A center pintle hub to be affixed to a base of a machine. The center pintle hub includes a base portion and a support portion. The base portion is formed to be affixed to the base. The support portion extends from the base portion and has a frusto-conical shape that can receive a center pintle shaft. The center pintle shaft can support a frame of the machine and provide rotation of the frame with respect to the base.

A shovel includes a lower traveling structure, an upper swing structure swingably mounted on the lower traveling structure, a first hydraulic pump provided on the upper swing structure, an attachment attached to the upper swing structure, a first actuator, a second actuator, a first directional control valve corresponding to the first actuator, a second directional control valve corresponding to the second actuator, a first conduit connecting the first hydraulic pump and the first directional control valve, a second conduit connecting the first conduit and the second directional control valve, a control valve installed in the second conduit, and processing circuitry configured to control the opening area of the control valve according to information on work details.

Provided is a construction machine which can promptly adjust the rotational speed of a swing motor to a target rotational speed. A controller calculates a target rotational speed of the swing motor based on input from an operation device, calculates a degree of deviation of a rotational speed detected by a rotational speed sensor from the target rotational speed, sets a target driving pressure of the swing motor according to a moment of inertia about a swing axis of a swing structure and a work device and controls a pressure adjusting device in such a manner as to reduce a difference between a driving pressure detected by a pressure sensor and the target driving pressure, when the degree of deviation is larger than a predetermined value, and controls the pressure adjusting device in such a manner as to reduce a difference between the rotational speed detected by the rotational speed sensor and the target rotational speed, when the degree of deviation is equal to or smaller than the predetermined value.

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.

Disclosed are a novel rotation control system and method for an excavator. The novel rotation control system comprises a controller, an electrical control handle, an instrument, a rotating motor, a rotating valve trim, a main pump, a first electromagnetic valve, a second electromagnetic valve, a first pilot pressure sensor, a second pilot pressure sensor, an overflow valve and a one-way valve, and further comprises a rotation sensor used for detecting whether an excavator is rotating, a regulator used for controlling the displacement of the main pump, and a temperature sensor used for monitoring the temperature of hydraulic oil in real time.

A device for detecting a rotary angle used for an excavator. The device can include: a synchronous belt, arranged around a rotating shaft of a slewing mechanism of the excavator, a tooth-shaped surface of the synchronous belt being away from a surface of the rotating shaft; a transmission part, engaged with the tooth-shaped surface of the synchronous belt and arranged on a supporting base; an angle detection part, in transmission connection to the transmission part; and the supporting base, connected to a chassis of the excavator.

A device for detecting a rotary angle used for an excavator. The device can include: a synchronous belt, arranged around a rotating shaft of a slewing mechanism of the excavator, a tooth-shaped surface of the synchronous belt being away from a surface of the rotating shaft; a transmission part, engaged with the tooth-shaped surface of the synchronous belt and arranged on a supporting base; an angle detection part, in transmission connection to the transmission part; and the supporting base, connected to a chassis of the excavator.

A swing drive for rotating a component of a work vehicle. The swing drive has an electric machine rotating an output shaft about a drive axis and having a planetary set disposed beneath the electric machine. The planetary set has a carrier with pinion shafts having oil passageways therethrough. A splash plate is disposed axially between the electric machine and the planetary set to direct lubricating oil from a face of the electric machine to the oil passageways of the pinion shafts and to direct lubricating oil from the face of the electric machine around the oil passageways. A drive gear is driven to rotate about the drive axis by the electric motor via the double planetary set.

A construction equipment includes a lower traveling body; an upper rotating body rotatably supported on the lower traveling body; a work machine which includes a boom, an arm, and a bucket operated by their respective hydraulic cylinder, wherein the work machine is supported by the upper rotating body; a control valve for controlling the hydraulic cylinder; an electronic proportional pressure reducing valve for controlling the spool of the control valve; an operation lever for outputting an operation signal corresponding to an operation amount of a driver; an information providing unit for providing information on the work machine and the work surface; and an electronic control unit for calculating and outputting a pilot pressure for the electronic proportional pressure reducing valve, wherein the electronic control unit controls the speed of the hydraulic cylinder by using the operation signal of the operation lever and the information provided by the information providing unit.

A hydraulic system of a construction machine includes: control valves interposed between a main pump and hydraulic actuators; and first solenoid proportional valves connected to pilot ports of the control valves. The hydraulic system further includes: a brake for a slewing motor; and a second solenoid proportional valve connected to a brake release port of the brake by a secondary pressure line and connected to an auxiliary pump by a primary pressure line. A switching valve including a pilot port connected to the secondary pressure line by a pilot line is interposed between the auxiliary pump and the first solenoid proportional valves.