Abstract: A hydraulic accumulator A to be removably attached to a support member includes a liquid chamber R2b having a predetermined volume even when no pressurized operating liquid is accumulated, and communicating with a liquid inflow port Pi and a liquid outflow port Po, which are disposed below the liquid chamber R2b. A liquid-chamber-R2b-side end of an outflow passageway So connecting the liquid chamber R2b and the liquid outflow port Po opens to an upper portion of the liquid chamber R2b. Further, an inflow passageway Si connecting the liquid chamber R2b and the liquid inflow port Pi is coaxially disposed within the outflow passageway So, and a liquid-chamber-R2b-side end of the inflow passageway Si opens to the upper portion of the liquid chamber R2b.

Abstract: In a hydraulic joint structure for joining respective tubular joint portions of two members, opposed pressure-contact surfaces of the two members for preventing loosening form a downstream space on the downstream side of a seal member. A passage is formed on the pressure-contact surfaces in such a manner that when working fluid leaks from the upstream side of the seal member to the downstream space via a clearance between the seal member and the tubular joint portions, the passage permits the working fluid to flow from the downstream space to an external space in the state in which the pressure-contact surfaces are in pressure contact. The passage is formed in such a manner that the passage extends in a circumferential direction of the thread portions, and communicates at one end with the downstream space and at the other end with the external space.

Abstract: A bellows-type hydraulic accumulator includes a main shell defining a pressure space, and a bellows unit sectioning the pressure space into a gas chamber and a liquid chamber. An auxiliary shell is disposed inside the liquid chamber and fixed to the main shell. The auxiliary shell has an auxiliary liquid chamber communicating with a liquid port. A movable wall member is disposed in the auxiliary shell in order to section the interior of the auxiliary shell into a first interior portion communicating with the liquid port and a second interior portion communicating with the liquid chamber via a communication passage formed in the auxiliary shell.

Abstract: In a hydraulic joint structure for joining respective tubular joint portions of two members, opposed pressure-contact surfaces of the two members for preventing loosening form a downstream space on the downstream side of a seal member. A passage is formed on the pressure-contact surfaces in such a manner that when working fluid leaks from the upstream side of the seal member to the downstream space via a clearance between the seal member and the tubular joint portions, the passage permits the working fluid to flow from the downstream space to an external space in the state in which the pressure-contact surfaces are in pressure contact. The passage is formed in such a manner that the passage extends in a circumferential direction of the thread portions, and communicates at one end with the downstream space and at the other end with the external space.

Abstract: A bellows-type hydraulic accumulator includes a main shell defining a pressure space, and a bellows unit sectioning the pressure space into a gas chamber and a liquid chamber. An auxiliary shell is disposed inside the liquid chamber and fixed to the main shell. The auxiliary shell has an auxiliary liquid chamber communicating with a liquid port. A movable wall member is disposed in the auxiliary shell in order to section the interior of the auxiliary shell into a first interior portion communicating with the liquid port and a second interior portion communicating with the liquid chamber via a communication passage formed in the auxiliary shell.

Abstract: A wheel brake pressure supplying device for supplying fluid pressure for a wheel brake cylinder of a wheel on an automotive vehicle includes a reservoir, a pump, a motor, an accumulator connected to the wheel brake cylinder, a fluid pressure sensor, an electric source, an operation time determining device and a motor control device. The reservoir stores a fluid and the pump is connected to the reservoir for pumping fluid in the reservoir. The motor operates the pump and the accumulator is connected to the pump for storing the fluid pumped by the pump so that fluid pressure in the accumulator increases through operation of the pump. The fluid pressure sensor senses when the fluid pressure in the accumulator is less than a predetermined pressure. The electric source is connected to the motor for supplying voltage to the motor and the operation time determining device determines a target operation time of the motor based on the voltage of the electric source.

Abstract: The invention is directed to a pressure supply system which has a fluid pump, an electric motor for driving the fluid pump to supply a hydraulic pressure in proportion to a current fed to the motor, and an accumulator for accumulating the hydraulic pressure supplied from the fluid pump. The pressure supply system includes a current detection device which detects the current fed to the motor, and a malfunction detection device which detects a malfunction of the pressure supply system on the basis of the output of the current detection device. The malfunction detection device is adapted to determine that the malfunction occurs when an increasing rate of the current fed to the motor is less than a predetermined rate, preferably after a predetermined time elapsed from the time when the current initially fed to the motor. The pressure supply system may further include such a warning device as a lamp or a buzzer, which will be activated when the malfunction detection device detects the malfunction of the system.

Abstract: The invention is directed to a pressure accumulating control system for use in a pressure supply apparatus which has a fluid pump, an electric motor for driving the fluid pump to supply a hydraulic pressure, and an accumulator for accumulating the hydraulic pressure supplied from the fluid pump. The system includes a pressure detection device for detecting the hydraulic pressure accumulated in the accumulator, and a continuous control device for feeding a current to the motor continuously. The continuous control device is adapted to feed the current to the motor continuously, when the pressure detected by the pressure detection device becomes less than a predetermined lower limit, and is adapted to terminate the continuous feeding of the current to the motor, when the pressure detected by the pressure detection device exceeds a predetermined upper limit. The system further includes an intermittent control device for feeding a current to the motor intermittently by a predetermined cycle of time.

Abstract: The invention is directed to a pressure monitoring system for monitoring a hydraulic pressure which is supplied from a fluid pump and accumulated in an accumulator. The pressure monitoring system includes an electric motor which drives the fluid pump to supply the hydraulic pressure in substantially linear proportion to a current fed to the motor, a current detection device which detects the current fed to the motor, and a pressure estimation device which estimates the hydraulic pressure accumulated in the accumulator in response to the current detected by the current detection device. A malfunction detection device may be provided for detecting a malfunction on the basis of the output of the pressure estimation device.