Abstract: A drive system having a belt with a length and a plurality of teeth spaced regularly along the length of the belt and a first pulley having a plurality of grooves for receiving the belt teeth with the belt and first pulley in operative relationship. The single pitch difference between the belt teeth and the grooves in the first pulley is between -0.04 mm and 0 mm.

Abstract: A power transmission belt having a body with an inside and an outside, a length, and a plurality of teeth on one of the inside and outside of the belt body and spaced in a likewise direction. A load carrying cord is embedded in the belt body and extends lengthwise thereof. The load carrying cord is made up of a first plurality of monofilament aramid fibers, each having a denier of 0.5 to 2.0 and bundled to define a combined diameter of 0.10 to 0.20 mm.

Abstract: A toothed belt having a body with a length, laterally spaced sides, an inside and an outside, and defining a plurality of teeth spaced in a lengthwise direction on one of the inside and the outside of the body. The body is defined at least in part by a rubber composition made up of at least an ethylene propylene diene monomer (EPDM) and a diene rubber. A cloth layer is provided on the teeth on the one of the inside and the outside of the body. The cloth layer is treated with a resorcin-formalin-latex solution.

Abstract: A power transmission toothed belt drive having a belt tooth power transmission surface defined by an arc having a radius centered on a point approximately one-half the belt tooth pitch from the centerline of the tooth. The pulley groove has a sidewall surface which confronts the power transmission surface of the belt tooth centered on the same point when the belt tooth is fully meshed with the pulley groove in the operation of the drive. A relatively small clearance with the pulley is provided adjacent the belt tooth root and a relatively large clearance is provided between the pulley groove inner surface and the tip surface of the belt tooth. In one form of the invention, both the power transmission surface and tip surface of the belt tooth are defined by a single radius and the confronting pulley groove sidewall surface and inner surface confronting the belt tooth power transmission surface and tip surface have a constant clearance therewith and are defined by continuous circular arcs.

Abstract: A power transmission toothed belt drive having a belt tooth power transmission surface defined by an arc having a radius centered on a point approximately one-half the belt tooth pitch from the centerline of the tooth. The pulley groove has a sidewall surface which confronts the power transmission surface of the belt tooth centered on the same point when the belt tooth is fully meshed with the pulley groove in the operation of the drive. A relatively small clearance with the pulley is provided adjacent the belt tooth root and a relatively large clearance is provided between the pulley groove inner surface and the tip surface of the belt tooth. In one form of the invention, both the power transmission surface and tip surface of the belt tooth are defined by a single radius and the confronting pulley groove sidewall surface and inner surface confronting the belt tooth power transmission surface and tip surface have a constant clearance therewith and are defined by continuous circular arcs.