55results about How to "Improve fretting performance" patented technology

The invention discloses a hydraulic control system and a hydraulic control method to solve the problems that an engine of the hydraulic control system has high model selection limitation, or the system has complicated pipelines, high heat productivity, many fault sources, not ideal micromotion performance of motions and the like in the prior art. The hydraulic control system comprises a first closed pump and a first engine connected with each other, a second closed pump and a second engine connected with each other, and a hydraulic motor, wherein the first closed pump, a second closed pump and the hydraulic motor are connected in parallel. Through the technical scheme, the hydraulic control system has the advantages of wider engine model selection range, higher reliability and better micromotion performance.

The invention discloses a cocurrent flow control system, a cocurrent flow control method and a crane and relates to the field of engineering machinery. By virtue of utilizing control logic based on an electromagnetic valve, a pilot operated directional control valve and a shuttle valve, automatic control and manual control for the coccurent flow of two dumps can be realized, and the operation rapidness and operation reliability of the crane are improved; during composite action, when the load pressure difference is increased to a certain extent, a dual-pump cocurrent flow state is automatically switched to a dual-pump independent oil supply non-coccurent flow state, performances are not mutually influenced and the composite action effect is improved; by the using of a dual-pump coccurent flow manual control mechanism, independent operations of the two pumps can be realized according to demands of actual working conditions, for instance, single-pump operation is realized when operations such as hoisting jiggle, amplitude variation decrease, and arm stretching and contraction are performed, so that the jiggle property is improved and the energy consumption is reduced.

The invention discloses an arm support motion control method including the following steps: two input components of arm support control signals are obtained; the judgment result whether the arm support is linked is obtained in the condition that both of the amplitudes of the two input components are greater than a preset control threshold value; if the arm support is linked, the two input components are respectively compared with corresponding preset benchmark values so as to determine a current linkage area; according to the difficulty value of a preset arm support motion direction, the input component corresponding to the direction in which the difficulty value of the current linkage area is smaller is selected to be a first target signal, and the other input component is selected to bea second target signal; a first and a second proportionality coefficients corresponding to the first and the second target signals are obtained, wherein, the first proportionality coefficient is smaller than 1 and the second proportionality coefficient is greater than or equal to 1; according to the first and the second proportionality coefficients, the first and the second target signals are respectively varied to generate two output components; and according to the two output components, telescopic and pitching driving signals of the arm support are respectively outputted. The invention cancoordinate the linkage of the arm support and correspondingly further discloses an arm support motion controller and a control system.

A valve element of a hydraulic multi-way valve comprises a valve element body, and the valve element body is provided with a first throttling groove set, a second throttling groove set, a third throttling groove set, a fourth throttling groove set and a fifth throttling groove set. The throttling groove sets of different shapes and different opening lengths are formed in the valve element body so that the flow of the valve element can be directly proportional to the whole process of valve element displacement; the impact phenomenon generated in the opening and closing process of the valve element can be effectively avoided, motion stationarity can be effectively achieved, and therefore microoperation performance and precise location of lifting or descending of a working device of a loader are improved.

The invention relates to a platform swing system and a swing control method, and particularly relates to an aerial work platform swinging system and a swing control method. The invention belongs to the technical field of aerial work platforms. A swing controller obtains the position state of a handle, the swing controller can control the working state of a switching valve, a second three-positionfour-way reversing valve, and the shunt module according to the position state of the handle, so that the speed of the swing oil cylinder driving the hanging basket is matched with the current position state of the handle, namely, different flow rates can be provided to the swing cylinder according to the position state of the handle, so that the speed of the swing oil cylinder driving swing basket can be hierarchically and discretely controlled, and the controllability and the micro-motion are high, safe and reliable. When the handle is in a neutral state, the constant-pressure variable pumpworks in a pressure cut-off state, and the output flow is almost zero,; when the handle is in the non-neutral state, the constant-pressure variable pump works in the constant pressure variable state,the flow rate is automatically adjusted according to the system demand, thereby improving the energy saving performance of the swing system.

The invention relates to a confluent switching system with multiple oil supply units. The confluent switching system comprises a confluent component (7) and at least two oil supply units, wherein the confluent component (7) is arranged between the oil supply units. Confluent oil supply or independent oil supply can be selectively switched based on parameters for representing pilot control oil pressure in the oil supply units. When an executive element of the confluent switching system with the multiple oil supply units needs high-speed running, the flow demand of the whole system can be met by confluent oil supply. When the executive element needs low-speed running, the confluent oil supply mode is switched into an independent oil supply mode to reduce pulsation of the executive element at small flow, so that the executive element more stably runs, and the speed regulation property, the inching property and the energy-saving property of a hydraulic system are improved.

The invention provides a winch control system which comprises a winch motor, a load sensing pump and a main control valve group. The main control valve group comprises a first working oil port, a second working oil port, an oil inlet and a load feedback oil port, the first working oil port of the main control valve group is connected with a first oil port of the winch motor, the second working oil port of the main control valve group is connected with a second oil port of the winch motor, the oil inlet of the main control valve group is connected with an oil supply port of the load sensing pump, and the load feedback oil port of the main control valve group is connected with a feedback oil port of the load sensing pump. The winch control system further comprises a damping pressure-stabilizing valve group, wherein the damping pressure-stabilizing valve group is installed on the hydraulic pipe between the load feedback oil port of the main control valve group and the feedback oil port of the load sensing pump and used for retarding oil fluctuation in the winch control system. The winch control system effectively eliminates pressure fluctuation in the system, enables the motor to be capable of well working under the low-rotation-speed working condition and remarkably improves the slight movement performance of a crane hoisting mechanism.

The invention discloses a multi-way valve hydraulic system, which includes a parallel multi-way valve group connected with the actuator, and a first oil pump and a second oil pump connected with the oil supply circuit of the valve group; A confluence device, the diversion and confluence device is arranged between the second oil pump and the oil supply circuit, and when the difference between the oil supply pressure of the oil supply circuit and the load pressure of the hydraulic system is greater than a preset value, the diverter The converging device is in the first state, so that the hydraulic oil output by the second oil pump flows back to the oil tank through the dividing and converging device; when the difference is smaller than the preset value, the dividing and converging device is in the second state so that the hydraulic oil output by the second oil pump enters the oil supply passage and merges with the first oil pump. The hydraulic system can output the corresponding flow according to the flow required by the actuator, avoiding energy waste, and improving the smoothness and micro-movement of the system. The invention also discloses a crane using the above-mentioned multi-way valve hydraulic system.

The invention discloses a load sensitive hydraulic control system, comprising a multipath directional control valve and a load sensitive pump having a load sensitive valve, wherein, a liquid inlet and an oil drain port of the multipath directional control valve are respectively communicated with a liquid outlet and an oil tank of the load sensitive pump, a load feedback port of the multipath directional control valve is communicated with a sensitive cavity of the load sensitive valve, and each uniting valve oil port of the multipath directional control valve is respectively connected with the corresponding executive component; the passage between the load feedback port of the multipath directional control valve and the sensitive cavity of the load sensitive valve is provided with a damper valve; the oil duct between an oil inlet and an oil outlet of the damper valve is provided with at least two dampings, and the oil duct between the adjacent two dampings is provided with a chamber having an enlarged cross section; and the oil outlet is communicated with the load feedback port of the multipath directional control valve, and the oil inlet is communicated with the sensitive cavity of the load sensitive valve. In addition, the invention provides a crane having the load sensitive hydraulic control system.