DE2118574A1 - Fluid pumping device - Google Patents

Description

The invention relates to fluid pumping devices, and more particularly to motor-driven ones Hydraulic pumps and gas compressors.

Conventional motor-driven pumps have the disadvantage that when sufficient pressure is reached, the pump continues to operate and discharges an excess of fluid under high pressure through a pressure relief valve, thereby generating a considerable amount of heat and unnecessary power consumption. Also be High pressure relief valves, which work as excess valves, are incapable of being eroded by the fluid Resist, and they have generally proven to be

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proved impractical. In addition, a system that includes pressure switches and hydraulic accumulators is also at a great deal impractical and cumbersome at high pressures.

Furthermore, the conventional, air-driven type of high pressure pumps has the disadvantage that it is a local Requires supply of compressed air, which often proves to be insufficient to the considerable To supply air demand, which is necessary to drive the pump, and also this type is often subject to large pressure fluctuations resulting from other requirements that are placed on the compressed air supply by others independent bodies. In addition, other problems arise due to the fact that " Excess of water, oil and rust that can be carried into the air supply and the working parts of the air motor that drives the pump. In addition, air driven pumps are in their power consumption very wasteful.

The invention consists in one aspect of a fluid pumping device having at least one A pair of cooperating elements movable with respect to one another to increase the fluid pressure, one of the elements being resiliently supported and resiliently limiting movement of that one element is, the movement of this one element is used to the operation of the device when reaching a desired pressure.

A pump using the device according to the invention can be more than four times as powerful in their use of electrical power like comparable air-hydraulic pumps.

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In a preferred embodiment, the device consists of at least one reciprocating piston, which is movable in a cylinder body which is movable independently of the piston, and the movement of the cylinder body is critically limited by a preloaded compression spring, so that the movement of the cylinder body can only enter the cylinder body when a predetermined pressure is reached. The movement of the cylinder body operates a switch to stop the operation of the pumping device.

The invention consists in another respect \

from a hydraulic pump unit with a high pressure pump, a motor for driving this pump, a pressure switch, which can be actuated when a desired pressure is reached, and a quick brake that acts on the Switch responds and is intended to stop the pump.

The invention is explained in more detail below with reference to the drawing. Show in it:

Fig. 1 is a side view of a hydraulic pump unit and

Fig. 2 is a vertical section through a hydraulic pump.

According to FIG. 1, a hydraulic pump is driven by an electric motor X, which is equipped with a magnetic Rapid brake Y is equipped, which is intended to stop the motor and the pump when the electric Power is turned off. Hydraulic fluid is the

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OfUGiNAL INSPECTED

Pump ¥ supplied from a tank V via a line Z.

In Fig. 2, the pump is shown in detail. A drive shaft of the electric motor is splined provided to drive an eccentric curve A, which is arranged in a crankcase U. The curve A carries a ball bearing Q, the outer ring of which rests freely on a pair of crankshaft jaws B. With each of the crankshaft jaws is a reciprocating plunger D connected, which is arranged to be in a Cylinder body G slides. Balls R form pressure joint connections between the jaws B and the bases of the Piston D.

Each of the pistons D is supported by crosshead bearings P that reciprocate with the pistons D. can and be guided in bores S in order to limit all side forces caused by the movement of the pistons be generated. In each of the bores S a return spring F is included, the pressure between the Crosshead bearings P and their associated pistons D, the balls R and the crankshaft jaws B with the ball bearing Q is maintained so that rotation of the eccentric curve A causes the pistons D to reciprocate.

Each piston and cylinder body unit is provided with a high pressure hydraulic fluid inlet valve C. and a high pressure outlet valve E connected. The cylinder body G are provided with seals T, the one Create a seal against the pistons D to ensure that through the inlet valve C from the crankcase U drawn-in liquid is discharged through the outlet valves.

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The ends of the cylinder bodies G, which are applied to the crankcase, are provided with roller bearings H which abut on angle levers I. A movement of the lever I is limited by a loaded compression spring L, the load of which can be adjusted by a handwheel M. The load on the spring L is determined so that each cylinder body G can move in the direction of the pressure stroke of the piston D only when a critical pressure is reached in the cylinder body. A microswitch J is connected to one of the levers I and arranged such that it actuates the brake Y to the engine X wherein movement of each ä

the lever I to stop. A worm stop K prevents the spring L from being overloaded by the setting wheel M.

Since each lever I is connected to one end of the compression spring L, the movement of each lever becomes the microswitch Press J.

During operation, hydraulic fluid is drawn from the tank V into the crankcase U and the eccentric curve A. is rotated by the drive shaft from motor X.

The pressure generated by the rotation of curve A.

is transferred via the jaws B and the balls R to %

to cause the pistons D to reciprocate in the cylinder body G. Included in the crankcase U. Liquid is sucked into the cylinder body G through the inlet valves C and through the outlet valves E submitted. As the pumping continues, the thrust resulting from the pressure will develop in the cylinder bodies G is generated, transferred via the roller bearing H to the angle lever I. The movement of the levers I is limited by the spring L, so only if a

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critical pressure is reached in at least one of the cylinder bodies G, the cylinder body the corresponding one Lever I will move. The microswitch J will then work and thereby switch off the motor X and the brake Apply Y and thereby stop the pump.

The arrangement of the points around which the levers I pivot and the construction through which they touch is maintained between the levers I and the roller bearings H, when the levers pivot, the same Change in the spring force during the movement of the lever and therefore allows the load in the spring to be accurately determined to be determined beforehand.

During the short period in which the engine is stopped by the brake, the cylinder body G, which has been moved, will continue its movement with the piston D and thereby any further displacement of Prevent fluid during this period.

Thus, when sufficient pressure has been created by the pump, the motor will stop working and stops until the pump needs to work again. Since the pump energy in the compression spring before Shutting down the engine stores, it has been found possible to control the pressure with great accuracy under conditions to control, -which the amount of liquid delivered by the pump between zero and maximum delivery rate the pump fluctuates. The pump is particularly useful at very high pressures in the range from 700 to 7000 kg / cm, but it can be used at low pressures as well.

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The cylinder bodies float and are therefore effective around

i) switch off the engine and force braking;

ii) to allow the cylinder to move freely with the piston, thereby creating another To avoid displacement of fluid into the system during part of a stroke while the Brake the pump stops;

iii) to store energy in the spring element during the movement of the cylinder, so that liquid under g Pressure can be promoted after the engine has stopped and before the engine has taken effect the resilient force starts up again, pushing the cylinder back into the piston, during the Piston is held rigidly by the brake to resist the force.

The main advantages of the pump described are that no power is dissipated in the form of heat, if the pump only maintains the pressure and that the pump does not have a pressure reducing valve to control the Depends on the pressure.

In addition, the pump does not depend on a supply of compressed air and therefore eliminates the operational problems and the ineffectiveness associated with this form of driving force. Furthermore, the pump is used for pumping Hydraulic oil or a mixture of lubricating oil and water is suitable, and in a modified embodiment, in which inserted the intake valves C into the cylinder head

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are, so that nothing of the pumped liquid passes through the crankcase U, can also other liquids including pure water can be pumped. The use of horizontally opposite Double cylinders actually lead to impulse-free pumping.

Another method of controlling the pump that can be used when a tank or system to be filled with a large capacity uses a pressure switch in the system to control the start-up and stopping the pump. Such a design has proven to be advantageous in terms of the accuracy of the control and the ease of changing the control pressure setting. In addition, the basic remains Pump control, which is influenced by the floating cylinder body G, is effective and would be with higher pressure set to ensure the ultimate safety of the pump and system. A pump like them essentially is shown in Fig. 2, in combination with a drive motor and a magnetic quick brake respond with great accuracy to a pressure switch or an electrical contact inserted into a pressure gauge is used.

The use of a quick brake brings the following advantages in both respects of the invention:

1) Stopping the engine quickly prevents it Exceeding the pressure as a result of the uncontrolled mechanical moment of the pump,

2) After the pump is stopped, the piston is held rigidly, together with the column of liquid,

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which it carries under pressure, thereby preventing any pressure drop that would occur if the Piston could freely fall back, whereby a small pressure drop could occur due to the fact that the exhaust control valve has to settle.

3) Since the charge in the cylinder is maintained in the manner described under 2), the pump can compensate for the smallest changes in pressure by introducing liquid as a fraction of the displacement of one stroke at a time, and this effect is possible because the rapid brake is provided, and can thus move the motor further i by a fraction of a revolution at any time, with at least one cylinder always remaining in the charged state.

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Claims (10)

Patent claims: 1.) Fluid pumping device with at least a pair of cooperating elements movable with respect to one another to apply the fluid pressure increase, characterized in that one of the elements (G) is resiliently supported and the movement of this one Element is resiliently limited, and that the movement of this one element is used to operate the device stop when a desired pressure is reached. 2. Apparatus according to claim 1, characterized. shows that the compliant element (L) is critically loaded is, so that the movement of one of the elements (G) takes place only when a predetermined pressure is reached. 3. Device according to claim 2, characterized in that that means (M) are provided for adjusting the load in a flexible element (L), the forms the limit. 4. Device according to one of claims 1 to 3, characterized in that each pair of cooperating Elements consists of a reciprocating piston (D) which can be moved in a cylinder body (G). 5. Apparatus according to claim 4, characterized in that one end of the cylinder body (G) at one Lever (I) is applied, the movement of which is subject to the flexible limitation. 109849/1042 iNSPECTH! - 11 - ^ ■ -. -j _-> _t j ι 6. Apparatus according to claim 5, characterized ?: calibrates that the lever (I) touches the cylinder body via a roller bearing (H) in order to change the flexible To compensate for the load as the lever moves. 7. Device according to one of claims 1 to 6, characterized in that the movement of one of the elements (G) operates a switch (J) to stop the operation of the pumping device. 8. Fluid pumping device having at least one reciprocating piston which is in a cylinder body is movable, wherein the cylinder body is movable independently of the piston, characterized in that that the movement of the cylinder body (G) is critically limited by a resilient element (L), so that the movement can only take place when a predetermined pressure is reached in the cylinder body, and that the Movement is used to stop the operation of the device when a desired pressure is reached. 9. Device according to one of claims 1 to 8 g marked with a motor for driving the pumping device, characterized by a safety brake which can be actuated during the movement of the elements to stop the motor and thus the operation of the fluid-pumping device. 10. Hydraulic pump unit with a high pressure pump, a motor for driving the pump and a pressure switch, which can be actuated when a desired pressure is reached, characterized in that a quick brake (Y) responds to the switch (J) and the pump (W) can stop. 109849/1042