A hydraulic system and method for a closed static pressure rotary device

Abstract

The invention discloses a hydraulic system and method of a closed hydraulic rotary device, a pressure oil supply system of a closed hydrostatic rotary device, an oil inlet pipe and an oil outlet pipe of the closed hydrostatic rotary device respectively connected to an oil outlet end and an oil return end of the hydraulic oil supply system; the hydraulic oil supply system comprises an oil tank, and an oil supply oil circuit of the hydraulic oil supply system comprises an oil outlet pump, a one-way valve, a solenoid valve, and a pressure reducing valve in sequence from the oil tank to the oil outlet end; the oil return oil circuit of the hydraulic oil supply system comprises an oil return pump; the hydraulic oil supply system also comprises a cooling circulation pipe, the cooling circulation pipe comprises an oil cooler and a cooling circulation pump connected in series, and the oil inlet end and the oil outlet end of the cooling circulation pipe are both connected to the oil tank; when the temperature sensor senses that the temperature in the oil tank rises to a threshold value, the cooling circulation pump is turned on to cool the hydraulic oil in the oil tank, thereby ensuring the heat exchange efficiency of the hydraulic circulation loop to the rotary device of the closed hydrostatic bearing.

Description

Technical Field

[0001] The invention belongs to the field of hydraulic systems. Background Art

[0002] The closed hydrostatic slewing device is a sliding bearing that adopts the principle of static lubrication. High-pressure lubricant is injected into the bearing through an external pressure system to form a stable lubricating film, thereby achieving smooth rotation of the rotating parts. Once the hydraulic pressure in the closed hydrostatic slewing device is lost, the isolation oil film of the parts that originally rotated relatively will lose its effect, resulting in direct contact friction and subsequent damage. At the same time, the closed hydrostatic bearing will spontaneously generate a lot of heat under high load operation. Its hydraulic system must not only solve the stability of the hydraulic pressure and sudden failures, but also take into account its heat exchange cycle to avoid damage caused by excessive temperature during equipment operation. Summary of the invention

[0003] Purpose of the invention: In order to overcome the deficiencies in the prior art, the present invention provides a hydraulic system and method for a closed hydrostatic rotary device. When the oil delivery pump fails and stops running, the hydraulic accumulator will continue to supply oil to the pressure reducing valve, thereby maintaining the normal operation of the closed hydrostatic rotary device.

[0004] Technical solution: To achieve the above-mentioned purpose, the present invention provides a hydraulic system of a closed hydraulic rotary device, a closed hydrostatic rotary device and a hydraulic oil supply system, wherein the oil inlet pipe and the oil outlet pipe of the closed hydrostatic rotary device are respectively connected to the oil outlet end of the hydraulic oil supply system and the oil return end of the hydraulic system.

[0005] The hydraulic oil supply system includes an oil tank, and the oil supply oil circuit of the hydraulic oil supply system includes an oil outlet pump, a one-way valve, a solenoid valve, and a pressure reducing valve from the oil tank to the oil outlet end; the oil return oil circuit of the hydraulic oil supply system includes an oil return oil pump;

[0006] The oil inlet of the oil outlet pump is connected to the oil tank, the oil outlet is connected to the oil inlet of the one-way valve, the oil outlet of the one-way valve is connected to the oil inlet of the solenoid valve, the oil outlet of the solenoid valve is connected to the oil inlet of the pressure reducing valve, and the oil outlet of the pressure reducing valve is the oil outlet of the hydraulic oil supply system;

[0007] It also includes a cooling circulation pipe, which includes an oil cooler and a cooling circulation pump connected in series, and the oil inlet end and the oil outlet end of the cooling circulation pipe are both connected to the oil tank.

[0008] Furthermore, it also includes a hydraulic accumulator, a safety valve combination, a pressure relay and a b pressure relay. The pressure end of the hydraulic accumulator is connected to the oil pipe between the solenoid valve and the one-way valve through a pressure pipe bypass connection; the pressure end of the a pressure relay is connected to the pressure pipe in a bypass connection, the pressure end of the b pressure relay is connected to the oil pipe connected to the oil outlet end of the pressure reducing valve in a bypass connection, the a pressure relay is connected to the solenoid valve in a linkage control connection, and the b pressure relay is connected to the oil return pump in a linkage control connection.

[0009] Furthermore, the safety valve combination includes a ball valve, b ball valve and a relief valve, wherein the a ball valve is connected in series to the pressure pipe and is initially in an open state; the oil inlet end of the a relief valve is bypass-connected between the a ball valve and the pressure end of the hydraulic accumulator; the oil outlet end of the a relief valve is connected to the oil tank, and the b ball valve, which is initially closed, is connected in parallel with the a relief valve.

[0010] Furthermore, it also includes a b overflow valve and a c overflow valve, the b overflow valve is connected in parallel with the oil return pump; the oil inlet end of the c overflow valve is connected to the oil inlet end of the one-way valve, and the oil outlet end is connected to the oil tank.

[0011] Furthermore, it also includes a pressure gauge a that can detect the pressure at the oil inlet end of the overflow valve a, a pressure gauge b that can detect the pressure at the oil inlet end of the check valve, and a pressure gauge c that can detect the pressure at the oil outlet end of the pressure reducing valve.

[0012] Furthermore, an oil filter is connected in series to the oil outlet end of the oil outlet pump; a liquid level sensor, a temperature sensor and an air filter are arranged in the oil tank.

[0013] Furthermore, the bottom of the oil tank is connected to an oil drain ball valve which is initially closed.

[0014] Further, a working method of a hydraulic system of a closed hydraulic rotary device:

[0015] In the initial state, the solenoid valve and the return oil pump are both closed, and the oil outlet pump is started. Driven by the oil outlet pump, the hydraulic oil in the oil tank passes through the oil outlet pump, the oil line filter and the one-way valve in turn. The hydraulic oil flowing out of the one-way valve is gradually pressed into the hydraulic accumulator through the pressure pipe, so that the hydraulic accumulator is gradually charged. When the pressure at the pressure end of the a pressure relay rises to P1, the a pressure relay controls the solenoid valve to open, and then the hydraulic oil is pressed into the closed static pressure rotary device through the solenoid valve and the pressure reducing valve. After the pressure at the pressure end of the b pressure relay rises to more than P2, the b pressure relay controls the return oil pump to run, and keeps the oil flow of the return oil pump consistent with the oil flow of the oil outlet pump, so that the oil hole system, the oil film layer and the oil storage tank in the closed static pressure rotary device are maintained on the basis of stable pressure, so as to achieve the purpose of continuously cooling and discharging the heat in the closed static pressure rotary device;

[0016] When the temperature sensor senses that the temperature in the oil tank rises to a threshold value, the cooling circulation pump is turned on to cool the hydraulic oil in the oil tank.

[0017] Beneficial effect: When the temperature sensor senses that the temperature in the oil tank rises to a threshold value, the cooling circulation pump is turned on to cool the hydraulic oil in the oil tank, thereby ensuring the heat exchange efficiency of the hydraulic circulation loop to the rotary device of the closed static pressure bearing;

[0018] When the oil delivery pump stops running due to a fault, the hydraulic accumulator will continue to supply oil to the pressure reducing valve, thereby maintaining the normal operation of the closed hydrostatic rotary device. If the oil delivery pump can eliminate the fault in a short time, the system will automatically continue to operate stably. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a schematic diagram of the overall structure of the hydraulic system of this scheme;

[0020] Figure 2 for Figure 1 A schematic diagram of the enlarged structure at the mark 25;

[0021] Figure 3 It is a schematic diagram of the overall structure of a closed static pressure rotary device. DETAILED DESCRIPTION

[0022] The present invention will be further described below in conjunction with the accompanying drawings.

[0023] As attached Figures 1 to 3 A hydraulic system of a closed hydraulic rotary device, a closed static pressure rotary device 1 and a hydraulic oil supply system, as shown in Figure 3 The oil inlet pipe and the oil outlet pipe of the closed static pressure rotary device 1 are respectively connected to the oil outlet end 29 of the hydraulic oil supply system and the oil return end 30 of the hydraulic system; the hydraulic oil supply system includes an oil tank 70, and the oil supply oil circuit of the hydraulic oil supply system includes an oil outlet pump 40, a one-way valve 36, a solenoid valve 35, and a pressure reducing valve 33 from the oil tank 70 to the oil outlet end 29; the oil return oil circuit of the hydraulic oil supply system includes an oil return pump 45; the oil inlet end of the oil outlet pump 40 is connected to the oil tank 70, and the oil outlet end is connected to the oil inlet end of the one-way valve 36, the oil outlet end of the one-way valve 36 is connected to the oil inlet end of the solenoid valve 35, the oil outlet end of the solenoid valve 35 is connected to the oil inlet end of the pressure reducing valve 33, and the oil outlet end of the pressure reducing valve 33 is the oil outlet end 29 of the hydraulic oil supply system.

[0024] The cooling circulation pipe 93 is also included. The cooling circulation pipe 93 includes an oil cooler 92 and a cooling circulation pump 91 connected in series. The oil inlet end and the oil outlet end of the cooling circulation pipe 93 are both connected to the oil tank 70.

[0025] It also includes a hydraulic accumulator 34, a safety valve assembly 25, a pressure relay 28 and a pressure relay 31; a hydraulic accumulator is a device that can store and release liquid pressure energy, which is similar to a capacitor in a circuit and plays an important role in energy buffering, storage and release in a hydraulic system; the pressure end of the hydraulic accumulator 34 is connected to the oil pipe between the solenoid valve 35 and the one-way valve 36 through a pressure pipe 100; the pressure end of the a pressure relay 28 is connected to the pressure pipe 100, and the pressure end of the b pressure relay 31 is connected to the oil pipe connected to the oil outlet end of the pressure reducing valve 33 through a bypass connection, and the a pressure The relay 28 is connected to the solenoid valve 35 for linkage control, and the b pressure relay 31 is connected to the return oil pump 45 for linkage control; when the pressure of the a pressure relay 28 gradually increases from normal pressure to more than P1, the a pressure relay 28 is linked to control the solenoid valve 35 to open; when the pressure of the b pressure relay 31 increases to P2, the b pressure relay 31 is linked to control the return oil pump 45 to operate; when the pressure of the b pressure relay 31 decreases to less than P2, the b pressure relay 31 is linked to control the return oil pump 45 to close, P1>P2, P2 is the hydraulic working pressure in the closed hydrostatic rotary device 1.

[0026] The safety valve assembly 25 includes a ball valve 49, b ball valve 48 and a relief valve 47. The a ball valve 49 is connected in series to the pressure pipe 100 and is initially in an open state. The oil inlet end of the a relief valve 47 is connected between the a ball valve 49 and the pressure end of the hydraulic accumulator 34 in a bypass manner. The oil outlet end of the a relief valve 47 is connected to the oil tank 70. The b ball valve 48, which is initially closed, is connected in parallel with the a relief valve 47.

[0027] It also includes a b overflow valve 44 and a c overflow valve 37, the b overflow valve 44 is connected in parallel with the return oil pump 45; the oil inlet end of the c overflow valve 37 is connected to the oil inlet end of the one-way valve 36, and the oil outlet end is connected to the oil tank 70; it also includes an a pressure gauge 46 that can detect the pressure of the oil inlet end of the a overflow valve 47, a b pressure gauge 38 that can detect the pressure of the oil inlet end of the one-way valve 36, and a c pressure gauge 32 that can detect the pressure of the oil outlet end of the pressure reducing valve 33; the oil outlet end of the oil outlet pump 40 is connected in series with an oil filter 39; the oil tank 70 contains a liquid level sensor, a temperature sensor 42 and an air filter 43; the bottom of the oil tank 70 is connected to an oil drain ball valve 41 that is initially closed.

[0028] Working method and working principle of the hydraulic system of the hydraulic slewing device:

[0029] In the initial state, the solenoid valve 35 and the return oil pump 45 are both in the closed state, and then the oil delivery pump 40 is started. Under the drive of the oil delivery pump 40, the hydraulic oil in the oil tank 70 passes through the oil delivery pump 40, the oil filter 39 and the one-way valve 36 in sequence. Since the solenoid valve 35 is in the closed state, the hydraulic oil flowing out of the one-way valve 36 is gradually pressed into the hydraulic accumulator 34 through the pressure pipe 100, so that the hydraulic accumulator 34 is gradually charged, thereby gradually increasing the pressure at the pressure end of the hydraulic accumulator 34, and then the pressure at the pressure end of the a pressure relay 28 gradually increases synchronously with the pressure at the pressure end of the hydraulic accumulator 34; as the hydraulic accumulator 34 is continuously charged, when the pressure at the pressure end of the a pressure relay 28 rises to P1, it means that the hydraulic accumulator 34 has been fully charged, and the a pressure relay 28 controls the solenoid valve 35 to open, and then the hydraulic oil passes through the solenoid valve 35. The valve 35 and the pressure reducing valve 33 are pressed into the closed static pressure rotary device 1, so that the oil passage hole system, the oil film layer and the oil storage tank in the closed static pressure rotary device 1 are gradually filled with oil and pressurized. When the oil pressure in the closed static pressure rotary device 1 rises to P2, the closed static pressure rotary device 1 enters the working state and starts to rotate. At the same time, after the pressure at the pressure end of the b pressure relay 31 rises to exceed P2, the b pressure relay 31 controls the return oil pump 45 to operate, and makes the pumping oil flow of the return oil pump 45 basically consistent with the pumping oil flow of the oil outlet pump 40, so that on the basis of maintaining the pressure in the oil passage hole system, the oil film layer and the oil storage tank in the closed static pressure rotary device 1 stable, the hydraulic oil in the oil passage hole system, the oil film layer and the oil storage tank in the closed static pressure rotary device 1 is continuously discharged, so as to achieve the purpose of continuously cooling and discharging the heat in the closed static pressure rotary device 1;

[0030] As time goes by and the oil circuit continues to circulate, the temperature in the oil tank 70 will gradually increase. When the temperature sensor 42 senses that the temperature in the oil tank 70 has increased to a threshold value, the cooling circulation pump 91 is turned on to cool the hydraulic oil in the oil tank 70.

[0031] When the pressure of the b pressure relay 31 drops to a preset value, the b pressure relay 31 controls the oil return pump 45 to close, and P1 is greater than P2, where P2 is the hydraulic working pressure in the closed hydrostatic rotary device 1.

[0032] When the oil outlet pump 40 stops running due to a fault, the hydraulic accumulator 34 will continue to supply oil to the pressure reducing valve 33, thereby maintaining the normal operation of the closed static pressure rotary device 1. If the oil outlet pump 40 can eliminate the fault in a short time, the system will automatically continue to operate stably. If the fault of the oil outlet pump 40 is not eliminated in a short time, the pressure at the pressure end of the hydraulic accumulator 34 will gradually decrease with the release of oil, and the pressure at the pressure end of the hydraulic accumulator 34 will gradually decrease from P1 to P2, so that the inlet and outlet ends of the pressure reducing valve 33 are consistent, and the pressure continues to decrease synchronously. When the pressure of the b pressure relay 31 just starts to drop below P2, the b pressure relay 31 controls the oil return pump 45 to close, thereby sealing the oil return pump 45. The return oil pipeline is blocked, thereby preventing the hydraulic oil pressure in the oil circuit hole system, oil film layer and oil storage tank in the closed hydrostatic rotary device 1 from further decreasing, thereby ensuring that the closed hydrostatic rotary device 1 can basically maintain normal operation and avoid damage due to internal wear. At this time, since the oil circuit circulation has been suspended, the heat in the closed hydrostatic rotary device 1 is not easy to discharge, and therefore the closed hydrostatic rotary device 1 needs to be gradually suspended. This process reserves sufficient buffer time for the stopping process of the closed hydrostatic rotary device 1, to avoid the problem that when the hydraulic system fails, the pressure in the closed hydrostatic rotary device 1 drops rapidly, and the rotating structure in the closed hydrostatic rotary device 1 cannot stop immediately due to inertia, causing wear and damage.

[0033] Although the above scheme solves the problem of instantaneous failure of the hydraulic device when the oil outlet pump 40 stops running due to a fault, it cannot ensure that the device continues to operate normally. For this purpose, the following improvement scheme is provided: the return oil pump 45 in this case is a two-way liquid pump, and the pressure reducing valve 33 is a pressure reducing valve that allows reverse flow. During reverse flow, the pressure reducing valve 33 may not have the pressure reducing function, and the return oil pump 45 acts as a normal oil return function when operating in the forward direction; when the hydraulic system is operating normally, once the oil outlet pump 40 stops operating due to a fault, the return oil pump 45 is controlled to operate in the reverse direction, and the liquid in the return oil pipe connected to the return oil pump 45 flows in the reverse direction and continuously draws the hydraulic oil in the oil tank 70 and presses it into the closed hydrostatic rotary device 1 through the hydraulic system return oil end 30. At the same time, the overflow valve 47 continuously overflows the over-pressure hydraulic oil to ensure that a certain hydraulic pressure and flow are still maintained in the closed hydrostatic rotary device 1, thereby maintaining the normal operation of the system. If the overflow pressure of the overflow valve a 47 is too large, the following method can also be adopted: once the oil delivery pump 40 stops running due to a fault, the return oil pump 45 is immediately controlled to run alternately in forward and reverse directions periodically, so that the hydraulic accumulator 34 follows and performs release and energy storage actions periodically, and the overflow valve a 47 does not overflow, ensuring that a certain hydraulic pressure and flow are still maintained in the closed hydrostatic rotary device, thereby maintaining temporary normal operation of the system for a short period of time.

[0034] The above are only preferred embodiments of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A hydraulic system of a closed hydraulic rotary device, characterized in that: A closed type hydrostatic rotary device (1) and a hydraulic oil supply system, wherein an oil inlet pipe and an oil outlet pipe of the closed type hydrostatic rotary device (1) are connected to an oil outlet end (29) of the hydraulic oil supply system and an oil return end (30) of the hydraulic system respectively; The hydraulic oil supply system comprises an oil tank (70); an oil supply oil circuit of the hydraulic oil supply system from the oil tank (70) to the oil outlet end (29) comprises an oil outlet pump (40), a one-way valve (36), a solenoid valve (35), and a pressure reducing valve (33) in sequence; and an oil return oil circuit of the hydraulic oil supply system comprises an oil return pump (45); The oil inlet end of the oil outlet pump (40) is connected to the oil tank (70), the oil outlet end is connected to the oil inlet end of the one-way valve (36), the oil outlet end of the one-way valve (36) is connected to the oil inlet end of the solenoid valve (35), the oil outlet end of the solenoid valve (35) is connected to the oil inlet end of the pressure reducing valve (33), and the oil outlet end of the pressure reducing valve (33) is the oil outlet end (29) of the hydraulic oil supply system; It also includes a cooling circulation pipe (93), the cooling circulation pipe (93) includes an oil cooler (92) and a cooling circulation pump (91) connected in series, and the oil inlet end and the oil outlet end of the cooling circulation pipe (93) are both connected to the oil tank (70); The invention also comprises a hydraulic accumulator (34), a safety valve assembly (25), a pressure relay (28) and a pressure relay (31). The pressure end of the hydraulic accumulator (34) is connected to the oil pipe between the solenoid valve (35) and the one-way valve (36) through a pressure pipe (100). The pressure end of the pressure relay (28) is connected to the pressure pipe (100) through a bypass connection. The pressure end of the pressure relay (31) is connected to the oil pipe connected to the oil outlet end of the pressure reducing valve (33) through a bypass connection. The pressure relay (28) is connected to the solenoid valve (35) through a linkage control connection. The pressure relay b (31) is connected to the oil return pump (45) in a linkage control manner; the safety valve assembly (25) comprises a ball valve a (49), a ball valve b (48) and an overflow valve a (47); the ball valve a (49) is connected in series to the pressure pipe (100) and is initially in an open state; the oil inlet end of the overflow valve a (47) is bypass-connected between the ball valve a (49) and the pressure end of the hydraulic accumulator (34); the oil outlet end of the overflow valve a (47) is connected to the oil tank (70); the ball valve b (48) which is initially closed is connected in parallel to the overflow valve a (47); The invention also comprises a b overflow valve (44) and a c overflow valve (37), wherein the b overflow valve (44) is connected in parallel with the oil return pump (45); the oil inlet end of the c overflow valve (37) is connected to the oil inlet end of the check valve (36), and the oil outlet end is connected to the oil tank (70); the invention also comprises an a pressure gauge (46) capable of detecting the pressure at the oil inlet end of the a overflow valve (47), a b pressure gauge (38) capable of detecting the pressure at the oil inlet end of the check valve (36), and a c pressure gauge (32) capable of detecting the pressure at the oil outlet end of the pressure reducing valve (33); and a temperature sensor (42) is arranged in the oil tank (70).

2. The hydraulic system of a closed hydraulic rotary device according to claim 1, characterized in that: The bottom of the oil tank (70) is connected to an oil drain ball valve (41) which is initially closed.

3. A working method of a hydraulic system of a closed hydraulic rotary device according to claim 2: In the initial state, the solenoid valve (35) and the return oil pump (45) are both closed, and the oil delivery pump (40) is started. Under the drive of the oil delivery pump (40), the hydraulic oil in the oil tank (70) passes through the oil delivery pump (40), the oil line filter (39) and the one-way valve (36) in sequence. The hydraulic oil flowing out of the one-way valve (36) is gradually pressed into the hydraulic accumulator (34) through the pressure pipe (100), so that the hydraulic accumulator (34) is gradually charged. When the pressure at the pressure end of the a pressure relay (28) rises to P1, the a pressure relay (28) is linked to control the solenoid valve (35) to open, and then the hydraulic oil passes through the solenoid valve (35) and the pressure reducing valve ( 33) is pressed into the closed static pressure rotary device (1), and after the pressure at the pressure end of the b pressure relay (31) rises to a value exceeding P2, the b pressure relay (31) is linked to control the return oil pump (45) to operate, and the pumping oil flow of the return oil pump (45) is kept consistent with the pumping oil flow of the oil outlet pump (40), so that the hydraulic oil in the oil passage hole system, the oil film layer and the oil storage tank in the closed static pressure rotary device (1) is continuously discharged on the basis of maintaining the stability of the pressure in the oil passage hole system, the oil film layer and the oil storage tank in the closed static pressure rotary device (1), thereby achieving the purpose of continuously cooling and discharging the heat in the closed static pressure rotary device (1); When the temperature sensor (42) senses that the temperature in the oil tank (70) has risen to a threshold value, the cooling circulation pump (91) is turned on to cool the hydraulic oil in the oil tank (70).

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