FLUID BRAKE DEVICE AND VARIABLE VALVE TIMING APPARATUS

• Main Authors: YAMADA JUN, WASHINO SEIICHIROU, SASAKI TAKETSUGU, OTSUBO MAKOTO, OE SHUHEI, OKA KUNIAKI
• Format: Patent
• Language: English
• Published: 24.01.2013
• Subjects: BLASTING; BRAKES; CLUTCHES; COUPLINGS FOR TRANSMITTING ROTATION; CYCLICALLY OPERATING VALVES FOR MACHINES OR ENGINES; CYLINDERS; ENGINE PLANTS IN GENERAL; ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVEFUNCTIONING OF MACHINES OR INSTALLATIONS; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MEANS FOR DAMPING VIBRATION; MECHANICAL ENGINEERING; PISTONS; SEALINGS; SHOCK-ABSORBERS; SPRINGS; STEAM ENGINES; THERMAL INSULATION IN GENERAL; WEAPONS

A fluid brake device has a brake shaft which penetrates a case. The case provides a fluid chamber for a magneto-rheological fluid. A magnetic seal has a magnetic seal sleeve which holds a small amount of the magneto-rheological fluid by magnetic flux. In addition to the magnetic seal, an axially pumping element is provided on an axial outside of the magnetic seal. The axially pumping element is provided by a shaft helical groove formed on an opposing wall of the brake shaft and/or a case helical groove formed on a surrounding wall. As the brake shaft rotates, the helical groove pushes the magneto-rheological fluid back to the magnetic seal. A combination of the magnetic seal and the axially pumping element may reduce leakage of the magneto-rheological fluid.