Abstract: An electromagnetic-brake cooling structure of a phase-variable device having an electromagnetic brake means (40) and varying the phase of a camshaft, wherein engine oil in an oil sump (74) on the radial inner side of a clutch case (60) led to the relative sliding surfaces of a friction material (66) and a rotary drum (44) through a notch (61) provided in the clutch case (60) at the front edge part of the inner peripheral wall of the clutch case (60), a notch (61b) for leading oil to the front edge part of the clutch case outer peripheral wall (60b), the oil on the relative sliding surfaces of the friction material (66) and the rotary drum (44) is discharged positively to the outside, and the circulation of the cooling oil is activated to increase the cooling effect of the sliding surface of the friction material (66).

Abstract: An electromagnetic-brake cooling structure of a phase-variable device having an electromagnetic brake means (40) and varying the phase of a camshaft, wherein engine oil in an oil sump (74) on the radial inner side of a clutch case (60) led to the relative sliding surfaces of a friction material (66) and a rotary drum (44) through a notch (61) provided in the clutch case (60) at the front edge part of the inner peripheral wall of the clutch case (60), a notch (61b) for leading oil to the front edge part of the clutch case outer peripheral wall (60b), the oil on the relative sliding surfaces of the friction material (66) and the rotary drum (44) is discharged positively to the outside, and the circulation of the cooling oil is activated to increase the cooling effect of the sliding surface of the friction material (66).

Abstract: A variable valve timing apparatus has a rotational torque transmission path that changes the relative phases of a camshaft that moves an engine valve and a rotary crank body that is coupled to the crankshaft. The rotational torque transmission path has uses an electromagnetic brake delay rotation of a drum, which is coupled to the rotary crank body by a biasing member and a moving member. When rotation of the drum is delayed, the moving member changes the angular orientation between the drum and the rotary crank body against the biasing force of the biasing member. The electromagnetic brake is coupled to a cover by two protrusions and two concavities. The protrusions are arranged to prevent contact between the electromagnetic brake and the drum due to tension of the chain.