaft 2 by being rotated, is placed between the upper surface of the driving wheel 1 and the lower surface of the driven wheel 3, and frictionally transmits rotational force from the driving wheel 1 to the driven wheel 3. a friction member that
5 is a crimping spring that generates a crimping force on the friction member that determines the amount of attenuation of rotational force due to the friction transmission; 6 is a locking member for locking the drive wheel 1, the friction member 4, and the crimping spring 5; It shows.

The conventional friction torque generating device is constructed as described above, and when the driving wheel 1 is rotated along the outer peripheral surface of the shaft portion of the driven wheel 3 by, for example, tilting means, the crimping force of the crimping spring 5 is already applied. Friction transmission begins between the upper surface of the driving wheel 1, which is being pushed upward, and the friction member 4, and at the same time, friction transmission of rotational force begins between the friction member 4 and the lower surface of the driven wheel 3. A constant, attenuated friction torque is transmitted to the driven wheel 3, and the driven wheel 3 rotates together with the rotating wheel 2.

Here, the friction torque transmitted by the above two types of friction transmission is determined by the compression spring 5.

However, in the conventional friction torque generator, the transmission mechanism for frictionally transmitting the rotational force transmitted to the driving wheel 1 from the driving wheel 1 to the rotating shaft 2 and the driven wheel 3 is as shown in FIG. A friction member 4 is sandwiched between the lower surface of the wheel No. 3 and the upper surface of the drive wheel 1, and a crimping spring 5 is sandwiched between the lower surface of the drive wheel 1 and the upper surface of the locking member 6. Because of the structure, there is a limit to how much the height can be reduced, making it quite difficult to install a conventional friction torque generator in a narrow space and adjust the friction torque.

The present invention has been devised to eliminate the above-mentioned drawbacks, and aims to provide a friction torque generating device that can be used between constrictions and can further adjust the friction torque.

The cross sections of one embodiment of the present invention are shown below in Figures 2, 4, and 5.
A longitudinal section is shown in FIG. 3.

Here, the same or equivalent parts in the conventional example are given the same reference numerals.

In the figure, 1 is a driving wheel as a first driving wheel that has a hollow part and a plurality of grooves with different groove widths on the inner peripheral surface of the hollow part and is driven by some means from a driving source, and 2 is a driving wheel that is connected to an external mechanism. A rotatable rotary shaft 3 that transmits rotational force by a lateral means is a second rotary shaft that rotates within the hollow part of the drive wheel 1 together with the rotary shaft 2 by press-fitting the rotary shaft 2. Driven wheel as a driving wheel, 4
7 is an annular friction member that is wrapped around the outer peripheral surface of the driven wheel 3 and slides on the outer peripheral surface of the driven wheel 3; 7 is an annular friction member that elastically compresses the friction member 4 and slides on the outer peripheral surface of the friction member 4; A plurality of groove portions 9-a, 9-b, 9- which control sliding rotation between the outer peripheral surface of the driven wheel 3 and the friction member 4 at the same time and have different groove widths on the outer periphery of the driving wheel 1. The engaging portion 7A is an elastic body that rotates in the hollow part of the driving wheel 1 together with the driving wheel 1 by having an engaging portion 7A for engaging with one of the parts c. consists of a pair of protruding pieces 7a and 7b extending outward from both ends of the cut-off portion of the member in a substantially parallel manner facing each other.

Reference numeral 8 designates a locking member for locking the driving wheel 1, the rotating shaft 2, the driven wheel 3, the friction member 4, and the elastic body 7.

The friction torque generating device according to the present invention is configured as described above, and when the drive wheel 1 is rotated along the outer peripheral surface of the rotation shaft 2 by, for example, tilting means, the plurality of An elastic body 7 having an engaging portion 7A engaged with one of the grooves having different groove widths rotates together with the drive wheel 1 within the hollow portion of the drive wheel 1.

Next, friction transmission is started between the outer circumferential surface of the friction member 4, which has already been compressed by the elasticity of this elastic body, and the inner circumferential surface of the elastic body 7, and at the same time, the inner circumferential surface of the friction member 4 and the driven wheel 3 Friction transmission also starts between the outer peripheral surface of the drive wheel 1 and the attenuated constant friction torque is transmitted to the driven wheel 3, which rotates together with the rotation shaft 2 within the hollow part of the drive wheel 1. The rotational force is transmitted from the rotation shaft 2 to the external mechanism by the means.

Here, the frictional torque transmitted by the above two types of frictional transmission is transmitted between the engaging part provided on the outer periphery of the elastic body 7 and the plurality of grooves having different widths provided on the inner peripheral surface of the drive wheel 1. It is determined by which one of the two is engaged.

That is, the protruding pieces 7a, 7 in the engaging portion 7A of the elastic body 7A
b is a groove portion 9-a of the drive wheel 1 having a groove width different from that of the groove portion 9-a.
, 9-b, 9-c By selectively engaging the protruding pieces 7a and 7b so that the interval between them can be changed, the inner diameter of the elastic body 7 is changed to decrease or expand, thereby preventing the occurrence of The resulting friction torque will be different.

Figure 2 shows the engagement that generates standard friction torque;
The figure shows an engagement that generates friction torque higher than standard.
The figure shows an engagement that produces substandard frictional torque.

As described above, according to the friction torque generating device according to the present invention, the rotational force transmitted to the drive wheel 1 is transferred from the drive wheel 1 to the rotation shaft 2.
The transmission mechanism for transmitting friction to the driven wheels 3 is shown in FIG.
As shown in FIGS. 3, 4, and 5, the outer circumferential surface of the sliding friction member 4 and the inner circumference of the elastic body 7 are located between the outer circumferential surface of the driven wheel 3 and the inner circumferential surface of the friction member 4. The engagement portion on the outer periphery of the sliding elastic body 7 with the surface engages with any one of a plurality of groove portions with different groove widths on the inner circumferential surface of the drive wheel 1, and the elastic body 7. Since the structure is such that the friction member 4, driven wheel 3, and rotating shaft 2 are installed inside the hollow part of the driving wheel 1, it is easy to adjust the magnitude of the friction torque, and the height, size, etc. of the residue can be reduced. It is also easier to install between canine strictures than traditional friction torque generators.

Further, in this embodiment, there are three grooves having different groove widths, but as the number increases, it becomes possible to increase the range of adjustment of the friction torque.

[Brief explanation of drawings]

Fig. 1 is a longitudinal sectional view of a conventional friction torque generating device, Figs. 2 to 5 are diagrams showing a friction torque generating device according to the present invention, and Figs. 2 and 3 show the standard generation of friction torque. A cross-sectional view and a vertical cross-sectional view showing the engagement, FIG. 4 is a cross-sectional view showing the engagement when excessive friction torque is generated, and FIG. 5 is a cross-sectional view showing the engagement when the friction torque is decreased. , 1 is a driving wheel, 2 is a rotating shaft, 3 is a driven wheel, 4 is a friction member, 5 is a pressure spring, 6 is a locking member, 7 is an elastic body, 7A is an engaging part, 7a and 7b are protruding pieces , 8 is a locking member, 9-a is in the groove, 9-b is in the groove,
9-c indicates the groove size.

Claims (1)

[Scope of utility model registration request] A first driving wheel having a hollow part and having a plurality of grooves having different groove widths on the inner periphery of the hollow part, comprising a ring-shaped member provided in the hollow part and partially cut away, from both ends of the cut-off part of the member. An engaging portion consisting of 1,000 pairs of protruding pieces facing each other in substantially parallel and extending outward is provided in the plurality of grooves so that the interval between the pair of protruding pieces can be changed so that the engagement portion can be selectively inserted into and engaged with the plurality of grooves. an elastic body that rotates together with the first driving wheel; an annular friction member that is provided within a ring of the elastic body and rotates or slides while receiving a predetermined constant pressure due to the elasticity of the elastic body; A second driving wheel is provided in the annular ring of the friction member and slides on the inner peripheral surface of the friction member with its outer peripheral surface under a predetermined constant pressure due to the elasticity of the elastic body, and rotates together with the second driving wheel. A friction torque generating device characterized by comprising a moving rotary wheel.