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EP-4741272-A1 - HYDRAULIC TRANSMISSION FOR A TWO-WHEELER

EP4741272A1EP 4741272 A1EP4741272 A1EP 4741272A1EP-4741272-A1

Abstract

The present invention relates to a hydraulic transmission for a two-wheeler, comprising at least one turbine (100) with a turbine shaft (22) which can be connected to a hub of at least one wheel of the two-wheeler, a rotor (24) which is connected to the turbine shaft (22), and a housing (31) in which the rotor (24) is arranged, wherein the rotor (24) forms at least two channels (28) in the housing (31) which are arranged concentrically to the turbine shaft (22) at different distances, and in which one or more rotor blades (42) are arranged in each channel; and a pump (200) which can be connected to a drive shaft (51) of the two-wheeler, to which at least one crank (43, 50) is attached, wherein the pump (200) is configured to pump fluid in a circuit from an outlet (60) of the pump through one of the at least two channels (28) of the turbine (100) back to an inlet (52) of the pump (200).

Inventors

  • FEHMI, Mustafa

Assignees

  • FNF Innovation Sh.P.K.

Dates

Publication Date
20260513
Application Date
20241106

Claims (15)

  1. Hydraulic transmission for a two-wheeler, comprising - at least one turbine (100) with a turbine shaft (22) that can be connected to a hub of at least one wheel of the two-wheeler, a rotor (24) that is connected to the turbine shaft (22), and a housing (31) in which the rotor (24) is arranged, wherein the rotor (24) forms at least two channels (28) in the housing (31), which are arranged concentrically to the turbine shaft (22) at different distances, and in which one or more rotor blades (42) are arranged; and - a pump (200) that can be connected to a drive shaft (51) of the two-wheeler, to which at least one crank (43, 50) is attached, wherein the pump (200) is configured to pump fluid in a circuit from an outlet (60) of the pump through one of the at least two channels (28) of the turbine (100) back to an inlet (52) of the pump (200).
  2. Hydraulic transmission according to claim 1, wherein each of the at least two channels (28) of the turbine (100) has an inlet (29) and an outlet (26).
  3. Hydraulic transmission according to claim 2, wherein a switching device (150) is arranged upstream of the inputs (29) of the at least two channels (28) of the turbine (100), which is configured to direct the fluid into one of the channels (28).
  4. Hydraulic transmission according to claim 3, wherein the switching device (150) is connected to a shift lever of the two-wheeler.
  5. Hydraulic transmission according to claim 3 or 4, wherein the switching device (150) is integrated into the housing (31) of the turbine (100).
  6. Hydraulic transmission according to one of the preceding claims, wherein the output (52) of the pump (200) is connected to an input (17) of the switching device (150) by means of a first hydraulic connection (53), and the outputs (26) of the channels (28) of the turbine (100) are connected to the input (52) of the pump (200) by means of a second hydraulic connection (59).
  7. Hydraulic transmission according to claim 6, wherein the first and/or the second hydraulic connection (53, 59) are made of a transparent material.
  8. Hydraulic transmission according to one of the preceding claims, wherein the pump (200) is connected to the drive shaft (51) via a freewheel (61, 46), on the outside (46) of which one or more pump vanes (44) are arranged.
  9. Hydraulic transmission according to one of the preceding claims, wherein the pump (200) has a circulation channel (70) concentric to the drive shaft (51) which connects the inlet (60) and the outlet (52) of the pump (200), and a sealing channel (71) which is arranged between the inlet (60) and the outlet (52) of the pump (200) and is closed by means of a valve (57).
  10. Hydraulic transmission according to claim 9, wherein the inlet (60) of the pump (200) is configured to introduce the fluid in a tangential direction to a circle concentric with the drive shaft (51) into the circulation channel (70), and the outlet (52) of the pump (200) is configured to discharge the fluid from the circulation channel (70) in a tangential direction to the circle concentric with the drive shaft (51).
  11. Hydraulic transmission according to one of claims 8 to 10, wherein a rear side of each pump vane (44) extends radially outwards perpendicular to the outside (46) of the freewheel (61, 46) and a front side of each pump vane (44) extends at an angle of inclination from the outside (46) of the freewheel (61, 46) to an outer edge of the rear side.
  12. Hydraulic transmission according to one of claims 9 to 11, wherein each pump vane (44) is configured to open the valve (57) when a pump vane (44) passes through the sealing channel (71).
  13. Hydraulic transmission according to one of claims 9 to 12, wherein a section (64) of the locking channel (71) which is arranged between the valve (57) and the outlet (52) of the pump (200) is connected to the outlet (51) of the pump (200) by means of a bypass channel (54).
  14. Use of a hydraulic transmission according to one of claims 1 to 13 for driving a two-wheeler, in particular a bicycle or a motorcycle.
  15. Two-wheeler, in particular a bicycle or a motorcycle, comprising at least one hydraulic transmission according to one or more of claims 1 to 13.

Description

The present invention relates to a novel hydraulic transmission for a two-wheeler. Hydraulic transmissions for bicycles are known in the state of the art. For example, it shows DE 196 12 519 A1 Such a hydraulic transmission comprises a hydraulic pump arranged on the crankshaft of a bicycle, which is fluidically connected to a hydraulic motor on a wheel hub of the bicycle. The hydraulic pump is designed as a vane pump with multiple pumping cells, wherein a circumferential surface of at least one pumping cell is formed by a displacement flap that is radially adjustable relative to a pump drive shaft. In this way, the pumping volume of the vane pump can be varied, thereby changing the transmission ratio between the crankshaft and the wheel hub. The present invention aims to provide a hydraulic transmission for a two-wheeler that has high efficiency as well as a robust and compact design. The present invention therefore presents a hydraulic transmission for a two-wheeler, comprising at least one turbine with a turbine shaft that can be connected to the hub of at least one driven wheel of the two-wheeler. The turbine shaft can include an output shaft or an output shaft section that can be connected to the hub of the driven wheel, for example, by means of a conventional shaft-hub connection. The turbine comprises a rotor connected to the turbine shaft and a housing in which the rotor is located. The rotor can be rigidly connected to the turbine shaft, for example, by means of a conventional shaft-hub connection. It is also possible for the rotor to be pressed onto the turbine shaft or for the turbine shaft and rotor to be manufactured as a single unit. The turbine shaft can be supported in the turbine housing by means of suitable bearings. The turbine housing can be designed in two parts, in particular, to facilitate the easy arrangement of the turbine shaft and rotor within it. The two housing parts can, for example, be bolted together. Any other suitable connection between the two housing parts is also possible. The rotor forms at least two channels within the turbine housing, arranged concentrically to the turbine shaft at different intervals, each containing one or more rotor blades. The rotor blades can be mounted on the circumference of the turbine shaft and extend from there to an outer circumference of the rotor, so that each channel is divided into individual segments by the rotor blades. Alternatively, separate rotor blades can be arranged in each channel, each attached, for example, to a ring arranged concentrically to the turbine shaft within the channel. The rings can be connected to the turbine shaft, for instance, by means of radial struts or spokes. Several seals, in particular sealing rings, can be installed between the rotor and the turbine housing to seal the individual channels in the turbine housing in such a way that no fluid can pass from one channel to another. A number of seals can be specifically adapted to a number of channels in the turbine housing. According to one embodiment, each of the at least two channels of the turbine can have an inlet and an outlet. The seals can be located, in particular, at the individual inlets and outlets of the channels between the rotor and the turbine housing. The fluid can be directed through the respective inlet onto the rotor blades of one of at least two channels, driving the rotor at a circumference determined by the distance of the channel to the turbine shaft. In this way, different rotational speeds and torques can be easily provided to the driven wheel. This allows for high torque and low rotational speed. This is achieved when the fluid is directed into a channel that is a large distance from the turbine shaft, and vice versa. In particular, the rotor can form a multitude of concentric channels with varying distances from the turbine shaft within the turbine housing, enabling a variety of different gear ratios at the driven wheel. The fluid can flow back through the outlet of each channel to a pump of the hydraulic transmission, which pumps it in a circuit, particularly a closed fluid circuit, from a pump outlet through one of the turbine's at least two channels back to a pump inlet. The pump can be, in particular, a vane pump comprising a housing in which the pump inlet and outlet are located. Analogous to the turbine housing, the pump housing can be made of two parts, with the two housing parts being, for example, bolted together. Any other suitable connection between the two housing parts is also possible. The pump can be connected to a drive shaft of the two-wheeler, to which at least one crank is attached, onto which force can be applied. In this way, the drive shaft can be driven with a specific torque and a specific speed, enabling the pump to deliver fluid to the turbine at a specific pressure. The torque (crank torque) can, for example, be applied to the at least one crank by the muscle power of a rider on the two-wheeler in a known