Synchronized transmission

Patent metadata

Field	Value
Publication number	US-11292328-B2
Application number	US-201716464891-A
Country	US
Kind code	B2
Filing date	Nov 30, 2017
Priority date	Dec 1, 2016
Publication date	Apr 5, 2022
Grant date	Apr 5, 2022

Abstract

A synchronized transmission (1) used in a motorcycle, wherein a crankshaft actuated by the engine and a driven shaft, connected to a rear wheel, are substantially parallel and kinematically connected therebetween, comprising a first axial actuation synchronizer (16) placed at the front of the crankshaft (2) and a second axial actuation synchronizer (17) arranged at the front of a driven shaft kinematically connected to a rear wheel, each synchronizer (16, 17) comprising a respective rotating cam actuator (26, 29) having a cam (29) apt to be rotated by a respective cam spindle (30) by determining a translation thereof which interferes with an actuation end of the respective synchronizer (16, 17).

First claim

The invention claimed is:

1. A synchronized transmission used in a motorcycle, wherein a crankshaft actuated by an engine and a driven shaft, connected to a rear wheel, are substantially parallel and kinematically connected therebetween, comprising a first axial actuation synchronizer placed at a front of the crankshaft and a second axial actuation synchronizer arranged at a front of the driven shaft kinematically connected to the rear wheel, each synchronizer comprising a respective rotating cam actuator having a cam apt to be rotated by a respective cam spindle by determining a translation thereof which interferes with an actuation end of the respective synchronizer.

2. The synchronized transmission according to claim 1 , further comprising:
a toothed control wheel, keyed on one of the cam spindles, actuated in rotation by means of an electric motor equipped with a toothed shaft engaged in said toothed control wheel; and
a first actuating pulley, connected to the one of the cam spindles corresponding to said control wheel, and a second actuating pulley, connected to the other cam spindle, said pulleys being connected by a belt which causes the simultaneous rotation thereof by actuating said control wheel, each of a plurality of speeds corresponding to an angular position of said first and second actuating pulleys.

3. The synchronized transmission according to claim 2 , wherein said first and second actuation pulleys are keyed on a distal end of one of the respective cam spindles projecting outside the one of the respective synchronizers.

4. The synchronized transmission according to claim 2 , wherein said belt is of filiform type.

5. The synchronized transmission according to claim 2 , wherein the rotation of the control wheel is arranged so as to determine, in sequence, the activation of the second synchronizer (second speed), followed by the de-activation thereof and by the simultaneous activation of the first synchronizer (third speed), in turn followed by the simultaneous activation of both synchronizers (fourth speed), starting from both de-activated synchronizers (first speed).

6. The synchronized transmission according to claim 5 , wherein said sequence is controlled by the rotation of the control wheel, a step of said sequence corresponding to each rotation angle of 90° thereof.

7. The synchronized transmission according to claim 2 , wherein the electric motor has a rotating shaft controlling a screw toothed shaft.

8. The synchronized transmission according to claim 1 , wherein each rotating cam actuator has the cam apt to be rotated by an actuation of the respective cam spindle of the cam which determines the translation of a cam follower which in turn interferes with the actuation end of the respective synchronizer in opposition to a spring.

9. The synchronized transmission according to claim 1 , wherein a bearing is provided between a cam follower and the actuation end.

10. A motorcycle comprising a propulsion unit arranged in a position below a saddle, inside a chassis extending from a front wheel to the rear driving wheel, comprising, between said propulsion unit and said rear wheel a transmission according to claim 1 , received in a container closed, on an exposed side of the motorcycle, by a cover.

Assignees

• Piaggio & C Spa

Inventors

• Nuti Luca
• Mariotti Walter

Classifications

• F16H63/18

  the final actuating mechanism comprising cams · CPC title

• B60Y2200/12

  Motorcycles, Trikes; Quads; Scooters · CPC title

• F16H7/02

  with belts; with V-belts · CPC title

• F16D2023/123

  Clutch actuation by cams, ramps or ball-screw mechanisms · CPC title

• B62M7/06

  directly under the saddle or seat · CPC title