CN106761760A - The power shovel lifting system of electro-hydraulic combination drive - Google Patents

Abstract

The electric shovel lifting system driven by electro-hydraulic hybrid belongs to the field of large-scale equipment for open-pit mining. DC/DC converter, super capacitor bank; DC/DC converter is connected to the DC bus of the hoisting motor inverter, the DC/DC converter is connected to the super capacitor bank, and the hydraulic pump/motor is placed between the reducer and the hoisting motor The oil port of the output end of any drive shaft is connected with the accumulator group. The invention can store the electric energy generated by the lifting motor when the electric shovel bucket falls in the supercapacitor group, reduces the peak current of the electric shovel motor and improves its working stability. At the same time, the gravitational potential energy of the electric shovel bucket during the falling process is converted into hydraulic energy and stored in the accumulator group. When the bucket is lifted, the energy will be effectively used to assist the motor to work, reducing the installed power of the electric shovel lifting motor. The working efficiency of the electric shovel is improved.

Description

Electric shovel lifting system driven by electro-hydraulic hybrid

technical field

The invention belongs to the field of large-scale equipment for open-pit mining, and in particular relates to an electric shovel lifting system driven by electro-hydraulic mixing.

Background technique

With the rapid development of the national economy, my country's energy industry, especially the development of the coal industry, has encountered bottlenecks. How to achieve coal mining and transportation with high efficiency and energy saving has become the theme of the current development of the coal industry. The electric shovel (also known as large-scale mining machinery front shovel excavator) has a large bucket capacity, a wide range of operations, strong environmental adaptability, can withstand large vibration and impact loads, high working reliability, and low maintenance costs. It is one of the main equipments in large-scale open-pit coal mines, iron ore and non-ferrous metal mine stripping and mineral mining operations. In the intermittent mining process and semi-continuous mining process system of open-pit mines, the electric shovel is an indispensable key mining equipment. However, with the rapid development of foreign mining technology, my country's mining industry is facing a severe test. How to effectively improve the production efficiency of open-pit mining in a clean and green way while reducing production costs has become an urgent problem for the current coal industry. The problem.

The Chinese Invention Patent Publication No. CN105089087 published by the National Patent Office in 2015, a lifting system for electric shovels, discloses a new type of lifting system for electric shovels. The reel is reversed to drive the internal motor to rotate to generate electricity, and after rectification and inversion, it is fed back to the grid or other electrical equipment. However, since the electric shovel will randomly feed power to the grid during its movement, and the peak current of the lifting device is still very large, it will cause a large current impact and harmonic interference to the grid, which affects the working stability and reliability of the electric shovel.

Similarly, a Chinese invention patent published by the National Patent Office in 2015, a mining excavator lifting mechanism, publication number: CN104555774A, discloses a transmission device for a new type of mining excavator lifting mechanism, which optimizes the lifting mechanism. structure, starting from reducing the self-weight of the lifting mechanism to achieve the purpose of energy saving and emission reduction, but although the weight reduction can reduce part of the energy consumption, it does not make full use of the electric energy generated by the electric shovel lifting device.

The above two energy-saving methods do not reduce the installed power and peak current of the electric shovel hoisting motor, nor do they fully utilize the potential energy during the descent of the electric shovel.

Contents of the invention

In order to save electric energy, improve the production efficiency of the electric shovel, and reduce the use cost of the electric shovel, the invention designs an electric shovel lifting system driven by an electro-hydraulic hybrid drive.

The technical solution of the present invention: electric shovel lifting system driven by electro-hydraulic hybrid drive, is characterized in that a hydraulic pump/motor is added to the existing electric shovel lifting system, and the hydraulic pump/motor is placed in any position between the lifting motor and the reducer. The output end of the transmission shaft, its oil port is connected with the accumulator group, the potential energy of the falling bucket is converted into hydraulic energy and stored in the accumulator group, when the hydraulic pump/motor is in the working state of the hydraulic pump, the oil is sucked into the accumulator Among the accumulator group; when the hydraulic pump/motor is in the working state of the motor, the accumulator group can release energy to drive the hydraulic pump/motor to work; the DC bus of the hoisting motor inverter is connected to the DC/DC converter, and the DC/DC conversion The inverter is connected with the supercapacitor bank to store the electric energy generated when the electric motor is powered up.

When the electric shovel bucket falls, the hoisting motor is in the power generation state, the DC bus voltage in the frequency converter rises, and after passing through the DC/DC converter, it charges the super capacitor bank. At the same time, the hydraulic pump/motor is in the pumping state, and the The oil is sucked into the accumulator group, and the gravitational potential energy of the falling bucket is converted into hydraulic energy and stored in the accumulator group.

When the electric shovel bucket is lifted, the hoisting motor is in the electric state, and the DC bus voltage in the inverter will not increase. After the supercapacitor bank passes through the DC/DC converter, it provides electric energy for the hoisting motor to assist its work. At the same time, the hydraulic pressure The pump/motor is in the working state of the motor, releasing the hydraulic energy stored in the accumulator group when falling, driving the motor to work, and assisting the lifting motor to work.

When the auxiliary work of the accumulator group is not needed, adjust the swing angle of the hydraulic pump/motor to zero, that is, the displacement of the hydraulic pump/motor is zero. At this time, the hydraulic pump/motor is idling, which increases the damping for the lifting motor and improves the lifting capacity. The stability of the electric shovel lifting system.

The existing electric shovel lifting system includes a bucket, a lifting drum, a reducer, a lifting motor, a high-pressure accumulator group, an overflow valve, a low-pressure accumulator group, a pressure sensor, a check valve, a charge pump, and a charge pump motor , frequency converter.

The electro-hydraulic hybrid driving electric shovel lifting mechanism of the present invention has the following advantages:

The electric energy generated by the lifting motor when the electric shovel bucket is falling is stored in the supercapacitor group, which reduces the peak current of the electric shovel motor and improves its working stability. At the same time, the gravitational potential energy of the electric shovel bucket during the falling process is converted into hydraulic energy and stored in the accumulator group. When the bucket is lifted, this energy will be effectively used to assist the motor to work, reducing the installed power of the electric shovel lifting motor. The working efficiency is improved, and the purpose of environmental protection is achieved, and the working reliability and stability of the electric shovel are also improved.

Description of drawings

Fig. 1 is the structural representation of embodiment 1 of the present invention;

Fig. 2 is a diagram of the hydraulic control system of Embodiment 2 of the present invention, which only contains one group of accumulators and has a pressurized oil tank.

Fig. 3 is a hydraulic control system diagram of Embodiment 3 of the present invention, including a proportional valve group composed of four two-position two-way proportional reversing valves.

In the figure: 1. Bucket; 2: Hoist drum; 3: Reducer; 4: Hoist motor; 5: Hydraulic pump/motor; 6: High pressure accumulator group; 7: I relief valve; 8: Low pressure Accumulator group; 9: Relief valve II; 10: Pressure sensor; 11: Check valve, 12: Charge pump; 13: Charge pump motor; 14: Frequency converter; 15: DC/DC converter; 16: Supercapacitor group; 17: accumulator group; 18: relief valve; 19: two-position two-way electromagnetic reversing valve; 20: pressurized oil tank; 21: two-position two-way proportional reversing valve group.

detailed description

Embodiment 1: As shown in Figure 1, the electric shovel lifting system driven by electro-hydraulic hybrid includes a bucket 1, a lifting reel 2, a reducer 3, a lifting motor 4, a hydraulic pump/motor 5, a high-pressure accumulator group 6, a I relief valve 7, low-pressure accumulator group 8, second relief valve 9, pressure sensor 10, check valve 11, charge pump 12, charge pump motor 13, frequency converter 14, DC/DC converter 15, super Capacitor bank 16. The hydraulic pump/motor 5 is placed on the output shaft of any transmission shaft between the reducer and the motor, as shown in Figure 1, the outline drawing of the hydraulic pump/motor drawn by the dotted line indicates the position where the hydraulic pump/motor 5 can be placed, if The hydraulic pump/motor is directly connected with the hoisting motor 4, and the hoisting motor 4 is a double output shaft motor. The DC/DC converter 15 is connected to the DC bus of the hoisting motor 4 frequency converter 14, and the DC/DC converter 15 is connected to the supercapacitor bank 16; The low-pressure accumulator group 8 is connected with the first relief valve 7, and its oil discharge port is connected with the high-pressure accumulator group 6, and the high-pressure accumulator group 6 is connected with the second relief valve 9, supplementing The oil discharge port of the oil pump 12 is connected with the one-way valve 11 .

When the electric shovel bucket is lowered, the lifting motor 4 is in the power generation state, the DC bus voltage in the frequency converter 14 rises, and the supercapacitor bank 16 is charged through the DC/DC converter 15, and at the same time, the hydraulic pump/motor 5 is in pumping operation state, the oil suction port is connected to the low-pressure accumulator group 8, and the oil discharge port is connected to the high-pressure accumulator group 6, and the oil is sucked from the low-pressure accumulator group 8 into the high-pressure accumulator group 6, and the bucket The falling gravitational potential energy is converted into hydraulic energy and stored in the high-pressure accumulator group 6. If the pressure of the low-pressure accumulator group 8 drops, the pressure sensor detects this information, and the controller controls the charge pump motor 13 to work to drive the charge pump. 12 replenish oil for the system.

When the electric shovel bucket is lifted, the lifting motor 4 is in the electric state, the DC bus voltage in the frequency converter 14 remains unchanged, the supercapacitor group 16 supplies power to the lifting motor 4 through the DC/DC converter 15, and the hydraulic pump/motor 5 is at the same time In the working state of the motor, the high-pressure accumulator group 6 releases the stored energy, drives the hydraulic pump/motor 5 to work, and assists the lifting motor 4 to work, increasing its working capacity and efficiency.

If you want to disconnect the hydraulic pump/motor 5 from the transmission shaft, you only need to adjust the swing angle of the hydraulic pump/motor to zero, that is, the flow rate is zero. At this time, the hydraulic pump/motor is idling, and the damping of the lifting motor is increased. Improved system stability.

Explanation: The hydraulic pump/motor 5 of this embodiment can be a one-way pump/motor, or a two-way pump/motor, and multiple sets of pumps/motors can be used in parallel.

Embodiment 2: As shown in Figure 2, the working principle of this embodiment is similar to that of Embodiment 1, and the difference is that the charging pump 12, the charging pump motor 13, the high-pressure accumulator group 6 and the first overflow valve 7, the low-pressure accumulator The energy device group 8 and the second relief valve 9 are added, and the two-position two-way electromagnetic reversing valve 19 and the pressurized oil tank 20 are added.

When the electric shovel bucket falls, the lifting motor 4 is in the power generation state, the DC bus voltage in the frequency converter 14 rises, and the supercapacitor group 16 is charged through the DC/DC converter 15, and at the same time, the hydraulic pump/motor 5 is in pumping operation state, the oil suction port is connected to the one-way valve 11, and the oil discharge port is connected to the accumulator group 17 to store energy for the accumulator group 17, and convert the gravitational potential energy of the bucket into hydraulic energy and store it in the accumulator group 17 , this moment, the electromagnet of electromagnetic reversing valve 19 must not be electrified.

When the electric shovel bucket is lifted, the hoisting motor 4 is in the electric state, the DC bus voltage in the frequency converter 14 remains unchanged, and the stored electric energy is supplied by the supercapacitor group 16 to the hoisting motor 4 through the DC/DC converter 15, while the hydraulic pump The /motor 5 is in the working state of the motor, the electromagnet 19 of the electromagnetic reversing valve is energized, the accumulator group 17 releases the stored energy, drives the hydraulic pump/motor 5 to work, and the auxiliary lifting motor 4 works.

Embodiment 3: As shown in Figure 3, the working principle of this embodiment is similar to that of Embodiment 1, and the difference is that the charging pump 12, the charging pump motor 13, the high-pressure accumulator group 6 and the first overflow valve 7, the low-pressure accumulator The energy device group 8 and the second relief valve 9 add a proportional reversing valve group 21 composed of four two-position two-way proportional reversing valves, and the two two-position two-way proportional reversing valves connected to the P port It is in the normally closed state, and the two two-position two-way proportional directional valves connected to the T port are in the normally open state. By adjusting the throttle opening of any two-position two-way proportional directional valve, the hydraulic pump/motor can be controlled. Speed regulation, while increasing system damping, improves system stability.

Claims (6)

1. the power shovel lifting system of electro-hydraulic combination drive, it is characterized in that：Including scraper bowl, hoisting drum, decelerator, lifting motor, Hydraulic pump/motor, accumulator group, overflow valve, frequency converter, DC/DC converters, super capacitor group；Lifting motor frequency converter it is straight DC/DC converters are connected on stream bus, DC/DC converters are connected with super capacitor group；Hydraulic pump/motor is placed in lifting motor The output end of any power transmission shaft between decelerator.

2. the power shovel lifting system of electro-hydraulic combination drive according to claim 1, it is characterized in that：The accumulator group difference It is high pressure accumulator group, low pressure accumulator group, low pressure accumulator group is connected with the inlet port of hydraulic pump/motor, high pressure accumulator Group is connected with the oil discharge outlet of hydraulic pump/motor；Slippage pump is connected by check valve with hydraulic pump/motor, and slippage pump is by slippage pump Motor drives.

3. the power shovel lifting system of electro-hydraulic combination drive according to claim 2, it is characterized in that：When power shovel scraper bowl declines When, lifting motor is in generating state, and the DC bus-bar voltage in frequency converter is raised, and is super capacitor by DC/DC converters Group charges, meanwhile, hydraulic pump/motor is in pump work state, and its inlet port is connected with low pressure accumulator group, oil discharge outlet and high pressure Accumulator group is connected, and fluid is drawn into high pressure accumulator group from low pressure accumulator group, the gravitional force that scraper bowl is fallen Hydraulic energy is converted into be stored in high pressure accumulator group；When pressure sensor detects the reduction of low pressure accumulator group pressure, pass through Controller control repairing pump motor work, drives slippage pump repairing；When power shovel scraper bowl is lifted, lifting motor is in electronic shape State, the DC bus-bar voltage in frequency converter is constant, super capacitor group by DC/DC converters for lifting motor is powered, while liquid Pressure pump/motor is in operation status of motor, the energy release that high pressure accumulator group will be stored, and drives hydraulic pump/motor work, auxiliary Lifting motor is helped to work；If disconnecting the connection of hydraulic pump/motor and lifting motor, only need to be by the pivot angle of hydraulic pump/motor Zero degree is adjusted, now, hydraulic pump/motor idle running, discharge capacity is zero, increased the damping of lifting motor, improves the steady of system It is qualitative.

4. the power shovel lifting system of electro-hydraulic combination drive according to claim 1, it is characterized in that：The hydraulic pump/motor A hydraulic fluid port connected by check valve, solenoid directional control valve and pressurized reservoir, its another hydraulic fluid port is connected with accumulator group.

5. the power shovel lifting system of electro-hydraulic combination drive according to claim 4, it is characterized in that：When power shovel scraper bowl falls When, lifting motor is in generating state, and the DC bus-bar voltage in frequency converter is raised, and is super capacitor by DC/DC converters Group charges, meanwhile, hydraulic pump/motor is in pump work state, is that accumulator group stores by fluid from pressurized reservoir through check valve Can, by the transform gravitational energy of scraper bowl for hydraulic energy is stored in accumulator group, now solenoid directional control valve electromagnet must not electricity；When When power shovel scraper bowl is lifted, lifting motor is in motoring condition, and the DC bus-bar voltage in frequency converter is constant, and super capacitor group passes through DC/DC converters are powered for lifting motor, while hydraulic pump/motor is in operation status of motor, the energy that accumulator group will be stored Amount release, drives hydraulic pump/motor work, the work of service hoisting motor.

6. according to the power shovel lifting system of the electro-hydraulic combination drive described in any 1 of claim 1 ~ 5, it is characterized in that：Hydraulic pump/ Motor for it is following any one：

（1）Unidirectional pump/motor；

（2）Two-way pump/motor；

（3）One group of hydraulic pump/motor；

（4）Multigroup hydraulic pump/motor is in parallel.