Belt-Type Continuously Variable Transmission and Straddle-Type Vehicle
AssigneeYamaha Hatsudoki Kabushiki Kaisha
InventorsYousuke ISHIDA, Akifumi OISHI, Takuji MURAYAMA
Life of this patent
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Abstract
Abrasion of a V-belt in a belt type continuously variable transmission accommodated in an engine unit of a motorcycle is suppressed. A V-belt wound around and contacting a primary sheave and a secondary sheave 72 is at least partially formed from a resin. A plurality of grooves aligned at a predetermined pitch in a radial direction are formed on sheave surfaces of the primary and secondary sheaves. The average pitch P(mm) of the grooves is P≦−0.08K×10−3+0.18, where K(Hv) indicates surface hardness of the sheave surfaces.
Claims20
A belt type continuously variable transmission comprising
- a primary sheave,
- a secondary sheave, and
- a V-belt wound round and contacting the primary sheave and the secondary sheave, and being at least partially formed from a resin, and
- wherein a plurality of grooves aligned in a radial direction of the sheaves are formed on a sheave surface of at least one of the primary and secondary sheaves, and
- an average pitch P(mm) of the grooves is P≦−0.08K×10−3+0.18, where K(Hv) indicates surface hardness of the sheave surface.
A method of manufacturing a sheave of a belt type continuously variable transmission, which comprises a primary sheave, a secondary sheave, and a V-belt wound round and contacting the primary sheave and the secondary sheave, the V-belt being at least partially formed from a resin, the sheave being the primary sheave or the secondary sheave, the method comprising the steps of:
- forming a plurality of grooves aligned on a sheave surface in a radial direction of the sheaves, wherein an average pitch P(mm) of the grooves is P≦−0.08K×10−3+0.18, where K(Hv) indicates surface hardness of the sheave surface, and
- applying plating to that sheave surface, on which the grooves are formed.
Dependencies are inferred from the claim text.