Plunger pump capable of reducing inlet pressure pulsation and provided with booster impeller

Abstract

The invention discloses a plunger pump with a booster impeller capable of reducing inlet pressure pulsation, the booster impeller is arranged at an inlet of the plunger pump, and the booster impeller is mounted on a rotating shaft of the plunger pump and coaxially rotates with a plunger of the plunger pump; an outlet of the booster impeller is communicated with an oil inlet of a plunger of the plunger pump through a volute and a connecting pipeline; the number of blades of the pressurizing impeller is equal to that of plungers of the plunger pump; the assembling relation of the pressurizing impeller and the plungers meets the condition that when any plunger is located at the dead point position, an outlet of one blade of the pressurizing impeller is located at the baffle tongue position of the volute. According to the plunger pump, pressure pulsation caused by introduction of the pressurizing impeller can be reduced while inlet pressure is increased, new parts do not need to be added, and the plunger pump is simple and compact in structure.

Description

Technical Field

[0001] The invention relates to the field of plunger pumps, and in particular to a plunger pump with a booster impeller capable of reducing inlet pressure pulsation. Background Art

[0002] Piston pumps are widely used in hydraulic systems due to their high pressure and large flow output. Piston pumps often produce cavitation due to insufficient inlet suction pressure. When bubbles flow through the high-pressure area, they will collapse due to the sharp increase in pressure, thereby damaging the surface of the structure and eventually shortening the life of the axial piston pump. Therefore, in order to ensure that the oil pressure inside the pump is higher than the saturation pressure where cavitation occurs, the inlet pressure of the axial piston pump should be higher, and the inlet pressure at this time is the critical inlet pressure. In order to increase the inlet pressure of the piston pump, the prior art proposes to add a booster turbine at the inlet to ensure that the suction oil pressure of the piston pump is higher than the critical pressure. However, after the introduction of the booster impeller, the rotation of the turbine itself will generate pressure pulsation, and the piston pump will also generate pressure pulsation when the oil pressure is periodically inhaled. The coupling of these two pressure pulsations may increase the pressure pulsation of the inlet oil pressure, thereby worsening the inlet conditions and bringing instability to the operation of the pump. This pulsation not only affects the working performance of the pump, but also causes vibration, noise and premature wear of system components. In the prior art, physical vibration reduction devices or additional accumulators are often used to alleviate pulsation, but these methods are often large in size, high in cost and have limited effect. Therefore, there is an urgent need for a simple and efficient low-pulsation design method to solve the problem of plunger pump inlet pressure pulsation. Summary of the invention

[0003] In view of the deficiencies of the prior art, the present invention provides a plunger pump with a booster impeller capable of reducing inlet pressure pulsation, which can not only increase the inlet pressure of the plunger pump, but also reduce the pressure pulsation caused by the introduction of the booster impeller.

[0004] The purpose of the present invention is achieved through the following technical solutions:

[0005] A plunger pump with a booster impeller capable of reducing inlet pressure pulsation, wherein the booster impeller is arranged at the inlet of the plunger pump, the booster impeller is mounted on the rotating shaft of the plunger pump, and rotates coaxially with the plunger of the plunger pump;

[0006] The outlet of the boost impeller is connected to the oil inlet of the plunger of the plunger pump through the volute and the connecting pipe;

[0007] The number of blades of the booster impeller is equal to the number of plungers of the plunger pump;

[0008] The assembly relationship between the boost impeller and the plunger satisfies:

[0009] When any plunger is located at the dead point, the outlet of one of the blades of the boost impeller is located at the tongue position of the volute.

[0010] Furthermore, the boost impeller is a centrifugal turbocharger impeller.

[0011] Furthermore, the boost value p of the boost impeller is calculated by the following formula:

[0012] p=(1.1~1.3)(p k -p min )

[0013] Among them, p min and p k It is the minimum pressure when the plunger pump is running without a booster impeller and the critical pressure without cavitation.

[0014] Furthermore, the connecting pipe connecting the volute and the oil inlet of the plunger of the plunger pump is a connecting pipe with a streamlined flow channel.

[0015] The beneficial effects of the present invention are as follows:

[0016] The plunger pump with a booster impeller capable of reducing inlet pressure pulsation provided by the present invention utilizes the controllability of the pulsation waveform generated by the booster impeller and the controllability of the pressure pulsation waveform generated by the plunger pump, thereby improving the pressure pulsation at the inlet of the plunger pump, while utilizing the controllability of the pressure pulsation waveform generated by the turbine and the controllability of the pressure pulsation waveform generated by the plunger pump, and by limiting the number of blades of the booster impeller and the installation positions of the booster impeller and the plunger, thereby reasonably setting the phase difference between the two pulsation waveforms, thereby achieving the weakening of pressure pulsation by waveform superposition, without adding new components, and the plunger pump has a simple and compact structure and is easy to manufacture, install and manufacture. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic structural diagram of a plunger pump with a booster impeller capable of reducing inlet pressure pulsation according to an embodiment of the present invention.

[0018] Figure 2 for Figure 1 AA section view and partial enlarged view.

[0019] Figure 3 for Figure 1 BB cross-sectional view.

[0020] Figure 4 The waveform diagrams are the pressure pulsation generated at the outlet of the booster impeller and the pressure pulsation generated at the inlet of the plunger pump.

[0021] In the figure, 1 is a boost impeller, 2 is a connecting pipe, 3 is an oil inlet of a plunger pump, 4 is an oil outlet of a plunger pump, 5 is a rotating shaft, 6 is a cylinder of a plunger pump, 7 is a plunger, 8 is a sliding shoe, and 9 is a swash plate. DETAILED DESCRIPTION

[0022] The present invention will be described in detail below based on the accompanying drawings and preferred embodiments, and the purpose and effects of the present invention will become more clear. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0023] like Figure 1 As shown, the plunger pump with a booster impeller capable of reducing inlet pressure pulsation of this embodiment includes a booster impeller 1, a connecting pipe 2, a plunger oil inlet 3, a plunger oil outlet 4, a rotating shaft 5, a plunger pump cylinder 6, a plunger 7, a slipper 8 and a swash plate 9.

[0024] The boost impeller 1 is arranged at the inlet of the plunger pump, and the boost impeller 1 is installed on the rotating shaft 5 of the plunger pump through a spline. The outlet of the boost impeller 1 is connected to the oil inlet of the plunger 7 through the volute and the connecting pipe 2, so that the oil pressurized by the boost impeller 1 is delivered to the plunger 7. The rotating shaft 5 and the plunger pump cylinder 6 are also connected through a spline, and the rotating shaft 5 drives the plunger pump cylinder 6 and the boost impeller 1 to rotate synchronously. The number of blades of the boost impeller 1 is equal to the number of plungers 7 of the plunger pump.

[0025] like Figure 2 and Figure 3 As shown, the assembly relationship between the boost impeller 1 and the plunger 7 satisfies:

[0026] When any plunger is located at the dead point, the outlet of one of the blades of the boost impeller 1 is at the tongue position of the volute.

[0027] In this embodiment, the boost impeller 1 is a centrifugal turbocharger impeller, the number of plungers 7 is 9, and the number of blades of the boost impeller 1 is also 9.

[0028] The connecting pipe 2 is a connecting pipe with a streamlined flow channel.

[0029] When there is no booster impeller 1, the pressure pulsation waveform at the inlet of the plunger pump is as follows Figure 4 As shown by the solid line in the middle, when the plunger moves to the top dead center, the plunger switches from the oil pressure state to the oil suction state at this position. Due to the inertia of the oil, the oil at the inlet of the plunger pump cannot meet the sudden increase in the oil suction demand. The waveform shows that the pressure at the inlet of the plunger pump is the lowest at this time. The pressure will recover when the plunger cavity continues to rotate. When the plunger pump is not considered, the outlet pressure pulsation waveform of the booster impeller is as follows Figure 4As shown by the dotted line, when the impeller blades sweep over the volute tongue position, a compression effect will be produced on the oil, and the pressure formed at this time is the highest. Since the pressure propagates at the speed of sound in the oil, the length of the oil outlet pipeline connecting the boost impeller is much smaller than the speed of sound. Therefore, it can be considered that when the plunger pump is installed with the boost impeller, the two pressure waves received by the inlet flow channel of the plunger pump arrive almost at the same time. The pressure wave is a mechanical wave, and the synthesis of the pressure waves can be superimposed. In this embodiment, when the plunger pump and the boost impeller are assembled, any plunger 7 is installed at the dead point position, and any blade of the boost impeller 1 is installed at the volute tongue position, so that when any plunger is at the dead point position, the outlet of one of the blades of the boost impeller 1 is at the volute tongue position. At this time, the pressure pulsation wave generated by the boost impeller 1 and the pressure pulsation wave generated by the operation of the plunger pump are just half a cycle apart in phase, that is, when the plunger pump produces the lowest pressure, the boost impeller produces the highest pressure, and the superposition of the two waves suppresses most of the fluctuation peaks. Thereby achieving the purpose of reducing the pressure pulsation at the inlet of the plunger pump.

[0030] Those skilled in the art can understand that the above are only preferred examples of the invention and are not intended to limit the invention. Although the invention is described in detail with reference to the above examples, those skilled in the art can still modify the technical solutions recorded in the above examples or replace some of the technical features therein with equivalents. Any modification, equivalent replacement, etc. made within the spirit and principle of the invention shall be included in the protection scope of the invention.

Claims

1. A plunger pump with a booster impeller capable of reducing inlet pressure pulsation, characterized in that: The boost impeller (1) is arranged at the inlet of the plunger pump, and the boost impeller (1) is installed on the rotating shaft (5) of the plunger pump and rotates coaxially with the plunger (7) of the plunger pump; The outlet of the boost impeller (1) is connected to the oil inlet of the plunger (7) of the plunger pump through a volute and a connecting pipe; The number of blades of the booster impeller (1) is equal to the number of plungers (7) of the plunger pump; The assembly relationship between the boost impeller (1) and the plunger (7) satisfies: When any plunger is located at the dead point, the outlet of one of the blades of the boost impeller (1) is located at the tongue position of the volute.

2. The plunger pump with a booster impeller capable of reducing inlet pressure pulsation according to claim 1, characterized in that: The supercharging impeller (1) is a centrifugal turbocharger impeller.

3. The plunger pump with a booster impeller capable of reducing inlet pressure pulsation according to claim 1, characterized in that: The boost value p of the boost impeller is calculated by the following formula: p=(1.1~1.3)(p k -p min ) Among them, p min and p k It is the minimum pressure when the plunger pump is running without a booster impeller and the critical pressure without cavitation.

4. The plunger pump with a booster impeller capable of reducing inlet pressure pulsation according to claim 1, characterized in that: The connecting pipe connecting the volute and the oil inlet of the plunger (7) of the plunger pump is a connecting pipe with a streamlined flow channel.

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