Abstract: Formed in a pinion (74) are pinion-side helical external teeth (74A) that mesh with a ring gear 823), and pinion-side helical internal teeth (74a) that mesh with a pinion inner (71). Formed in the pinion inner (71) are pinion inner-side helical external teeth (73) that mesh with the pinion-side helical internal teeth (74a). The configuration is formed so that when the rotational speed of the pinion (74) is slower than that of the ring gear (23), a thrust load is generated in a direction toward the ring gear (23), and when the rotational speed of the pinion (74) is faster than that of the ring gear (23), a thrust load is generated in a direction away from the ring gear (23).

Abstract: Formed in a pinion (74) are pinion-side helical external teeth (74A) that mesh with a ring gear 823), and pinion-side helical internal teeth (74a) that mesh with a pinion inner (71). Formed in the pinion inner (71) are pinion inner-side helical external teeth (73) that mesh with the pinion-side helical internal teeth (74a). The configuration is formed so that when the rotational speed of the pinion (74) is slower than that of the ring gear (23), a thrust load is generated in a direction toward the ring gear (23), and when the rotational speed of the pinion (74) is faster than that of the ring gear (23), a thrust load is generated in a direction away from the ring gear (23).

Abstract: In an internal combustion engine, an actuator for driving a control shaft of a variable valve-operating mechanism is disposed in a space surrounded by a cylinder head having a plurality of intake ports, an intake manifold having a plurality of branch pipes connected to the intake ports, and a throttle body disposed at one end in a direction of arrangement of the branch pipes. Thus, the actuator can be disposed by effectively utilizing such an unused space surrounded by the cylinder head, the intake manifold and the throttle body, thereby reducing the entire length and the entire height of the internal combustion engine including the actuator.

Abstract: In an internal combustion engine, an actuator for driving a control shaft of a variable valve-operating mechanism is disposed in a space surrounded by a cylinder head having a plurality of intake ports, an intake manifold having a plurality of branch pipes connected to the intake ports, and a throttle body disposed at one end in a direction of arrangement of the branch pipes. Thus, the actuator can be disposed by effectively utilizing such an unused space surrounded by the cylinder head, the intake manifold and the throttle body, thereby reducing the entire length and the entire height of the internal combustion engine including the actuator.

Abstract: An accessory mounting structure has an accessory bracket holding accessories thereon and attached to the engine body of an internal combustion engine, to provide a shortest possible overall length. The accessory mounting structure includes an end part, with respect to a direction parallel to a crankshaft, of the engine body, provided with a passage, a part of the engine body, provided with a recess extending along the passage, and the accessory bracket partly sunk in the recess and fastened to the engine body. At least one accessory, such as an automatic tensioning device is held on the accessory bracket.

Abstract: An auxiliary machinery mounting structure of an engine which can reduce the entire length of the engine, enhance the rigidity of a cover seal surface to improve the sealing effect, and also enhance the mounting rigidity of an auxiliary machinery. The auxiliary machinery mounting structure includes a mount seat that is integrally formed on an end surface of a cylinder block extending vertically to a crank shaft of the engine to lie outward of and along a cover seal surface that is a surface engaging with a cover laid over the end surface, and the auxiliary machinery is mounted on the mount seat.

Abstract: An accessory mounting structure has an accessory bracket (20) holding accessories thereon and attached to the engine body (1) of an internal combustion engine, to provide a shortest possible overall length. The accessory mounting structure includes an end part, with respect to a direction parallel to a crankshaft (2), of the engine body (1), provided with a passage (7), a part of the engine body (1), provided with a recess (3d) extending along the passage (7), and the accessory bracket (20) partly sunk in the recess (3d) and fastened to the engine body (1). At least one accessory, such as an automatic tensioning device (33) is held on the accessory bracket (20).

Abstract: An auxiliary machinery mounting structure of an engine is provided, which can reduce the entire length of the engine, enhance the rigidity of a cover seal surface to improve the sealing effect, and also enhance the mounting rigidity of an auxiliary machinery. The auxiliary machinery mounting structure includes a mount seat (3a) that is integrally formed on an end surface of a cylinder block (3) extending vertically to a crank shaft of the engine to lie outward of and along a cover seal surface (3d) that is a surface engaging with a cover 10 laid over the end surface (3), and the auxiliary machinery (26) is mounted on the mount seat (3a).