RU2451832C1 - Hydraulic diaphragm pump - Google Patents

Abstract

FIELD: mechanical engineering.

SUBSTANCE: hydraulic diaphragm pump station comprises a plunger (6) sliding in a central portion inside a cylinder (5) of the station between first and second diaphragms (4, 10) in the form of a sylphon. The ends of the plunger (6) are coupled with the first and second diaphragms (4, 10) in the form of the sylphon to form first and second annular spaces (a) respectively which are independent from each other so that fluid pressure in the first annular space (a) does not depend on fluid pressure in the second annular space (a). The station can also comprise a hydromechanical switch for switching the valve (102) for the purpose of automatic control of hydraulic fluid supply into the hydraulic cylinder during the preset moments of a running cycle of the station.

EFFECT: improved reliability of the sylphon operation.

10 cl, 5 dwg

Description

FIELD OF THE INVENTION

The invention relates to machines with a hydraulic drive, in particular to machines for pumping difficult to pump fluid materials such as minerals, ores, sludges, suspensions, solutions and gels. In this context, these pumping machines will simply be called pumps or machines.

State of the art

Conventional pumping machines that can be used to pump difficult to pump materials have moving parts such as pistons, plungers, peristaltic sleeves, etc. However, such moving bodies are subject to frictional wear, and the drive of the machine is not properly isolated from the material being pumped.

WO 2005/119063 describes a hydraulically driven multi-cylinder diaphragm pumping machine, in particular for pumping difficult to pump materials. This pumping machine comprises a plurality of pumping cylinders, each of which has one end with an inlet and an outlet for a pumped fluid and another end with an inlet and an outlet for a hydraulic fluid. These inputs and outputs can be separate inlet and outlet (for hydraulic fluid) or a combined inlet / outlet (for pumped fluid). Inputs and outputs are associated with the corresponding inlet and outlet valves.

In such a machine, the separator is located inside and can move back and forth along each pump cylinder. One side of the movable separator is facing the end of the cylinder for the pumped material, and the other is the end of the cylinder for the fluid. This movable separator is connected to the inner side of the end of the cylinder for the pumped material by a first flexible diaphragm in the form of a bellows, which can be straightened and compressed inside the cylinder in its longitudinal direction with the reciprocating motion of the separator along the cylinder. A movable separator limits the first cavity inside the flexible diaphragm by the type of bellows to enclose a variable volume of pumped fluid therein, and this cavity communicates through an inlet and outlet with a manifold and a system for the pumped fluid. The movable separator is also connected to the inner side of the second end of the cylinder by a second flexible diaphragm in the form of a bellows, which can be straightened and compressed in the longitudinal direction of the cylinder in accordance with the straightening and compression of the first flexible diaphragm. The second side of the movable separator delimits the second cavity inside the expandable and contracting diaphragm for enclosing a variable volume of hydraulic fluid therein, this second cavity communicating with the second input and output. An annular space is formed between the outer surface of the first and second diaphragms and the inner wall of the pump cylinder, which, when using the device, contains the same fluid as the hydraulic fluid, or having similar hydraulic characteristics.

This pumping machine is driven directly by a hydraulic pumping drive, which greatly simplifies the machine and provides simple means of changing and controlling the flow rate of the pumped fluid. In addition, the dual-diaphragm design provides dual protection for the fluid being pumped against the motive fluid.

Other structural details of the machine are described in WO 2005/119063, the contents of which are incorporated herein by reference.

Additional studies of such machines have shown that they can be improved in aspects such as the reliability of the diaphragm by the type of bellows.

Disclosure of invention

The objective of the invention is to improve the machine of this type or, more broadly, other machines with hydraulic drive.

In one aspect, the invention relates to an improvement of the hydraulic machine described above, in which the movable separator is made in the form of a plunger mounted to slide in the middle part inside the cylinder between the first and second diaphragms in the form of a bellows, with one end of the plunger connected to the first diaphragm in the form of a bellows and the other end of the plunger is connected to the second diaphragm in the form of a bellows to form respectively the first and second annular spaces, namely the first annular space between the outer side of the first diaphragm in the form of a bellows and the inner wall of the pump cylinder, and the second annular space between the outer side of the second diaphragm in the form of a bellows and the inner wall of the pump cylinder, while the first and second annular spaces are independent of each other, and the fluid pressure in the first annular space independent of fluid pressure in the second annular space.

Preferably, the plunger is slidably mounted in a sealing element fixed inside the middle part in the cylinder. Moreover, the first and second annular spaces are not connected to each other, and the pressure of the fluid in these two cavities can be different and independent of each other. The outer diameter of the plunger corresponds to the average working diameter of the first and second diaphragms in the form of a bellows, and the volume of the first and second spaces during operation remains essentially constant.

Thanks to the described inventive solution, the radial deformation of the diaphragms in the form of a bellows is eliminated or significantly reduced, which provides increased reliability and durability of the diaphragms.

Another aspect of the hydraulic machine described above or, in general terms, of any other hydraulic machine is that it comprises a hydraulic cylinder in which there is a component mounted for cyclic linear reciprocating movement along the hydraulic cylinder, and a valve switching means for controlling the hydraulic feed fluid into the hydraulic cylinder at predetermined moments of the operating cycle of the machine, while the means of switching the valve contain a hydromechanical switch containing connecting th mechanism for converting the linear motion of a machine component into rotational motion; cam driven by a connecting mechanism; and a spring configured to compress to accumulate energy by rotating the cam during the stroke of this component of the machine and releasing the stored energy to switch the valve to control the flow of hydraulic fluid into the hydraulic cylinder of the machine when said component reaches predetermined positions along the length of the hydraulic cylinder.

The spring can be a compression spring mounted on a rod extending from the cam in such a way that when the cam rotates the drive, the end of the spring near the cam is compressed until the spring reaches the point of unstable equilibrium, beyond which the spring releases stored energy for switching the valve. So, for example, when a spring releases stored energy, it first sharply drives the cam, and after turning a certain angle, the cam rotates the component to switch the valve. The connecting mechanism is configured to rotate the cam at an angle of less than 180 ° at each stroke of the machine component.

Through the use of a hydromechanical switch, the control of the hydraulic machine can be carried out without the need for valves with an electromagnetic actuator and electronic control, as a result of which the machine is less complex and more reliable.

The switching device also relates to a cyclic hydraulic working machine, which contains a linear motion working component and requires automatic switching of the hole connections to achieve the desired working cycle parameters, such as pressure values, cycle phase duration and others.

Other aspects and advantages of the invention are set forth in the detailed description, and specific features of the invention are reflected in the claims.

Brief Description of the Drawings

Next, with reference to the accompanying schematic drawings, exemplary embodiments of a hydraulic driven pumping machine according to the invention will be described in detail. In the drawings:

figure 1 depicts a pumping machine according to the invention in an exemplary embodiment with four cylinders,

figure 2 depicts in section a cylinder of a pumping machine according to the invention,

figure 3 depicts in perspective an internal structure of a hydromechanical switch,

4 schematically depicts a portion of a cylinder into which a hydromechanical switch is integrated,

figure 5 depicts in perspective with a breakaway connection of the spring with the cam in the hydromechanical switch according to the invention.

The implementation of the invention

The main improvement according to the invention relates to a plunger device for ensuring the separation of fluids and, as a secondary aspect, to a hydromechanical switch. It should be understood that these two aspects can be implemented in a pumping machine with a hydraulic drive individually or in combination.

Fluid separator

Shown in figure 1, the pumping machine with a hydraulic drive contains one or more cylinders 5, a switching control system 1 and a block 3 of a hydraulic drive. Typically, a machine is a multi-cylinder machine. The basic multi-cylinder hydraulic machine is described in detail in the publication WO 2005/119063 of the international application.

In order to increase the durability of the diaphragms according to the type of corrugated accordion or bellows, namely, to eliminate their radial deformation under the influence of the pressure difference created between the inner and outer cavities of the bellows, the basic machine described in WO 2005/119063 was improved as follows.

The pump cylinder 5 contains two bellows 4 and 10 (see figure 2), mechanically connected to each other by means of a plunger 6, which during the working cycle moves inside the annular sealing element 7 installed in the middle height of the cylinder 5. The combination of the plunger 6 with the sealing element 7 replaces the separator used in the solution of the prototype.

Two oil-filled cavities “a” are located outside the bellows 4 and 10 inside the cylinder 5. The plunger 6 is hydraulically sealed in the sealing element 7. This allows the cavities “a” to be independent of each other. The outer diameter of the plunger is equal to the average working diameter of the bellows. This allows you to maintain a constant volume of each of the cavities "a" during the working movement of the plunger. Because of this, the pressure values in each of the outer cavities "a" of the bellows are precisely controlled by the pressure in the corresponding internal cavity "b" or "c" of the bellows.

The pressure in the internal cavities "b" and "c" of the bellows varies between the suction and discharge cycles and depends on the operating mode of the machine. The cavity "b" is located inside the membrane 10 in the form of a bellows, and the cavity "c" inside the membrane 4 in the form of a bellows.

During each phase of the operating cycle of the machine, the pressure values in the cavities "b" and "c" are approximately equal, since the pressure of the moving cavity is transmitted to the drive cavity through the cap of the plunger 6. For example, during the suction stroke, the cavity "c" is the leading one and the cavity " with "drive; during the feed stroke, they change roles. To ensure this, the hydraulic pressure supplied to the machine must be sufficient to overcome mechanical and hydraulic resistances, since the machine does not have mechanical means to complete the suction stroke. However, a small part of the energy of the driving cavity is always consumed by the aforementioned switching device and other hydraulic and mechanical resistances, therefore, a small pressure drop occurs between these cavities “b” and “c”.

In the design of the prototype, having a single common cavity "a", this pressure differential causes the action of the cavity "a" as equalizing means, that is, the pressure in the cavity "a" becomes the average between the pressure values in the cavities "b" and "c". Accordingly, the pressure values acting on the outer and inner surfaces of each bellows are not equal, and the bellows must undergo some radial deformation for which they are not designed.

In the solution according to the invention, the pressure difference between the cavities "b" and "c" is not equalized by the cavities "a", since they are not hydraulically connected to each other. The pressure in the cavities "b" and "c" always acts on the fluid in two independent cavities "a" through the walls of the bellows. The corresponding pressure in the cavities "a" precisely compensates for this effect and independently equalizes the pressure values acting on the inner and outer surfaces of the bellows. The achieved equilibrium eliminates radial deformation and significantly increases the durability of the bellows.

During operation, the pressure in the cavities "a" rises to the minimum necessary value, which is sufficient to prevent radial deformation of the bellows wall due to the low compressibility of the fluid. This pressure does not depend on the pressure difference between the cavities "b" and "c", which affects only the upper and lower surfaces of the plunger 6.

The solution according to the invention eliminates the additional radial deformation of the bellows, which would inevitably be created in the solution of the prototype with the integrated cavity "a".

Another advantage of the solution according to the invention is the improved protection of the driving fluid from the pumped fluid and vice versa. The design of the prototype could lead to the mixing of fluids and the corresponding malfunctions in the operation of the machine in the event that two cavities in the sequence of cavities become leaky, namely the cavity "b" and the combined cavity "a". In this solution, there are two independent cavities "a", so that another cavity is added to the sequence. Due to this, triple hydraulic protection is provided instead of double.

The described pump operates as follows (see figure 2).

During the suction stroke, the internal cavity "c" of the bellows 4 is filled with pumped material from the inlet manifold 8 through the lower valve module 9. The material is pumped under low pressure (for example, from 3 to 8 bar), which causes the plunger 6 to move up. Accordingly, the bellows 4 is stretched, and the bellows 10 is compressed, which leads to the displacement of the driving hydraulic fluid from the cavity "b" in the intake manifold of the hydraulic drive system. The pressure of the pumped material in the cavity "c" on the inner surface of the bellows 4 is balanced by a corresponding increase in the pressure of the fluid in the cavity "a", which acts on the outer surface of the bellows 4. Similarly, the increase in pressure in the cavity "b" is balanced by an increase in the pressure of the fluid in the outer the cavity "a" of the bellows 10.

As soon as the suction stroke is completed, the control system 1 switches, and the driving hydraulic fluid is pumped by a hydraulic actuator under high pressure (for example, 200 bar) into the cavity “b” of the bellows 10. This causes the plunger 6 to move down and creates a feed stroke. During the feed stroke, the bellows 10 is stretched and the bellows 4 is compressed. Accordingly, as before, the pressure in the cavities “b” and “c” (which is now increasing) is balanced by the pressure (which is increasing) in the two independent cavities “a”, which prevents radial deformation of the bellows 4, 10 throughout the entire stroke filing. The compressed pumped material is displaced from the cavity “c” through the valve module 8 into the discharge manifold 11. At the end of the feed stroke, the control system 1 switches again, and the duty cycle of the machine starts again.

Thanks to the inventive solution described, the radial deformation of the diaphragms in the form of a bellows, which took place in the known solution due to the pressure difference, is eliminated or significantly reduced, which increases the reliability of the diaphragms and their resistance to loads.

Hydromechanical switch

Typically, valves with electromagnetic control and electronic control are used to control the cyclic operation of hydraulic machines and mechanisms. These multi-level, sophisticated control systems complicate hydraulic machines and reduce their reliability.

The hydraulic machine may include a “hydromechanical switch” to simplify the control system and increase the reliability of this class of machines. In a hydromechanical switch, the communication of hydraulic holes is carried out using only mechanical means, without electronic or magnetic devices. The use of a hydromechanical switch allows you to expand the scope of controlled machines in harsh environmental conditions, reduces and simplifies maintenance, training, etc.

The hydromechanical switch of FIGS. 3-5 may in principle be used in any hydraulic machine comprising a hydraulic cylinder 107 in which there is a component, namely a piston 106, mounted for cyclic linear reciprocating movement along cylinder 107, and valve switching means 102 for controlling the supply of hydraulic fluid to the hydraulic cylinder at predetermined times of the machine’s duty cycle. The hydromechanical switch comprises a connecting mechanism (screw nut 108, screw 109) for converting the linear motion of the piston 106 into rotation; a cam 103 driven by this connecting mechanism; and a spring 115, which is configured to compress and store energy due to the rotation of the cam 103 during the stroke of the piston 106. One end of the spring 115 is located near the cam 103, and its other free end rests on the flange 114. In addition, the spring 115 can release the accumulated energy for switching the valve 102 to control the flow of hydraulic fluid into the hydraulic cylinder 107 of the machine when the piston 106 is in predetermined positions along the length of the hydraulic cylinder 107.

The spring 115 is a compression spring mounted on a link 150 (FIG. 2) extending from the cam 103 in such a way that when the cam 103 is rotated by the connecting mechanism (108, 109), the end of the spring near the cam is compressed until the spring reaches a point “A” of unstable equilibrium, after which the spring releases the stored energy to switch the valve 102. When the spring 115 releases the stored energy, it first sharply brings the cam 103 to a predetermined rotation angle (for example, 45 °), and then, when the cam is extended When it rotates, it rotates the part for switching valve 102, turning it, for example, by an angle equal to 45 °.

The connecting mechanism (108, 109) is configured to rotate the cam by an angle less than 180 ° at each stroke of the piston 106. It contains, for example, a screw nut 108 and a screw 109, forming a connecting mechanism with a helical gear.

The principle of operation of the hydromechanical switch is based on the consumption of part of the energy of the linear motion of the machine. A small part of this energy is taken out through a helical gear and stored in the energy of elastic deformation of the spring 115. Then, this accumulated energy is released to provide the necessary openings and switching at predetermined moments of the machine’s working cycle.

The hydromechanical switch can be made in the form of a rotary cylindrical valve (see FIG. 3), which contains a stationary body 101, a rotary valve body 102, a cam 103, a moving spring 115 and a helical gear (108, 109) to convert the linear motion of the piston 106 into rotational movement of the cam 103.

When the hydromechanical switch is integrated in the pumping machine of FIGS. 1 and 2, this part, intended for cyclic reciprocating movement along the cylinder, is a piston 106 or a plunger or other part attached to them.

The hydromechanical switch shown operates as follows.

Together with the linear motion of the piston 106, the nut 108 also moves. This movement causes the screw 109 to rotate. The axial movement of the screw 109 is blocked by the support and sealing block 111. Another task of the block 111 is to tightly hold the screw 109 in the cover 110. The screw shaft 112 rotates the cam 103 by pin 113 and pin 104. Compression of the spring 115 occurs simultaneously with the rotation of the cam 103. The spring also pivots about its free end and reaches point “A” of unstable equilibrium at the end of the piston stroke. This point of unstable equilibrium corresponds to the maximum compression of the spring 115, and then the transverse axis of the spring 115 intersects the axis of rotation of the cam 103. At this point, the elastic force of the spring is maximum, but does not create torque on the cam due to the lack of a lever arm. Further rotation of the cam 103 by a small angle creates a small lever arm, and the release of energy accumulated by the spring 115 begins. Figure 5 shows a spring transversely displaced from the equilibrium position, while it is in a less compressed state at the beginning of its compression stroke and is ready for beginning of a turn.

When you turn beyond the point "A" of unstable equilibrium, the spring 115 begins to release the stored energy, and the switching process begins without any connection with the movement of the piston, that is, automatically. Initially, the straightening of the spring after the passage of point "A" sharply rotates only the cam 103, since the straightening energy overcomes only the friction forces of the cam connection 113 and the hydraulic resistance of the damper 116. The latter is designed to stabilize the speed of the spring. After the cam rotates about 45 ° freely, its tooth 117 begins to act on the pin 118 of the valve 102 and drives the valve 102 into angular movement. A further rotation of the cam 103 causes a simultaneous rotation of the valve 102 by an angle of approximately 45 °, and the corresponding necessary switching of the hydraulic channels in the body of the valve 102 or in its body 101. Thus, by turning the valve 102, the desired switching of the openings for controlling the machine is achieved.

Ball retainer 119 is provided to limit the rotation of the valve in extreme positions. The valve reaches the stop 120 and is fixed with a ball lock 119 at the end of the turn.

The following features increase the reliability of the hydromechanical switch.

The tooth 117 is equipped with a rubber damper 121 to minimize impact with the contact of the pin 118 and the stop 120.

The rotary valve 102 is statically and dynamically balanced hydraulically to compensate for radial pressure components that would otherwise cause friction when the valve is rotated.

Compression of the spring 115 occurs throughout the entire stroke of the piston for uniform energy storage. For this, the spring is soft and has a corresponding low change in resistance during the course of the stroke.

The round surface "B" of the pin 113 is supported by balancing the pressure directed from the inner cavity of the cylinder through a special channel, while the surface area "B" is equal to the cross-sectional area of the shaft 112 to balance the traction that acts on the screw 109 due to internal pressure in the cylinder.

The hydromechanical switch is equipped with an indicator 122 for monitoring the positions of the valve and piston, direction of movement, speed and operation. If necessary, instead of a mechanical indicator, any angular position sensor can be used to electronically monitor the operation of the machine.

Spiral slots 124 and 125 on the cam shaft are used to adjust the piston stroke and the position of the arrow 123 of the pointer during the assembly process.

Bolts 126 are designed to fine-tune the angle of rotation of the cam 103 and the entire operation of the hydromechanical switch.

The rotary connecting device 127 is designed to adjust the action of the spring 115.

After the initial fine-tuning, the hydromechanical switch works automatically, that is, the working machine controls itself. For example, if the piston speed changes, the valve continues to operate at the right time, since the switching process depends only on the position of the piston, and not on speed or acceleration.

This solution increases the reliability of the machine and eliminates the need for maintenance of any control system.

Claims (9)

1. A diaphragm pumping machine with a hydraulic drive, in particular for pumping difficult to pump materials, containing at least one pump cylinder (5), which has a first end with a first inlet and outlet (11) for the fluid to be pumped and a second end with a second inlet and outlet (1) for the hydraulic fluid, the inputs and outputs being connected to the corresponding valves, a separator (6) located inside, arranged for reciprocating movement along the pump cylinder RA, and the movable separator (6) has a first side facing the first end of the cylinder and a second side facing the second end of the cylinder,
- a movable separator (6) is connected to the inner side of the first end of the cylinder by a first flexible diaphragm (4) in the form of a bellows, which can be straightened and compressed inside the cylinder (5) in its longitudinal direction with the reciprocating movement of the separator (6) along the cylinder, the first side of the movable separator delimits the first cavity (c) inside the expandable and compressible flexible diaphragm (4) to enclose a variable volume of pumped fluid in it in communication with the first input and output;
- a movable separator (6) is connected to the inner side of the second end of the cylinder (5) by a second flexible diaphragm (10) in the form of a bellows, which can be straightened and compressed in the longitudinal direction of the cylinder (5) in accordance with the straightening and compression of the first flexible diaphragm (4) moreover, the second side of the movable separator limits the second cavity (b) inside the second rectifiable and compressible flexible diaphragm (10) for enclosing in it a variable volume of hydraulic fluid in communication with the second input and output; and
- between the outer side of the first and second diaphragms (4, 10) and the inner wall of the pump cylinder (5), an annular space (a) is formed, and this annular space (a) during operation encloses a fluid medium that is the same fluid medium as a hydraulic fluid, or has similar hydraulic characteristics, characterized in that the movable separator (6) is made in the form of a plunger, which is mounted with the possibility of sliding in the middle part inside the cylinder (5) between the first and second diaphragms (4, 10) in form a bellows, and one end of the plunger (6) is connected to the first diaphragm (4) in the form of a bellows, and the other end of the plunger (6) is connected to the second diaphragm (10) in the form of a bellows to form respectively the first and second annular spaces (a), namely the first annular space (a) between the outer side of the first diaphragm (4) in the form of a bellows and the inner wall of the pump cylinder (5) and the second annular space (a) between the outer side of the second diaphragm (4) in the form of a bellows and the inner wall of the pump cylinder (5) ), while the first and ond annular space (a) are independent from each other, and the fluid pressure in the first annular space (a), irrespective of the fluid pressure in the second annular space (a). 2. The machine according to claim 1, characterized in that the plunger (6) is mounted with the possibility of sliding in the sealing element (7), mounted inside the middle part in the cylinder (5). 3. The machine according to claim 1, characterized in that the outer diameter of the plunger (6) corresponds to the average working diameter of the first and second diaphragms (4, 10) in the form of a bellows. 4. The machine according to claim 1, characterized in that during operation the volume of the first and second annular spaces (a) remains essentially constant. 5. Machine according to any one of the preceding paragraphs, characterized in that it contains means for automatically switching the valve (102) to control the flow of hydraulic fluid into the hydraulic cylinder at predetermined moments of the machine’s working cycle, said valve switching means comprising a hydromechanical switch, comprising:
- a connecting mechanism (108, 109) for converting the linear motion of the component (106) of the machine into rotational motion;
- a cam (103) driven into rotation by a connecting mechanism (108, 109);
- a spring (115) made with the possibility of compression to accumulate energy by rotating the cam (103) during the course of the specified component (106) of the machine and releasing the stored energy to switch the valve (102), in order to control the flow of hydraulic fluid into the hydraulic cylinder (107 ) machine, when the specified component (106) is in predetermined positions along the length of the hydraulic cylinder (107), thereby controlling the working cycle of the machine. 6. Machine according to claim 5, characterized in that the spring (115) is a compression spring mounted on a rod (150) passing from the cam (103) in such a way that when the cam (103) is rotationally driven, the connecting mechanism (108, 109 ) the end of the spring near the cam is compressed until the spring reaches the “A” point of unstable equilibrium, beyond which the spring releases the stored energy for switching the valve (102). 7. The machine according to claim 6, characterized in that when the spring releases the stored energy, it first sharply drives the cam (103), and after turning a certain angle, the cam (103) turns the component to switch the valve (102). 8. The machine according to claim 5, characterized in that the connecting mechanism (108, 109) is configured to rotate the cam by an angle less than 180 ° at each stroke of the component (106) of the machine. 9. The machine according to claim 5, characterized in that the connecting mechanism (108, 109) is a helical gear containing a nut (108) and a screw (109).

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