A cooling air introduction path is formed in a base of a sound proof case of an engine-driven work machine. The base is divided into upper and lower portions, and a space in the upper portion is divided by a separation wall and arranged below an air discharging chamber. The upper part of one space is covered with a arranging plate, a partition wall is erected on the arranging plate, and a cooling air introduction port is provided between the partition wall and the separation wall to provide an engine chamber and one space are communicated, a hole is provided in the plate below the chamber, and one space and the space in the lower portion are communicated and located below the chamber. A cooling air intake port is provided on lateral walls of the lower portion to communicate the space inside the lower portion with the outside of the machine.

A cooling air introduction path is formed in a base of a sound proof case of an engine-driven work machine. The base is divided into upper and lower portions, and a space in the upper portion is divided by a separation wall and arranged below an air discharging chamber. The upper part of one space is covered with a arranging plate, a partition wall is erected on the arranging plate, and a cooling air introduction port is provided between the partition wall and the separation wall to provide an engine chamber and one space are communicated, a hole is provided in the plate below the chamber, and one space and the space in the lower portion are communicated and located below the chamber. A cooling air intake port is provided on lateral walls of the lower portion to communicate the space inside the lower portion with the outside of the machine.

A machine such as a material processing apparatus comprises a mechanical transmission system coupled to a mechanical load such as a crusher. An internal combustion engine is coupled to the mechanical transmission system, and at least one motor-generator is coupled to an electrical system and to the mechanical transmission system. In at least one mode of operation, the electrical system delivers electrical power to the motor-generator(s), the motor-generator(s) generating mechanical power from the electrical power and delivering the mechanical power to the mechanical transmission system to drive the mechanical load.

A machine such as a material processing apparatus comprises a mechanical transmission system coupled to a mechanical load such as a crusher. An internal combustion engine is coupled to the mechanical transmission system, and at least one motor-generator is coupled to an electrical system and to the mechanical transmission system. In at least one mode of operation, the electrical system delivers electrical power to the motor-generator(s), the motor-generator(s) generating mechanical power from the electrical power and delivering the mechanical power to the mechanical transmission system to drive the mechanical load.

An engine generator coupled to an external battery. The engine generator includes: an engine; a motor generator configured to apply a starting force to the engine at a start of the engine, and to perform power generation by a driving force of the engine during driving of the engine;

a first step-down section and an engine accessory, the first step-down section being configured to step down a voltage of the external battery to obtain a first stepped-down voltage, and supply the first stepped-down voltage to the engine accessory; and a power converter that converts power of the external battery and supplies the converted power to the motor generator.

An engine generator coupled to an external battery. The engine generator includes: an engine; a motor generator configured to apply a starting force to the engine at a start of the engine, and to perform power generation by a driving force of the engine during driving of the engine;

a first step-down section and an engine accessory, the first step-down section being configured to step down a voltage of the external battery to obtain a first stepped-down voltage, and supply the first stepped-down voltage to the engine accessory; and a power converter that converts power of the external battery and supplies the converted power to the motor generator.

In an aspect, a power transfer device, such as a decoupler, is provided for transferring torque between a shaft and a belt. The device includes: a hub configured to couple to the shaft, a pulley rotatably coupled to the hub that includes a power transmitting surface configured to engage the belt, an isolation spring to transfer a rotational load from one of the pulley and the hub to the other of the pulley and the hub, optionally a one-way clutch to permit overrunning of one of the pulley and the hub relative to the other of the pulley and the hub in a first direction, and a damping member positioned to be driven into frictional engagement with a friction surface by a force from the isolation spring acting on the damping member that varies based on the rotational load transferred by the isolation spring.

In an aspect, a power transfer device, such as a decoupler, is provided for transferring torque between a shaft and a belt. The device includes: a hub configured to couple to the shaft, a pulley rotatably coupled to the hub that includes a power transmitting surface configured to engage the belt, an isolation spring to transfer a rotational load from one of the pulley and the hub to the other of the pulley and the hub, optionally a one-way clutch to permit overrunning of one of the pulley and the hub relative to the other of the pulley and the hub in a first direction, and a damping member positioned to be driven into frictional engagement with a friction surface by a force from the isolation spring acting on the damping member that varies based on the rotational load transferred by the isolation spring.

A thermal choke, includes (1) a body, comprising a heat conductive material, (2) an electric heater, on or in the body, (3) a temperature sensor, on or in the body, and (4) a fin, in a channel surrounded by the body. The thermal choke is configured to fit between a throttle assembly and a cylinder of a spark ignition engine.

A coupling is disclosed for connecting rotating components of a generator and a prime mover in a power generation system. The coupling comprises a hub, a coupling flange and an elastomeric component located between the hub and the coupling flange. The elastomeric component is removable radially from the coupling.