Phase varying device of engine

Abstract

[PROBLEMS] To prevent generation of heat by friction in a phase varying device of the engine of an automobile. [MEANS FOR SOLVING PROBLEMS] The phase varying device of an engine comprises an outer casing section ( 10 ) having a sprocket ( 12 ) for transmitting rotation of the crankshaft of the engine, an inner casing section ( 20 ) capable of rotating relatively to the outer casing section and coupled with a cam shaft ( 2 ) for opening/closing the intake valve or the exhaust valve of the engine, and an intermediate member ( 30 ) meshing with the outer casing section and the inner casing section through a helical spindle, wherein relative rotation is generated between the outer casing section and the inner casing section by moving the intermediate member in the axial direction thus varying the open/close timing of the intake valve or the exhaust valve. The phase varying device of an engine is further provided with an electromagnetic control means ( 40 a ) having a permanent-magnet rotary drum ( 44 ) being screwed on the intermediate member, and an electromagnetic clutch ( 42 ) for braking or accelerating the rotary drum.

1 . A phase varying device of an engine comprising: an outer casing section having a sprocket to which rotation of a crankshaft of the engine is transmitted; an inner casing section capable of rotating relatively to the outer casing section and coupled with a camshaft for opening/closing an intake valve or an exhaust valve of the engine; and an intermediate member meshing with the outer casing section and the inner casing section through helical splines, relative rotation being generated between the outer casing section and the inner casing section by moving the intermediate member in an axial direction thus varying an open/close timing of the intake valve or the exhaust valve, wherein
 the phase varying device of an engine comprises an electromagnetic control means having a rotary drum being screwed on the intermediate member and provided as a permanent magnet and an electromagnetic clutch for braking the rotary drum.   
   
   
       2 . The phase varying device of an engine according to  claim 1 , wherein a plurality of magnetic poles are formed on the rotary drums, and by arranging electromagnets in the electromagnetic clutch so that magnetic poles corresponding to the magnetic poles are also formed and changing polarity of the electromagnets with an appropriate phase relative to the magnetic poles of the rotary drum, the rotary drum is braked or accelerated. 
   
   
       3 . The phase varying device of an engine according to  claim 1 , wherein the electromagnetic clutch is disposed in proximity to an interior side surface of the rotary drum. 
   
   
       4 . The phase varying device of an engine according to  claim 1 , wherein only a vicinity of an outer circumference of the rotary drum is magnetized, and the electromagnetic clutch is arranged in proximity to the vicinity of the outer circumference of the rotary drum.