Class / Patent application number | Description | Number of patent applications / Date published |
060468000 | Of by-pass of motor, pump or flow control element | 19 |
20080236158 | Hydraulic oil supply structure and vehicle drive apparatus provided with the same - The hydraulic control apparatus includes a separating plate that is interposed between an upper valve body and a lower valve body. The separating plate and the lower valve body provide a projecting portion that projects toward a discharge opening side of the oil pump with respect to the upper valve body. A first oil feed path is provided at the projecting portion, is formed between the separating plate and the lower valve body, and receives the hydraulic oil from the oil pump and guides the hydraulic oil to an upper valve body disposition side. | 10-02-2008 |
20080307784 | HYDRAULIC TRANSMISSION ASSEMBLY - The present disclosure relates to a hydraulic transmission assembly for a ground vehicle comprises a pump unit and a hydraulic motor assembly connected to the pump unit. The pump unit includes a driven shaft configured to operably connect to a motor of the ground vehicle. The hydraulic motor assembly includes a motor housing configured to rotatably mount to a wheel assembly of the ground vehicle. The housing has a central opening. A stationary output shaft has a first end section received in the central opening and a second end section configured to rigidly attach to a frame of the ground vehicle. The output shaft includes at least one internal fluid passage in fluid communication with at least one fluid passage of the pump unit. Pressurization of the hydraulic motor assembly via the pump unit rotates the motor housing relative to the stationary output shaft which, in turn, rotates the wheel assembly in one of a first direction and second direction. | 12-18-2008 |
20090308068 | CONTROL CIRCUIT FOR CONSTRUCTION MACHINE - Boom operating valves, a stick operating valve, etc. for respectively controlling hydraulic fluid fed from hydraulic pumps to boom cylinders, a stick cylinder, and other actuators are provided with center by-pass lines Cb. A stick-in meter-out load pressure compensating valve is provided on a rod-side return line, which extends from a rod side of the stick cylinder to a tank. A pressure sensor is provided at the rod side of the stick cylinder so as to detect pressure of hydraulic fluid fed to the rod side. The center by-pass line Cb associated with the stick operating valve is provided with an electromagnetic relief valve for controlling the pressure in the portion of the center bypass line downstream from the stick operating valve so as to increase the pressure in accordance with. | 12-17-2009 |
20100319338 | HYDRAULIC CONTROL SYSTEM FOR EXCAVATOR - A hydraulic circuit for an excavator is provided, which includes at least one first working device control valve having a first traveling control valve and a first boom control valve successively installed along a first center bypass line from a downstream side of a first hydraulic pump, at least one second working device control valve having a second traveling control valve and a second boom control valve successively installed along a second center bypass line from a downstream side of a second hydraulic pump, a third hydraulic pump providing fluid pressure to a swing motor installed on a third center bypass line, a swing control valve installed on a downstream side of the third hydraulic pump and shifted, in accordance with a valve switching signal input from the outside, to supply hydraulic fluid discharged from the third hydraulic pump to the swing motor, and a boom confluence line connected between an output port of the swing control valve and an input port of the boom control value to make the hydraulic fluid discharged from the third hydraulic pump join hydraulic fluid on the input port side of the boom control valve through the third center bypass line when the direction of the boom control valve is changed. | 12-23-2010 |
20110154816 | FLUID BYPASS SYSTEM - A method for actuating a bypass control valve assembly of a fluid system includes receiving a first input signal at an electronic control unit. The first input signal is related to an active position of a direction control valve that is in fluid communication with a fluid pump and a fluid actuation device. The directional control valve includes a neutral position that provides fluid communication between a fluid inlet port of the directional control valve and a fluid outlet port of the directional control valve. A second input signal is received at the electronic control unit. The second input signal is related to the rotational speed of the fluid pump. The second input signal is compared to a limit. A drain valve of a bypass valve assembly is actuated so that fluid communication between the fluid pump and a fluid reservoir through the bypass valve assembly is blocked. | 06-30-2011 |
20120124989 | Hydraulic Power Unit With Auto-Load Sensing - A hydraulic power unit is disclosed that is selectively connectable to a hydraulic tool. The hydraulic power unit automatically detects the attached or detached state of the tool and/or operates an unloading valve during activation of the tool. | 05-24-2012 |
20120317968 | DUMP TRUCK - A dump truck includes: an oil-cooling center brake; a first hydraulic pump supplying cooling oil to the center brake; a second hydraulic pump supplying cooling oil to the center brake in addition to the cooling oil from the first hydraulic pump; a hydraulic motor driving the second hydraulic pump; a third hydraulic pump supplying hydraulic oil to the hydraulic motor; an open/close valve letting the hydraulic oil bypass the hydraulic motor; and a controller controlling a bypass flow amount at the open/close valve. A capacity of the first hydraulic pump corresponds to a flow amount of the cooling oil required to lubricate a transmission. A capacity of the second hydraulic pump corresponds to a flow amount for compensating the cooling oil from the first hydraulic pump when a brake is off. A capacity of the third hydraulic pump is smaller than the capacity of the second hydraulic pump. | 12-20-2012 |
20120317969 | HYDRAULIC PRESSURE CONTROLLER FOR CONTINUOUSLY VARIABLE TRANSMISSION - Disclosed is a hydraulic control device for a continuously variable transmission which changes the transmission gear ratio by changing the hydraulic pressure (Pin, Pout) supplied to hydraulic pressure chambers ( | 12-20-2012 |
20130008155 | SWING BRAKE CONTROL APPARATUS FOR CONSTRUCTION MACHINERY - The present disclosure relates to an apparatus for controlling a swing brake for construction machinery, comprising: a lower travel body; an upper swinging body supported at the lower travel body such that the upper swing body is capable of being swung; a swing motor for driving the upper swing body; a swing brake for braking the swing motor; a swing brake valve which operates to control the braking and releasing operations of the swing brake; a solenoid valve mounted on the swing brake valve to control the operation of the swing brake valve; an operation sensor which applies a first reference signal and a second reference signal in accordance with the motion of a swing operation control unit for controlling the operation of the upper swinging body, wherein said second reference signal is generated when an amount of displacement of the swing operation control unit is larger than the first reference signal; and a control unit, which operates the swing brake valve to release the swing brake when the first reference signal is inputted from the operation sensor, and which operates the swing motor when the second reference signal is inputted. | 01-10-2013 |
20130091837 | HYDRAULIC TRANSMISSION SYSTEM FOR ZERO-TURN VEHICLE - A hydraulic transmission system for a zero-turn vehicle, comprises first and second transaxles each of which includes an axle, a casing supporting the axle, a fluid sump provided in the casing, first and second ports provided on the casing and opened outward from the casing, an HST circuit, a charge pump disposed in the casing, and a charge passage disposed in the casing to supply the HST circuit with fluid delivered from the charge pump. A first pipe connects the first ports of the transaxles, thereby making the flow of fluid from the charge pump of the first transaxle to the fluid sump of the second transaxle. A second pipe connects the second ports of the transaxles, whereby overflowing fluid of the fluid sump of the second transaxle is released to the fluid sump of the first transaxle via the second pipe. | 04-18-2013 |
20130111893 | Hydrostatic Drive - A hydrostatic drive includes a hydraulic pump configured to drive at least two hydraulic motors. The hydraulic motors each include an inlet side and an outlet side. The hydraulic motors are each connected on the inlet side to a respective outlet of a flow divider, which is arranged downstream of the hydraulic pump. The hydraulic motors are each connected on the outlet side to a respective inlet of a flow divider, which is arranged upstream of the hydraulic pump. | 05-09-2013 |
20130160443 | HYDRAULIC SYSTEM WITH FLUID FLOW SUMMATION CONTROL OF A VARIABLE DISPLACEMENT PUMP AND PRIORITY ALLOCATION OF FLUID FLOW - A system has a variable displacement pump that supplies pressurized fluid to power a plurality of hydraulic functions. Each hydraulic function has a control valve with a variable source orifice controlling fluid flow between the pump and a flow summation node, and a variable metering orifice controlling fluid flow between the flow summation node and a hydraulic actuator. Variable bypass orifices in the control valves are connected in series between the flow summation node and a tank. As the metering orifice in a control valve enlarges, the source orifice enlarges and the bypass orifice shrinks. This alters pressure at the flow summation node, which is used to control the output of the pump. Components are provided to give selected hydraulic functions different levels of priority with respect to consuming fluid flow from the pump. | 06-27-2013 |
20150059332 | HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINE - A hydraulic circuit for a construction machine including a direction control valve group including direction control valves provided in tandem to a center bypass passage, and a bleed-off valve provided to the center bypass passage downstream of the direction control valve group. | 03-05-2015 |
20150292181 | Hydrostatic Drive - Disclosed is a hydrostatic drive for a slewing gear of a stationary or mobile work machine, comprising a first hydraulic machine, a second hydraulic machine, an inflow channel fluidly connecting the first and second hydraulic machines, a return flow channel fluidly connecting the second hydraulic machine to a pressure medium sink, and a feed connection for compensating a leakage or a differential volume flow. The feed connection is selectively fluidly connected to whichever of the inflow channel and a return flow channel having higher pressure. | 10-15-2015 |
20150316078 | HYDRAULIC CIRCUIT FOR CONSTRUCTION MACHINES - A hydraulic circuit for a construction machine is disclosed, which increases the temperature of hydraulic fluid up to an appropriate level for equipment operation even in a state where an operator does not sit on an operator's seat before starting working during the winter season or the like. The hydraulic circuit for a construction machine includes first and second hydraulic pumps and a pilot pump, a first hydraulic actuator connected to the first hydraulic pump through a first center bypass path, a second hydraulic actuator connected to the second hydraulic pump through a second center bypass path, an operation lever, a main control valve controlling flow directions of the hydraulic fluid supplied from the first and second hydraulic pumps to the first and second hydraulic actuators, respectively, first and second center bypass valves installed to be opened and closed on downstream sides of the first and second center bypass paths in the main control valve, and a switching valve installed to be opened and closed in a signal path between the pilot pump and the first and second center bypass valves. | 11-05-2015 |
20160017897 | REGENERATIVE CIRCUIT OF HYDRAULIC APPARATUS - An object of the present invention is to solve such problems associated with installing of a spool-type regenerative valve, in that an overall installation space of a hydraulic valve increases and processing that requires accuracy becomes complex. A regenerative circuit includes: a regenerative oil path provided in a valve body of a direction switching valve so as to connect a supply oil path connected to one side of a hydraulic actuator and a discharge oil path connected to the other side; and a regenerative valve which is a poppet-type flow regulating valve that is screwed into and attached to the valve body so as to control the flow of oil in the regenerative oil path according to an operation state of the direction switching valve. | 01-21-2016 |
20160017898 | MERGING CIRCUIT OF HYDRAULIC APPARATUS - An object of the present invention is to solve such problems associated with a merging circuit using a pair of spool-type direction switching valves, in that the installation space of a hydraulic valve device increases and the processing that requires accuracy becomes complex. A merging circuit includes a direction switching valve that merges oil discharged from first and second pumps to supply the oil to an actuator; and a controller. The direction switching valve includes a central bypass oil path connected to the discharge oil paths of the first and second pumps, a first parallel supply oil path connected to the discharge oil path of the first pump, and a second parallel supply oil path connected to the discharge oil path of the second pump and connected to a first parallel oil path via a poppet-type flow regulating valve. The poppet-type flow regulating valve regulates the flow rate to a predetermined magnitude according to a signal of the controller. | 01-21-2016 |
20160017901 | PRESSURE LOSS REDUCING CIRCUIT FOR A WORKS MACHINE - A pressure loss reducing circuit reduces a pressure loss of oil returning from an actuator to a direction switching valve with a simple configuration while suppressing an increase in the manufacturing cost and substantially eliminating the need of an additional installation space. The pressure loss reducing circuit includes a bypass valve disposed between an actuator oil path and a tank oil path of a direction switching valve, and opened and closed according to a signal from a controller, and moreover screwed into and attached to the direction switching valve. According to an operation signal of a switching spool when oil returning from an actuator is caused to flow to the actuator oil path, the controller opens the bypass valve so that the actuator oil path and the tank oil path communicate with each other and supplies the returning oil to the switching spool and the bypass valve to reduce a pressure loss. | 01-21-2016 |
20160251831 | FLOW CONTROL VALVE FOR CONSTRUCTION EQUIPMENT, HAVING FLOATING FUNCTION | 09-01-2016 |