Rear of a motorcycle with cardan-shaft transmission and related motorcycle

Patent metadata

Field	Value
Publication number	US-10486766-B2
Application number	US-201615763869-A
Country	US
Kind code	B2
Filing date	Sep 27, 2016
Priority date	Sep 29, 2015
Publication date	Nov 26, 2019
Grant date	Nov 26, 2019

Abstract

The rear of a motorcycle with cardan suspension comprising a rear frame, a fork, hinged to said frame about a hinging axis, the fork rotatably supporting the rotation pin of a rear wheel of the motorcycle around a rotation axis, the fork supporting a cardan-shaft transmission comprising at least one first transmission shaft, suitable to be connected to a power take-off of an associable engine, at least one final shaft provided with a pinion rotatably connected to said rear wheel, wherein between the first transmission shaft and the final shape is interposed a first cardan joint, a floating arm that supports said pinion of the final shaft, the arm being floating around said rotation axis of the rear wheel. The floating arm comprises a cup portion arranged coaxially to the rotation pin and having at least an inner end that houses and supports said pinion.

First claim

The invention claimed is:

1. A rear of a motorcycle with a cardan-shaft transmission comprising:
a rear frame;
a fork hinged to the frame around a hinge axis, the fork rotatably supporting a rotation pin of a rear wheel of the motorcycle around a rotation axis,
the fork supporting a cardan-shaft transmission comprising at least a first transmission shaft suitable to be connected to a power take-off of an associable engine, at least one final shaft fitted with a pinion rotatably connected to said rear wheel, wherein between the first transmission shaft and the final shaft a first cardan joint is interposed; and
a floating arm which supports said pinion of the final shaft, the arm floating around said rotation axis of the rear wheel,
wherein the floating arm comprises a cup portion placed coaxially to the rotation pin and having at least one inner end housing and supporting said pinion, and an outer appendix positioned cantilevered with respect to said cup portion,
wherein the cup portion is rotatably released from the rotation pin of the rear wheel,
wherein the outer appendix is mechanically connected to the rear frame by an interposition of a reaction rod hinged at opposite axial ends, to the rear frame and to the outer appendix, respectively,
wherein the fork comprises a front cover panel, placed at least partially coaxially to the rotation pin on the opposite side to a centreline plane of the associable rear wheel, and
wherein the outer appendix comprises a first section which projects in relation to the cup portion in an axial direction, parallel to said rotation axis in order to come out axially from said cover panel, and a second section which comprises a portion axially recessed towards said centreline plane of the associable rear wheel.

2. The rear of the motorcycle according to claim 1 , wherein the second section is substantially counter-shaped to an outer side wall of the front cover panel so as not to interfere with said panel when the panel floats around the rotation axis.

3. The rear of the motorcycle according to claim 1 , wherein the front cover panel is frusto-conical around said rotation axis and the second section is substantially straight and parallel to a generatrix straight line of said frusto-conical panel.

4. The rear of the motorcycle according to claim 1 , wherein the outer appendix is shaped so that the reaction rod places itself parallel to said centreline plane of the associable rear wheel.

5. The rear of the motorcycle according to claim 1 , wherein the fork comprises a rear housing facing a wheel rim of the rear wheel, the rear housing being mechanically coupled to the front cover panel at a coupling surface placed near the centreline plane of the associable rear wheel.

6. The rear of the motorcycle according to claim 1 , wherein the fork comprises a rear housing mechanically coupled to the front cover panel, wherein the front cover panel and the rear housing enclose an unwetted space devoid of lubricating oil or grease, said space housing therein the cup portion and the inner end.

7. The rear of the motorcycle according to claim 1 , wherein the fork comprises a hollow three-dimensional structure which extends monolithically along a main extension axis from a first hollow part, which connects the fork to the rear frame to a second hollow part which connects the fork to the rotation pin of the rear wheel.

8. The rear of the motorcycle according to claim 1 , wherein the reaction rod comprises a first adjuster of the length of the reaction rod so as to adjust the distance between the axial ends of said reaction rod.

9. The rear of the motorcycle according to claim 1 , wherein the outer appendix comprises a second adjuster of the length of the distance between the rotation axis and a hinging point of the corresponding axial end of the reaction rod.

10. The rear of the motorcycle according to claim 9 , wherein said first and/or second adjusters comprise screw adjusters.

11. The rear of the motorcycle according to claim 1 , wherein the fork is operatively connected to a suspension having a first end hinged to the fork and a second end hinged to said rear frame.

12. A motorcycle comprising the rear according to claim 1 .

Assignees

• Piaggio & C Spa

Inventors

• Soatti Piero

Classifications

• B62K25/005 Primary

  characterised by the axle being supported at one end only · CPC title

• B62M17/00

  Transmissions characterised by use of rotary shaft, e.g. cardan shaft · CPC title

• B62K25/283

  for cycles without a pedal crank, e.g. motorcycles · CPC title

• B62K25/04

  for mounting axles resiliently on cycle frame or fork (for sidecars, forecars or the like B62K27/06) · CPC title

• B62K25/286

  the shock absorber being connected to the chain-stay via a linkage mechanism · CPC title