Linear layout hydraulic driving system based on topology principle

Abstract

The invention discloses a linear layout hydraulic driving system based on a topology principle, which belongs to the technical field of hydraulic driving and comprises a first hydraulic cylinder, a second hydraulic cylinder, a third hydraulic cylinder and an oil tank, the hydraulic cylinders are connected in series through a bus for oil supply, and additional driving pumps are added among the hydraulic cylinders. A driving pump and hydraulic cylinders form topological form distribution, the oil way flow direction and pressure distribution in the hydraulic system are dynamically adjusted by means of the flexibility of network topology according to the requirement of driving force, an energy transmission path can be optimized, pressure and flowing of hydraulic oil can be reasonably distributed, and the problems that a traditional pump control system is poor in dynamic performance and poor in stability are solved. According to the device, under the condition that the driving power is not increased, the maximum driving force of a single hydraulic cylinder can be improved, the driving force of each hydraulic cylinder can be finely controlled, and a hydraulic driving system is more flexible.

Description

Technical Field

[0001] The present invention relates to the field of hydraulic drive technology, and in particular to a linear layout hydraulic drive system based on topological principles. Background Art

[0002] With the development of social economy and the requirements of environmental protection, the industry has put forward higher demands on economy and energy efficiency, requiring both energy conservation and improved productivity.

[0003] The current traditional pump-controlled hydraulic system has insufficient dynamic performance and limited energy efficiency improvement. It is already a very mature industry, resulting in insufficient research and development motivation. The current hydraulic drive system is gradually unable to meet production needs, especially in multi-drive systems. The traditional pump-controlled system is a pump driving a hydraulic system, which cannot achieve fine control. As a result, no matter how large the driving force required, it relies on the same hydraulic system to drive, resulting in energy waste. Moreover, the driving force is consistent, and it can only be controlled with maximum force during design. The flow and power distribution cannot be refined, which limits the development and use of multi-drive systems.

[0004] Electro-hydraulic variable speed drive technology is a relatively advanced energy conversion and control technology. It cleverly converts the electrical energy generated by an electric motor into hydraulic energy in a hydraulic system. By precisely adjusting the speed of the hydraulic pump or motor, this technology can flexibly control the operating state of the hydraulic system, thereby achieving precise control of the hydraulic system's operating speed and position. This electronic control of the hydraulic system currently changes the way the driving force is controlled, while the drive oil circuit system remains the same.

[0005] When traditional pump control systems are used for simultaneous operation of multiple actuators, each actuator must be designed according to the two extreme working conditions of maximum torque and maximum speed, resulting in large installed power and high operating costs.

[0006] Based on this, the present invention designs a linear layout hydraulic drive system based on topological principles to solve the above problems. Summary of the Invention

[0007] The purpose of the present invention is to provide a linear layout hydraulic drive system based on topological principles. This device connects multiple hydraulic cylinders in series with a bus to supply oil, and adds an additional drive pump between each hydraulic cylinder, so that the drive pump and each hydraulic cylinder are distributed in a topological form. With the help of the flexibility of the network topology, the oil flow direction and pressure distribution in the hydraulic system are dynamically adjusted according to the demand of driving force, which can optimize the energy transmission path, reasonably distribute the pressure and flow of hydraulic oil, and solve the shortcomings of traditional pump control systems with poor dynamic performance and limited energy efficiency improvement. This device can increase the maximum driving force of a single hydraulic cylinder without increasing the driving power, and can also finely control the driving force of each hydraulic cylinder, making the hydraulic drive system more flexible.

[0008] The present invention is implemented as follows: a linear layout hydraulic drive system based on topological principles, comprising:

[0009] a first hydraulic cylinder, a second hydraulic cylinder, a third hydraulic cylinder and an oil tank;

[0010] The first hydraulic cylinder, the second hydraulic cylinder and the third hydraulic cylinder are all linear hydraulic cylinders;

[0011] The inner cavity of the first hydraulic cylinder is divided into a left cavity and a right cavity by a piston seal;

[0012] The inner cavity of the second hydraulic cylinder is divided into two left cavities and two right cavities by a piston seal;

[0013] The inner cavity of the third hydraulic cylinder is divided into three left cavities and three right cavities by a piston seal;

[0014] The left chamber and the right chamber are connected via a high-pressure hose, and a first pump is also provided between the left chamber and the right chamber;

[0015] A second pump is provided between the second right chamber and the third left chamber, and the oil passages at both ends of the second pump are sealedly connected to the second right chamber and the third left chamber respectively;

[0016] A third pump is also connected between the three left chambers and the three right chambers, and the oil pipes at both ends of the third pump are sealed and connected to the three left chambers and the three right chambers respectively through high-pressure hoses;

[0017] The oil tank is a closed box body, the inner cavity of the oil tank is connected to the oil supply pipe, and the oil supply pipe is provided with an oil supply pump;

[0018] The first left chamber, the second left chamber and the third right chamber are all connected to the oil supply pipe, and the first left chamber, the second left chamber and the third right chamber are all connected to the oil tank through the oil supply pump.

[0019] Furthermore, the first left chamber, the second left chamber and the third left chamber are all rodless chambers of the hydraulic cylinder;

[0020] The first right chamber, the second right chamber and the third right chamber are all rod chambers of the hydraulic cylinder.

[0021] Furthermore, the oil supply pipe is a high-pressure hose.

[0022] Furthermore, the first pump, the second pump, the third pump and the oil supply pump are all variable speed hydraulic metering pumps;

[0023] The first pump, the second pump, the third pump and the oil supply pump are all provided with flow meters and pressure meters.

[0024] The beneficial effects of the present invention are as follows: 1. The present invention adds multiple drive pumps, and through the distribution of the drive pumps, it is possible to flexibly adjust the flow direction of the hydraulic oil between the various chambers of the hydraulic cylinder, and thus flexibly adjust the direction and position of the driving force, so that the hydraulic drive system can reasonably distribute the flow, improve the coordination of compound actions, reduce the energy caused, and improve the energy efficiency of the system under the same power;

[0025] 2. The driving method of this system can reduce the demand for the maximum driving force of each pump and the hydraulic system as a whole to a certain extent, thereby making the system form a smaller energy consumption and achieve a greater driving effect. It does not add an additional hydraulic pump for driving. This driving system integrates the cavity sharing between multiple actuators to couple the actuators with each other, reducing the required drive units, and also reducing the total installed power and the number of equipment, thereby achieving the purpose of reducing costs and increasing efficiency. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0027] Figure 1 It is a schematic diagram of the overall drive system layout structure of the present invention.

[0028] In the accompanying drawings, the components represented by the reference numerals are as follows:

[0029] 1-first hydraulic cylinder, 11-first pump, 12-first left chamber, 13-first right chamber, 2-second hydraulic cylinder, 21-second pump, 22-second left chamber, 23-second right chamber, 3-third hydraulic cylinder, 31-third pump, 32-third left chamber, 33-third right chamber, 4-oil tank, 41-oil supply pump, 42-oil supply pipe. DETAILED DESCRIPTION

[0030] See also Figure 1 As shown, the present invention provides a linear layout hydraulic drive system based on topological principles. In order to better understand the above technical solution, the above technical solution will be described in detail below in conjunction with the drawings in the specification and specific implementation methods.

[0031] In a specific embodiment of the technical solution of the present invention:

[0032] It includes a first hydraulic cylinder 1, a second hydraulic cylinder 2, a third hydraulic cylinder 3 and an oil tank 4;

[0033] The first hydraulic cylinder 1, the second hydraulic cylinder 2 and the third hydraulic cylinder 3 are all linear hydraulic cylinders;

[0034] The inner cavity of the first hydraulic cylinder 1 is divided into a left cavity 12 and a right cavity 13 by a piston seal;

[0035] The inner cavity of the second hydraulic cylinder 2 is divided into two left cavities 22 and two right cavities 23 by a piston seal;

[0036] The inner cavity of the third hydraulic cylinder 3 is divided into three left cavities 32 and three right cavities 33 by a piston seal;

[0037] A left chamber 12 and a right chamber 13 are connected via a high-pressure hose, and a first pump 11 is provided between the left chamber 12 and the right chamber 13;

[0038] A second pump 21 is provided between the second right chamber 23 and the third left chamber 32, and the oil passages at both ends of the second pump 21 are sealedly connected to the second right chamber 23 and the third left chamber 32 respectively;

[0039] A third pump 31 is also connected between the third left chamber 32 and the third right chamber 33. The oil pipes at both ends of the third pump 31 are sealed and connected to the third left chamber 32 and the third right chamber 33 respectively through high-pressure hoses.

[0040] The first left chamber 12, the second left chamber 22 and the third left chamber 32 are all rodless chambers of the hydraulic cylinder;

[0041] The first right chamber 13, the second right chamber 23 and the third right chamber 33 are all rod chambers of the hydraulic cylinder.

[0042] The first pump 11, the second pump 21, the third pump 31 and the oil supply pump 41 are all variable speed hydraulic metering pumps;

[0043] Flow meters and pressure gauges are installed on the first, second, and third pumps 11, 21, 31, and oil supply pump 41. Controlled by a controller, the entire system achieves automated control of the oil circuit. This controller can be a standard oil circuit controller; simply setting the oil flow direction and the hydraulic pump's drive direction achieves the desired driving force. The variable-speed hydraulic metering pump also compensates for the additional flow demand caused by the differential cylinder area difference, maintaining overall system flow balance.

[0044] The oil tank 4 is a closed box body, and the inner cavity of the oil tank 4 is connected to the oil supply pipe 42, which is a high-pressure hose. The oil supply pump 41 is provided on the oil supply pipe 42; this device does not use any valves at all, and only uses the control software system of the hydraulic pump. It is a commonly used device for hydraulic equipment, especially three-arm cranes, excavators, etc. The software system and oil circuit control system on such equipment can control this oil circuit system.

[0045] The first left chamber 12 , the second left chamber 22 and the third right chamber 33 are all connected to the oil supply pipe 42 , and the first left chamber 12 , the second left chamber 22 and the third right chamber 33 are all connected to the oil tank 4 through the oil supply pump 41 .

[0046] It should be noted that:

[0047] 1. Transmission drive mode: Each hydraulic cylinder requires a separate oil pump to drive it, and they do not interfere with each other, so as to achieve the purpose of fine control of the individual hydraulic cylinders. The entire device is only the drive system. As for the oil circuit control system, other software is required for coordinated control. This system only proposes a drive distribution to enable the system to achieve better drive strength and obtain greater driving force with less total power;

[0048] 2. There is also a large-power hydraulic equipment to drive multiple hydraulic cylinders. This large hydraulic cylinder is too large in size, consumes too much energy, and has limited installation space and use environment. This system only installs the first pump 11, the second pump 21, and the third pump 31 in a topologically distributed manner between the first hydraulic cylinder 1, the second hydraulic cylinder 2, the third hydraulic cylinder 3 and the oil tank 4, and forms a special connection layout through pipelines. Multiple small hydraulic cylinders are used to achieve the function of a large hydraulic cylinder. Each hydraulic cylinder can also be used separately, and the topological distribution can be used to achieve flexible driving of each hydraulic cylinder. All hydraulic cylinders can also be driven synchronously. The three oil pumps can simultaneously drive a single hydraulic cylinder in an integrated manner to maximize the driving force. The three oil pumps can also drive their respective hydraulic cylinders separately to achieve independent control of the driving force, which is very flexible to use.

[0049] 3. This device does not utilize any valves. Traditional hydraulic systems typically use valve-controlled systems. However, since valves are required to adjust flow and pressure, this regulation method results in significant throttling and overflow losses, wasting significant energy and leading to low energy efficiency, typically below 40%. This system utilizes a hydraulic pump entirely to control the driving force and adjust the direction, eliminating the need for additional valve control. Instead, the oil supply pump 41 compensates for the reverse oil pressure difference, achieving hydraulic balance and compensation.

[0050] 4. Traditional pump control technologies mainly include single-pump-controlled differential cylinders and dual-pump-controlled hydraulic cylinders. The single-pump-controlled differential cylinder solution has a simple structure and requires additional auxiliary circuits and components to balance the flow difference. However, it cannot control the pressure in the non-driving chamber, causing the low-pressure chamber to approach the pressure in the oil tank. The overall drive stiffness of the system is low and the dynamic characteristics are poor. The dual-hydraulic pump-controlled differential cylinder solution relies on setting the displacement ratio of the two pumps to balance the flow difference. The servo motor series and parallel drive dual hydraulic pump solution also has the above problems due to its single degree of control freedom. In addition, the pump control of both is only suitable for single actuator scenarios. This device forms multiple pumps in a linear series mode and is controlled separately to achieve the purpose of optimizing the oil circuit system.

[0051] Application of this drive system in excavators:

[0052] Specifically, the first hydraulic cylinder 1 is the excavator's drive arm hydraulic cylinder, the second hydraulic cylinder 2 is the dipper arm hydraulic cylinder, and the third hydraulic cylinder 3 is the bucket hydraulic cylinder. The four variable speed displacement units are the first pump 11, the second pump 21, the third pump 31, and the oil supply pump 41. This drive system utilizes a bus topology to connect the various chambers.

[0053] The three cylinders are arranged in a linear topology to coordinate and control the hydraulic drive system, and can be in an extended or retracted state at the same time.

[0054] Flow direction 1 of the driving arm extension oil circuit: When all three cylinders are in the extended state, the first pump 11 sucks out the hydraulic oil from the right chamber 13 of the first hydraulic cylinder 2, and pumps the oil into the left chamber 12, the second left chamber 22 and the third right chamber 33, thereby pushing the first hydraulic cylinder 1 of the driving arm to extend and generate driving force.

[0055] The boom extends through oil circuit flow 2: at the same time, the second pump 21 pumps the oil in the second right chamber 23 into the third left chamber 32, causing the second right chamber 23 to generate negative pressure, which can cooperate with the driving force of the previous oil circuit flow 1 and achieve the purpose of driving the second hydraulic cylinder 2 to extend, making the power required for driving smaller, which is equivalent to the second left chamber 22 pushing and the second right chamber 23 sucking, and driving in the same direction to achieve the effect of coordinated driving.

[0056] Bucket extension oil flow 3: The third pump 31 extracts hydraulic oil from the third right chamber 33 and pumps it into the third left chamber 32, thereby extending the third hydraulic cylinder 3. Similarly, the third right chamber 33 is sucked by the third pump 31, forming a negative pressure, while the third left chamber 32 is pumped, forming a positive pressure, making the extension of the third hydraulic cylinder 3 more effortless. Even though the first pump 11 is also pumping into the third right chamber 33, only one-third of the pressure is pumped into the third right chamber 33. The suction force of the third pump 31 offsets the driving force of the first pump 11, and there is still a surplus. Therefore, the third right chamber 33 remains in a negative pressure state, while the third left chamber 32 receives simultaneous pumping from the second pump 21 and the third pump 31, which can form a greater positive pressure, making the extension of the third hydraulic cylinder 3 less effort.

[0057] Moreover, each pump is a fixed-displacement pump, which can control the pumping amount to change the driving force, and can control the amount of oil entering the first left chamber 12, the second left chamber 22 and the third right chamber 33 in the oil circuit of the oil supply pipe 42, so as to achieve the purpose of controlling the oil inlet direction and the pumping amount.

[0058] When in reverse motion, the pumping directions of the first, second, and third pumps 11, 21, and 31 are reversed, pumping the oil from the first left chamber 12 into the first right chamber 13, and the oil from the second left chamber 22 into the first right chamber 13 via the first left chamber 12. Alternatively, the oil from the first and second left chambers 12, 22 connected by the entire oil supply pipe 42 can be pumped into the oil tank 4. Similarly, the third pump 31 pumps the oil from the third left chamber 32 into the third right chamber 33, and the second pump 21 pumps the oil from the third left chamber 32 into the second right chamber 23, creating a shared oil system and achieving the effect of fully retracting all three cylinders.

[0059] Generally, the three hydraulic cylinders will not extend or retract in the same direction at the same time, but one will be pushed while the others will be stationary, or two hydraulic cylinders will be extended or retracted while the other one will be stationary, because it is also difficult for the operator to operate the three hydraulic cylinders at the same time.

[0060] In this way, the device achieves the effect of labor-saving, oil-sharing, coordinated driving, and high driving force with low power.

[0061] Although the specific embodiments of the present invention are described above, those skilled in the art should understand that the specific embodiments described are merely illustrative and are not intended to limit the scope of the present invention. Equivalent modifications and changes made by those skilled in the art in accordance with the spirit of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. A linear layout hydraulic drive system based on topological principles, characterized in that: include: A first hydraulic cylinder (1), a second hydraulic cylinder (2), a third hydraulic cylinder (3) and an oil tank (4); The first hydraulic cylinder (1), the second hydraulic cylinder (2) and the third hydraulic cylinder (3) are all linear hydraulic cylinders; The inner cavity of the first hydraulic cylinder (1) is divided into a left cavity (12) and a right cavity (13) by a piston seal; The inner cavity of the second hydraulic cylinder (2) is divided into two left cavities (22) and two right cavities (23) by a piston seal; The inner cavity of the third hydraulic cylinder (3) is divided into three left cavities (32) and three right cavities (33) by a piston seal; The left chamber (12) and the right chamber (13) are connected via a high-pressure hose, and a first pump (11) is also provided between the left chamber (12) and the right chamber (13); A second pump (21) is provided between the second right chamber (23) and the third left chamber (32), and the oil passages at both ends of the second pump (21) are sealed and communicated with the second right chamber (23) and the third left chamber (32) respectively; A third pump (31) is further connected between the three left chambers (32) and the three right chambers (33), and the oil pipes at both ends of the third pump (31) are sealed and communicated with the three left chambers (32) and the three right chambers (33) respectively through high-pressure hoses; The oil tank (4) is a closed box body, the inner cavity of the oil tank (4) is connected to an oil supply pipe (42), and an oil supply pump (41) is provided on the oil supply pipe (42); The first left chamber (12), the second left chamber (22) and the third right chamber (33) are all connected to the oil supply pipe (42), and the first left chamber (12), the second left chamber (22) and the third right chamber (33) are all connected to the oil tank (4) through the oil supply pump (41).

2. The linear layout hydraulic drive system based on topological principle according to claim 1, characterized in that: The first left chamber (12), the second left chamber (22) and the third left chamber (32) are all rodless chambers of the hydraulic cylinder; The first right chamber (13), the second right chamber (23) and the third right chamber (33) are all rod chambers of the hydraulic cylinder.

3. The linear layout hydraulic drive system based on topological principles according to claim 1, characterized in that: The oil supply pipe (42) is a high-pressure hose.

4. The linear layout hydraulic drive system based on topological principles according to claim 1, characterized in that: The first pump (11), the second pump (21), the third pump (31) and the oil supply pump (41) are all variable speed hydraulic metering pumps; The first pump (11), the second pump (21), the third pump (31) and the oil supply pump (41) are all provided with flow meters and pressure meters.

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