US 7,427,248 B2 · Continuously variable transmission

Abstract

Cooling efficiency of cooling air is enhanced and durability of a continuously variable transmission is improved. The continuously variable transmission to be mounted on a vehicle has a transmission case. A primary pulley driven by an engine and a primary pulley linked to drive wheels are rotatably accommodated in the transmission case. A V-belt is provided to extend for winging between the primary pulley and the secondary pulley, and the rotation of the primary pulley is continuously changed and transmitted to the secondary pulley. Fan blades are formed in the primary pulley, and a scroll surface is formed in transmission case from an intake region of the cooling air toward a discharge region thereof so as to gradually away from top faces of the fan blades in a radial-outer direction. Thereby, blowing efficiency of the cooling air can be enhanced and an interior of the transmission case can be sufficiently cooled, whereby the durability of the V-belt can be enhanced.

Claims28

Dependent claims

A continuously variable transmission for transmitting a rotation of a primary pulley to a secondary pulley through a drive belt and continuously changing a speed ratio between the pulleys, the continuously variable transmission comprising:

a fan blade provided to at least one of said primary pulley and said secondary pulley;
a case rotatably accommodating said one of the pulleys;
a shroud wall formed about a circumference of said one of the pulleys;
a scroll surface formed on said shroud wall and said case about a circumference of said one of the pulleys;
an intake port for introducing a cooling air into said case;
and
a clearance in a radial direction of said one of the pulleys between an outermost end of said fan blade and said scroll surface increases with a rotational direction of said fan blade,
wherein said shroud wall is positioned as to cover the outermost end of said fan blade such that a flow of said cooling air radially exiting from said outermost end of said fan blade is channeled by said shroud wall until reaching a case defined portion of said scroll surfaced, and
wherein said shroud wall has a laterally extending interior surface which promotes the lateral passage of said cooling air exiting from said intake port into contact with said fan blade.

6 more elements

a fan blade provided to at least one of said primary pulley and said secondary pulley;
a case rotatably accommodating said one of the pulleys;
a shroud wall formed about a circumference of said one of the pulleys;
a scroll surface formed on said shroud wall and said case about a circumference of said one of the pulleys;
an intake port for introducing a cooling air into said case;
and
a clearance in a radial direction of said one of pulleys between an outermost end of said fan blade and said scroll surface increases with a rotational direction of said fan blade,
wherein said intake port feeds cooling air initially into said case at a position adjacent said fan blade and such that said cooling air exiting from said intake port is laterally directed into contact with said fan blade, and
wherein said shroud wall has a laterally extending interior surface which promotes the lateral passage of said cooling air exiting from said intake port into contact with said fan blade.

6 more elements

Dependencies are inferred from the claim text.

Continuously variable transmission

Life of this patent

Continuously variable transmission

Life of this patent

Abstract

Claims28