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ROTARY DRIVE SYSTEM AND HYDRAULIC EXCAVATOR

A rotary drive system includes an electric motor, a speed reducer, and a lubricating oil-circulating unit. The electric motor has an electric motor casing forming a first accommodating space and a communication hole communicating downward. The speed reducer has a speed reducer casing forming a second accommodating space communicating with the first accommodating space through the communication hole. The lubricating oil-circulating unit has a lubricating oil flow path and a lubricating oil pump. The lubricating oil flow path connects the first accommodating space and the second accommodating space at the outside. The lubricating oil pump pumps lubricating oil from the second accommodating space side to the first accommodating space side.

Hydraulic drive system of construction machine

A hydraulic drive system of a construction machine includes: an over-center pump connected to a turning motor; a regulator that adjusts tilting angle of the over-center pump; a main pump coupled to over-center pump; and a controller that controls the regulator such that when a turning deceleration operation is performed, the over-center pump's tilting angle decreases in accordance with decrease in a turning operation signal outputted from a turning operation device. The controller: when a pressure accumulation condition satisfied, switches a switching valve to pressure accumulation position to bring an accumulator into communication with a delivery line of the main pump; when a pressure release condition is satisfied, switches the switching valve to a pressure release position to bring accumulator into communication with a suction line of main pump; and when neither the pressure accumulation condition nor pressure release condition is satisfied, switches the switching valve to a neutral position.

ELECTRIC MOTOR, ROTARY DRIVE SYSTEM, AND HYDRAULIC SHOVEL
20210189686 · 2021-06-24 ·

An electric motor includes a rotor having a rotary shaft rotating around a vertically extending axis and a rotor core fixed to an outer peripheral surface of the rotary shaft, a stator surrounding the rotor core from an outer peripheral side, a lower bottom portion as a partition wall partitioning a first space where the rotor and the stator are disposed and a lubricating oil is supplied from an outside, a storage portion configured to store the lubricating oil supplied into the first space, a brake mechanism as a drive unit discharging the lubricating oil inside the storage portion into the first space, and sliding portions into each of which the lubricating oil discharged from the inside of the storage portion is introduced.

Locking system for a work machine

To provide a work machine that can stop unexpected operation of actuators faster than it actually occurs even if unintended operation occurs at the time of gate lock lever switching that leads to such unexpected operation. In the work machine, a controller switches a lock valve from a lock position to a release position in a case where a lock operation device is operated from a permission position to a prohibition position; decides, on the basis of a result of detection by a pressure sensor, whether or not a pilot hydraulic fluid has been output from a pilot valve until first time elapses after the lock valve is switched to the release position; keeps the lock valve at the lock position if it is decided that the pilot hydraulic fluid has been output until the first time elapses; and switches the lock valve from the lock position to the release position if it is decided that the pilot hydraulic fluid has not been output until the first time elapses, and second time elapses.

LOADING MACHINE CONTROL DEVICE AND CONTROL METHOD
20210102357 · 2021-04-08 ·

A control device of a loading machine includes an adjustment determination unit and an operation signal output unit. The loading machine includes a swing motor and a swing body. The adjustment determination unit determines whether or not an angle formed by an azimuth direction of a swing body when the swing body stops and a target stop azimuth direction is less than an allowable angle based on an azimuth direction, a swing speed, and the target stop azimuth direction of the swing body during braking of the swing motor. The operation signal output unit outputs a swing control signal for driving the swing motor in a case in which it is determined that the angle formed by the azimuth direction of the swing body when the swing body stops and the target stop azimuth direction is equal to or greater than the allowable angle.

Swing-back preventing apparatus

Provided is a swing-back preventing apparatus capable of preventing a hydraulic actuator in a stop state from operating by undesired load. The swing-back preventing apparatus includes a housing, a piston, and a pair of biasing members. First and second spaces are formed between the piston and the housing, and the piston includes a pair of communication passages that are communicable with first and second spaces. When the piston is located at a first offset position, the first space is blocked from a first port. When the piston separates from the first offset position, the first space is connected to the first port. When the piston is located at a second offset position, the second space is blocked from a second port. When the piston separates from the second offset position, the second space is connected to the second port. When the piston is located at a position on the first offset position side of a neutral position, a first communication passage is connected to the first space. When the piston is located in a range from the neutral position to the second offset position, the first communication passage is blocked from the first space. When the piston is located at a position on the second offset position side of the neutral position, a second communication passage is connected to the second space. When the piston is located in a range from the neutral position to the first offset position, the second communication passage is blocked from the second space.

Pivoting unit for construction equipment

A pivoting unit for construction equipment is provided which can ensure a brake performance for an upper pivoting body thereof for any pivoting power source applied thereto without a limitation to the applied pivoting power source. The pivoting unit for a construction equipment, comprises a pivoting motor, a pivoting reducer connected to the pivoting motor, and a parking brake device which is installed between the pivoting motor and the pivoting reducer and restricts the rotation of the pivoting reducer independently of the pivoting motor.

Work Machine

To provide a work machine that can stop unexpected operation of actuators faster than it actually occurs even if unintended operation occurs at the time of gate lock lever switching that leads to such unexpected operation. In the work machine, a controller switches a lock valve from a lock position to a release position in a case where a lock operation device is operated from a permission position to a prohibition position; decides, on the basis of a result of detection by a pressure sensor, whether or not a pilot hydraulic fluid has been output from a pilot valve until first time elapses after the lock valve is switched to the release position; keeps the lock valve at the lock position if it is decided that the pilot hydraulic fluid has been output until the first time elapses; and switches the lock valve from the lock position to the release position if it is decided that the pilot hydraulic fluid has not been output until the first time elapses, and second time elapses.

SHOVEL
20210025135 · 2021-01-28 ·

A shovel includes an undercarriage, an upper swing structure swingably mounted on the undercarriage, an object detector provided on the upper swing structure, and a hardware processor configured to automatically braking a drive part of the shovel according to a predetermined braking pattern, in accordance with a distance between the shovel and an object, the distance being detected by the object detector.

SLEWING-TYPE WORK MACHINE

A slewing-type work machine includes a slewing state determination section which determines whether or not slewing motion of an upper slewing body is in a deceleration state, and a capacity control section which controls a motor capacity. The capacity control section sets the motor capacity to a capacity set for a combined operation during a performance of the combined operation in which an operation for slewing the upper slewing body and an operation for actuating an attachment are performed simultaneously, while setting the motor capacity to a preset default capacity even during the performance of the combined operation when the slewing state determination section determines that the slewing motion of the upper slewing body is in the deceleration state.