JPS5920905B2 - Internal floating wheel of transmission device with automatic tension adjustment function of transmission band - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a ring-shaped internally floating bundle with an internal gear in a transmission device such as a belt or chino having an automatic tensioning function of the transmission band.

FIGS. 1 and 2 show an example of a transmission device having an automatic tension adjustment function of a transmission band, which is applied to a bicycle drive device.

In the figure, 1 is a drive shaft, 2 is an external gear fixed to the drive shaft 1, and 3 is a ring-shaped internal floating bundle with internal teeth 3a on the inner periphery. They interlock.

4 is a driven shaft held at a position separated from the drive shaft 1;
Reference numeral 5 designates a driven wheel provided on the driven shaft 4, and 6 represents a transmission band extending between the outer periphery of the internally floating bundle 3 and the outer periphery of the driven wheel 5. This transmission band may be either a belt or a chino.

In this embodiment, a toothed belt (timing belt) is used.

When tension as shown by arrow B in FIG. 1 acts on the transmission band 6 of this transmission device, if the transmission band 6 is loose, the internal floating bundle 3 moves eccentrically downward, causing the transmission band 6 to move eccentrically downward. Automatically absorbs slack.

This function is the automatic tension adjustment function of the transmission band.

However, when assembling a transmission mechanism having an internal floating bundle as described above into a vehicle such as a bicycle, it is necessary to make the entire device as light as possible, but it is recommended to use a toothed belt or chain for the transmission band 6. At the time, transmission teeth must be carved on both the inner and outer peripheries of the inscribed floating bundle 31, so ribs etc. cannot be provided on the inner and outer peripheries, and the outer periphery cannot be provided with chinos or Since the belt is wound, it is necessary to have not only the width shown in FIG. 2 but also a sufficient thickness H in the circumferential direction so that the ring-shaped internal floating bundle 3 does not bend.

However, if the width and wall thickness H of the inscribed floating bundle 3 are set to be sufficient in terms of strength, a problem arises in that the weight increases.

In addition, as shown in FIG. 3, in order to prevent the external gear 2 and the internal floating bundle 3 from shifting in the axial direction, a hollow disk 7 is tightened with screws 8 or the like on both sides of the internal floating bundle 3. However, even if the screw is tightened in this way, the intermediate part between the screw part and the tightening part will bend, so the number of tightening parts must be very large. A problem arises.

The present invention was made to solve the above-mentioned problems.
A flange is formed integrally with the inscribed floating bundle on one side ζ of the inscribed floating bundle (thereby, the strength of the inscribed floating bundle is increased and the weight of the inscribed floating vehicle is reduced. The purpose is to

The present invention will be described in detail below with reference to FIGS. 4 to 7.

In the figure, the same reference numerals as the above-mentioned reference numerals indicate equivalent parts.

Note that 2a is the external tooth of the external gear 2, 3b is the tooth that meshes with the toothed belt 6 provided on the outer periphery of the internal floating wheel 3, and 9 is the drive shaft 1.
It is an integrated crank arm.

In the present invention, on one side 5 of the internal floating wheel 3,
The gear 2 is slidably overlapped with one side 2b of the external gear 2.
Inner flange 3 that guides to prevent 3 from disengaging.
c is integrally provided with the internal floating wheel 3 and protrudes inward (
This, the toothed belt 6 is opposite to one side of the toothed belt 6.
Outer flange 3 that guides the
d is integrally provided with the internal floating wheel 3 so as to protrude outward.

On the other hand, the toothed belt slideably overlaps with the other side surface 2c of the externally toothed gear 2 and guides the gears 2 and 3 to prevent them from coming out of mesh. A hollow disk-shaped cover 10 which prevents the toothed belt 6 from coming out of engagement by facing the other side of the internal floating wheel 3 is placed on the side surface of the internal floating wheel 3 and fixed with a plurality of screws IH.

Note that the inner diameter of the inner flange 3c is 180 degrees from the meshing portion of the internal floating wheel 3 in the state in which it meshes with the external gear 2.
It is sufficient that the diameter of the tooth bottom of the external gear 2 at the position where the degree phase is shifted is hidden.

Further, the outer diameter of the outer flange 3d may be slightly larger than the pitch circle diameter of the gear formed by the teeth 3b provided on the outer periphery of the internal floating wheel 3.

The inner diameter and outer diameter of the cover 10 may be approximately equal to the inner diameter of the inner flange 3c and the outer diameter of the outer flange 3d, respectively.

Note that in the case of the transmission band 6 or the chain, the outer flange 3d and the cover 10 do not need to protrude outward from the outer periphery of the internal floating wheel 3.

5 to 7 show an actual design example in which the present invention is applied to a bicycle drive device. In this case, the external gear 2 and the crank arm 9 are made of aluminum alloy, and the internal floating wheel 3 is made of aluminum alloy. And the cover 10 is made of plastic.

Further, reference numeral 12 shown in FIG. 6 is an 01J ring made of Teflon, which is fitted into the annular groove 2d provided on both outer peripheries of the external gear 2, and is slidably connected to the inner surface of the inner flange 3c and the inner surface of the cover 10, respectively. It functions as a seal when touched.

Further, the screw 11 in FIGS. 5 and 6 is a bolt, and 11a
is that nut.

As described above, in the present invention, at least the inner flange 3c is formed integrally with the internal floating wheel 3 on one side of the internal floating wheel 3, so that the internal teeth 3a are formed on the inner peripheral surface of the internal floating wheel 3. Even if the teeth 3b for the toothed belt 6 are formed on the outer peripheral surface, the inner flange 3c or the outer flange 3d is integral, so even when the transmission band 6 such as a toothed belt is stretched, there is no internal floating. There is no fear that the car 3 will be deformed or bent.

In particular, the width of the inner flange 3c shown in FIG. 4 is advantageous in terms of strength because even if the inner flange 3c is widened, it will not cause any other trouble.

In the case of the internal floating wheel 3 in which the flange 3C or 3d is integrally provided, the flange serves as a strength member, so the circumferential thickness H (see Fig. 4) of the internal floating wheel 3 body is forced to be increased by t. Since it is possible to obtain sufficient strength at least, the present invention has the effect that it is possible to provide a light internal floating vehicle 3.

In addition, a flange 3 integrally formed on one side of the internal floating wheel 3
c, 3d, and a hollow disk-shaped cover 10 attached to the other side.
This prevents the external gear 2 and the internal floating wheel 3 from coming out of mesh, and the transmission band 6 stretched around the outer periphery of the internal floating wheel 3.
It goes without saying that it is possible to stabilize the meshing of each by restricting the axial movement of the

[Brief explanation of drawings]

Figure 1 is a front view of a transmission device with a transmission band tension adjustment function, Figure 2 is a sectional view taken along line A-A in Figure 1, and Figure 3 is a drive with hollow discs screwed onto both sides of the drive wheel. FIG. 4 is a sectional view of the device, and FIG. 5 is a sectional view of the drive device using the internal floating wheel of the present invention.
The figure is a partially cutaway front view showing an example in which the present invention is applied to a bicycle drive device, FIG. 6 is a longitudinal sectional view thereof, and FIG. 7a is a front view of the internally floating vehicle. Figures 1 and 2C are rear views of the same. 1... Drive shaft, 2... External gear, 2a
...External tooth, 3...Internal floating wheel, 3a.
...Internal teeth, 3b...External teeth, 3c...
...Inner flange, 3d...Outer flange, 4
・・・・・・Driven shaft, 5・・・Driven car (transmission car)
, 6... Transmission band (toothed belt), 1...
...Hollow disc, 8...Screw, 9...Crank arm, 10...Cover, 11...
...Screw (bolt), 11a...Nut, 12
...0 ring.

Claims (1)

[Claims] 1. A transmission device in which a ring-shaped internal floating bundle with internal teeth on the inner periphery is meshed with an external gear, and a transmission band is stretched between a transmission wheel provided at a separate position and the outer periphery of the internal floating bundle. In,
A flange for guiding one side of the external gear is integrally formed on one side of the internal floating bundle, and a hollow disc-shaped cover for guiding the other side of the external gear is attached to and detached from the other side of the internal floating bundle. An internal floating bundle of a transmission device having an automatic tension adjustment function of a transmission band, characterized in that it is freely provided.