Suspension and movement system of operating element of mining mill

Abstract

FIELD: mining.SUBSTANCE: invention which can be used to mechanize cleaning and preparatory work during underground mining of coal and other embedded minerals. The suspension and movement system of the operating element of the mining combine consists of a rotary gearbox, pivotally mounted on the body of the mining combine, a hydraulic jack located between the body of the combine and the rotary gearbox, an executive body mounted on the output shaft of the rotary gearbox, as well as a hydraulic power drive including a high-pressure plunger pump for feeding working fluid into the piston and rod cavities of the hydraulic jack along the discharge line, equipped with a hydraulic unit with controlled hydraulic locks for locking the piston and rod cavities of the hydraulic jack and safety valves for protecting the cavities of the hydraulic jack from overloads. The hydraulic power drive is equipped with an auxiliary low-pressure pump for feeding the plunger pump, hydraulically connected by an additional discharge line, connected to the discharge line safety valve, with the piston and rod cavities of the hydraulic jack through check valves installed on it.EFFECT: effective damping of the amplitude and frequency of oscillations of the operating element relative to the face, an increase in the efficiency of rock mass destruction, and an increase in the reliability and service life of the mining machine.5 cl, 2 dwg

Description

[0001] The invention relates to mining and can be used to mechanize cleaning and preparatory work in underground mining of coal and other bedded minerals.

[0002] Systems are known for suspending and moving the executive bodies of mining combines in the form of augers or drums with a horizontal axis of rotation, including rotary cutting blocks, pivotally connected to the body of the combine and a hydraulic drive for adjusting the position of the executive body based on hydraulic jacks, the working fluid to which is supplied from hydraulic pumps, while the hydraulic jacks are located between the body of the combine and the rotary blocks.

[0003] Such combines include domestic cleaning combines of the early period of creation: 1K101U, 1GSh68, RKU13 (60-70s of the 20th century), as well as modern combines UKD400, KDK400, KDK500 (2000-2010). Despite some differences in the layout schemes, the presence of a hydraulic drive with hydraulic jacks is common to all suspension systems (Mining machines for underground coal mining: A textbook for universities / P.A. Gorbatov, G.V. Petrushkin, N.M. Lysenko et al. - Donetsk: Nord Computer, 2006. - pp. 241-249).

[0004] It should be noted that actual hydraulic fluid, in the form of oils, supplied to hydraulic jacks contains undissolved air (in the form of bubbles), which, at the appropriate percentage, significantly reduces the bulk modulus of the two-phase working fluid. Therefore, hydraulic jacks in suspension systems can be considered a kind of hydraulic spring, due to the compressibility of the actual working fluid trapped within their cavities.

[0005] It is the compressibility of the working fluid that leads to the main drawback of the suspension systems under consideration: significant vibrations of the actuator during the destruction of the rock mass, commensurate with the cutting depth.

[0006] The suspension and movement system for the cutting unit of a shearer, described in the above-mentioned source, was chosen as a prototype. The system is represented by a general view of the shearer (p. 244) and a hydraulic diagram (p. 248).

[0007] The suspension and movement system of the executive body of the mining (cleaning) combine consists of a rotary gearbox, pivotally mounted on the body of the mining combine, a hydraulic jack located between the body of the combine and the rotary gearbox, an executive body mounted on the output shaft of the rotary gearbox, as well as a hydraulic power drive that includes a high-pressure plunger pump for supplying working fluid to the piston and rod cavities of the hydraulic jack, equipped with a hydraulic unit with controlled hydraulic locks for locking the piston and rod cavities of the hydraulic jack and safety valves for protecting the cavities of the hydraulic jack from overloads.

[0008] The main drawback of the prototype, as well as of its analogues, is caused by the ability of the working fluid, locked in the cavities of the hydraulic jack, to compress and spring under the influence of loads, which causes increased vibrations of the executive bodies relative to the destroyed face, leading to a significant deterioration in the cutting mode of the mineral, its over-crushing, increased failure of cutters, an increase in dynamic loads on the executive bodies and rotary gearboxes, as well as a significant decrease in the reliability and service life of the entire mining machine.

[0009] The invention is based on the task of, in the suspension and movement system of the executive body of a mining combine, by changing the design, ensuring:

[0010] - effective reduction (damping) of the amplitude and frequency of oscillations of the executive body relative to the face during the destruction of the rock mass by increasing the modulus of bulk elasticity of the working fluid locked in the piston and rod cavities of the hydraulic jack;

[0011] - increasing the efficiency of rock mass destruction by reducing the consumption of cutting tools, increasing the reliability and service life of the mining machine by reducing dynamic loads on the working element.

[0012] The problem is solved as follows.

[0013] In the suspension and movement system of the executive body of a mining combine, consisting of a rotary gearbox, pivotally mounted on the body of the mining combine, a hydraulic jack located between the body of the combine and the rotary gearbox, an executive body mounted on the output shaft of the rotary gearbox, as well as a power hydraulic drive, including a high-pressure plunger pump for feeding working fluid into the piston and rod cavities of the hydraulic jack, equipped with a hydraulic unit with controlled hydraulic locks, for locking the piston and rod cavities of the hydraulic jack and safety valves for protecting the cavities of the hydraulic jack from overloads, according to the invention, the power hydraulic drive is equipped with an auxiliary low-pressure pump for feeding the plunger pump, while additional lines for pumping working fluid from the auxiliary low-pressure pump are connected to the piston and rod cavities of the hydraulic jack,and check valves are installed in each additional line.

[0014] The stated problem is also solved in cases where:

[0015] - the executive body of the mining combine is made in the form of a screw conveyor of a cleaning combine;

[0016] - the executive body of the mining combine is made in the form of the cutting body of a tunneling combine;

[0017] - the cutting element of the roadheader is made in the form of a cutting drum;

[0018] - the cutting element of the tunnel boring machine is made in the form of a longitudinal-axial or transverse-axial cutting crown.

[0019] The essence of the invention is explained by the drawings. Fig. 1 shows a general view of the mechanical part of the suspension system and the movement of the working element of a mining combine, using a shearer as an example. Fig. 2 shows a hydraulic diagram of the suspension system and the movement of the working element of a mining combine.

[0020] Since mining combines include both cutting machines and tunneling machines, the operating units of which have similar suspension and movement systems, and operate under similar conditions of loads from the destruction of the face, this technical solution, presented using the example of a cutting machine, can also be used in tunneling machines with various operating units (with a cutter drum or cutter crowns, both longitudinal-axial and transverse-axial).

[0021] The suspension and movement system of the working element of the mining combine consists of a rotary gearbox 1, pivotally mounted on the housing 2 of the mining combine, and an working element 3, installed on the output shaft of the gearbox 1. Between the housing of the combine 2 and the rotary gearbox 1, a hydraulic jack 4 is located, providing adjustment of the position of the working element 3. The housing of the hydraulic jack 4 is equipped with a hydraulic unit 5 with controlled hydraulic locks 6 for locking the piston and rod cavities of the hydraulic jack 4 at a fixed position of the working element, and safety valves 7 for protecting the cavities of the hydraulic jack 4 from overloads. Adjustment of the position of the working element 3 is provided by means of a power hydraulic drive 8, including a plunger pump 9 of high pressure and an auxiliary pump 10 of low pressure. Various types of pumps, such as gear or vane pumps, can be used as low pressure auxiliary pumps.

[0022] The high-pressure plunger pump 9 is hydraulically connected to the piston and rod cavities of the hydraulic jack 4 through the control unit 11, the hydraulic unit 5 with the controlled hydraulic locks 6. The low-pressure auxiliary pump 10 is also hydraulically connected to the piston and rod cavities of the hydraulic jack 4 by an additional discharge line 12, connected to the safety valve 13 and equipped with check valves 14.

[0023] The technical result is achieved as follows.

[0024] The working fluid from the high-pressure plunger pump 9 is supplied through the control unit 11 to the hydraulic unit 5 and then, through the controlled hydraulic locks 6, to the piston and rod cavities of the hydraulic jack 4. In addition, from the low-pressure auxiliary pump 10, the working fluid is continuously supplied to the same cavities through the additional discharge line 12 with a pressure determined by the setting of the safety valve 13. The outflow of the working fluid from the piston and rod cavities of the hydraulic jack 4 into the additional discharge line 12 and its flow between the cavities are excluded by check valves 14 built into the hydraulic unit 5 of the hydraulic jack 4.

[0025] After the actuator 3 is set by the hydraulic jack 4 in a given fixed position and the pressure in the lines of the controlled hydraulic locks 6 is disconnected, the piston and rod cavities are self-locking. In this case, the pressure in the piston cavity of the hydraulic jack, determined by the mass of the actuator and the rotary gearbox, as well as the piston area, is very insignificant - (0.3 - 0.5 MPa). From literary sources (Kovalevsky V.F., Zheleznyakov N.T., Beilin Yu.E. Handbook of hydraulic drives of mining machines. M. Nedra. 1973. pp. 84-86) it is known that a real working fluid containing undissolved air (on average up to 6%) has a bulk modulus of elasticity significantly less than the bulk modulus of elasticity of a degassed working fluid.At pressures up to 10 MPa, the volumes of liquid locked in the piston and rod cavities of the hydraulic jack act as unique gas-hydraulic springs, which, under highly dynamic loads, allow the actuator to vibrate to an extent exceeding the cutting depth, which significantly worsens the destruction mode of the rock mass.

[0026] A sharp displacement from impact loads of the actuator 3 in any direction leads to a sudden increase (spike) in pressure in one of the cavities of the hydraulic jack 4 and an adequate drop in pressure (vacuum) in the opposite cavity.

[0027] Low pressure pump 10, constantly supplying working fluid through additional discharge line 12 into the piston and rod cavities of hydraulic jack 4, with the setting pressure of safety valve 13 equal to 3.5-5 MPa, provides a significant increase in the bulk elastic modulus of the compressed fluid, leading to an effective reduction in the amplitude of oscillations of the actuator 3.

[0028] At the same time, the presence of liquid constantly supplied at a certain pressure to the relaxation zones in the piston and rod cavities will ensure the braking of the oscillatory process in the hydraulic jack 4 and the reduction of dynamic loads in the suspension system and the combine as a whole.

[0029] The implementation of the invention will allow for the effective damping of the amplitude and frequency of oscillations of the operating element relative to the face, which will ensure an increase in the efficiency of rock mass destruction by reducing the consumption of the cutting tool, increasing the reliability and service life of the mining machine by reducing the dynamic loads on the operating element.

Claims

1. A suspension and movement system for the actuator of a mining combine, consisting of a rotary gearbox pivotally mounted on the body of the mining combine, a hydraulic jack located between the body of the combine and the rotary gearbox, an actuator mounted on the output shaft of the rotary gearbox, as well as a hydraulic power drive including a high-pressure plunger pump for feeding working fluid into the piston and rod cavities of the hydraulic jack along the discharge line, equipped with a hydraulic unit with controlled hydraulic locks for locking the piston and rod cavities of the hydraulic jack and safety valves for protecting the cavities of the hydraulic jack from overloads, characterized in that the hydraulic power drive is equipped with an auxiliary low-pressure pump for feeding the plunger pump, hydraulically connected by an additional discharge line associated with the safety valve of the discharge line,with the piston and rod cavities of the hydraulic jack through the check valves installed on it.

2. The system according to paragraph 1, characterized in that the executive element of the mining combine is made in the form of a shearer auger.

3. The system according to paragraph 1, characterized in that the executive element of the mining machine is made in the form of a cutting element of a tunneling machine.

4. The system according to paragraph 3, characterized in that the cutting element of the tunneling machine is made in the form of a cutting drum.

5. The system according to paragraph 3, characterized in that the cutting element of the tunneling machine is made in the form of a longitudinal-axial or transverse-axial cutting crown.

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