The invention relates to a belt drive (24) with (a) a first pulley wheel (12) in the form of a drive sprocket with drive teeth (16), (b) a second pulley wheel in the form of an output sprocket (18) and (c) a toothed belt (22) that (i) connects the drive sprocket (12) and the output sprocket (18) for transmitting a force and (ii) has a belt back (38) and (iii) a plurality of teeth (34), wherein a tooth base (36) is situated between two adjacent teeth. According to the invention, (d) the toothed belt (22) comprises a plurality of recesses (26), each of which is configured in a tooth base (36), and (e) at least one pulley wheel features guide projections (28) for engaging in the recesses (26).

In a tractor, a radiator is arranged on one front-rear side relative to an engine. A cooling fan is provided between the radiator and an engine. A fan drive belt is wound around a fan support shaft and around an output shaft of the engine extending below the fan support shaft. A compressor is located above the output shaft and is supported to the engine at a position offset to one lateral side of the engine relative to the fan support shaft. A compressor drive belt is wound around the output shaft and a compressor drive shaft. The compressor drive belt is located on a side where the compressor is located relative to the fan support shaft, when viewed in a front-rear direction.

In a tractor, a radiator is arranged on one front-rear side relative to an engine. A cooling fan is provided between the radiator and an engine. A fan drive belt is wound around a fan support shaft and around an output shaft of the engine extending below the fan support shaft. A compressor is located above the output shaft and is supported to the engine at a position offset to one lateral side of the engine relative to the fan support shaft. A compressor drive belt is wound around the output shaft and a compressor drive shaft. The compressor drive belt is located on a side where the compressor is located relative to the fan support shaft, when viewed in a front-rear direction.

A transmission belt is provided which has a first elastomeric material, a plurality of longitudinal inserts comprising a first material, a working surface covered by a covering including a second material, and an opposite surface to said working surface. At least one of the first material and the second material is a fibrous metallic material. Advantageously, the transmission belt is a toothed belt.

A structure for belt installation of an engine for a vehicle is provided. The structure includes a damper pulley that is mounted to a crankshaft of the engine and a stretch belt that has a first end mounted on the damper pulley and a second end connected to an upper portion of a pulley portion of an accessory. The accessory is mounted on the engine at a position spaced apart from the damper pulley. The pulley portion includes a guide member on a front center thereof which guides installation of the stretch belt to the pulley portion.

A structure for belt installation of an engine for a vehicle is provided. The structure includes a damper pulley that is mounted to a crankshaft of the engine and a stretch belt that has a first end mounted on the damper pulley and a second end connected to an upper portion of a pulley portion of an accessory. The accessory is mounted on the engine at a position spaced apart from the damper pulley. The pulley portion includes a guide member on a front center thereof which guides installation of the stretch belt to the pulley portion.

A power transmission mechanism includes: a first pulley driven about a first axis; a second pulley rotatable about a second axis, separated from and parallel to the first axis; and a third pulley rotatable about a third axis parallel to the first axis and between the first axis and the second axis. The third pulley is configured such that a large-diameter pulley having a larger diameter than the first pulley and a small-diameter pulley having a smaller diameter than the second pulley are coaxially fixed to each other. A first belt is looped between the first pulley and the large-diameter pulley. A second belt is looped between the small-diameter pulley and the second pulley. The third pulley is supported such that a position is adjustable, along a first plane orthogonal to the third axis, in a direction intersecting a second plane including the first axis and the second axis.

A power transmission mechanism includes: a first pulley driven about a first axis; a second pulley rotatable about a second axis, separated from and parallel to the first axis; and a third pulley rotatable about a third axis parallel to the first axis and between the first axis and the second axis. The third pulley is configured such that a large-diameter pulley having a larger diameter than the first pulley and a small-diameter pulley having a smaller diameter than the second pulley are coaxially fixed to each other. A first belt is looped between the first pulley and the large-diameter pulley. A second belt is looped between the small-diameter pulley and the second pulley. The third pulley is supported such that a position is adjustable, along a first plane orthogonal to the third axis, in a direction intersecting a second plane including the first axis and the second axis.

A toothed belt power-transmission apparatus includes: a toothed belt which includes a cord and a plurality of belt tooth portions; and a plurality of toothed pulleys which include a plurality of pulley tooth portions. The cord includes a carbon fiber cord formed by combining and secondarily twisting a plurality of primary twisted yarns including a carbon fiber. A twisting direction of a primary twist of the primary twisted yarns is the same as a twisting direction of the secondary twist. A primary twisting coefficient of the primary twist is 0.62 to 1.30. A secondary twisting coefficient of the secondary twist is 2.06 to 3.95. A tooth pitch of the toothed belt is within a range of −0.4% to +0.1% relative to a tooth pitch of the toothed pulley around which the toothed belt is wound.

This toothed belt transmission device (1) includes a toothed belt (10) in which belt teeth (13) and belt tooth bottom parts (14) are alternately formed, and a toothed pulley (50) in which pulley teeth (53) and pulley tooth bottom parts (54) are alternately formed so as to mesh with the toothed belt (10). The tips of the belt teeth (13) come into contact with the pulley tooth bottom parts (54), but the tips of the pulley teeth (53) do not come into contact with the belt tooth bottom parts (14), and gaps (S) are provided between the tips of the pulley teeth (53) and the belt tooth bottom parts (14).