CN101240794A - Method and device for reducing axial plunger pump geometric flow pulsation - Google Patents

Abstract

The present invention discloses method and device for decreasing axial plunger pump geometric properties flow pulsation; the method is that the arrangement between plunger piston of axial plunger pump and sliding track of swash plate touch contact is mathematics function arrangement, every plunger piston in different instantaneous displacement amount is controlled in the rotating process of cylinder block, the grand total of total oil supply amount of every plunger piston in different instant is tending constants to decrease geometric properties flow pulsation of axial plunger pump. The present invention can decrease geometric properties flow pulsation of axial plunger pump, can provides stable quantity of flow for hydraulic system, and can decrease vibration and noise caused by flow pulsation.

Description

A kind of method and device that reduces axial plunger pump geometric flow pulsation

Technical field

The present invention relates to a kind of method and device that reduces axial plunger pump geometric flow pulsation, belong to the plunger pump technique field.

Background technique

Axial piston pump is the important executive component of hydraulic system, its working principle is to be provided with some plunger holes on cylinder body, be installed in spring and plunger in the plunger hole, one end of plunger withstands on the swash plate under the effect of spring, when swash plate or cylinder body rotation, when plunger when the peak of swash plate turns to the minimum point of swash plate, plunger stretches out from the plunger hole of cylinder body at the effect lower plunger of spring, by valve liquid is sucked the cylinder body from fuel tank; When plunger when the minimum point of swash plate turns to the peak of swash plate, plunger is pressed in the plunger hole of cylinder body at the promotion lower plunger of swash plate, and liquid is extruded from the plunger hole of cylinder body; For hydraulic system provides hydraulic flow.

Present swash plate is a tilted-putted disk, when the rotation of swash plate or cylinder body, during the diverse location of plunger on swash plate, the rate of displacement of plunger is different, plunger is when the highs and lows of swash plate, and the rate of displacement of plunger equals zero, and this moment, the flow of pump also equalled zero; Plunger is pressed into the speed maximum of cylinder body plunger hole at the mid point plunger of swash plate uphill process, this moment pump feed flow flow maximum; Plunger at the mid point plunger of swash plate decline process by the speed maximum of spring liftout tank scapus consent, this moment pump imbibition flow maximum; So just a problem occurs, there is geometric flow pulsation in axial piston pump.This flow pulsation will cause the pressure pulsation of hydraulic system, thereby cause vibration and noise.Flow pulsation coefficient coefficient table when having listed different plunger in the Traditional Textbooks.

The plunger number	3	4	5	6	7	8	9	10	11
										Ripple factor	14.03	32.53	4.98	14.03	2.53	7.81	1.53	4.98	1.02

The pulsation that can see outflow from last table is also relevant with the quantity of plunger, the flow pulsation coefficient when in general the flow pulsation coefficient during the even number plunger is far longer than the odd number plunger, and also along with the increase of plunger number, factor of non-uniform flow reduces.Reduce flow pulsation, need to increase the plunger number, tend to be subjected to the intensity restriction but increase the plunger number, or make the pump structure complexity.Therefore it is significant for the performance that improves hydraulic system to reduce flow pulsation.

Summary of the invention

The objective of the invention is to, a kind of method and device that reduces axial plunger pump geometric flow pulsation is provided, reduces the geometric flow pulsation that axial piston pump produces, for hydraulic system provides stable flow rate, reduce because flow pulsation causes vibration and noise, to solve the deficiencies in the prior art.

The present invention realizes like this, the method that reduces axial plunger pump geometric flow pulsation of the present invention is: the mathematical function of the sliding trajectory of plunger on the axial piston pump and swash plate point of contact being pressed angle of swing distributes, make cylinder body in rotary course, control the displacement amount of each plunger in different moments, make each plunger be tending towards constant, to reduce axial plunger pump geometric flow pulsation in total fuel supply flow rate sum of different moments.

In the above-mentioned method that reduces axial plunger pump geometric flow pulsation, described mathematical function is determined the geometrical shape of the sliding trajectory that plunger is different with the swash plate point of contact according to the parity of plunger quantity or plunger quantity.

According to the aforesaid device that reduces axial plunger pump geometric flow pulsation that reduces the method structure of axial plunger pump geometric flow pulsation, it comprises cylinder body 1, cylinder body 1 is provided with the plunger hole 2 more than three or three, be provided with spring 3 and plunger 4 slidably in the plunger hole 2, the end of plunger 4 is provided with swash plate 5; It is characterized in that: swash plate 5 is provided with slideway 6, and the geometrical shape of slideway 6 bottoms is provided with by the mathematical function rule of angle of swing.

In the above-mentioned device that reduces axial plunger pump geometric flow pulsation, be provided with the piston shoes 7 more than three or three in the described slideway 6, the bottom of piston shoes 7 and side are provided with ball 8, and ball 8 and slideway 6 rolls and be connected, 9 universal connections of bulb on piston shoes 7 tops and the plunger 4.

Compared with prior art, method and the device that reduces axial plunger pump geometric flow pulsation provided by the present invention has following beneficial effect:

1, the oblique disk structure supporting plunger motion that adopts method of the present invention to provide, can make the instantaneous flow of axial piston pump is constant, thereby reduces axial plunger pump geometric flow pulsation.

2, the oblique disk structure supporting plunger motion that adopts method of the present invention to provide can make axial piston pump not need to consider the influence of even number plunger, odd-numbered columns plug flow amount ripple factor.

3, the oblique disk structure supporting plunger motion that adopts method of the present invention to provide can have good flow stationarity equally under the few situation of axial plunger pump plunger quantity.Overcome and will reduce flow pulsation, needing increases plunger quantity, causes the increase of plunger quantity to be subjected to the intensity restriction and makes the contradiction of pump structure complexity.

4, in the structure of the present invention, change the friction structure of swash plate and plunger into rolling friction by sliding friction, help improving the contact performance of cam-type axial piston pump.

5, for multicolumn plug axial piston pump, adopt same principle, can determine the swash plate curve under the different plunger situations, realize reducing axial plunger pump geometric flow pulsation.According to the symmetry properties that the axial plunger pump plunger distributes, as long as solved the geometric flow pulsation of k plunger axial piston pump, the geometrical shape of its sliding trajectory will be adapted to the axial piston pump of kn plunger.Axial piston pump with 12 plungers is an example, can adopt the geometrical shape of 3 plunger sliding trajectories or the geometrical shape of 4 plunger sliding trajectories.

6, the further investigation of using in hydraulic system along with variable-frequency control technique, the frequency conversion variable might extensive use.The oblique disk structure supporting plunger motion that adopts method of the present invention to provide might form application preferably for the frequency conversion variable.

Description of drawings

Accompanying drawing 1 is the structural representation of axial piston pump of the present invention;

Accompanying drawing 2 is partial enlarged drawings that plunger is connected with swash plate in the accompanying drawing 1;

Accompanying drawing 3 is working principle sketches of conventional axial plunger pump;

Being labeled as in the accompanying drawing: 1-cylinder body, 2-plunger hole, 3-spring, 4-plunger, 5-swash plate, 6-slideway, 7-piston shoes, 8-ball, 9-bulb.

Embodiment

Embodiment: ignoring the compressibility of liquid, ignoring and leak and recharge etc. under the situation, at first the instantaneous flow of conventional axial plunger pump is analyzed, by analysis as can be known, the instantaneous flow of axial piston pump is decided by the formed active chamber geometric space of axial piston pump Der Grundsatz der Maschinen variance ratio fully.Analytic process is as shown in Figure 3: when plunger turned to position B by upper dead center position A with cylinder body, the coordinate of plunger and swash plate point of contact track was:

$x_1{\mathrm{\&Phi;}}_1=-\frac{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">D</figure-callout>}}{2}\tan \mathrm{\&delta;}-\frac{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">D</figure-callout>}}{2}\cos \mathrm{\&Phi;}\tan \mathrm{\&delta;}=-\frac{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">D</figure-callout>}}{2}\tan {\mathrm{\&delta;}}_{1}1+\cos {\mathrm{\&Phi;}}_1$

In the formula: x (Ф) ... the x coordinate of plunger and swash plate point of contact track

D ... plunger distribution map diameter

δ ... swashplate angle

Plunger displacement: $x1=x_1{\mathrm{\&Phi;}}_1+D\tan \mathrm{\&delta;}=\frac{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">D</figure-callout>}}{2}\tan {\mathrm{\&delta;}}_{1}1-\cos {\mathrm{\&Phi;}}_1$

X1 ... plunger displacement

Plunger motion speed: $v=\frac{\mathrm{dx}1}{\mathrm{dt}}=\frac{\mathrm{dx}}{\mathrm{dt}}=\frac{\mathrm{dx}}{\mathrm{d\&Phi;}}\frac{\mathrm{d\&Phi;}}{\mathrm{dt}}=\frac{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">D</figure-callout>}}{2}\mathrm{\&omega;}\tan \mathrm{\&delta;}\sin \mathrm{\&Phi;}$

When plunger pump rotates with constant rotational speed, the instantaneous flow of single plunger (the definition oil extraction is for negative):

$Q_i^{\&prime;}=-\frac{\mathrm{\&pi;}}{4}{d}^2{v}_i=-\frac{\mathrm{\&pi;}}{4}{d}^2\frac{\mathrm{<figure-callout\; id="2"\; label="D"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">D</figure-callout>}}{2}\mathrm{\&omega;}\tan \mathrm{\&delta;}\sin {\mathrm{\&Phi;}}_i$

In the formula: Q ' _IThe instantaneous flow of i plunger

D ... the diameter of plunger

ω ... the pump angular velocity of rotation

φ _iThe angle of swing of i plunger

The instantaneous flow of pump: $Q_B^{\&prime;}=\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}{Q}^{\&prime;}=-\frac{\mathrm{\&pi;}}{8}{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\mathrm{D\&omega;}\tan \mathrm{\&delta;}\underset{i=1}{\overset{k}{\mathrm{\&Sigma;}}}\sin {\mathrm{\&Phi;}}_i$

In the formula: Q ' _BThe instantaneous flow of pump

K ... be in the plunger number in oil extraction district simultaneously

The flow pulsation coefficient and the plunger number of axial piston pump are closely related, and ripple factor is defined as (5):

$\mathrm{\&delta;}=\frac{Q_{B\max }^{\&prime;}-Q_{B\min }^{\&prime;}}{Q_{\mathrm{Bt}}}$

In the formula: Q ' _BmaxThe instantaneous flow maximum value of pump

Q ' _BminThe instantaneous flow minimum value of pump

Q ' _BtThe theoretical delivery of pump

$Q_{\mathrm{Bt}}=-\frac{\mathrm{\&pi;}}{4}{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\mathrm{Dz}{n}_B\tan \mathrm{\&delta;}$

In the formula: z ... the plunger number of pump

n _BThe rotating speed of pump

Flow pulsation coefficient coefficient table when having listed different plunger in the Traditional Textbooks.

The plunger number	3	4	5	6	7	8	9	10	11
										Ripple factor	14.03	32.53	4.98	14.03	2.53	7.81	1.53	4.98	1.02

The pulsation that can see outflow from last table is also relevant with the quantity of plunger, the flow pulsation coefficient when in general the flow pulsation coefficient during the even number plunger is far longer than the odd number plunger, and also along with the increase of plunger number, factor of non-uniform flow reduces.Reduce flow pulsation, need to increase the plunger number, tend to be subjected to the intensity restriction but increase the plunger number, or make the pump structure complexity.

By above analysis, the present invention improves the swash plate of axial piston pump, specific implementation method is: the sliding trajectory of plunger on the axial piston pump and swash plate point of contact is pressed mathematical function distribute, make rotor in rotary course, control the displacement amount of each plunger in different moments, make each plunger be tending towards constant, to reduce axial plunger pump geometric flow pulsation in total fuel supply flow rate sum of different moments.Described mathematical function is determined the geometrical shape of the sliding trajectory that plunger is different with the swash plate point of contact according to the parity of plunger quantity or plunger quantity.

The instantaneous flow of the single plunger of axial piston pump is

$Q_i^{\&prime;}=-\frac{\mathrm{\&pi;}}{4}{d}^2{v}_i=-\frac{\mathrm{\&pi;}}{4}{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\frac{\mathrm{dx}}{\mathrm{d\&Phi;}}\frac{\mathrm{d\&Phi;}}{\mathrm{dt}}=-\frac{\mathrm{\&pi;}}{4}{\mathrm{<figure-callout\; id="2"\; label="d"\; filenames="A20081030057100101.png"\; state="\{\{state\}\}">d</figure-callout>}}^2\mathrm{\&omega;}\frac{\mathrm{dx}}{\mathrm{d\&Phi;}}$

When ω was constant, its instantaneous flow depended on

Can find out,

Be a structural variable, i.e. the related variable of situation that only changes with Ф with the x coordinate of plunger and swash plate point of contact track.Since

It is one the related variable of situation that changes with Ф with the x coordinate of plunger and swash plate point of contact track.

The present invention is directed to the pump of different plunger quantity, determine the curvilinear equation of the x coordinate of different plungers and swash plate point of contact track with the Ф variation.

For three plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{9}{4{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<\mathrm{\&pi;}/3\\ D\tan \mathrm{\&delta;}(\frac{3}{2\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{5}{4})& \mathrm{\&pi;}/3\&le;\mathrm{\&Phi;}<2\mathrm{\&pi;}/3\\ D\tan \mathrm{\&delta;}(-\frac{9}{4{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{9}{2\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{9}{4})& 2\mathrm{\&pi;}/3\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For four plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{2}{{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<\mathrm{\&pi;}/2\\ D\tan \mathrm{\&delta;}(\frac{4}{\mathrm{\&pi;}}\mathrm{\&Phi;}-2-\frac{2}{{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2)& \mathrm{\&pi;}/2\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For five plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{25}{12{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}\&le;2\mathrm{\&pi;}/5\\ D\tan \mathrm{\&delta;}(\frac{5}{3\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{4}{3})& 2\mathrm{\&pi;}/5\&le;\mathrm{\&Phi;}\&le;3\mathrm{\&pi;}/5\\ D\tan \mathrm{\&delta;}(\frac{-25}{12{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{25}{6\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{25}{12})& 3\mathrm{\&pi;}/5\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For six plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{9}{4{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<\mathrm{\&pi;}/3\\ D\tan \mathrm{\&delta;}(\frac{3}{2\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{5}{4})& \mathrm{\&pi;}/3\&le;\mathrm{\&Phi;}<2\mathrm{\&pi;}/3\\ D\tan \mathrm{\&delta;}(-\frac{9}{4{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{9}{2\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{9}{4})& 2\mathrm{\&pi;}/3\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For seven plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{49}{24{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<3\mathrm{\&pi;}/7\\ D\tan \mathrm{\&delta;}(\frac{7}{4\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{11}{8})& 3\mathrm{\&pi;}/7\&le;\mathrm{\&Phi;}<4\mathrm{\&pi;}/7\\ D\tan \mathrm{\&delta;}(-\frac{49}{24{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{49}{12\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{49}{24})& 4\mathrm{\&pi;}/7\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For eight plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{8}{3{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<\mathrm{\&pi;}/4\\ D\tan \mathrm{\&delta;}(\frac{4}{3\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{7}{6})& \mathrm{\&pi;}/4\&le;\mathrm{\&Phi;}<3\mathrm{\&pi;}/4\\ D\tan \mathrm{\&delta;}(-\frac{8}{3{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{16}{3\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{8}{3})& 3\mathrm{\&pi;}/4\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

Perhaps: $x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{2}{{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<\mathrm{\&pi;}/2\\ D\tan \mathrm{\&delta;}(\frac{4}{\mathrm{\&pi;}}\mathrm{\&Phi;}-2-\frac{2}{{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2)& \mathrm{\&pi;}/2\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For nine plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{81}{32{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<2\mathrm{\&pi;}/9\\ D\tan \mathrm{\&delta;}(\frac{9}{8\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{9}{8})& 2\mathrm{\&pi;}/9\&le;\mathrm{\&Phi;}<7\mathrm{\&pi;}/9\\ D\tan \mathrm{\&delta;}(-\frac{81}{3{2\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{81}{16\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{81}{32})& 7\mathrm{\&pi;}/9\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

Perhaps: $x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{9}{4{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<\mathrm{\&pi;}/3\\ D\tan \mathrm{\&delta;}(\frac{3}{2\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{5}{4})& \mathrm{\&pi;}/3\&le;\mathrm{\&Phi;}<2\mathrm{\&pi;}/3\\ D\tan \mathrm{\&delta;}(-\frac{9}{{4\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{9}{2\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{9}{4})& 2\mathrm{\&pi;}/3\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For ten plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{25}{8{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<\mathrm{\&pi;}/5\\ D\tan \mathrm{\&delta;}(\frac{5}{4\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{25}{8})& \mathrm{\&pi;}/5\&le;\mathrm{\&Phi;}<4\mathrm{\&pi;}/5\\ D\tan \mathrm{\&delta;}(-\frac{25}{{8\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{25}{4\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{25}{8})& 4\mathrm{\&pi;}/5\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

Perhaps: $x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{25}{12{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}\&le;2\mathrm{\&pi;}/5\\ D\tan \mathrm{\&delta;}(\frac{5}{3\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{4}{3})& 2\mathrm{\&pi;}/5\&le;\mathrm{\&Phi;}\&le;3\mathrm{\&pi;}/5\\ D\tan \mathrm{\&delta;}(\frac{-25}{{12\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{25}{6\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{25}{12})& 3\mathrm{\&pi;}/5\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

For 11 plunger axial piston pumps:

$x_1{\mathrm{\&Phi;}}_1=\left\{\begin{array}{cc}D\tan \mathrm{\&delta;}(\frac{11}{3{\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2-1)& 0\&le;\mathrm{\&Phi;}<3\mathrm{\&pi;}/11\\ D\tan \mathrm{\&delta;}(\frac{2}{\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{14}{11})& 3\mathrm{\&pi;}/11\&le;\mathrm{\&Phi;}<8\mathrm{\&pi;}/11\\ D\tan \mathrm{\&delta;}(-\frac{11}{{3\mathrm{\&pi;}}^2}{\mathrm{\&Phi;}}^2+\frac{22}{3\mathrm{\&pi;}}\mathrm{\&Phi;}-\frac{11}{3})& 8\mathrm{\&pi;}/11\&le;\mathrm{\&Phi;}\&le;\mathrm{\&pi;}\end{array}\right.$

Change with Ф, change, can eliminate the geometric flow pulsation of axial piston pump from principle if the x coordinate of plunger and swash plate point of contact track is pressed the following formula rule.Below only be the curvilinear equation between 0≤Ф≤π, can be simply definite for the curve between π≤Ф≤2 π by symmetry properties.

The structure of axial plunger pump geometric flow pulsation of the present invention as shown in Figure 1, it comprises cylinder body 1, cylinder body 1 is provided with the plunger hole 2 more than three or three, is provided with spring 3 and plunger 4 slidably in the plunger hole 2, the end of plunger 4 is provided with swash plate 5; Swash plate 5 is provided with slideway 6, and the geometrical shape of slideway 6 bottoms is provided with by the mathematical function rule of angle of swing.Be provided with the piston shoes 7 more than three or three in the described slideway 6, the bottom of piston shoes 7 and side are provided with ball 8, and ball 8 and slideway 6 rolls and be connected, 9 universal connections of bulb on piston shoes 7 tops and the plunger 4.Directly contact because the swash plate curve in traditional axial piston pump is a plunger ball, be unfavorable for swash plate and plunger ball work with swash plate formation point.Be to improve plunger ball and swash plate contact performance, the coupling platform structure that the present invention proposes plunger ball and swash plate as shown in Figure 2.This structure changes the sliding friction between plunger ball piston shoes and the swash plate slideway into rolling friction, can improve the performance of contact.Slide in the slideway of ball on the piston shoes on swash plate, the curved surface of slideway bottom is by curve design proposed by the invention.

Swash plate proposed by the invention not only is applicable to through the linkage structure of piston shoes and plunger and the curvilinear structures of the cam-type axial piston pump that the present invention proposes equally also is applicable to traditional cam-type axial piston pump.

Claims (4)

1. method that reduces axial plunger pump geometric flow pulsation, it is characterized in that: this method is that the sliding trajectory with plunger on the axial piston pump and swash plate point of contact distributes by mathematical function, make cylinder body in rotary course, control the displacement amount of each plunger in different moments, make each plunger be tending towards constant, to reduce axial plunger pump geometric flow pulsation in total fuel supply flow rate sum of different moments.

2. the method that reduces axial plunger pump geometric flow pulsation according to claim 1 is characterized in that: described mathematical function is determined the geometrical shape of the sliding trajectory that plunger is different with the swash plate point of contact according to plunger quantity

3. device that reduces axial plunger pump geometric flow pulsation, it comprises cylinder body (1), cylinder body (1) is provided with the plunger hole (2) more than three or three, is provided with spring (3) and plunger (4) slidably in the plunger hole (2), and the end of plunger (4) is provided with swash plate (5); It is characterized in that: swash plate (5) is provided with slideway (6), and the geometrical shape of slideway (6) bottom is provided with by the mathematical function rule of angle of swing.

4. the device that reduces axial plunger pump geometric flow pulsation according to claim 3, it is characterized in that: be provided with the piston shoes (7) more than three or three in the described slideway (6), the bottom of piston shoes (7) and side are provided with ball (8), ball (8) and slideway (6) roll and are connected, the universal connection of bulb (9) on piston shoes (7) top and the plunger (4).

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