Abstract: An automotive variable valve timing engine arranged to control the quantity of intake air to be supplied to a cylinder by regulating valve timings of an intake valve. An intake air quantity measuring device is provided for measuring the intake air quantity. An intake air quantity estimating system is provided including a control unit which is programmed to carry out (a) judging that a trouble arises in the intake air quantity measuring device, so as to provide a judgment result, and (b) calculating the intake air quantity in accordance with the valve timing of the intake valve, upon providing the judgment result.

Abstract: An axially-compact camshaft phaser wherein the phaser bearing flange on the camshaft, connected to a timing chain sprocket or cam drive gear, is axially inverted in comparison to prior art cam phasers so that the bearing flange extends axially and inwardly of the phaser stator and rotor such that radial drive load on the phaser is sustained within the hydraulic portion of the phaser rather than externally thereof. The overall axial length of the phaser may be reduced thereby by about 25% relative to some prior art phasers and the Phaser Envelop volume may be reduced by 15% while maintaining an equivalent torque capacity.

Abstract: A compact cam phaser has a flexible spline deformed into a nonround shape and engaging a mating ring gear or circular member at angularly spaced locations for transferring camshaft drive torque between them. The spline has projecting lobes with teeth or friction surfaces which engage like surfaces formed on the mating gear or member. The spline and ring gear have a differential length or number of teeth. The phaser includes a plurality of angularly spaced radial piezo actuators, which expand and contract to cause the projecting lobes (but not the flexible spline itself) to travel around the circular ring gear in rotating waves. Thus, each point of the flexible spline is moved sequentially into and out of contact with the ring gear as the contact points (lobes) rotate in waves. Since the number of spline teeth differs from the ring gear, one revolution of the waves causes the spline to move relative to the ring gear a number of teeth equal to the differential.

Abstract: The valve timing adjusting apparatus comprises a bias means that generates an urging force between the casing and the rotor, and the thus generated urging force is set to the level equal to or below the average inertia torque of the camshaft within the time period until the spark ignition is generated after one rotation of the crank shaft at the starting time of the combustion engine, so that by the varied torque at the time of starting of the combustion engine and the urging force, the rotor can be rapidly shifted toward the advance side or retard side with a relatively small force, improving thereby the response characteristic of the valve opening/closing system.

Abstract: An electromagnetic actuator for the operation of a gas change valve has two electromagnets placed opposite to one another and an armature acting on the gas change valve that can be moved against the force of at least one valve spring. In an actuator of this kind, fluctuations of operational system parameters can lead to incorrect functioning and to increased wear of the actuator. With a new method for driving an actuator, the acceleration curve of the gas change valve is measured with an acceleration sensor and the energy supplied to the electromagnet capturing the armature is controlled according to the acceleration curve of the gas change valve. In this way, kinetic energy losses due to disturbances can be compensated so that the armature impacts the capturing electromagnet with a predetermined velocity.