bicycle bottom bracket

Abstract

The present invention provides a bicycle bottom bracket, comprising an outer shell, a central shaft rod inserted into the outer shell, an elastic ring and a bearing seat sleeved on the central shaft rod, a bearing sleeved on the bearing seat, and an adjusting member. The bearing seat comprises a push portion protruding from an outer surface, and the outer surface is provided with a threaded portion and a bearing mounting portion located on both sides of the push portion. The elastic ring is disposed between the central shaft rod and the inner surface of the bearing seat. The inner ring of the bearing abuts the push portion and the bearing mounting portion of the bearing seat, and the outer ring abuts the outer shell, so that the bearing seat, the elastic ring, and the central shaft rod can rotate together relative to the outer shell. The adjusting member is threadedly connected to the threaded portion of the bearing seat, so that a user can rotate the adjusting member to move the adjusting member and the bearing seat relative to each other, thereby eliminating the gap between the crank and the bearing and preventing the bearing from being subjected to excessive preload.

Description

Technical Field

[0001] The present invention relates to a bicycle, and in particular to a bicycle bottom bracket (BB). Background Art

[0002] Referring to Patent No. M434732, a conventional bicycle crank assembly includes a bottom bracket mounted on a bottom bracket tube of a bicycle frame, and two cranks disposed at either end of the bottom bracket for mounting a sprocket on the bottom bracket. A pedal is mounted at the end of each crank, allowing a user to rotate the sprocket and thereby the wheel by stepping on the pedal.

[0003] Because bicycle bottom brackets and cranks come in various sizes and are not necessarily identical, some bottom brackets include a gap adjustment member. As disclosed in the aforementioned patent, the gap adjustment member is mounted on a central shaft of the bottom bracket and positioned between the crank and the bearing at one end of the central shaft. The gap adjustment member primarily comprises a first member for user rotation and a second member threadedly connected to the first member. When the first member rotates, the first and second members move relative to each other along the central shaft. This gap adjustment member fills the gap between the crank and the bearing and can be adjusted to accommodate different sizes and specifications when the gap varies. However, a disadvantage of commonly used gap adjustment members in bicycle bottom brackets is that users may over-rotate the first member, causing excessive preload on the bearing. Summary of the Invention

[0004] In view of the above-mentioned shortcomings, the main purpose of the present invention is to provide a bicycle bottom bracket, which can not only eliminate the gap between the bottom bracket and the crank, but also prevent the bearing from being subjected to excessive preload.

[0005] To achieve the above-mentioned objectives, the present invention provides a bicycle bottom bracket comprising a housing, a central shaft, an elastic ring, a bearing seat, a bearing, and an adjustment member. The central shaft is disposed within the housing, the elastic ring and the bearing seat are sleeved on the central shaft, the bearing seat comprises an inner surface, an outer surface, and a push portion protruding from the outer surface, the outer surface being provided with a threaded portion and a bearing mounting portion, the push portion being located between the threaded portion and the bearing mounting portion, the elastic ring being disposed between the central shaft and the inner surface of the bearing seat, the bearing being sleeved on the bearing mounting portion of the bearing seat, the bearing comprising an inner ring and an outer ring, the inner ring abutting the push portion and the bearing mounting portion of the bearing seat, and the outer ring abutting the housing, such that the bearing seat, the elastic ring, and the central shaft can rotate together relative to the housing. The adjustment member is sleeved on the bearing seat and threadedly engaged with the threaded portion of the bearing seat, so that a user can rotate the adjustment member to cause relative movement between the adjustment member and the bearing seat.

[0006] The bicycle bottom bracket of the present invention is thus configured to accommodate a crank mounted at one end of the central shaft, with the adjusting member and the bearing seat positioned between the crank and the bearing. After the crank is mounted on the bicycle bottom bracket, the user can rotate the adjusting member to move the adjusting member and the bearing seat relative to each other, thereby causing the adjusting member and the bearing seat to abut against the crank and the bearing, respectively, to eliminate the gap. If the user continues to rotate the adjusting member, the force acting on the bearing seat will become greater than the friction between the bearing seat and the elastic ring, causing the bearing seat and the elastic ring to slip. The bearing seat and the adjusting member will then rotate together without relative movement, thereby preventing further compression of the bearing and preventing excessive preload on the bearing.

[0007] The detailed structure, features, assembly, and usage of the bicycle bottom bracket provided by the present invention will be described in the detailed description of the embodiments that follow. However, those skilled in the art will appreciate that the detailed description and the specific embodiments listed for implementing the present invention are intended only to illustrate the present invention and are not intended to limit the scope of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 and Figure 2 They are respectively a three-dimensional assembly diagram and a three-dimensional exploded diagram of a bicycle middle shaft and a sprocket provided by a first preferred embodiment of the present invention.

[0009] Figure 3 It is a partial cross-sectional view of the bicycle's middle shaft.

[0010] Figure 4 Similar to Figure 3 , but it shows the bicycle's bottom bracket after the cranks are installed and the gap is eliminated.

[0011] Figure 5 A partial cross-sectional view of a bicycle bottom bracket provided in accordance with a second preferred embodiment of the present invention.

[0012] Figure 6 A partial cross-sectional view of a bicycle bottom bracket provided in accordance with a third preferred embodiment of the present invention.

[0013] Figure 7 A partial cross-sectional view of a bicycle bottom bracket provided in accordance with a fourth preferred embodiment of the present invention.

[0014] [Description of Reference Numerals]

[0015] 10-Bicycle bottom bracket

[0016] 11-First end

[0017] 12-Second end

[0018] 14-Middle section

[0019] 16-sprocket

[0020] 17-Crank

[0021] 18-Adjustment unit

[0022] 21- Shell

[0023] 22-Center shaft

[0024] 221-Adjustment unit installation section

[0025] 222-Outer surface

[0026] 224-Groove

[0027] 226-crank mounting section

[0028] 23-Elastic ring

[0029] 24-Bearing

[0030] 241-Inner Circle

[0031] 242-outer ring

[0032] 25-Bearing seat

[0033] 251-Inner surface

[0034] 252-Outer surface

[0035] 253-Pushing part

[0036] 254-convex wall

[0037] 255-threaded part

[0038] 256-Bearing installation part

[0039] 257-anti-slip structure

[0040] 26-Adjustment parts

[0041] 261-Gripping part

[0042] 262-threaded part

[0043] 27-Fixer DETAILED DESCRIPTION

[0044] The applicant would like to first clarify that in the following embodiments and drawings, identical reference numbers represent identical or similar components or structural features. It should be noted that the components and structures in the drawings are for illustrative purposes only and are not drawn to scale or actual number. Furthermore, features from different embodiments may be interchangeably applied, if practically possible.

[0045] Please see first Figure 1The bicycle bottom bracket 10 provided in a first preferred embodiment of the present invention includes a first end portion 11, a second end portion 12, and an intermediate section 14. The intermediate section 14 is used to be disposed in a bottom bracket tube (not shown) of a bicycle frame. The first end portion 11 is used to dispose a sprocket 16 and a crank (not shown) located outside the sprocket 16. The second end portion 12 is used to dispose another crank 17 (such as Figure 4 (as shown), and the second end portion 12 is provided with an adjustment unit 18 for eliminating the gap. The technical feature of the present invention lies in the adjustment unit 18 of the second end portion 12, which will be described in detail below. The remaining parts are not relevant to the technical features of the present invention and will not be described in detail here.

[0046] See also Figure 2 The bicycle bottom bracket 10 includes a housing 21 and a central shaft 22 extending through the housing 21. The housing 21 is fixed relative to the aforementioned bottom bracket. The aforementioned adjustment unit 18 is mounted on an adjustment unit mounting section 221 of the central shaft 22. The adjustment unit 18 includes two elastic rings (O-rings) 23, a bearing 24, a bearing seat 25, an adjustment member 26, and a fixing member 27.

[0047] See also Figure 2 and Figure 3 The adjustment unit mounting section 221 of the central shaft 22 includes an outer surface 222 and two grooves 224 recessed from the outer surface 222 . The elastic ring 23 is sleeved on the central shaft 22 and respectively disposed in the grooves 224 .

[0048] The bearing seat 25 is annular and includes an inner surface 251, an outer surface 252, a push portion 253 that protrudes a considerable distance from the outer surface 252 and extends along the outer surface 252, and a flange 254 that protrudes slightly from the outer surface 252 and extends along the outer surface 252. The outer surface 252 of the bearing seat 25 is provided with a threaded portion 255 and a bearing mounting portion 256 having a smooth surface. The push portion 253 is located between the threaded portion 255 and the bearing mounting portion 256. The flange 254 is located at one end of the bearing seat 25 and is located on the same side of the push portion 253 as the bearing mounting portion 256. That is, the bearing mounting portion 256 is located between the push portion 253 and the flange 254.

[0049] The bearing 24 is mounted on the bearing mounting portion 256 of the bearing seat 25 and is positioned between the abutment portion 253 and the raised wall 254. More specifically, the inner ring 241 of the bearing 24 abuts the abutment portion 253 and the raised wall 254 on both sides. The bearing 24 is first mounted on the bearing mounting portion 256 of the bearing seat 25. The bearing seat 25 and the bearing 24 are then mounted together on the adjustment unit mounting section 221 of the center shaft 22, with the elastic ring 23 positioned between the center shaft 22 and the inner surface 251 of the bearing seat 25. At this point, the outer ring 242 of the bearing 24 abuts the housing 21, allowing the bearing seat 25, the elastic ring 23, and the center shaft 22 to rotate relative to the housing 21. More specifically, the friction between the inner surface 251 of the bearing seat 25 and the elastic ring 23 is greater than the friction of the bearing 24 when it rotates. When the user pedals the crank, the inner ring 241 of the bearing 24, the bearing seat 25, the adjustment member 26, the elastic ring 23 and the central shaft 22 rotate together.

[0050] Adjustment member 26 is annular in shape, with a gripping portion 261 on its outer surface for the user to grasp and a threaded portion 262 on its inner surface. Adjustment member 26 is sleeved over threaded portion 255 of bearing seat 25, and threaded portion 262 of adjustment member 26 is threadedly engaged with threaded portion 255 of bearing seat 25. This allows the user to rotate adjustment member 26, thereby moving the adjustment member 26 relative to the bearing seat 25, thereby eliminating any gap (described in detail below). After adjustment is complete, fixing member 27 is threadedly secured to adjustment member 26, preventing it from rotating.

[0051] See also Figure 3 and Figure 4 The bicycle bottom bracket 10 is provided with a crank mounting section 226 for the crank 17 mounted on the central shaft 22, such that the adjusting member 26 and the bearing seat 25 are positioned between the crank 17 and the bearing 24. After the user installs the crank 17 on the bicycle bottom bracket 10, they can rotate the adjusting member 26 to move the adjusting member 26 and the bearing seat 25 relative to each other, thereby causing the adjusting member 26 and the bearing seat 25 to abut against the crank 17 and the bearing 24, respectively, to eliminate the gap. At this point, if the user continues to rotate the adjusting member 26, the force acting on the bearing seat 25 will become greater than the friction between the bearing seat 25 and the elastic ring 23, causing the bearing seat 25 and the elastic ring 23 to slip. The bearing seat 25 and the adjusting member 26 will rotate together without relative movement, thus preventing further compression of the bearing 24. In other words, with the aforementioned structure of the present invention, even if the user excessively rotates the adjusting member 26, the bearing 24 can still be protected from excessive preload.

[0052] See also Figure 5 The second preferred embodiment of the present invention is similar to the first preferred embodiment described above, except that Figure 5In the second preferred embodiment shown, the inner surface 251 of the bearing seat 25 has an anti-slip structure 257. The anti-slip structure 257 can be formed by surface treatment or coating with an anti-slip material. The bearing seat 25 of this embodiment abuts against the elastic ring 23 with the anti-slip structure 257, so that there is more appropriate friction between the bearing seat 25 and the elastic ring 23. When the user eliminates the gap, the bearing seat 25 and the adjustment member 26 can move smoothly relative to each other and thus abut against the bearing 24 and the crank 17 respectively. After the bicycle bottom bracket 10 and the crank 17 are installed and adjusted, the bicycle bottom bracket 10 can be smoothly driven by the crank 17 to rotate.

[0053] The aforementioned embodiments all use two elastic rings 23, and the cross-sectional shape of the elastic rings 23 is circular. However, the number and shape of the elastic rings of the present invention are not limited, that is, the present invention may include at least one elastic ring, and may also use elastic rings with non-circular cross-sectional shapes, such as Figure 6 and Figure 7 The third and fourth preferred embodiments of the present invention use an elastic ring 23 with a flat cross-section.

[0054] Figure 6 The third preferred embodiment shown is similar to the first preferred embodiment described above, except that the cross-section of the elastic ring 23 is flat, which makes it easier for the bearing seat 25 to be mounted on the central shaft 22 on which the elastic ring 23 is mounted.

[0055] Figure 7 The fourth preferred embodiment shown is similar to the first preferred embodiment described above, except that only one elastic ring 23 is provided. The cross-section of the elastic ring 23 is a flat, rectangular shape of considerable width. The width of the groove 224 in the central shaft 22 where the elastic ring 23 is located is greater than the width of the elastic ring 23. The elastic ring 23 can be secured to the central shaft 22 with an adhesive to prevent displacement within the groove 224. This elastic ring 23 not only facilitates the installation of the bearing seat 25 onto the central shaft 22 where the elastic ring 23 is located, but also provides a larger contact area between the elastic ring 23 and the bearing seat 25.

[0056] Finally, it must be stated again that the constituent components disclosed in the previously disclosed embodiments of the present invention are for illustrative purposes only and are not intended to limit the scope of this case. Replacements or variations of other equivalent components should also be covered by the scope of the patent application of this case.

Claims

1. A bicycle middle shaft, characterized in that: Includes: a shell; a central shaft extending through the housing; an elastic ring, sleeved on the central shaft; a bearing seat sleeved on the central shaft, the bearing seat comprising an inner surface, an outer surface, and a push portion protruding from the outer surface, the outer surface being provided with a threaded portion and a bearing mounting portion, the push portion being located between the threaded portion and the bearing mounting portion, and the elastic ring being disposed between the central shaft and the inner surface of the bearing seat; a bearing mounted on the bearing mounting portion of the bearing seat, the bearing comprising an inner ring and an outer ring, the inner ring abutting the pushing portion and the bearing mounting portion of the bearing seat, and the outer ring abutting the housing, so that the bearing seat, the elastic ring, and the central shaft can rotate together relative to the housing; and An adjusting piece is sleeved on the bearing seat and is threadedly connected with the threaded portion of the bearing seat so as to allow a user to rotate the adjusting piece to move relative to the bearing seat.

2. The bicycle bottom bracket according to claim 1, characterized in that: The inner surface of the bearing seat has an anti-slip structure, and the anti-slip structure abuts against the elastic ring.

3. The bicycle bottom bracket according to claim 1, characterized in that: The bearing seat further comprises a convex wall protruding from the outer surface thereof, and the bearing is clamped between the pushing portion and the convex wall.

4. The bicycle bottom bracket according to claim 1, characterized in that: The central shaft comprises an outer surface and a groove recessed from the outer surface. The elastic ring is arranged in the groove.

5. The bicycle bottom bracket according to claim 1, characterized in that: The elastic ring is adhered to the central shaft.

6. The bicycle bottom bracket according to claim 1, characterized in that: The cross-section of the elastic ring is circular.

7. The bicycle bottom bracket according to claim 1, characterized in that: The cross-section of the elastic ring is flat.

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