A self-unloading modular conveyor device designed for standard trailers, trucks, and similar transport vehicles, enabling them to transport and unload loose materials efficiently. The device generally includes a chassis, conveyor, motor, left door, right door, and front door, with optional components like a hydraulic power unit and a self-driven sandbagging device. Engineered for easy installation on the bed of a standard transport vehicle without permanent modifications, the device can be removed when not in use. The invention also provides methods for converting standard trailers, trucks, or similar transport vehicles into self-unloading ones; self-unloading loose material from the beds of standard transport vehicles; and moving and unloading loose material using the self-unloading modular conveyor device. This invention enables trailers, trucks, and similar transport vehicles to be suitable for efficiently transporting and self-unloading loose materials utilizing a conveyor mechanism.

Provided are a hydraulic control valve, a hydraulic control system, and a transmission. The hydraulic control valve includes a valve body, a slidable valve cartridge, and a pressing mechanism. A valve hole, a first oil supply port, a second oil supply port, and an oil discharge port are formed at the valve body, and each of the first oil supply port, the second oil supply port, and the oil discharge port is in communication with the valve hole. Both the slidable valve cartridge and the pressing mechanism are accommodated within the valve hole. The slidable valve cartridge has a small end close to an end of the valve hole and a large end abutting against the pressing mechanism. The pressing mechanism is disposed at another end of the valve hole.

Methods and systems for an electric vehicle (EV). The EV system includes an electric drive axle that includes a first electric motor configured to transfer mechanical power to a first drive wheel, a second electric motor configured to transfer mechanical power to a second drive wheel, and a motor coupling clutch configured to selectively rotationally couple the first electric motor to the second electric motor. The EV system further includes a controller configured to selectively rotationally couple the first electric motor to the second electric motor via operation of the motor coupling clutch based on vehicle load.