Motorcycle

• US 7,690,466 B2
• Filed: 11/28/2007
• Issued: 04/06/2010
• Est. Priority Date: 11/29/2006
• Status: Expired due to Fees

• Current Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Original Assignee: Yamaha Hatsudoki Kabushiki Kaisha (Yamaha Corporation)
• Inventors: Ishida, Yousuke, Oishi, Akifumi
• Primary Examiner(s): Morris; Lesley
• Assistant Examiner(s): FIORE, LEVON J
• Application Number:
  US11/946,713
• Publication Number:
  US 20080121454A1
• Time in Patent Office: 860 Days
• Field of Search: 180/219, 180/230, 180/69.1
• US Class Current: 180/230
• CPC Class Codes: F01M 9/06 Dip or splash lubrication
• CPC Class Codes: F02B 61/02 for driving cycles
• CPC Class Codes: F16H 2057/0203 the gearbox is associated or combined with a crank case of an engine
• CPC Class Codes: F16H 2057/02065 for motorcycles or squads
• CPC Class Codes: F16H 57/035 Gearboxes for gearing with endless flexible members
• CPC Class Codes: F16H 57/0489 with endless flexible members, e.g. belt CVTs
• CPC Class Codes: F16H 9/18 only one flange of each pulley being adjustable

Abstract

A motorcycle having a belt type CVT and an engine unit in which an axial length of a cylinder is restricted. A body frame comprises a down frame extending vertically. The engine unit comprises a four-stroke engine, a belt type CVT, a clutch and a crank case. A cylinder is arranged rearwardly of the down frame with an axis thereof extending vertically. The clutch is provided between a secondary sheave shaft and an output shaft. The crank case is formed with an oil reservoir portion below a crank shaft to store lubricating oil. A rear end of the oil reservoir portion is rearward of a front end of a secondary sheave. An axis of the crank shaft is below an axis of the secondary sheave shaft.

Claims

1. A motorcycle comprising:

an engine unit having an output shaft;

a drive wheel;

a power transmission mechanism that transmits motive power to the drive wheel from the output shaft; and

a body frame having a down frame extending vertically, wherein

the engine unit comprises;

a four-stroke engine including a cylinder body that forms a cylinder arranged rearwardly of the down frame with an axis thereof extending vertically, and a crank shaft arranged below the cylinder;

a continuously variable transmission including a primary sheave provided on the crank shaft, a secondary sheave shaft arranged rearwardly of the crank shaft to be connected to the output shaft, a secondary sheave provided on the secondary sheave shaft, and an endless belt wound round the primary sheave and the secondary sheave;

a clutch provided between the secondary sheave shaft and the output shaft; and

an engine case that supports the crank shaft, the secondary sheave shaft, and the output shaft and in which an oil reservoir portion is formed below the crank shaft to store a lubricating oil, wherein

a rear end portion of the oil reservoir portion is rearward of a front end of the secondary sheave, and

an axis of the crank shaft is below an axis of the secondary sheave shaft.

2. The motorcycle according to claim 1, wherein the engine unit further comprises:

a starter motor for rotation of the crank shaft; and

a balancer having a different axis from the axis of the crank shaft and rotating with the crank shaft, wherein

the axis of the balancer and an axis of the starter motor are forward of an imaginary plane including the axis of the cylinder and the axis of the crank shaft in side view.

3. The motorcycle according to claim 2, wherein in a vertical direction, the axis of the balancer is positioned on one side of a further imaginary plane including the axis of the crank shaft and an axis of the secondary sheave shaft while the axis of the starter motor is positioned on the other side of the further imaginary plane.

4. The motorcycle according to claim 1, wherein the rear end portion of the oil reservoir portion is rearward of an axis of the secondary sheave shaft.

5. The motorcycle according to claim 1, further comprising a clutch chamber housing the clutch and including an oil supply hole, wherein the oil supply hole is arranged to deliver the lubricating oil scattered by the crank shaft to the clutch housed in the clutch chamber.