TWI684548B - Crank device for bicycle - Google Patents

Abstract

The invention provides a crank device to solve the problems of low strength and poor labor saving effect of the transmission mechanism of the conventional crank assembly for bicycles. The crank device includes: a housing for connecting to a bicycle bracket; a transmission member, which is housed in the housing in a loose-fitting manner; a support shaft, which is partially housed in the transmission member in a loose-fitting manner; and two Drive the assembly. Each driving assembly includes: a driving member, fixed to the transmission member and used for connecting to the sprocket, and one end of the support shaft passing through the transmission member and the driving member in a loose-fitting manner; and a force applying arm, including a fixing member to the driving member The ear and the convex part pivotally connected to one end of the support shaft. The invention enables the crank device to transmit greater force and improve the labor-saving effect.

Description

Crank device for bicycle

The invention relates to a crank device and a driving assembly used for a bicycle, in particular to a crank device and a driving assembly which do not pass the center of the sprocket or drive the support shaft.

As shown in FIG. 1, the conventional crank assembly 1 for a bicycle includes a first crank arm 11, a sprocket 12 fixed to the first crank arm 11, a crank shaft 13 connected to the first crank arm 11 at one end, and connected to the crank The second crank arm 14 at the other end of the shaft 13. A plurality of splines are formed on the outer peripheral surfaces of both ends of the crank shaft 13, and spline holes 15 are formed at one ends of the first crank arm 11 and the second crank arm 14 for connecting the crank shaft 13 for accommodating the crank shaft 13 respectively At both ends, the splines on the crank shaft 13 engage the splines in the spline holes 15 of the first crank arm 11 and the second crank arm 14. Thereby, when the rider of the bicycle exerts force on the end of the second crank arm 14 for connecting the pedal, the second crank arm 14 rotates the crank shaft 13 by the spline formed on one end of the crank shaft 13, and the crank The shaft 13 rotates the sprocket 12 by a spline formed at the other end of the crank shaft 13.

However, there are many problems in the design of the above-mentioned conventional crank assembly 1 in which the crank shaft 13 and the sprocket 12 are driven by splines.

First of all, the small size of the spline is weak, so when the bicycle is used a After a period of time, the spline will wear or deform, causing backlash between the crank shaft 13 and the first crank arm 11 and the second crank arm 14, resulting in inaccurate transmission. In particular, the resistance of off-road bicycles when traveling on rough terrain is quite large. At this time, the force of the spline in order to drive the sprocket 12 and the chain is also quite large, which causes the spline to break suddenly and lose the transmission function and fall. Passenger safety. In other words, the spline strength of the conventional crank assembly 1 is weak, and its transmission force is not large enough.

Secondly, both the first crank arm 11 and the second crank arm 14 are used to drive the crank shaft 13, so the urging arms of the first crank arm 11 and the second crank arm 14 are limited by the distance between the pedal and the crank shaft 13. , The length of the force-applying arm can no longer be increased, that is, the effect of saving energy can no longer be improved.

Furthermore, one end of the first crank arm 11 and the second crank arm 14 is formed with a spline hole 15. The thickness of the material around the spline hole 15 is thin, which reduces the strength of the end of the first crank arm 11 and the second crank arm 14. As a result, the outer periphery of the first crank arm 11 and the second crank arm 14 surrounding the spline hole 15 is split.

In addition, the conventional crank assembly 1 has many parts and high cost.

Therefore, one object of the present invention is to provide a crank device and a driving assembly for a bicycle, which are not driven by the support shaft located at the center of the sprocket, but by the transmission member and its end face, so Can transmit greater force and ensure the safety of the rider.

Another object of the present invention is to provide a crank device and a driving assembly for a bicycle, the longitudinal axis of the force applying arm does not pass through the support shaft, because This can increase the length of the force-applying arm and improve the labor-saving effect.

Still another object of the present invention is to provide a crank device and a driving assembly for a bicycle, in which a hole is not formed on the longitudinal axis of the force applying arm, so the strength of the force applying arm can be improved.

Still another object of the present invention is to provide a crank device and a driving assembly for a bicycle, which have few parts and low cost.

Thus, an aspect of the present invention provides a crank device for a bicycle. The crank device includes: a housing for connecting to the bicycle bracket; a transmission member, which is housed in the housing in a loose-fitting manner; a supporting shaft, which is partially accommodated in the transmission member in a loose-fitting manner; And two drive assemblies.

Each driving assembly includes: a driving member fixed to the transmission member and used for connecting to the bicycle sprocket, and one end of the support shaft passes through the transmission member and the driving member in a loose fit manner; and applying force Arm, including an ear fixed to the drive member and a convex portion pivotally connected to the one end of the support shaft; thereby, when a force is applied to the force applying arm of either of the two drive assemblies , The force-applying arm will pivot around the support shaft, and the force will be transmitted from the ear to the drive member of another drive assembly via the drive member and the transmission member.

Preferably, one end surface of the transmission member contacts and is fixed to a side surface of the driving member.

Preferably, the support shaft is located at the center of at least one of the transmission member, the driving member, and the sprocket.

Preferably, the driving part and the sprocket are integrated into a single part.

Preferably, the crank device further includes a fastener, which is partially buckled into the support shaft to prevent the support shaft from moving along the longitudinal axis of the support shaft.

Preferably, the crank device further includes a bearing and a cover member; the bearing is provided between the housing and the transmission member; the cover member is provided between the bearing and the drive member, for preventing the bearing from transmitting along the transmission The longitudinal axis of the piece moves.

Preferably, the housing has a first shoulder against the outer ring of the bearing; the transmission member has a second shoulder against the inner ring of the bearing.

Preferably, the convex portion extends a distance from the force applying arm in a direction crossing the longitudinal axis of the force applying arm, so that the support shaft pivotally connected to the convex portion is located outside the longitudinal axis of the force applying arm.

Preferably, the ear portion extends a distance from the force applying arm in a direction crossing the longitudinal axis of the force applying arm, and the ear portion and the convex portion are respectively located on both sides of the longitudinal axis of the force applying arm.

Preferably, the ear portion extends from one end of the force applying arm, and the convex portion extends from between the two ends of the force applying arm.

Another aspect of the invention provides a drive assembly for a bicycle. The driving assembly includes: a driving member for connecting to the sprocket of the bicycle; and a force applying arm.

The force applying arm includes: an ear portion fixed to the driving member; and a convex portion extending from the force applying arm in a direction crossing the longitudinal axis of the force applying arm to a distance outside the longitudinal axis of the force applying arm for A pivot shaft pivotally connected to the bicycle.

Preferably, the point for the convex portion to be pivotally connected to the support shaft is located at the center of the driving member, and the ear portion is at an end of the force applying arm.

The advantages of the present invention over the prior art have already been described for the above purposes. Those familiar with this technology can understand the other benefits and other purposes of the present invention as defined in the claims after reading the description.

1‧‧‧Crank assembly

2‧‧‧Crank device

3‧‧‧Housing

4‧‧‧ Transmission parts

5‧‧‧Support shaft

6‧‧‧bearing

7‧‧‧Cover

8‧‧‧(first) drive assembly

9‧‧‧ (second) drive assembly

11‧‧‧ First crank arm

12‧‧‧Sprocket

13‧‧‧Crankshaft

14‧‧‧Crank arm

15‧‧‧spline hole

31‧‧‧First hole

32‧‧‧Second hole

33‧‧‧First shoulder

41‧‧‧The first section

42‧‧‧Second Section

43‧‧‧Second shoulder

44‧‧‧First threaded hole

51‧‧‧slot

52‧‧‧Fastener

71‧‧‧Through hole

81‧‧‧ (first) force applying arm

82‧‧‧(first) drive part

83‧‧‧(first) pedal

91‧‧‧ (second) force-applying arm

92‧‧‧ (second) drive parts

93‧‧‧ (second) pedal

811‧‧‧ (first) ear

812‧‧‧(first) convex part

813‧‧‧(first) through hole

814‧‧‧(first) through hole

821‧‧‧(first) perforation

822‧‧‧(second) threaded hole

F1‧‧‧force

F2‧‧‧(first) reaction force

F3‧‧‧(second) reaction force

1 is a perspective assembly view of a conventional crank assembly; FIG. 2 is a perspective assembly view of a crank device of the present invention mounted on a bicycle; FIG. 3 is an exploded perspective view of the crank device after removing the drive assembly of the present invention; FIG. 4 It is a partial perspective exploded view of the crank device of the present invention; FIG. 5 is a combined front view of the crank device of the present invention; FIG. 6 is a combined cross-sectional view taken along line AA of FIG. 5.

The foregoing and other technical contents, features, and effects of the present invention will be clearly understood in the following detailed description with reference to the drawings and preferred embodiments.

As shown in FIGS. 2, 3 and 4, the preferred embodiment of the crank device 2 for a bicycle of the present invention includes: a housing 3 for a bracket fixed to a bicycle, a transmission member 4 assembled in the housing 3, The support shaft 5 inserted into the central hole of the transmission part, two bearings 6 which are respectively assembled around the outer ends of the transmission part 4 Two cover members 7 fixed on both end faces of the transmission member 4, a first drive assembly 8 fixed on one of the cover members 7, and a second drive assembly 9 fixed on the other cover member 7.

The housing 3 may be, for example, a hollow cylindrical shape, and its inside may include a first hole 31 at a middle section with a smaller inner diameter, two second holes 32 at both ends with a larger inner diameter, and a first The first shoulder 33 at the junction of the hole 31 and the second hole 32.

The transmission member 4 may be, for example, in the shape of a roller, which may include a first section 41 located at the middle section and having a larger outer diameter, two second sections 42 located at both ends and having a smaller outer diameter, located at the first section A second shoulder 43 at the boundary between the 41 and the second section 42, a central hole penetrating the center of the transmission member in the longitudinal axis direction, and a plurality of first screw holes 44 respectively formed on both end surfaces of the transmission member 4.

The support shaft 5 may include two grooves 51 respectively formed near both ends and surrounding the outer peripheral surface of the support shaft.

The cover member 7 may be, for example, disc-shaped, and may include a central hole and a plurality of through holes 71 located around the central hole.

The first driving assembly 8 may include a rod-shaped first force-applying arm 81, a disc-shaped first drive member 82 connected to the first end of the first force-applying arm 81 and fixed to a bicycle sprocket, The first pedal 83 pivotally connected to the second end of the first force applying arm 81.

The first force applying arm 81 includes a first ear portion 811 extending a distance from its first end in a transverse direction crossing or substantially perpendicular to its longitudinal axis, and along the longitudinal direction from between the first end and the second end The axis crossing or substantially perpendicular transverse direction extends a distance and is located opposite to the first ear 811 at the longitudinal axis The first convex portion 812 on the opposite sides, the first through hole 813 formed in the first ear portion 811, and the first through hole 814 formed in the first convex portion 812.

The first driving member 82 may include a central hole at the center, a plurality of first through holes 821 formed at the periphery of the central hole, and a second threaded hole 822 provided near the outer edge of the first driving member.

The structure of the second drive assembly 9 is similar to that of the first drive assembly 8, the difference between the two is that the drive member [such as the second drive member 92] of one of the first drive assembly 8 and the second drive assembly 9 does not Secure to sprocket. Therefore, the second driving assembly 9 may include a rod-shaped second force-applying arm 91, a disk-shaped second drive member 92 connected to the first end of the second force-applying arm 91, and pivotally connected to the second force-applying arm 91 The second pedal 93 of the second end.

The second force applying arm 91 includes a second ear portion extending a distance from the first end along a transverse direction crossing or substantially perpendicular to its longitudinal axis, and along the longitudinal axis from between the first end and the second end A second convex portion that extends a distance in a cross or substantially vertical lateral direction and is located on opposite sides of the longitudinal axis from the second ear portion, a second through hole formed in the second ear portion, and a second convex portion Second through hole.

The second driving member 92 may include a central hole at the center, a plurality of second perforations formed at the periphery of the central hole, and a third threaded hole provided near the outer edge of the second driving member.

Assemble

As shown in FIGS. 3 to 6, first, a bearing 6 is assembled in the second hole 32 at one end of the housing 3, and secondly, the first section 41 of the transmission member 4 is assembled in the housing 3 The second hole 42 in the first hole 31 of one end of the transmission member 4 is fitted in the central hole of the bearing 6. Then, another bearing 6 is assembled between the second hole 32 at the other end of the housing 3 and the second section 42 at the other end of the transmission member 4. At this time, one side of the outer ring of each bearing 4 abuts the first shoulder 33 of the housing 3, and one side of the inner ring of each bearing 4 abuts the second shoulder 43 of the transmission member 4, each The outer peripheral surface of the outer ring of the bearing 4 and the inner surface of the second hole 32 of the housing 3 form a tight fit, the inner surface of the inner ring of each bearing 4 and the outer peripheral surface of the second section 42 of the transmission member 4 form The tight fit, the outer peripheral surface of the first section 41 of the transmission member 4 and the inner surface of the first hole 31 of the housing 3 form a loose fit.

Next, insert the support shaft 5 into the central hole of the transmission member 4 in a loose-fitting manner, so that the two grooves 51 of the support shaft 5 are located outside the two end surfaces of the transmission member 4, respectively, and then use two fasteners [ For example, the C-shaped retaining ring] 52 is respectively fastened to the support shafts at the two grooves 51, so that a part of the fastener 52 is accommodated in the groove 51, and the other part of the fastener 52 protrudes out of the groove 51. They respectively abut against the two end surfaces of the transmission member 4 to restrict the support shaft 5 from sliding relative to the transmission member 4 along the longitudinal axis of the transmission member 4.

Secondly, the two cover members 7 are respectively assembled on both ends of the support shaft 5 so that the two ends of the support shaft 5 pass through and protrude from the central holes of the two cover members 7 respectively. Next, the first driving member 82 of the first driving assembly 8 and the second driving member 92 of the second driving assembly 9 are respectively assembled on the two ends of the support shaft 5 so that the two ends of the support shaft 5 pass through Pass and protrude the center hole of the first driving member 82 and the center hole of the second driving member 92. Then, a plurality of bolts are respectively passed through the first through hole 821 of the first driving member 82, the second through hole of the second driving member 92, and the through hole 71 of the cover member 7 to lock the first hole in the end surface of the transmission member 4 Threaded hole 44. At this time, the side surface of the cover member 7 tightly abuts against the end surface of the transmission member 4 and the inner ring of the bearing 6, thereby preventing the bearing 6 from sliding along the longitudinal axis of the transmission member 4.

Next, the first through hole 814 of the first urging arm 81 and the second through hole of the second urging arm 91 respectively accommodate the two ends of the support shaft 5 in a loose-fitting manner. Then use two bolts to pass through the first through hole 813 of the first force applying arm 81 and the second through hole of the second force applying arm 91 respectively, and lock into the second threaded holes 822 and The third threaded hole of the second driving member 92 locks the first urging arm 81 and the second urging arm 91 to the first driving member 82 and the second driving member 92, respectively. Finally, the first pedal 83 and the second pedal 93 are pivotally connected to the second ends of the first urging arm 81 and the second urging arm 91, respectively, to complete the assembly of the crank device 2.

effect

The crank device 2 of the present invention includes a first drive assembly 8 and a second drive assembly 9 that are similar to each other, so when a member containing the words "first" or "second" is to be mentioned, the "first "And "Second" and use their component names directly to make the description more concise. For example, when referring to "first force applying arm 81" or "second force applying arm 91", "first" and "second" will be omitted and directly referred to as "force applying arm". In other words, when the term "force applying arm" is used, it means "first force applying arm 81" and/or "second force applying arm 91".

Since the forcing arms 81 and 91 of the present invention are pivotally connected to the support shaft 5 by the convex portions 812 and fixed to the driving members 82 and 92 by the ear portions 811 at the first ends of the forcing arms 81 and 91, The rider applies force to the forcing arms 81, 91 When the pedal at the second end is applied, the biasing arms 81 and 91 will rotate around the support shaft 5 with the convex portion 812 [the convex portion 812 rotates relative to the support shaft 5] and directly drive the driving members 82 and 92 with the ear portion 811. The sprocket and chain of the bicycle are transmitted without driving the support shaft 5 located at the center of the driving member 82, 92 or the transmission member 4. In contrast, the second crank arm 14 of the prior art must first drive the crank shaft 13 and then drive the sprocket 12 via the spline of the crank shaft 13. Therefore, the crank device 2 of the present invention has no risk of spline wear and breakage, not only can bear greater force, but also can ensure the safety of the rider.

On the other hand, in the present invention, the side surfaces of the driving members 82 and 92 contact the side surface of the cover member 7 and then the end surface of the transmission member 4, and then a plurality of bolts penetrate through the side surfaces of the driving members 82, 89 and the cover member 7 , 89 and the cover member 7 are tightly locked to the end surface of the transmission member 4. In addition to the friction between the side surface and the end surface can help to transfer the force, because the area of the end surface of the transmission member 4 is larger than the area of the surrounding surface of the conventional crankshaft 13, the end surface of the transmission member 4 can accommodate many large The diameter of the bolt is used to bear the force transmitted between the transmission member 4 and the cover member 7 and the driving members 82 and 89. Therefore, the crank device 2 of the present invention can not only bear greater force, but also ensure the safety of the rider.

Furthermore, since the biasing arms 81 and 91 of the present invention directly drive the driving members 82 and 92 without driving the support shaft 5, and the longitudinal axis of the biasing arms 81 and 91 does not pass through the support shaft 5, the biasing arm 81 The length of 91 is not limited by the support shaft 5. In other words, the length of the forcing arm 81, 91 can extend from the position of the pedals 83, 93 across the support shaft 5 to the ear 811 fixed near the outer edges of the driving members 82, 92, so the forcing arm 81 of the present invention The length of 91 is much longer than that of the conventional crank arms 11 and 14, which can greatly improve the labor saving effect.

Secondly, no holes are formed in the longitudinal axis of the urging arms 81, 91 of the present invention, not only does not reduce the thickness of the material, but also there is no hole to cause stress concentration, so the strength of the urging arms 81, 91 can be improved. Furthermore, as shown in FIG. 5, the convex portion 812 and the ear portion 811 are located on both sides of the longitudinal axis of the force applying arm, and the ear portion 811 and the force F1 applied to the pedals 83 and 93 are located on the same side, and the convex portion 812 The sum force F1 is on the opposite side, so when the force F1 is applied to the pedals 83, 93, the ear 811 receives the material at the first reaction force F2 of the bolt and the protrusion 812 receives the material at the second reaction force F3 of the support shaft 5 The thickness is equal to or greater than the full thickness of the forcing arms 81, 91, so the strength of the forcing arms 81, 91 is greatly improved. In particular, the outer peripheral materials of the force applying arms 81 and 91 above the bolts and below the support shaft 5 are not subjected to external forces, so the outer peripheral materials will not break, which can fundamentally solve the strength problem of the conventional crank arm.

In addition, the crank device of the present invention includes few parts and low cost.

Other embodiments

The first driving member 82 and the second driving member 92 of the above embodiment are respectively located on both sides of the bicycle bracket, and one of the first driving member 82 and the second driving member 92 is fixed to the sprocket. However, in another embodiment, one of the first driving member 82 and the second driving member 92 fixed to the sprocket may be integrated with the sprocket into a single part.

The cover member 7 can be integrated with the driving members 82, 92 into a single part. In other words, the cover member 7 can be integrated into the driving members 82, 92 to become a flange on the side of the driving members 82, 92, for abutting the end face of the transmission member 4 and the inside of the bearing 6 ring.

The force-applying arms 81 and 91 may be curved or non-linear.

The ear portion 811 of each biasing arm 81, 91 may have two through holes 813 for two bolts to be locked to the driving members 82, 92.

Each force applying arm 81, 91 may include a plurality of ears 811. The ears 811 may be distributed on both sides of the longitudinal axis of the force applying arms 81, 91 to reinforce the strength of the driving members 82, 92.

Although the driving members 82 and 92 are disk-shaped, they can form partial openings or even non-circular irregular sheets to reduce the weight of the driving members 82 and 92. In addition, ribs may be provided on the sides of the driving members 82 and 92 to increase the strength of the driving members 82 and 92.

A bolt with a washer can be used to lock the end surface of the support shaft 5 to block the convex portion 812, thereby restricting the biasing arms 81, 91 from sliding along the longitudinal axis of the support shaft 5.

The diameter of the housing 3 and the transmission member can be increased to accommodate more or larger diameter bolts to withstand greater transmission force.

However, the above are only the preferred embodiments of the present invention, which should not be used to limit the scope of the implementation of the present invention, that is, simple equivalent changes and modifications made according to the scope of the patent application of the present invention and the content of the invention description, All should still fall within the scope of this invention patent.

2‧‧‧Crank device

3‧‧‧Housing

5‧‧‧Support shaft

8‧‧‧(first) drive assembly

9‧‧‧ (second) drive assembly

81‧‧‧ (first) force applying arm

82‧‧‧(first) drive part

83‧‧‧(first) pedal

91‧‧‧ (second) force-applying arm

92‧‧‧ (second) drive parts

93‧‧‧ (second) pedal

Claims (3)

A crank device (2) for a bicycle, the crank device includes: a housing (3) for connecting to a bracket of the bicycle; a transmission member (4) is received in the housing (3) in a loose-fitting manner ); the support shaft (5) is partially accommodated in the transmission part (4) in a loose-fitting manner; and two drive assemblies (8, 9), each of the two drive assemblies Including: a driving member (82, 92), fixed to the transmission member (4) and used for connecting to the bicycle sprocket, and one end of the supporting shaft (5) passes through the transmission member (4) in a loose-fitting manner ) And the drive member (82, 92); and the force applying arm (81, 91), including the ear (811) fixed to the drive member (82, 92) and pivotally connected to the support shaft (5) A convex portion (812) at one end; wherein the convex portion (812) extends from the force applying arm (81, 91) along a direction crossing the longitudinal axis of the force applying arm for a distance so as to pivotally connect to the convex portion (812) 812) the support shaft (5) is located outside the longitudinal axis of the force applying arm (81, 91); thereby, when a force is applied to any one of the two drive assemblies (8, 9) When the force applying arm (81, 91), the force applying arm will pivot around the support shaft (5), and the force from the ear (811) via the drive member (82, 92) and the transmission member (4) The drive is transmitted to another drive assembly. The crank device for a bicycle as described in item 1 of the patent application scope, wherein the ear portion (811) extends from the force applying arm (81, 91) in a direction crossing the longitudinal axis of the force applying arm, and The ear portion (811) and the convex portion (812) are respectively located on both sides of the longitudinal axis of the force applying arm. The crank device for a bicycle as described in item 2 of the patent application scope, wherein the ear portion (811) extends from one end of the force applying arm (81, 91), and the convex portion (812) extends from both ends of the force applying arm Extend between the ends.

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