Abstract: In a valve timing control system, a control command unit includes: a first stage setting block and a next stage setting block. The first stage setting block sets a retard holding command value as a control command value to introduce hydraulic fluid to each retard operation chamber under a state where a rotation phase is locked, to start applying an operation pressure more than or equal to an unlock pressure to a lock component. The next stage setting block sets an advance holding command value as a control command value to introduce hydraulic fluid to each advance operation chamber, after setting the retard holding command value, to maintain the applying of the operation pressure more than or equal to the unlock pressure to the lock component.

Abstract: In a valve timing control system, a control command unit includes: a first stage setting block and a next stage setting block. The first stage setting block sets a retard holding command value as a control command value to introduce hydraulic fluid to each retard operation chamber under a state where a rotation phase is locked, to start applying an operation pressure more than or equal to an unlock pressure to a lock component. The next stage setting block sets an advance holding command value as a control command value to introduce hydraulic fluid to each advance operation chamber, after setting the retard holding command value, to maintain the applying of the operation pressure more than or equal to the unlock pressure to the lock component.

Abstract: A device for rotating body capable of reducing fluid resistance loss by making use of the conventional bearing technology. The device is provided with a rotating body held rotatably; and one or more covering rotating bodies are installed on the outer side of the rotating body and held rotatably and coaxially with the rotating body. Bearing means are provided between the rotating body and the covering rotating body adjacent thereto or between the covering rotating bodies adjacent to each other, and bearings for the respective covering rotating bodies are disposed in series in relation to bearings for the rotating body. In addition, by filling up the interior of a case with hydrogen gas or helium gas, lower in density than air, windage loss can be further reduced.

Abstract: A device for rotating body windage loss reduction, capable of rotating a rotating body at a high peripheral speed in an environment at atmospheric pressure or close to atmospheric pressure while reducing fluid resistance loss at a low cost by making use of the conventional bearing technology, is implemented, thereby enhancing efficiency of an energy storage device such as, for example, a flywheel, and so forth. The device is provided with a rotating body held rotatably; and a covering rotating body installed on the outer side of the rotating body so as to enclose the same, held rotatably and coaxially with the rotating body. Further, optional plural numbers of the covering rotating bodies installed coaxially with the rotating body and covering the outer side of the device for rotating body windage loss reduction are provided on top of each other in sequence.