JP2005280591A - Bicycle transmission - Google Patents

Abstract

Provided is an internal bicycle transmission device that is simple in structure and can be attached to various bicycles for general use.
A low-speed rotating body 1 fixed to a crankshaft 51 rotated by a pedaling force and a high-speed rotating body 2 that can freely rotate with respect to the crankshaft 51 are opposed to each other, and the planetary gear 11 is opposed to the low-speed rotating body 1. , And the internal gear 13 engraved on the high speed rotator 2 is meshed with the outside of the planetary gear 11 so that the sun gear 12 fixed on the frame 53 side is engaged with the inside of the planetary gear 11. And ratchet pawls 14 and 15 are provided on the outer periphery of the high-speed rotating body 2, and ratchet teeth 16 engaged with the ratchet pawls 14 and 15 are formed inside the driven ring 4 integrated with the sprocket 3, A switching member 17 is provided through the high-speed rotating body 2, and is configured to change gears by switching engagement / disengagement between the ratchet pawl 15 and the ratchet teeth 16 of the high-speed rotating body 2 as the switching member 17 advances and retreats.
[Selection] Figure 1

Description

  The present invention relates to a transmission provided on a crankshaft portion of a bicycle using a planetary gear mechanism.

  In general, as a bicycle transmission that adjusts the pedal depression load according to the gradient of the road surface on which it travels, sports bicycles are equipped with exterior types that change chains on multiple stages of sprockets. In many cases, bicycles for street riding are equipped with an interior type using a planetary gear mechanism that can perform a shifting operation easily and smoothly.

  As this interior transmission, the following Patent Document 1 includes a gear case incorporated in a frame and a crankshaft that is rotatable by a pedaling force of a pedal, a rotatable rotating body is provided, and a sprocket is fixed to one side thereof, A plurality of planetary gears are pivotally supported on a carrier that rotates integrally with the crankshaft, and rotatable sun gears are engaged with the inner sides of the planetary gears. A ratchet mechanism that absorbs the rotational speed difference between the carrier and the driven rotating body is provided by meshing the internal gear provided on the body, and the switching operation of the one-way clutch that allows / blocks the rotation of the sun gear at each stage is performed. Thus, there is described a gear that changes speed by switching an internal gear that is accelerated with respect to the crankshaft.

  In Patent Document 2 below, a sprocket and a large-diameter sun gear are integrally formed on one side and the other side so as to be rotatable with respect to a gear case fixed to a frame and a crankshaft rotating by a pedaling force. The planetary gear is supported by a carrier that rotates integrally with the crankshaft, and a small-diameter sun gear that can rotate relative to the crankshaft is engaged inside the large-diameter step of the planetary gear. The planetary gear is meshed with the large-diameter sun gear inside the small-diameter step, and the planetary gear is meshed with the internal gear on the outside of each planetary gear to absorb the difference in rotational speed between the small-diameter sun gear and the driven rotor. A ratchet mechanism is provided to change the speed of the sun gear that is accelerated relative to the crankshaft by switching the one-way clutch that allows / blocks rotation of the internal gear of each stage relative to the gear case. Umono have been described.

JP-A-6-263081 JP-A-6-298153

  However, the transmission as described above has a problem that the structure is complicated because a large number of parts constituting a one-way clutch corresponding to the ratchet mechanism, the sun gear or the internal gear of each stage are required.

  Further, since the sprocket for hanging the chain is located on the side of the gear case, there is a problem that it cannot be attached later to a bicycle without a transmission.

  SUMMARY OF THE INVENTION An object of the present invention is to provide an internal bicycle transmission that has a simple structure and is universally attached to various bicycles.

  In order to solve the above-described problems, the present invention has a low-speed rotating body fixed to a crankshaft that is rotated by a pedaling force and a high-speed rotating body that is freely rotatable with respect to the crankshaft so as to face the low-speed rotating body. The sun gear fixed on the frame side is meshed with the inner side of the planetary gear, and the internal gear engraved on the high-speed rotating body is meshed with the outside of the planetary gear so that the low-speed rotating body and the high-speed rotating body The ratchet pawls are respectively provided on the outer peripheral portion of the slab, the ratchet teeth that engage with the ratchet pawls are formed inside the driven ring integrated with the sprocket, the switching member is provided through the high-speed rotating body, and the switching member With this advance and retreat, the engagement and disengagement between the ratchet pawl and the ratchet teeth of the high-speed rotating body is switched to change the speed.

  Further, a medium speed rotator is interposed between the low speed rotator and the high speed rotator, and a ratchet claw that engages with the ratchet teeth of the driven ring is provided on the outer periphery of the medium speed rotator, and the crankshaft And a bevel gear whose axis is orthogonal to the medium speed rotating body, and this bevel gear is engaged with an annular bevel formed on a high speed rotating body and a low speed rotating body, and the switching member is moved in the direction of the medium speed rotating body. The ring portion is extended and provided with an annular portion at the tip thereof, and the gears are shifted by switching the engagement and disengagement between the ratchet pawls and the ratchet teeth of the high-speed rotating body and the medium-speed rotating body as the switching member advances and retreats.

  In the bicycle transmission according to the present invention, the low-speed rotator and the high-speed rotator are always rotating, and the ratchet pawl of the high-speed rotator is engaged with and disengaged from the ratchet teeth of the driven ring as the switching member advances and retreats. Therefore, there is no need to provide multi-stage planetary gears, sun gears, and internal gears to switch these transmission paths, the structure is simplified, the manufacturing cost is reduced, and the reliability during use is improved.

  In addition, a medium speed rotator is provided between the low speed rotator and the high speed rotator, and the medium speed rotator is rotated at an intermediate speed between the low speed rotator and the high speed rotator via the bevel gear. If a ratchet pawl that engages and disengages with the ratchet teeth of the driven ring as the switching member advances and retreats is provided on the outer peripheral portion, a three-speed shift can be achieved with a compact and simple structure.

  First, as a first embodiment of the present invention, a two-speed bicycle transmission will be described with reference to FIGS.

  As shown in FIGS. 1 to 3, the transmission is configured such that a disk-like low-speed rotating body 1 and a high-speed rotating body 2 are opposed to each other, and the low-speed rotating body 1 is rotated by a pedal effort when attached to a bicycle. It arrange | positions at the crank arm 52 side of the crankshaft 51, and is comprised so that the high speed rotary body 2 may be arrange | positioned at the flame | frame 53 side. The low-speed rotator 1 is fixed to the crankshaft 51, and the high-speed rotator 2 is freely rotatable with respect to the crankshaft 51 via a bearing.

  On the outer peripheral side of the low-speed rotator 1 and the high-speed rotator 2, a driven ring 4 integrated with the sprocket 3 is provided on the inner diameter side of the sprocket 3 for hanging the chain. And it is rotatably held by a high-speed rotating body 2 via a bearing sandwiched between peripheral flanges.

  Three planetary gears 11 are axially attached to the low-speed rotating body 1 at intervals in the circumferential direction. Inside these planetary gears 11, a sun gear 12 fixed to the frame 53 side meshes, and the planetary gears 11. On the outside of the gear 11, an internal gear 13 engraved in the high speed rotating body 2 is meshed. A bearing is interposed between the inner diameter side of the sun gear 12 and the crankshaft 51.

  Four ratchet claws 14, 15 are provided on the outer peripheral portions of the low-speed rotating body 1 and the high-speed rotating body 2, and the tip ends of these ratchet claws 14, 15 are formed on the inner diameter side of the driven ring body 4. The ratchet teeth 16 are engaged. The ratchet claw 15 has a rear portion larger than the ratchet claw 14.

  A switching member 17 is provided on the frame 53 side of the high-speed rotating body 2 so as to advance and retract with respect to the rear inner peripheral side of the ratchet pawl 15 through a through hole. The switching member 17 is biased in a direction away from the ratchet claw 15 by a spring, and the pressing surface at the tip of the switching member 17 is inclined toward the ratchet claw 15.

  The rear portion of the switching member 17 has an annular shape, and a switching cylinder 18 is fixed to the frame 53 on the inner peripheral side thereof. A screw with a large lead is engraved on the outer periphery of the switching cylinder 18, and the switching ring 19 screwed into this screw rotates along the outer periphery of the switching cylinder 18 by wire operation and moves in the axial direction of the crankshaft 51. Then, the switching member 17 is advanced and retracted.

  In such a transmission, when the crankshaft 51 is rotated, the planetary gear 11 pivotally attached to the low-speed rotating body 1 revolves around the crankshaft 51 and the planetary gear 11 whose inner side meshes with the sun gear 12 is It rotates in the same direction as the crankshaft 51. For this reason, the high-speed rotating body 2 in which the internal gear 13 meshes with the outer side of the planetary gear 11 is rotated at a higher speed than the crankshaft 51.

  As shown in FIG. 1, when the switching member 17 is in the retracted position, the switching member 17 is separated from the ratchet pawl 15 of the high-speed rotating body 2, so that the ratchet pawl 15 biased in the protruding direction and the ratchet The engaged state with the teeth 16 is maintained, and the rotation of the high speed rotating body 2 is transmitted to the sprocket 3 via the ratchet pawl 15.

  At this time, the relative rotation between the low-speed rotating body 1 and the driven ring body 4 is allowed due to the sliding movement of the ratchet pawl 14 with respect to the ratchet teeth 16, and the low-speed rotating body 1 is connected to the crankshaft 51 regardless of the transmission of power. It is integrally rotating at a lower speed than the high-speed rotating body 2.

  On the other hand, as shown in FIG. 4, when the switching ring 19 is rotated along with the speed change operation, the switching member 17 is pushed forward by the switching ring 19, and the rear portion of the ratchet claw 15 is pressed by the switching member 17. As shown by the chain line in FIG. 2, the ratchet pawl 15 swings and the engagement between the ratchet pawl 15 and the ratchet teeth 16 is released.

  For this reason, due to the engagement of the ratchet pawl 14 and the ratchet teeth 16, the rotation of the low-speed rotating body 1 is transmitted to the driven ring 4, and the sprocket 3 rotates without being accelerated at the same speed as the crankshaft 51. .

  When the reverse speed change operation is performed from this state, the switching ring 19 is reversely rotated by the urging force of the spring, and the switching member 17 is retracted away from the ratchet pawl 15 as shown in FIG. Since the claw 15 and the ratchet teeth 16 are engaged again, the rotation of the crankshaft 51 is accelerated.

  Next, as a second embodiment of the present invention, a three-speed bicycle transmission will be described with reference to FIGS. In addition, description about the part common to the said 1st Embodiment is abbreviate | omitted here.

  In this transmission, as shown in FIGS. 5 to 8, a medium speed rotator 5 is interposed between the low speed rotator 1 and the high speed rotator 2, and a driven ring is also provided on the outer periphery of the medium speed rotator 5. There are provided ratchet claws 20 that engage the four ratchet teeth 16.

  Further, four bevel gears 21 whose axes are orthogonal to the crankshaft 51 are axially attached to the medium speed rotator 5 at intervals in the circumferential direction. The bevel gears 21 include the high speed rotator 2 and the low speed rotator 1. Meshed with the annular bevel teeth 22 and 23 formed on the top.

  The switching member 17 extends from the first pressing surface 24 inclined toward the ratchet pawl 15 of the high-speed rotating body 2 toward the medium-speed rotating body 5, and the annular portion 25 provided at the tip thereof has a middle portion. A second pressing surface 26 that is inclined toward the ratchet pawl 20 of the fast rotating body 5 is formed.

  In such a transmission, when the crankshaft 51 is rotated, the high-speed rotating body 2 is rotated at a higher speed than the low-speed rotating body 1 that rotates at the same speed as the crankshaft 51 by the action of the planetary gear 11. The medium speed rotating body 5 rotates at an intermediate speed between the high speed rotating body 2 and the low speed rotating body 1 by the action of the bevel gear 21.

  As shown in FIG. 5, when the switching member 17 is in the most retracted position, the pressing surfaces 24 and 26 of the switching member 17 are separated from the ratchet claws 15 and 20 of the high-speed rotating body 2 and the medium-speed rotating body 5. Therefore, the engagement state between the ratchet claws 15 and 20 urged in the protruding direction and the ratchet teeth 16 is maintained, and the rotation of the high-speed rotating body 2 is transmitted to the sprocket 3.

  Next, as shown in FIG. 9, when the switching ring 19 is rotated by one step and the switching member 17 is advanced to the intermediate position, the first pressing surface 24 of the switching member 17 causes the ratchet pawl 15 of the high-speed rotating body 2 to move. Since the ratchet pawl 15 and the ratchet teeth 16 are disengaged by pressing and swinging, the rotation of the medium-speed rotating body 5 is transmitted to the sprocket 3.

  Further, as shown in FIG. 10, when the switching ring 19 is rotated in two stages and the switching member 17 is pushed to the most advanced position, the annular portion 25 of the switching member 17 presses the ratchet pawl 20 of the medium speed rotating body 5. Since the engagement between the ratchet pawl 20 and the ratchet teeth 16 is also released, the rotation of the crankshaft 51 is not accelerated through the ratchet pawl 14 of the low-speed rotating body 1 and the sprocket 3 Communicated.

  Since the switching member 17 rotates at the same speed as that of the high-speed rotating body 2, a difference in rotational speed occurs between the intermediate rotating body 5, but an annular portion 25 is provided at the tip of the switching member 17. Therefore, the ratchet pawl 20 of the intermediate rotator 5 can be pressed in any phase.

Longitudinal side view showing a high-speed transmission state of the transmission according to the first embodiment The figure which shows the meshing state of a high-speed rotary body same as the above from the crank arm side The figure which shows a low-speed rotary body same as the above from the frame side Longitudinal side view of low speed transmission state of transmission as above Longitudinal side view showing a high-speed transmission state of the transmission according to the second embodiment The figure which shows the meshing state of a high-speed rotary body same as the above from the crank arm side The figure which shows the combined state of a medium speed rotary body and a low-speed rotary body same as the above from the frame side The figure which shows a low-speed rotary body same as the above from the frame side Longitudinal side view showing the medium speed transmission state of the above transmission Longitudinal side view showing the low-speed transmission state of the transmission as above

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Low-speed rotary body 2 High-speed rotary body 3 Sprocket 4 Driven ring body 11 Planetary gear 12 Sun gear 13 Internal gears 14 and 15 Ratchet claw 16 Ratchet tooth 17 Switching member 18 Switching cylinder 19 Switching ring 20 Ratchet claw 21 Bevel gears 22 and 23 Annular bevel tooth 24 first pressing surface 25 annular portion 26 second pressing surface 51 crankshaft 52 crank arm 53 frame

Claims (2)

  The low-speed rotating body fixed to the crankshaft that rotates by the pedal effort and the high-speed rotating body that can freely rotate with respect to the crankshaft are opposed to each other, and a planetary gear is attached to the low-speed rotating body and fixed to the frame side. The sun gear is engaged with the inner side of the planetary gear, the internal gear engraved on the high-speed rotating body is engaged with the outer side of the planetary gear, and ratchet claws are provided on the outer peripheral portions of the low-speed rotating body and the high-speed rotating body, respectively. A ratchet tooth that engages the ratchet pawl is formed inside the driven ring integrated with the sprocket, and a switching member is provided by penetrating the high-speed rotating body. As the switching member advances and retracts, the ratchet pawl of the high-speed rotating body A bicycle transmission that changes gears by switching between engagement and disengagement with the ratchet teeth.   A medium-speed rotating body is interposed between the low-speed rotating body and the high-speed rotating body, and a ratchet claw that engages with the ratchet teeth of the driven ring is provided on the outer periphery of the medium-speed rotating body, and the crankshaft and the axis line The bevel gears that are orthogonal to each other are mounted on the medium-speed rotating body, the bevel gears are engaged with annular bevel teeth formed on the high-speed rotating body and the low-speed rotating body, and the switching member is extended in the direction of the medium-speed rotating body. The bicycle according to claim 1, wherein an annular portion is provided at a tip of the switching member, and the engagement and disengagement between the ratchet pawls and the ratchet teeth of the high-speed rotating body and the medium-speed rotating body are switched as the switching member advances and retreats. Transmission.

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