Drive device for an electric bicycle

Patent metadata

Field	Value
Publication number	US-9302734-B2
Application number	US-201314394701-A
Country	US
Kind code	B2
Filing date	Apr 15, 2013
Priority date	Apr 17, 2012
Publication date	Apr 5, 2016
Grant date	Apr 5, 2016

Abstract

A drive device for an electric bicycle with a drive housing in which a hollow shaft is mounted which is connected to a chain wheel of a chain drive of the electric bicycle, a pedal crankshaft arranged coaxial to the hollow shaft and is couplable thereto, which crankshaft is connected to pedal cranks on each of its two ends and an electric motor the output of which can be coupled to the hollow shaft via a traction mechanism drive which drive means comprises a belt drive with a flexible traction mechanism in the form of a toothed belt, a flat belt, or a V-belt, or said drive means comprises a chain drive with a flexible traction mechanism in the form of a single or double roller chain.

First claim

The invention claimed is:

1. A drive device for an electric bicycle with a frame containing a seat tube, a lower tube and lower stays of a rear structure of the electric bicycle, and with
a drive housing in which a hollow shaft is mounted which is connected to a chain wheel of a chain drive of the electric bicycle,
a pedal crankshaft arranged coaxially to the hollow shaft and couplable thereto, which crankshaft is connected to pedal cranks on each of its two ends; and
an electric motor the output of which is coupled to the hollow shaft via a multistage drive, wherein the multistage drive comprises:
a traction mechanism drive having a traction mechanism drive gear and a traction mechanism driven gear that are interconnected via a flexible traction mechanism, and
a planetary drive having a fixed ring gear and planetary gears which are connected to a planetary gear carrier, and which planetary gears mesh with a sun gear and also engage an interior toothing of said ring gear;

wherein the drive housing has a housing frame having a first pipe flange which is connected to the seat tube, a second pipe flange which is connected to the lower tube, and a third pipe flange which is connected to the lower stays of the rear structure of the frame of the electric bicycle, the housing frame also having a first housing cover on a first side and a second housing cover on a second side, which first and second housing covers are connected to the housing frame; and wherein the electric motor and the multistage drive are located inside the drive housing, wherein the motor shaft of the electric motor is connected to the sun gear of the planetary drive, and wherein the planetary gear carrier is connected to the traction mechanism drive gear located in the extension of the motor shaft, and wherein the traction mechanism driven gear can be coupled to the hollow shaft, wherein the drive device in a preassembled state can be inserted into the housing frame connected to the first housing cover and wherein the second housing cover can be connected to the housing frame for encapsulating the drive device.

2. The drive device according to claim 1 , wherein the pipe flanges are connected to the seat tube, the lower tube and the lower stays of the rear structure by welding or soldering.

3. The drive device according to claim 1 , wherein the first and second housing covers have openings for passing through the ends of the pedal crankshaft.

4. The drive device according to claim 1 , wherein the traction mechanism drive comprises a belt drive or a chain drive.

5. The drive device according to claim 4 , wherein the belt drive is formed in a single-stage manner with a toothed belt, flat belt, or V-belt as the flexible traction mechanism.

6. The drive device according to claim 4 , wherein the chain drive is formed in a single-stage manner with a single or double roller chain as the flexible traction mechanism.

7. The drive device according to claim 1 , wherein a first drive stage is comprised of a spur-toothed or helically toothed single-stage planetary drive having a fixed ring gear which has planetary gears which are connected to a planetary gear carrier, and which mesh with a sun gear which is connected to the motor shaft of the electric motor, which planetary gears also engage the interior toothing of said ring gear; and in that a second drive stage is comprised of a traction mechanism drive having a traction mechanism drive gear which is connected to the planetary gear carrier and is rotatably mounted on an extension of the motor shaft.

8. The drive device according to claim 7 , wherein the traction mechanism drive comprises the traction mechanism drive gear which is connected to the planetary gear carrier of the planetary drive means, further comprises the flexible traction mechanism which engages the traction mechanism drive gear, and comprises a traction mechanism driven gear which engages the flexible traction mechanism and can be coupled to the hollow shaft.

9. The drive device according to claim 1 , wherein a first drive stage comprises a traction mechanism drive with a traction mechanism drive wheel connected to the motor shaft of the electric motor, a traction mechanism driven wheel couplable to the hollow shaft; and the flexible traction mechanism and the second drive comprises a spur-toothed or helically toothed single-stage planetary drive having a sun gear that is connected to the traction mechanism driven gear and has planetary gears connected to a planetary gear carrier which planetary gears meshingly engage the sun gear; and a fixed ring gear, wherewith the planetary gears engage the inner toothing of the ring gear; and in that the planetary gear carrier is couplable to the hollow shaft.

10. The drive device according to claim 1 , further comprising a deflecting device which is configured to deflect the flexible traction mechanism in an area between the traction mechanism drive gear and the traction mechanism driven gear.

11. The drive device according to claim 10 , wherein the deflecting device is pre-tensioned in a direction of increasing a wrap angle of the traction mechanism drive gear and/or of the traction mechanism driven gear.

12. The drive device according to claim 10 , wherein the deflecting device comprises a deflecting roller.

13. The drive device according to claim 12 , wherein the deflecting roller is adjustable essentially perpendicularly to a longitudinal extent of the flexible traction mechanism.

14. The drive device according to claim 13 , further comprising a spring element which urges the deflecting roller against the flexible traction mechanism.

Assignees

• Brose Fahrzeugteile
• Brose Fahrzeugteile

Inventors

• Getta Udo
• Noack Ullrich
• Fleischmann Karl-Heinz

Classifications

• B62K19/34

  Bottom brackets · CPC title

• B62M11/14

  with planetary gears · CPC title

• B62M6/55 Primary

  power-driven at crank shafts parts · CPC title

• B62M9/06

  using a single chain, belt, or the like · CPC title

• B62M11/145

  built in, or adjacent to, the bottom bracket · CPC title