Wheel hub transmission unit for a drive wheel of a vehicle, drive wheel, and vehicle having an auxiliary drive

Abstract

A wheel hub transmission unit for a drive wheel of a vehicle is provided. The wheel hub transmission unit includes a wheel axle, a pinion hub carrier concentrically arranged with respect to the wheel axle, a pinion mounted in a torsionally rigid manner onto said pinion hub carrier and configured to drive the drive wheel, and a torque transmission device having a transmission sleeve. The transmission sleeve is made from a magnetically coded material and includes a measuring area that is utilized to measure a torque by utilizing magnetic properties of the magnetically coded material of the transmission sleeve. An annular space is radially provided between the transmission sleeve and the wheel axle in the measuring area with a sensor coil being accommodated therein, the annular space being axially accessible from outside the transmission sleeve.

Claims

1. A wheel hub transmission unit for a drive wheel comprising: a wheel axle; a pinion hub carrier being concentrically arranged with respect to the wheel axle; at least one pinion being mounted in a torsionally rigid manner onto said pinion hub carrier and being configured to drive the drive wheel; a torque transmission device having a transmission sleeve and being radially arranged between the pinion hub carrier and the wheel axle; said transmission sleeve having a first longitudinal end and a second longitudinal end and being concentrically arranged with respect to the wheel axle; a drive coupling arrangement being provided on said first longitudinal end; said transmission sleeve being made from a magnetically coded material; said first longitudinal end and said pinion hub carrier being coupled via said drive coupling arrangement to one another in a rotationally rigid manner; said second longitudinal end being arranged to face away from the first longitudinal end; said second longitudinal end being arranged at an axial distance from said first longitudinal end; an output coupling arrangement being provided at said second longitudinal end via which a torque is transmitted from the transmission sleeve to the drive wheel; said transmission sleeve including a measuring area being axially provided between said drive coupling arrangement and said output coupling arrangement; said measuring area being utilized to measure the torque by utilizing magnetic properties of the magnetically coded material of the transmission sleeve which change under the influence of the torque; a radial bearing being configured to mount said transmission sleeve on the wheel axle in a cantilever manner at said first longitudinal end in an axial extended region of the drive coupling arrangement and to support said transmission sleeve at a radial distance from said wheel axle; an annular space being radially provided between the transmission sleeve and the wheel axle in said measuring area; a sensor coil being accommodated in said annular space and being configured to tap off the measuring area; and, said annular space being axially accessible at the second longitudinal end from outside the transmission sleeve.

2. The wheel hub transmission unit of claim 1, wherein the output coupling arrangement is centering the second longitudinal end of the transmission sleeve about the wheel axle during a transmission of the torque.

3. The wheel hub transmission unit of claim 2, wherein said output coupling arrangement is a freewheel.

4. The wheel hub transmission unit of claim 3, wherein said output coupling arrangement is a locking pawl freewheel having at least three locking pawls arranged at a same spacing over a circumference of the locking pawl freewheel.

5. The wheel hub transmission unit of claim 3, wherein said output coupling arrangement is a roller freewheel having at least three rollers arranged at a same spacing over a circumference of the roller freewheel, and wherein the at least three rollers are self-locking in a drive rotational direction.

6. The wheel hub transmission unit of claim 3, wherein said output coupling arrangement is a toothed disk freewheel.

7. The wheel hub transmission unit of claim 1, said pinion hub carrier being a sleeve which radially covers the measuring area of the transmission sleeve to the outside.

8. The wheel hub transmission unit of claim 1, said drive coupling arrangement having an axial block coupled in an axially fixed manner to the wheel axle; and, said pinion hub carrier bearing against said axial block and/or said transmission sleeve to axially fix the pinion hub carrier.

9. The wheel hub transmission unit of claim 8, said axial block being a projection which protrudes radially inward from the pinion hub carrier; said axial block being mounted on said pinion hub carrier; and, said transmission sleeve being axially supported by said axial block.

10. The wheel hub transmission unit of claim 9, further comprising an end face of the first longitudinal end of the transmission sleeve bearing against said axial block; said drive coupling having a first thread on the outer side of the first longitudinal end of the transmission sleeve and a second thread on the inner side of the pinion hub carrier; and, said first and second thread engaging into one another and being threaded about the wheel axle.

11. The wheel hub transmission unit of claim 10, wherein a winding direction of said first and second thread is configured such that said transmission sleeve is driven toward the axial block in an axial direction during a transmission of the torque.

12. The wheel hub transmission unit of claim 9, said drive coupling arrangement having a locating fit between an outer side of the first longitudinal end of the transmission sleeve and an inner side of the pinion hub carrier; and, said end face of the first longitudinal end of the transmission sleeve bearing against said axial block.

13. The wheel hub transmission unit of claim 1, said drive coupling arrangement having an adhesive bond between the pinion hub carrier and the transmission sleeve.

14. The wheel hub transmission unit of claim 1, said pinion hub carrier being made from an aluminum alloy; and, said transmission sleeve being made from a high-strength non-magnetic steel.

15. A drive wheel comprising: a wheel hub; the wheel hub transmission unit as claimed in claim 1; and, said wheel hub being coupled by said output coupling arrangement to said at least one pinion to transmit torque from said pinion to said wheel hub.

16. A vehicle comprising: an auxiliary drive with the drive wheel as claimed in claim 15; a drive assembly having a control device configured to alternatively drive said drive wheel in measured quantities; said sensor coil being accommodated in said annular space to tap off the measuring area of the transmission sleeve; and, said control device being controlled by said sensor coil such that a drive moment of the drive assembly is adapted to the torque to be transmitted by the wheel hub transmission unit.

17. The vehicle of claim 16, wherein the vehicle is an electric bicycle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) Example embodiments of the invention will now be described with reference to the drawings wherein:

(2) FIG. 1 shows a perspective illustration of a wheel hub according to an example embodiment.

(3) FIG. 2 shows an illustration of a longitudinal section of the wheel hub in FIG. 1 according to an example embodiment.

DESCRIPTION OF THE PREFERRED EMBODIMENTS OF THE INVENTION

(4) FIGS. 1 and 2 show a wheel hub 1 which has a wheel axle 2 and a hub body 3. The hub body 3 is mounted on the wheel axle 2 such that it can be concentrically rotated about the wheel axle 2 by a first wheel hub bearing 4 and a second wheel hub bearing 5.

(5) The wheel axle 2 completely axially extends through the wheel hub body 3, the first wheel hub bearing 4 being arranged at the one longitudinal end of the wheel hub body 3 and the second wheel hub bearing 5 being arranged at the other longitudinal end of the wheel hub body 2. Two flat rings which are arranged at an axial spacing from one another are provided on the wheel hub body 3, into which flat rings spokes can be hooked.

(6) Furthermore, the wheel hub 1 has a wheel hub transmission unit 6 which is laterally arranged about the wheel axle 2 next to the second wheel hub bearing 5 and on the other side of the first wheel hub bearing 4. The wheel hub transmission unit 6 has a pinion hub carrier 7 which is configured as a sleeve and has a splined shaft profile on its outer side for mounting at least one pinion on the pinion hub carrier 7. The pinion hub carrier 7 laterally protrudes from the hub body 3, the wheel axle 2 extending both through the hub body 3 and through the pinion hub carrier 7. On that side of the pinion hub carrier 7 which faces the wheel hub body 3, the pinion hub carrier 7 is radially mounted by a pinion hub carrier bearing 8 on the hub body 3, the pinion hub carrier bearing 8 bearing with its inner ring on the pinion hub carrier 7 and with its outer ring against the hub body 3.

(7) The wheel hub transmission unit 6 has a torque transmission device 9 which has a transmission sleeve 10. The transmission sleeve 10 is arranged within the pinion hub carrier 7 and, like the pinion hub carrier 7, concentrically about the wheel axle 2. The transmission sleeve 10 has a first longitudinal end 11 and a second longitudinal end 12, the first longitudinal end 11 being arranged to face away from the hub body 3 and the second longitudinal end 12 being arranged to face the hub body 3. At the first longitudinal end 11, the transmission sleeve 10 is coupled to the pinion hub carrier 7 by a drive coupling arrangement 13. The drive coupling arrangement 13 has an axial block 14 which radially protrudes to the inside on the pinion hub carrier 7.

(8) The axial block 14 is configured in one piece on the pinion hub carrier 7 and is arranged at that longitudinal end of the pinion hub carrier 7 which faces away from the hub body 3. Furthermore, the drive coupling arrangement 13 has an internal thread 15 which is arranged on the outer side of the first longitudinal end 11 of the transmission sleeve 10. In a manner which corresponds to the internal thread 15, the drive coupling arrangement 13 has an external thread 16 which is arranged on the inner side of the pinion hub carrier 7, the axial block 14 being arranged on that side of the pinion hub carrier 7 which faces away from the hub body 3. The transmission sleeve 10 is screwed by way of its external thread 16 to the internal thread 15 of the pinion hub carrier 7, the external thread 16 adjoining the end face 26 of the first longitudinal end 11 of the transmission sleeve 10, as a result of which the end face 26 bears against the axial block 14.

(9) An output coupling arrangement 17 which is formed by a locking pawl freewheel 18 is arranged at the second longitudinal end 12 of the transmission sleeve 10. The locking pawl freewheel 18 has at least three locking pawls 19 which are uniformly distributed over the circumference, the locking pawl freewheel 18 acting with its locking pawls 19 in a centering action on the second longitudinal end 12 of the transmission sleeve 10 during the transmission of a torque.

(10) The transmission sleeve 10 is produced from magnetically coded material, the area between the drive coupling arrangement 13 and the output coupling arrangement 17 being configured as a measuring area 20. A mounting arrangement 21 for the transmission sleeve 10 in a cantilever manner is provided in the axial region of the drive coupling arrangement 13, that is to say in the region of the axial extent of the threads 15, 16 and the axial block 14.

(11) The mounting arrangement 21 is provided in a cantilever manner and is formed by a first deep groove ball bearing 22 and a second deep groove ball bearing 23 which are arranged on the wheel axle 2 so as to lie next to one another and to support the transmission sleeve 10 at the first longitudinal end 11 at a radial spacing from the wheel axle 2. Immediately next to the deep groove ball bearings 22, 23, the measuring area 20 extends as far as directly to the drive coupling arrangement 13. An annular space 24 is produced below the measuring area 20, in which annular space 24 a sensor coil 25 having two coils for tapping off the measuring area 20 is arranged. The cabling of the sensor coil 25 is laid at the second longitudinal end 12 of the transmission sleeve 10, since the transmission sleeve 10 is accessible from the outside here on account of the mounting arrangement 21 in the cantilever manner. The cabling is arranged between the wheel axle 2 and the transmission sleeve 10. Passages for the cabling in the transmission sleeve 10 or the wheel axle are not provided.

(12) The torque which is oriented in accordance with a drive rotational direction acts on the pinion in order to drive the hub body 3. The locking pawl freewheel 18 is installed into the wheel hub 1 in such a way that the locking pawls 19 lock in the drive rotational direction. The torque is transmitted from the pinion via the splined shaft profile of the wheel hub carrier 7 to the latter. As a result of the screw connection of the threads 15, 16 and the bearing of the end face 26 against the axial block 14, the torque is transmitted from the wheel hub carrier 7 to the first longitudinal end 11 of the transmission sleeve 10. The radial support and mounting of the transmission sleeve 10 is achieved by the deep groove ball bearings 22, 23. The torque is transmitted to the hub body 3 at the second longitudinal end 12 of the transmission sleeve 10 by the locking pawl freewheel 18. The longitudinal ends 11, 12 are coupled in a torsionally rigid manner via the measuring area 20, as a result of which the measuring area 20 is twisted.

(13) The magnetization pattern which is applied on the measuring area 20 changes in a manner which is dependent on the magnitude of the torsion. Said change is detected by the sensor coil 25. By way of the cabling of the sensor coil 25, the electric signals of the latter are guided to the outside of the wheel hub 1.

(14) It is understood that the foregoing description is that of the preferred embodiments of the invention and that various changes and modifications may be made thereto without departing from the spirit and scope of the invention as defined in the appended claims.

LIST OF REFERENCE NUMERALS

(15) 1 Wheel hub 2 Wheel axle 3 Hub body 4 First wheel hub bearing 5 Second wheel hub bearing 6 Wheel hub transmission unit 7 Pinion hub carrier 8 Pinion hub carrier bearing 9 Torque transmission device 10 Transmission sleeve 11 First longitudinal end 12 Second longitudinal end 13 Drive coupling arrangement 14 Axial block 15 Internal thread 16 External thread 17 Output coupling arrangement 18 Locking pawl freewheel 19 Locking pawl 20 Measuring area 21 Cantilever mounting 22 First deep groove ball bearing 23 Second deep groove ball bearing 24 Annular space 25 Sensor coil 26 End face