Ntn Corporation

Yoshikazu Hida

Sadaji Katogi

Hisashi Hayakawa

Kazuki Kawashima

Tomoyoshi Izutsu

A hydraulic autotensioner for keeping constant the tension in a belt. It has a bolt threadedly fixed to a stationary member, an eccentric ring supported by the bolt at an off-center position so as to be pivotable about the bolt, a pulley rotatably mounted on the eccentric ring, and a tension adjusting spring for biasing the eccentric ring in such a direction that the belt is pressed by the pulley. A hydraulic damper having a damper body is mounted between the stationary member and the eccentric ring so as to abut the eccentric ring for damping the pushing force applied to the eccentric ring from the belt through the pulley. A coupling ring is provided to keep the eccentric ring and the hydraulic damper coupled together.

Hydraulic autotensioner

A hydraulic autotensioner unit having an actuator which can be assembled easily and which can use a spring having a large coil diameter and thus a large spring constant. The autotensioner includes a pivotable arm and a tension pulley rotatably supported on the arm. The actuator is coupled to the arm to press the tension pulley against a belt. The actuator has a cylinder, a rod inserted in the cylinder, and a hydraulic damper mechanism mounted in the cylinder to damp the pushing force applied to the rod when it is pushed into the cylinder. The spring is provided around the cylinder, so that its size is not limited by a housing. A spring seat is fixed to one end of the rod by a pin. The spring seat is coupled to an engine block by a coupling piece. The spring and the spring seat can be mounted after mounting the hydraulic damper within the cylinder, so that the actuator can be assembled easily.

Hydraulic autotensioner unit having an external spring encircling an

An arrangement which can reduce the space between a tension pulley of an autotensioner and an engine block and thus reduce the installation space of an autotensioner. A sub-reservoir is provided at the side of a plunger of a hydraulic damper. The hydraulic damper is arranged between the tension pulley and the engine block so that it is received inside the outer periphery of the tension pulley with its plunger abutting a pin of an eccentric ring. It is thus possible to reduce the space between the tension pulley and the engine block.

Autotensioner

An autotensioner which is of more compact structure and can be mounted in a limited space. The autotensioner has a fixed member, an arm pivotally mounted on the fixed member, a pulley support shaft mounted on the arm, a pulley rotatably mounted on the pulley support shaft, a cylinder having a damper mounted therein and mounted on the arm, the arm being pivotable about an axis and both the pulley support shaft and the cylinder being mounted on the arm at positions offset from the axis, the damper having a rod mounted in the cylinder so as to be pushed out of and into the cylinder, and a stopper fixed to the fixed member, the rod being kept in contact with the stopper.

Growing community of inventors

Iwata, Japan

Yoshikazu Hida