Abstract: A differential self-locking device includes a differential housing, a half-shaft output gear set disposed in the differential housing, an upper worm and worm gear mechanism, a lower worm and worm gear mechanism, a differential planetary gear set, and a worm gear shaft. The upper worm and worm gear mechanism and the lower worm and worm gear mechanism respectively convert a large output torque of the left half-shaft output gear and a large output torque of the right half-shaft output gear into small output torque thereof to lock the left half-shaft output gear and the right half-shaft output gear, thereby achieving automatic locking or unlocking of the differential self-locking device. A traction force of a vehicle is converted into torques of the left half-shaft output gear and the right half-shaft output gear, which improves passing ability of the vehicle.

Abstract: A differential self-locking device includes a differential housing, a half-shaft output gear set disposed in the differential housing, an upper worm and worm gear mechanism, a lower worm and worm gear mechanism, a differential planetary gear set, and a worm gear shaft. The upper worm and worm gear mechanism and the lower worm and worm gear mechanism respectively convert a large output torque of the left half-shaft output gear and a large output torque of the right half-shaft output gear into small output torque thereof to lock the left half-shaft output gear and the right half-shaft output gear, thereby achieving automatic locking or unlocking of the differential self-locking device. A traction force of a vehicle is converted into torques of the left half-shaft output gear and the right half-shaft output gear, which improves passing ability of the vehicle.

Abstract: Disclosed is an integrated construction method of fracturing and tertiary oil recovery for low-permeability reservoir, including the following steps: dividing the target layer into several fracturing intervals; determining the amount of fracturing fluid required for the target fracturing interval; determining the flow rate of the target fracturing interval; determining the pumping construction procedure for the target fracturing interval; perforating the target fracturing interval; injecting oil displacement fracturing fluid into the target fracturing interval for fracturing construction; wherein the oil displacement fracturing fluid is a fracturing fluid to which an oil displacement agent is added.

Abstract: Disclosed is an integrated construction method of fracturing and tertiary oil recovery for low-permeability reservoir, including the following steps: dividing the target layer into several fracturing intervals; determining the amount of fracturing fluid required for the target fracturing interval; determining the flow rate of the target fracturing interval; determining the pumping construction procedure for the target fracturing interval; perforating the target fracturing interval; injecting oil displacement fracturing fluid into the target fracturing interval for fracturing construction; wherein the oil displacement fracturing fluid is a fracturing fluid to which an oil displacement agent is added.

Abstract: A control method for idling anti-rollback of a pure electric vehicle is provided, where the pure electric vehicle has a vehicle controller, a motor controller, a motor, a brake pedal, a handbrake device, an accelerator pedal, and a power battery. The method makes use of the differences between a pure electric vehicle from conventional cars, and collects the states of individual parts of the vehicle through the vehicle controller, and controls the output of the torque of the motor based on the state information of various control components, to prevent the vehicle located on a slope from rolling back, and makes the vehicle move forward at idle.

Abstract: The present invention relates to a control method for idling anti-rollback of pure electric vehicle, which comprises the following steps: determining whether an anti-rollback control is needed by the current state of the vehicle or not with the vehicle controller according to the brake pedal, the handbrake device and the accelerator pedal; If needed, judging whether the working condition of the anti-rollback control is satisfied by the current states of the power battery, the motor controller, and the motor or not with the vehicle controller; If not satisfied, stopping the motor to output a torque; If satisfied, driving the motor to output the torque for the anti-rollback control.