A control device sets reverse rotation period as a cranking prohibition period, and when a start request of an engine is generated during reverse rotation period, cranking is started by driving either or both of the first starter and the second starter when it is detected that a crankshaft is shifted from reverse rotation to forward rotation based on an information of a rotation angle sensor. As a result, the delay from generation of the start request of the engine until cranking is started can be reduced, so that the starting time of the engine can be shortened.

A control device sets reverse rotation period as a cranking prohibition period, and when a start request of an engine is generated during reverse rotation period, cranking is started by driving either or both of the first starter and the second starter when it is detected that a crankshaft is shifted from reverse rotation to forward rotation based on an information of a rotation angle sensor. As a result, the delay from generation of the start request of the engine until cranking is started can be reduced, so that the starting time of the engine can be shortened.

An engine including an engine block having a cylinder defining a front of the engine, a blower housing coupled to the engine block and defining a hot half positioned adjacent the front of the engine and a cool half opposite the hot half, and an electric starter system positioned within the blower housing. The electric starting system includes a starter mount assembly coupled to the blower housing, an electric starter motor retained by the starter mount assembly and positioned in the cool half, and a battery mounted to the blower housing and positioned in the cool half. The battery is electrically coupled to the electric starter motor.

An engine including an engine block having a cylinder defining a front of the engine, a blower housing coupled to the engine block and defining a hot half positioned adjacent the front of the engine and a cool half opposite the hot half, and an electric starter system positioned within the blower housing. The electric starting system includes a starter mount assembly coupled to the blower housing, an electric starter motor retained by the starter mount assembly and positioned in the cool half, and a battery mounted to the blower housing and positioned in the cool half. The battery is electrically coupled to the electric starter motor.

A drive includes an electric motor disposed in a housing and driving a motor shaft, a Hall effect sensor adjacent to the motor, a power and control assembly, and a pinion gear driven by the motor shaft. A planetary gear reduction assembly is driven by the pinion gear, and an output axle has an axis of rotation that is offset from and parallel to the motor shaft axis of rotation. The reduction drive is substantially bilaterally symmetrical about a plane passing through the motor shaft axis of rotation and the output axle axis of rotation. The power and control assembly comprises a control board oriented perpendicular to a power board and includes a heat dissipation apparatus that applies multi-point, localized, indirect pressure to a plurality of field effect transistors mounted on the power board.

An engine including an engine block having a cylinder defining a front of the engine, a blower housing coupled to the engine block and defining a hot half and a cool half opposite the front half, a starter mount assembly coupled to the blower housing and positioned within the cool half, an electric starter motor retained by the starter mount assembly, and a battery mounted to the blower housing and positioned in the cool half. The battery is electrically coupled to the electric starter motor.

Internal combustion engine cranking is carried out including with a limited overlapping of cranking with a starter motor and a starter/generator during at least the initial compression stroke during a cranking cycle.

Methods and systems are provided for a starter motor system for cranking an engine. In one example, a starter motor system includes, a battery, two electric motors arranged in series, two main contactors, two auxiliary contactors, and two solenoid contactors. Each of the two electric starter motors may be simultaneously energized to crank the engine in tandem after the pinion gears of both the electric motors are coupled to the ring gear of the engine.

An engine including an engine block having a cylinder defining a front of the engine, a blower housing coupled to the engine block and defining a hot half and a cool half opposite the front half, a starter mount assembly coupled to the blower housing and positioned within the cool half, an electric starter motor retained by the starter mount assembly, and a battery mounted to the blower housing and positioned in the cool half. The battery is electrically coupled to the electric starter motor.

A spindle is radially and axially compact. An impact wrench includes a motor, a sun gear rotatable by the motor, a planetary gear meshing with the sun gear, an internal gear meshing with the planetary gear, a gear case holding the internal gear, a spindle holding the planetary gear, and a first bearing located between the gear case and the spindle, and supporting the spindle on an outer circumference and the gear case on an inner circumference.