Engine starter

An engine starter apparatus comprising:

• a clutch assembly having a plate structure, a drive hub, a clutch element, a carrier and an actuator, the actuator comprising an electromagnet and an armature, the electromagnet comprising a coil assembly having a housing and a coil, the housing defining an inner circumferential flange, an outer circumferential flange and an annular channel disposed between the inner and outer circumferential flanges, the coil being received into the annular channel, the armature comprising at least one tab that is configured to abut an axial end of the clutch element, the armature being axially movable in response to the generation of a magnetic field by the coil to initiate engagement of the clutch element to a circumferentially extending surface of the drive hub, the clutch element comprising a helically wound spring wire having a first end and a second end, the first end of the helically wound spring wire being received into the carrier and being configured to receive rotary power from the plate structure, the second end being coupled to the armature for rotation therewith, the carrier being split in a radial direction and received within the plate structure,
• a ring gear or a pulley coupled to the plate structure, and
• a friction material that is coupled to one of the armature and the housing of the coil assembly, the friction material having a thickness that is greater than or equal to 0.15 mm and less than or equal to 0.4 mm and a coefficient of static friction that is greater than or equal to 0.12.

An engine assembly comprising:

• an engine block;
• a crankshaft mounted for rotation in the engine block;
• a lubricating oil in the engine block, the lubricating oil being configured to be circulated in the engine block to lubricate engine components including the crankshaft;
• a flywheel or flexplate that is coupled for rotation with the crankshaft;
• and
• an engine starter having a motor, a transmission and a clutch, the transmission is driven by the motor and includes an output member, the clutch is disposed axially between the crankshaft and the flywheel or flexplate, the clutch including a clutch element that is configurable in a first state in which the output member of the transmission is not drivingly coupled to the flywheel or flexplate, the clutch element also being configurable in a second state in which the output member of the transmission is drivingly coupled to the flywheel or flexplate;
• wherein the lubricating oil is not employed to lubricate the clutch element;
• and
• wherein a drag force is employed to facilitate engagement of the clutch and wherein a magnetic field is employed to translate an element of the clutch into contact with another element to generate the drag force.