Bicycle with a drive device having a shaft arrangement

Abstract

A shaft arrangement has a shaft (1) for transmitting a torque between components coupled to the shaft (1), wherein the shaft (1) is rotatably mounted within a stationary tubular element (2). Within an annular gap (3) between an outer circumference of the shaft (1) and an inner circumference of the tubular element (2), at least one contour (7, 8) is provided on at least one surface of the shaft (1) and the tubular element (2), which contour is designed such that oil present within the annular gap (3) is driven from the sealing region (6) to the oil inlet region (4) due to rotation of the shaft (1) relative to the tubular element (2).

Description

[0001] The following describes a bicycle with a drive device that has a shaft arrangement with a rotatably mounted shaft that is intended for the transmission of torque.

[0002] Shaft assemblies with a rotatably mounted shaft are used in various technical applications. Shaft assemblies are known in which lubricating oil is used to lubricate the bearings for rotatably supporting the shaft. Furthermore, it is known that shaft sealing assemblies can be provided to restrict the space in which the lubricating oil is located. Examples of known shaft assemblies according to the prior art are disclosed in CN 2 01 963 751 U, CN 2 10 531 391 U, CN 2 03 262 792 U, JP S58 - 58 986 U, US 2005 / 0 221 940 A1, and CN 2 12 318 477 U.

[0003] The object is to provide a bicycle with a drive mechanism having an improved shaft arrangement that can be manufactured using simple means and with which leakage of used lubricating oil can be more effectively prevented. This object is achieved with a bicycle having the features of claim 1. Advantageous further developments are defined in the dependent claims.

[0004] A bicycle that can be operated at least temporarily using muscle power is provided with a drive device having a shaft arrangement designed to rotatably support a shaft configured as a crankshaft, which is provided for introducing muscle power into the drive device. The shaft arrangement has a shaft for transmitting torque between components coupled to the shaft, wherein the shaft is rotatably mounted within a stationary tubular element. An annular gap is formed between an outer circumference of the shaft and an inner circumference of the tubular element. The shaft arrangement further has an oil inlet region, in which oil can enter the annular gap, and a shaft sealing arrangement between the outer circumference of the shaft and the inner circumference of the tubular element in a sealing region. The oil inlet region and the sealing region are arranged at an axial distance from one another.

[0005] Within the annular gap, at least one contour is provided on at least one of the surfaces of the shaft and the tubular element, which contour is designed such that oil present within the annular gap is driven from the sealing region to the oil inlet region due to a rotation of the shaft relative to the tubular element.

[0006] The shaft can be designed as a rotationally symmetrical element. The shaft can be rotatably mounted at two or more axial positions. At least one rolling bearing can be used to support the shaft. Alternatively, at least one plain bearing can be used to support the shaft. The shaft can protrude from the tubular element at at least one axial end section. The components coupled to the shaft can form a drive and an output. In particular, a force can be introduced at one or more positions on the shaft and the force can be dissipated at one or more positions on the shaft. For this purpose, corresponding components can be provided on the shaft. The components can comprise a wheel, for example a gear or a chain wheel. Furthermore, the components can comprise crank arms of a crank device of a bicycle.

[0007] The tubular element can be mountable on a stationary component. Alternatively, the tubular element can be part of a stationary component or mounted thereon. The stationary component can be a drive device, for example, for a bicycle. The oil inlet region can be formed as a radial opening in the tubular element. The oil inlet region can have more than one opening. Alternatively or additionally, the oil inlet region can be formed by an arrangement for guiding oil in the shaft. For this purpose, a channel can be formed within the shaft. The channel formed within the shaft can open at a circumference of the shaft.

[0008] According to one embodiment, the at least one contour can be designed such that oil present within the annular gap is driven from the sealing region to the oil inlet region when the rotation of the shaft relative to the tubular element is a preferred direction of rotation. The shaft can in particular be mounted so as to be rotatable in both directions of rotation. Taking into account the specific application of the shaft arrangement, it can be provided that the shaft rotates in one direction for the majority of its operation. Thus, under the above assumption, the shaft is rotated in a preferred direction of rotation. In one application example, the preferred direction of rotation of the shaft is the direction of rotation in which, for example, a crank mechanism of a bicycle is rotated to propel the bicycle.However, the direction of rotation that is opposite to the direction of rotation with which, for example, the crank mechanism of the bicycle is rotated to propel the bicycle is not a preferred direction of rotation.

[0009] A contour may consist of at least one element that protrudes from an outer peripheral surface of the shaft. Furthermore, a contour may be configured as a recess in the outer peripheral surface of the shaft. The contour may be configured from a combination of elements that protrude from the outer peripheral surface of the shaft and that are configured as recesses in the outer peripheral surface of the shaft. The contour may comprise a plurality of the aforementioned elements.

[0010] According to one embodiment, the contour can be provided at least in sections on an outer circumference of the shaft. In particular, the contour can be provided on an axial section of the outer circumference of the shaft. The contour can be provided on the axial section of the shaft that extends between the sealing area and the oil inlet area.

[0011] According to one embodiment, the contour can have a helical structure, at least in sections. In particular, the contour can be arranged as a protrusion on the outer circumferential surface of the shaft such that it extends along a helical line on the outer circumferential surface of the shaft. The protrusion can be continuous or interrupted. Alternatively, the contour can be designed as a helical depression on the outer circumferential surface of the shaft. In particular, the contour can be arranged as a depression in the outer circumferential surface of the shaft such that it extends along a helical line on the outer circumferential surface of the shaft. The depression can be continuous or interrupted. Furthermore, it can be provided that individual elements protruding from the outer circumferential surface of the shaft are provided along a line that has a helical shape.

[0012] According to one embodiment, the direction of rotation of the helical structure can be oriented such that the oil present in the annular gap is driven from the sealing region to the oil inlet region when the preferred direction of rotation is present. In a known manner, helical structures can be provided in two opposite directions of rotation on an element relative to the axial direction of the element. The direction of rotation of the helical structure in the shaft arrangement can be selected from the two possible directions of rotation such that when the preferred direction of rotation is present, the helical structure creates a pumping effect within the tubular element, which moves the oil present in the annular gap from the sealing region to the oil inlet region when the preferred direction of rotation is present.

[0013] According to one embodiment, the contour can be formed on the outer circumference of the shaft. In particular, the contour can comprise one or more elements that are firmly connected to the outer circumference of the shaft.

[0014] According to one embodiment, the shaft and the contour can be formed as a single piece. In particular, the shaft and the contour can be formed from the same material.

[0015] According to one embodiment, the shaft with the contour can be manufactured by injection molding. In particular, a shape can be specified during injection molding that defines the shaft with the contour. In particular, the shaft with the contour can be manufactured by plastic injection molding. Alternatively, the shaft can be manufactured by insert injection molding, in which reinforcing materials are embedded in the shaft in addition to the plastic.

[0016] According to one embodiment, the contour can be provided on the inner circumference of the tubular element. In this case, the contour can be formed from at least one element that protrudes from the inner circumferential surface of the tubular element. Furthermore, the contour can have at least one recess in the inner circumferential surface of the tubular element.

[0017] According to one embodiment, the contour can have a helical structure at least in sections.

[0018] According to one embodiment, the direction of rotation of the helical structure can be oriented such that the oil present in the annular gap is driven from the sealing area to the oil inlet area when the preferred direction of rotation of the shaft is present. The direction of rotation of the helical structure is selected taking into account the specifications specified above for the direction of rotation of the helical structure for the shaft.

[0019] According to one embodiment, a contour can be provided on the inner circumference of the tubular element and a contour can be provided on the outer circumference of the shaft, wherein the contours are configured such that oil present within the annular gap is driven from the sealing region to the oil inlet region when the rotation of the shaft relative to the tubular element is a preferred direction of rotation. In this embodiment, contours are provided on the inner circumference of the tubular element and on the outer circumference of the shaft, which face each other in the radial direction. With this embodiment, the achieved pumping effect is enhanced and the efficiency of the shaft arrangement can be improved.

[0020] In one embodiment, the helical contour can be formed, at least in sections, by depressions or elevations. In particular, the contour can be provided with alternating depressions and elevations.

[0021] According to one embodiment, the shaft can extend through the drive device and have cranks at the opposite end portions. The drive device can comprise the tubular element. In particular, the tubular element can extend axially through the drive device. The oil inlet region of the tubular element can be connected to an oil supply through which oil can enter the annular gap between the outer circumference of the shaft and the inner circumference of the tubular element.

[0022] It should be noted that in bicycles with drive mechanisms, there is typically a preferred direction of rotation for the shaft, which is correlated with the direction of propulsion for the bicycle. In such a bicycle, when the drive mechanism is operating in the preferred direction of rotation of the shaft, oil present in the annular gap between the outer circumference of the shaft and the inner circumference of the tubular element can be forced from the shaft sealing arrangement to the oil inlet area, so that the shaft sealing arrangement is subjected to less oil. In this respect, the sealing of the shaft sealing arrangement can be improved, and at the same time, a simplified shaft sealing arrangement can be used. Fig. 1 shows a shaft arrangement in one embodiment in a cross-sectional view; and Fig. 2 shows a bicycle to which a drive device with the shaft arrangement according to the embodiment of Fig. 1 can be applied.

[0023] Fig. Figure 1 shows a shaft arrangement in a schematic cross-sectional view. As in Fig. 1, the shaft assembly comprises a shaft 1 arranged radially inside a tubular element 2. The Fig. 1 shown shaft 1 is rotatably supported by corresponding bearings which are in Fig. 1 are not shown. The shaft assembly further comprises an annular gap 3 located between the outer circumference of the shaft 1 and the inner circumference of the tubular element 2. The shaft assembly comprises on the right side in Fig. 1 has an oil inlet region 4 in which openings are provided that radially penetrate the tubular element 2. The openings of the oil inlet region 4 are connected to an oil supply, from which oil is conveyed to the oil inlet region 4. The oil conveyed to the oil inlet region 4 can enter the annular gap 3 through the openings in the oil inlet region 4.

[0024] On the left side of the Fig. 1, the shaft assembly comprises a shaft sealing assembly 5. In the present embodiment, the shaft sealing assembly 5 comprises a shaft sealing ring that is non-rotatably mounted on the tubular element 3 and seals against the outer circumferential surface of the shaft 1 by means of at least one sealing lip. In a modified embodiment, the shaft sealing assembly 5 comprises a shaft sealing ring that is non-rotatably mounted on the shaft 1 and seals against the inner circumferential surface of the tubular element 3 by means of at least one sealing lip. The shaft sealing assembly 5 prevents oil located in the annular gap 3 from escaping at the interface between the shaft 1 and the tubular element 2. The shaft sealing assembly 5 is located in a sealing region 6. The sealing region 6 is axially spaced from the oil inlet region 4.

[0025] A contour 7 is provided on the outer circumferential surface of the shaft 1. The contour 7 is designed as a helical elevation on the outer circumferential surface of the shaft 1. The contour 7 has a continuous elevation along a helical line that runs around the outer circumference of the shaft 1. The orientation or helical direction of the contour 7 is in the embodiment of Fig. 1 is selected so that the oil present in the annular gap 3 is driven from the sealing area 6 to the oil inlet area 4. When viewed in the direction of arrow A in Fig. 1, it is assumed below that the preferred direction is the clockwise direction of the shaft 1. In this case, the contour 7 with the helical structure is designed to produce a left-hand thread. In this way, the oil in the annular gap 3 is driven by the rotation of the shaft 1 in the preferred direction from the sealing area 6 to the oil inlet area 4. In the event that the preferred direction of rotation is counterclockwise when viewed along the direction of arrow A, the helical structure of the contour 7 is designed as a right-hand thread to achieve the corresponding effect.

[0026] The embodiment described above ensures that the oil in the annular gap 3 does not collect in the sealing area 6, thus increasing the pressure of the oil against the shaft sealing arrangement 5. Rather, the oil is driven back in the direction of the oil inlet area 4, so that a smaller amount of oil is present in the sealing area 6. This measure can minimize the leakage of oil from the shaft sealing arrangement 5. In particular, when using the shaft arrangement described above, a simplified shaft sealing arrangement 5 can be used, in which, for example, a poor surface quality of the outer circumference of the shaft 1, which comes into contact with a sealing lip of the shaft sealing arrangement 5, can be accepted.Furthermore, with the shaft arrangement described above, a shaft 1 made of plastic can be used, which has a reduced surface quality compared to a shaft made of ground metal. Furthermore, when using the shaft 1 manufactured by a plastic injection molding process, it is possible to provide the contour 7 on the outer circumference of the shaft 1 using simple means.

[0027] The shaft arrangement according to the embodiment of Fig. 1 is used in a drive device 9 for a bicycle 10, which is in Fig. 2 is shown schematically. The shaft assembly is integrated into the drive mechanism 9, and the shaft 1 of the shaft assembly serves as the crankshaft of the bicycle 10 for transmitting muscle power by a rider. The shaft assembly is integrated into the drive mechanism 9, and the opposite ends of the shaft 1 protrude from the opposite sides of the drive mechanism 9 and are connected to the corresponding cranks.

[0028] In the above-described embodiment of Fig.1, the contour 7 is provided on the outer circumferential surface of the shaft 1. In a modified embodiment, a contour 8 is provided on the inner circumferential surface of the tubular element. The design of the contour 8 on the inner circumferential surface of the tubular element 2 can be equivalent to the contour 7 provided on the outer circumferential surface of the shaft 1. In a further embodiment, the shaft 1 has the contour 7 on its outer circumferential surface, and the inner circumferential surface of the tubular element 2 also has the contour 8. The contours 7 and 8 can be adapted to one another in such a way that the function by which oil present within the annular gap 3 can be driven from the sealing region 6 to the oil inlet region 4 due to rotation of the shaft 1 relative to the tubular element 2 is enhanced. Reference symbol 1 wave 2 Tubular element 3 Annular gap 4 Oil inlet area 5 Shaft seal arrangement 6 Sealing area 7 Contour 8 Contour 9 Drive device 10 bicycles

Claims

[1] Bicycle (10) which can be operated at least temporarily with muscle power, with a drive device (9) which has a shaft arrangement which is designed to rotatably support a shaft (1) designed as a crankshaft, which is provided for introducing muscle power into the drive device, wherein the shaft (1) is designed to transmit a torque between components coupled to the shaft (1), wherein the shaft (1) is rotatably mounted within a stationary tubular element (2), wherein an annular gap (3) is formed between an outer circumference of the shaft (1) and an inner circumference of the tubular element (2), further comprising an oil inlet region (4) in which oil can enter the annular gap (3), and a shaft sealing arrangement (5) between the outer circumference of the shaft (1) and the inner circumference of the tubular element (2) in a sealing region (6), wherein the oil inlet region (4) and the sealing region (6) are arranged axially spaced from one another, characterized by that within the annular gap (3) on at least one of a surface of the shaft (1) and a surface of the tubular element (2) at least one contour (7, 8) is provided, which is designed such that oil present within the annular gap (3) is driven from the sealing area (6) to the oil inlet area (4) due to a rotation of the shaft (1) relative to the tubular element (2). [2] Bicycle (10) according to claim 1, characterized bythat the at least one contour is designed such that oil present within the annular gap (3) is driven from the sealing region (6) to the oil inlet region (4) when the rotation of the shaft (1) relative to the tubular element (2) is a preferred direction of rotation for propulsion of the bicycle (10). [3] Bicycle (10) according to claim 1 or 2, characterized by that the contour (7) is provided at least in sections on an outer circumference of the shaft (1). [4] Bicycle (10) according to one of the preceding claims, characterized by that the contour (7) has a helical structure at least in sections. [5] Bicycle (10) according to claim 4, characterized in that the direction of rotation of the screw-shaped structure is oriented such that the oil present in the annular gap (3) is driven from the sealing region (6) to the oil inlet region (4) when the preferred direction of rotation for propulsion of the bicycle (10) is present. [6] Bicycle (10) according to one of the preceding claims, characterized by that the contour (7) is formed onto the outer circumference of the shaft (1). [7] Bicycle (10) according to one of the preceding claims, characterized by that the shaft (1) and the contour (7) are formed in one piece. [8] Bicycle (10) according to one of the preceding claims, characterized by that the shaft (1) with the contour (7) is manufactured by injection molding. [9] Bicycle (10) according to one of the preceding claims, characterized by that the contour (8) is provided on the inner circumference of the tubular element (2). [10] Bicycle (10) according to claim 9, characterized by that the contour (8) has a helical structure at least in sections. [11] Bicycle (10) according to claim 10, characterized bythat the direction of rotation of the helical structure is aligned such that the oil present in the annular gap (3) is driven from the sealing area (6) to the oil inlet area (4) when the preferred direction of rotation for propulsion of the bicycle (10) is present. [12] Bicycle (10) according to one of the preceding claims, characterized by that a contour (8) is provided on the inner circumference of the tubular element (2) and a contour (7) is provided on the outer circumference of the shaft (1), wherein the contours (7, 8) are arranged such that oil present within the annular gap (3) is driven from the sealing area (6) to the oil inlet area (4) when the rotation of the shaft (1) relative to the tubular element (2) is a preferred direction of rotation for propulsion of the bicycle (10). [13] Bicycle (10) according to one of the preceding claims, characterized bythat the helical contour is formed at least in sections by depressions and / or elevations.

Images