CN101238288A

CN101238288A - Apparatus to concentrate a fluid and a multiple chamber pump

Info

Publication number: CN101238288A
Application number: CNA2006800287927A
Authority: CN
Inventors: P-B·卡特曼
Original assignee: Seneca S A
Current assignee: Seneca S A
Priority date: 2005-08-09
Filing date: 2006-06-09
Publication date: 2008-08-06
Also published as: EP1752662B1; PT1752662E; WO2007016988A1; EA200800551A1; ATE386884T1; US20090246045A1; JP2009504992A; ZA200802182B; ES2302105T3; AU2006278957A1; DE502005002928D1; EP1752662A1

Abstract

Disclosed is a device (V) for concentrating a liquid (F) which is pumped through a concentrating apparatus (3) by means of a differential piston pump and directly impinges the differential piston (K) in an assisting manner during the conveying stroke at a residual pressure as a concentrate (FK). The differential piston of said device (V) is driven by a drive shaft (12) that actuates a linearly guided valve control member (18) of an intake and discharge valve assembly (A). The differential piston pump is embodied as a radial piston pump (R) in which eccentric attachments (13, 14) for the differential piston (K) and the valve control member (18) are disposed on the drive shaft (12), the differential piston (K) and the valve control member (18) being hinged directly to the eccentric attachments (13, 14) by means of traction and pressure couplings (S).

Description

Liquid concentration device and differential pistonpump

Technical field

The present invention relates to a kind of device by the described type of claim 1 preamble, and a kind of by claim 2 differential pistonpump as described in the preamble.

Background technique

When liquid is concentrated, for example when desalination of sea water (reverse osmosis) or fruit juice production,, come pumping liquid, can produce extracting liquid simultaneously with higher relatively residual pressure with many primary energies according to manufacturing process.Especially the demand to primary energy is very high in desalting process, this is a known disadvantage for a long time, for example, all adopted following manner to reduce energy cost in the past, promptly utilize in extracting liquid and in delivery stroke, assist differential pistonpump, thereby save primary energy because the energy that residual pressure contained is next.

In the sea water desalinating unit known and in (Fig. 5) differential pistonpump shown in EP 0 450 257 B1 by EP 0 450 257 B1, control by feed liquor valve and liquid discharging valve, stepped piston produces extracting liquid and the penetrants with higher residual pressure with away from an end pumping of piston rod liquid to be concentrated (for example seawater) in the back via for example film with reverse osmosis work.Under the control of feed liquor and liquid discharging valve device, will be in piston rod one end that differential pistonpump is sent in extracting liquid circulation under the residual pressure, so that before discharging stress-free substantially extracting liquid, directly help out when the pumping by residual pressure.Be linked together with the crank pin that constitutes the live axle of bent axle by the bar of connecting rod the linear type guiding of stepped piston.Pressure chamber feed liquor and liquid discharging valve device are positioned at piston rod one end of stepped piston, have separately feed liquor and liquid discharging valve, and they overcome the acting force of the spring operation by the push rod of control cam by guiding linear type that is arranged on the live axle.

Because acting force of the spring has cumulative characteristic, therefore can produce unnecessary power loss.Bent axle-connecting rod means not only can cause the physical dimension of differential pistonpump to increase, and for example, connecting rod can produce disharmonic piston stroke motion under certain condition because turning to, thereby produce further power loss, and in the liquid of institute's pumping, cause pulsation.

Summary of the invention

The objective of the invention is to, a kind of the above-mentioned type device that only needs few primary energy just can work is provided, and a kind of extremely compactness, differential pistonpump efficiently.

This purpose of the present invention can realize by claim 1 or the described feature of claim 2.

In described device, the radial piston pump design proposal has the performance characteristic that physical dimension is little, pulsation is minimum, and lose little efficient tension and compress connecting mode owing to adopted, therefore few primary energy is just enough, and can make full use of, especially directly utilize energy contained in the extracting liquid.Straining and compress connecting mode can make stepped piston and valve control device produce extremely harmonious stroke motion.To the control of feed liquor in the pressure chamber and liquid discharging valve, with the mode of the stroke motion perfect match of stepped piston and on long working life, wear and tear and carry out littlely.This radial piston pump design proposal can realize and use customized compact type according to the demand of each building or architectural complex when the device of desalination of sea water, because employed primary energy is less, even the primary direct current of solar thermal collector generation, for example, can provide higher flows at sun-drenched riviera.Therefore can use this compact device and not need to connect power supply, perhaps do not having power supply or power shortage, or this type of compact device be used in the area of electricity price costliness.

Utilize the differential pistonpump of radial piston conceptual design not have connecting rod, especially the valve spring that does not have power consumption, and because physical dimension compactness, efficient are higher, its purposes is not limited in desalination of sea water, but be applicable to and need pumping liquid, and same liquid, concentrated liquid or any applicable cases of operational other liquid of abundant residual pressure is arranged.

In a kind of suitable mode of execution, for each liquid discharging valve and feed liquor valve are provided with a unique valve control device, so that energy consumption is reduced to minimum level.Since adopt compress with the tension mode coupled drive shaft on eccentric wheel, therefore saved the valve spring of power consumption, thereby help raising the efficiency, life-saving,, and do not contain any parts that are easy to damage because feed liquor carries out work with the liquid discharging valve device with relative less power.

In described a kind of suitable mode of execution, be arranged on the towed body on the eccentric wheel with being provided with a swivel bearing, the bar end is linked together with it with the shape locking mode, thereby can transmit eccentric rotatablely moving in harmonious mode.Slide guide device can be realized the lateral displacement motion between rotating eccentricity wheel and straight-line bar, and the wearing and tearing of not being worth mentioning, and does not also have noise or vibration.

The slide guide device of transferring between the bar of rotating eccentricity wheel and linear guiding can suitably constitute the anti-rotation lock of bar.But also can suitably design, make bar to rotate, to distribute wearing and tearing to slide guide device.

Advantageously, towed body owing to the reason of assembling or be designed to that halfbody by assembly unit constitutes or or even single-piece make it have an outwardly open groove that is used for bar, and groove is less than the external width of piston rod, so that form the sealed connection of shape.Between relatively large surface of contact, produce the shape locking action, thereby can avoid taking place concentrated wear.

Advantageously, piston rod is not put in the slide guide device on being fixed in housing, to eliminate the lateral load that acts in the course of the work on the piston rod.Slide guide device can be the plug-in type sliding sleeve.In addition, the mobile guide device with support shell of moulding snaps among the groove in the sliding fit mode, so that come the support piston bar by big as far as possible length.

For the ease of assembling, what conform with purpose is that piston rod or support shell or both all are positioned at towed body on the eccentric wheel vertically.

The bottom surface of groove should constitute the seal face (compressing connection) of bar end, owing to must slide, this pressure side will be longer than the external width of bar end.In bar, have two with terminal across a certain distance the parallel slot mutually of bar, its width is similar to the inner width of groove, and constitute on the bar end outwardly directed drivening piece snap in as engaged element (on the one or both ends at bar) side of groove recessed among (tension connects).Slip between piston-rod end and towed body preferably occurs near the eccentric wheel part, is beneficial to smoothness of operation.

In a kind of suitable mode of execution, the side in the groove is recessed to be parallel to the eccentric wheel tangent line, and side is recessed is longer than drivening piece in this direction, so that do not hinder slide relative.Side is recessed to can be designed as perforation, thereby can be convenient to the assembling of bar end in towed body, thereby towed body can be designed to single-piece in case of necessity.

Importantly, make corresponding to the eccentric wheel of the valve control device of stepped piston discharge opeing and feed liquor control valve unit around the axis of live axle with respect to 90 ° of the eccentric wheel biasings of this stepped piston, and it is leading in the rotary driving direction, thereby on delivery stroke, residual pressure is imposed on piston rod one side of stepped piston in the mode of accurate control, and on the revesal of stepped piston removal residual pressure immediately.

Aspect reducing running noise and reducing pulsation, what conform with purpose is, regularly three or more stepped piston is distributed in around the drive axis with star fashion, and to these stepped pistons a shared eccentric wheel and a shared towed body is set.So just can reduce moving-mass, and save installing space.Possible is along live axle a plurality of these type of stepped piston groups to be set.

Conform with the destination, also regularly the valve control device of the discharge opeing of a plurality of stepped pistons and feed liquor control valve device is distributed in around the drive axis with star fashion, should dispose a common eccentric wheel and a common towed body to valve control device simultaneously, so that save installing space.

In described a kind of suitable mode of execution, discharge opeing and feed liquor control valve unit are fixed on the housing, and have radially alignment and coaxial feed liquor valve seat and the discharge opeing valve seat towards drive axis, and wherein the discharge opeing valve seat is preferably than the close more live axle of feed liquor valve seat.By this location, make higher residual pressure action time long zone as far as possible away from live axle, and make sealing between feed liquor valve seat and the live axle be subjected to the effect of higher residual pressure hardly that perhaps only the short time is acted on.The structure of valve seat required installing space in the drive axis direction is less.

Valve control device should pass the discharge opeing valve seat with enough gaps and extend among the feed liquor valve seat, is provided with a seal area between the valve seat simultaneously, and also on the live axle opposite.First and second convex shoulders on the valve control device are used for lifting corresponding valve body from its valve seat, and wherein the motion of lifting of valve seat is reverse.That is to say that valve control device is opened the feed liquor valve when lifting, and when descending, open liquid discharging valve.

For the ease of assembling, convex shoulder should constitute by being fixed on the tube end that screw thread preferably is fixed on the valve control device, so that obtain big as far as possible contact area.

By more weak spring towards valve seat to the valve body application of force, wherein the feed liquor valve body is disk or the disk in can deciding by spring.Draining valve then is ring segment or the annular disk that guides on valve control device and can move with respect to valve control device.What conform with purpose is, is provided with bearing ring seal here between valve control device and draining valve, enters among the discharge opeing valve seat to avoid leakage around the draining valve.

In order after loading onto valve body, to realize the zero defect sealing, taper or spherical sealing surface can be set on the valve body, valve seat also can be designed to taper or spherical sealing surface.

For guarantee can not occur between liquid discharging valve and the feed liquor valve overlapping, just that is each valve only when another valve is closed, can open, importantly, vertically must be less than the spacing between the mounted valve body along valve control device in the spacing between the convex shoulder.Preferably so determine size, make two valve bodies be installed on the top dead center and lower dead center of stepped piston, and between valve control device and the corresponding convex shoulder certain interval is arranged.For example, this gap can be approximately between 0.1mm and the 0.4mm.

Valve control device can conform with the destination and repeatedly guide in its length range.

The guiding device of valve seat and valve control device can be installed among the sleeve body, and in shell wall that sleeve body is clamped in and live axle is adjacent and the housing chamber between the cap.Can have a liquid entering hole and two liquid ports on these sleeve bodies, another liquid entering hole then is arranged among the wall of housing inner chamber.This design proposal can be simplified assembling, and can make feed liquor valve and liquid discharging valve close mutually, thereby saves installing space.

In a kind of suitable mode of execution, be used for the eccentric measure-alike of stepped piston and valve control device, and have identical eccentricity.

In a kind of mode of execution of particularly suitable, can adjust eccentric eccentricity with respect to drive axis, so that can mate transmission power and/or performance characteristic as required.This for example can so realize, promptly eccentric wheel by two mutually nested, can relatively rotate and eccentric adjusting sleeve that relative position can be set arbitrarily constitutes.In addition, eccentric wheel also can be installed on the live axle replaceably, thereby can change eccentricity by changing eccentric mode.

Description of drawings

Mode of execution to theme of the present invention makes an explanation with reference to the accompanying drawings.Accompanying drawing is as follows:

Fig. 1 comprises the radial piston pump shown in the localized axial section to the schematic representation of apparatus that the liquid of institute's pumping concentrates, and stepped piston is in top dead center position,

Radial piston pump in Fig. 2 imbibition stroke,

Radial piston pump in Fig. 3 delivery stroke,

The radial piston pump design details cross section of Fig. 4 in the IV-IV of Fig. 5 section,

The axial cross section of the shown in Figure 4 details of Fig. 5 in the V-V section,

The schematic representation of the another kind of design details of Fig. 6, and

The another kind of design details of Fig. 7.

Embodiment

Shown in Figure 1 be used for for example forming at the same time liquid juice F _RSituation under liquid F is condensed into concentrate or extracting liquid F _KDevice V can be a kind of sea water desalting equipment according to principle of reverse osmosis work, or be used for equipment of concentrated juice or the like.In device V, stipulate in principle, utilize radial piston pump R to carry liquid F, and make it under pressure,, from this concentrator, produce extracting liquid F with obvious residual pressure by concentrator 3 guiding liquids _K, and liquid juice F _RBasically do not have pressure, for example it can be got up as the purified water collecting of handling through desalination of sea water.The extracting liquid F that will have obvious residual pressure _KBe used for radial piston pump R, utilize contained energy directly to support to carry liquid F, thereby make that only need consume less primary energy (for example power of electric current or motor P) just can make radial piston pump R work.Under the situation of carrying out the desalination of sea water processing, concentrator 3 for example is a kind of film system according to principle of reverse osmosis work.

Radial piston pump R among Fig. 1 sucks the liquid F (imbibition stroke) that has low initial pressure in case of necessity by at least one stepped piston K by pipeline 1 and liquid supply valve 16, sends into pipeline 2 by liquid discharging valve 17 then in delivery stroke.Pipeline 2 leads to concentrator 3, liquid juice F _RFrom this concentrator, flow out, then under the residual pressure effect, in pipeline 4 with extracting liquid F _KBe sent to liquid entering hole 5.Extracting liquid F _KBe used to impact after the stepped piston K in pressure chamber 36 in delivery stroke, described extracting liquid does not have pressure ground to discharge from liquid port 6 basically.

In order to be convenient to that device is started, can a control valve unit 7 be installed in pipeline 2, this control valve unit directly leads to liquid entering hole 5 by pipeline 8, but under normal circumstances uses hardly, perhaps only uses under a stable condition.

Radial piston pump R has the shell wall 10 that the chamber 11 with delivery area and working area and live axle 12 separates, and (for example) dismountable cap 9.

The eccentric wheel 13 that is used to drive stepped piston K is installed on the live axle 12 and another is used for the eccentric wheel 14 of actuating feed liquor and liquid discharging valve device A, and eccentric wheel 14 in the sense of rotation 40 of live axle 12 axis 38 with respect to about 90 ° of eccentric wheel 13 biasings.In mode of execution as shown in the figure, the size of two eccentric wheels 13 is different big, and is installed on the live axle 12 with different eccentricities.But it is onesize that two

eccentric wheels

13,14 can be designed to fully, and also can have identical eccentricity.

Eccentric wheel

13,14 can be fixed on the live axle 12, perhaps with the mode wedging that can change on live axle.In unshowned a kind of pattern, can change each eccentric eccentricity with respect to the axis 38 of live axle 12, for example by substitute mode, perhaps each

eccentric wheel

13 or 14 constitutes by two eccentric adjusting sleeves that can relatively rotate and can be fixed in the relative position.In Fig. 1,, represent the axis of eccentric wheels 14 with reference character 39 with the axis of reference character 37 expression eccentric wheels 13.

Stepped piston K has one in piston rod one side and compresses the bar 15 that connecting mode directly links to each other with eccentric wheel 13 by tension, and this bar is directly or indirectly guided point-blank and sealed along axis 37 in shell wall.Stepped piston K comprises a seal arrangement that pump chamber and pressure chamber 36 are separated.

Feed liquor and liquid discharging valve device A comprise a feed liquor valve that is made of valve body 32 and valve seat 27, and a liquid discharging valve that is made of valve body 29 and valve seat 28.

Valve seat

27,28 radially points to the axis 38 of live axle 12 and coaxial; 28 of discharge opeing valve seats point to live axle 12, and ratio is away from the close more live axle of the feed liquor valve seat 27 of live axle 12.For these two valves set a common valve control device 18, and directly or indirectly at least straight line motion of work and the sealing in shell wall 10 of this valve control device, by compressing and strain connection S it directly is hinged on the eccentric wheel 14; The piston rod 19 of valve control device 18 extend among the feed liquor valve seat 27 with certain radial clearance by discharge opeing valve seat 28 from connecting S.Seal arrangement 29 perhaps seals between liquid port 6 and feed liquor valve seat 27 between liquid discharging valve and chamber 11.In addition, between valve seat, also have another to be used for the guiding device 21 of valve control device 18.For example be fixed with a pipe 22 by screw thread on one section piston rod that reduces of valve control device 18, this pipe constitutes first convex shoulder 23 that points to draining valve 29 and second convex shoulder 24 that points to feed liquor valve body 32.When

valve body

29,32 places its

valve seat

27,28, spacing between the

convex shoulder

23,24 is less than the spacing between these valve bodies, thus when valve is closed for example each convex

shoulder

23 or 24 with

adjacent valve body

32 or 29 between exist 0.1mm to the gap between about 0.4mm.Feed liquor valve body 32 can be disk or disk, and by the more weak spring 33 of elastic force with its centering and towards feed liquor valve seat 27 application of forces.Valve body 29 can be annular disc or circular disk, and passes through spring 31 towards discharge opeing valve seat 28 application of forces.Between the piston rod 19 of draining valve 29 and valve control device 18, a bearing ring seal 30 can be set.Valve

body

32,29 can have taper or the circular fitting surface the same with valve seat 27,29.Feed liquor valve seat 27 can take shape among the ferrule element 25, and guiding device 21 and sealing 29 and discharge opeing valve seat 28 then can take shape among another ferrule element 26.

Sleeve body

25,26 is clamped among the housing between shell wall 10 and the cap 9.Liquid port in the sleeve body 26 leads to the liquid entering hole 35 of pressure chamber 36 in feed liquor valve seat 27 downstreams.On discharge opeing valve seat 28, liquid entering hole 35 links to each other with the chamber that is positioned at sleeve body 29 belows and contains draining valve 29 simultaneously.

Function:

By elementary driving source P for example motor or internal combustion engine drives live axle 12, so that make stepped piston K and valve control device 18 to-and-fro motion by connecting S.In the imbibition stroke, stepped piston K sucks liquid F away from an end of piston rod by the liquid supply valve of opening 16.In the imbibition stroke,

feed liquor valve

32,27 cuts out, and

liquid discharging valve

29,28 is opened.From pressure chamber 36, there is not pressure ground to discharge concentrated liquid F basically by liquid port 6 _KBefore the lower dead center that soon arrives stepped piston K, perhaps in the lower dead center zone,

liquid discharging valve

29,28 is closed, and just can open

feed liquor valve

27,32 when not having valve overlap.When delivery stroke begins, be in the extracting liquid F under the residual pressure _KWill in pressure chamber 36, impact piston rod one end of stepped piston K, so that work simultaneously with delivery stroke.Before the top dead center that soon arrives stepped piston K, perhaps in the top dead center zone, feed

liquor valve

32,27 cuts out again, and just can open

liquid discharging valve

29,28 when not having valve overlap.

Conform with purpose, regularly and star ground a plurality of stepped piston K and a plurality of feed liquor and liquid discharging valve device A are distributed in around the live axle 12, for example three or more at least.

At concentrated liquid F _KUnder its residual pressure booster action, only need a small amount of primary energy just make radial piston pump R work, thus can be by the direct current generator of solar thermal collector, make that sea water desalinating unit V can independent operation, for example for building or equipment potable water demand.

According to the liquid of need pumping and the flow-rate ratio between the concentrated liquid, stepped piston K is suitably adjusted away from an end of piston rod and the area ratio between piston rod one end, make the energy that can make full use of in the concentrated liquid come auxiliary rotating.Pressure difference on the seal arrangement of stepped piston K is smaller, and only 20 short time of seal area is applied residual pressure in the delivery stroke process.An oil groove can be set in housing inner chamber 11.

Figure 2 shows that the imbibition stroke of the stepped piston K among the radial piston pump R.Make concentrated liquid F in the pressure chamber 36 by opening

liquid discharging valve

28,29 _KRelease, and it is entered exhaust port 6, when

feed liquor valve

27,32 cuts out, will there be residual pressure in the liquid entering hole 5.Convex shoulder 23 stays open

liquid discharging valve

28,29, and convex shoulder 24 is then away from draining valve 32.When the residual pressure in the liquid entering hole 5 for example is 68 crust, the pressure of about 1 crust is only arranged in the pressure chamber 36.Liquid discharging valve 17 downstreams after closing, discharge pressure are approximately 70 crust, and after liquid supply valve 16 was opened, imbibition pressure was approximately 1 crust.So just there is approximately identical pressure at the two ends of stepped piston K.

Figure 3 shows that the delivery stroke of radial piston pump R, stepped piston K moves towards the top dead center direction.Valve control device 18 has been opened

feed liquor valve

32,27, and

liquid discharging valve

28,29 is then closed.The concentrated liquid F that has about 68 bar pressures _KAmong the feed pressure chamber 36, and auxiliary stepped piston K carries out work.Make

liquid discharging valve

28,29 keep closing with this pressure.Need the liquid of pumping to be under the pressure of about 70 crust, and liquid supply valve 16 closes, liquid discharging valve 17 is opened.Pressure difference on the seal arrangement of stepped piston K only has about 2 crust.

Figure 4 and 5 are depicted as for example mode of execution of the connection S between piston rod 15 and eccentric wheel 13.In Figure 4 and 5, constitute guiding device 37 shown in Figure 1 by the sliding sleeve in the shell wall 10 41, shell wall and two support shell 42 are submerged among the chamber 11, and along the sense of rotation of eccentric wheel 13 against horizontal force bar 15 are supported and lead.Support shell 42 stretches among the groove 45 of towed body 44 always, and towed body rotatably is fixed on the sliding shaft sleeve, perhaps be fixed on the needle bearing 43 on the eccentric wheel 13, and (for example) is positioned on the eccentric wheel 13 vertically by bar 15 and/or support shell 42.The inner width of groove 45 is approximately equal to the outside dimensions of support shell 42, thereby forms a simple sliding fit.In groove 45, be configured for the following seal face 49 (compressing connection) of bar end, and be configured for the tension face 50 (tension connects) of bar end in the side in the sidewall of groove 45 recessed 46.The bar end comprises two grooves that are parallel to each other 47, thereby can be at the drivening piece 48 among two of the terminal formations of bar outwards act on and snap in side recessed 46.Side recessed 46 is longer than the terminal external width of bar 15, and extends to the circumference of towed body 44 in case of necessity.

Towed body 44 can be a unibody construction, and perhaps (as shown in Figure 5) is assembled by halved body 44a and 44b.The anti-rotation lock of bar 15 also is formed on the sealed engagement of shape between drivening piece 48 and the side recessed 46.Groove 47 is included in the circumferential groove in case of necessity, and two drivening pieces 48 also constitute a round flange along the circumferential direction, makes bar 15 to rotate in connecting S.

In the mode of execution of simplification shown in Figure 6, a widened section is arranged on the end of bar 15, this widened section constitute one or two drivening pieces 48 ', and snap in the side of towed body 44 recessed 46 ' among.Along horizontal direction shown in Figure 6, drivening piece 48 ' and side recessed 46 ' between, and bar 15 and towards side recessed 46 ' liquid entering hole between be provided with enough gaps, when making circular movement around axis 37, can allow bar 15 to slide towards the double-head arrow direction with convenient eccentric wheel 13.

In mode of execution shown in Figure 7, bearing support 51 is arranged on the towed body 44, sliding pin 52 just is installed among the bearing support, and sliding pin passes the end of bar 15.Between bearing support 51, be provided with enough gaps, when making circular movement around axis 37, allow in the slide guide device of bar 15 towards double-head arrow direction sliding movement with convenient eccentric wheel.

Claims

1. device (V) to being concentrated by the liquid (H) of differential pistonpump pumping by enrichment facility (3), this liquid is as the extracting liquid (F that is under the residual pressure _K) auxiliary ground directly loads at least one stepped piston (K) when delivery stroke, wherein said stepped piston (K) is driven by live axle (12), at least one linear guide type valve control device (18) of this live axle operation feed liquor and liquid discharging valve device (A), it is characterized in that, differential pistonpump is a radial piston pump (R), on live axle (12), be provided for the eccentric wheel (13 of stepped piston (K) and valve control device (18), 14), and stepped piston (K) and valve control device (18) utilize tension and compress connection (S) and directly be hinged on the eccentric wheel (13,14).

2. the differential pistonpump of liquid (F) has: a housing, housing have and are used to treat the import and the outlet of pumping liquid (F) and are used to be in liquid (F under the residual pressure _K) liquid entering hole (5) and liquid port (6); At least one is transported to the stepped piston (K) of outlet with liquid (F) from import, and this stepped piston can be driven by live axle (12), also can directly be driven by residual pressure in delivery stroke, and this stepped piston separates a pump chamber and pressure chamber (36); At least one is used for the feed liquor of pressure chamber (36) and at least one valve control device (18) of liquid discharging valve device (A) and feed liquor and liquid discharging valve device (A), this valve control device is guided point-blank and is handled by live axle (12), it is characterized in that, differential pistonpump is a radial pump (R), on live axle (12), be provided for the eccentric wheel (13 of stepped piston (K) and valve control device (18), 14), and stepped piston (K) and valve control device (18) utilize tension and compress connection (S) and directly be hinged on the eccentric wheel (13,14).

3. differential pistonpump according to claim 2 is characterized in that, for feed liquor and liquid discharging valve device (A) are provided with a unique valve control device (18).

4. differential pistonpump according to claim 2, its spy just is, strain and compress connection (S) and have a swivel bearing in eccentric wheel (13,14) towed body on (44) and at least one are arranged on the bar (15 of stepped piston (K) or valve control device (18), 19) engaged element (48) on the end, and between engaged element (48) and towed body (44), be provided with one and in the tangent line of eccentric wheel (13,14) slide guide device be set in the sealed engagement of the shape of radially working with in the circumferencial direction preferred parallel basically.

5. differential pistonpump according to claim 4 is characterized in that slide guide device is configured for the anti-rotation lock of bar (15,19).

6. differential pistonpump according to claim 4, it is characterized in that, be used for bar (15,19) towed body (44) has cut in a slide guide device bottom and outwardly open groove (45), the inner width of seeing vertically of groove is less than bar (15,19) external width, this towed body preferably include two axial assembly units halfbody (44a, 44b) or all-in-one-piece.

7. differential pistonpump according to claim 6, it is characterized in that, the bar (15 of stepped piston (E) and/or valve control device (18), 19) be arranged in the mobile guide device (37) that is fixed on the housing, this mobile guide device (37) has sliding sleeve (41), and this sliding sleeve (41) and the support shell (42) that is shaped, align mutually along the sense of rotation of eccentric wheel (13,14) snap between the sidewall of groove (45) with sliding matching mode.

8. differential pistonpump according to claim 6 is characterized in that, towed body (44) is positioned on the eccentric wheel (13,14) vertically by slide guide device and/or support shell (42).

9. differential pistonpump according to claim 6, it is characterized in that, the bottom of groove constitutes the seal face (49) of bar end, this seal face is longer than the external width of bar end, terminal mutually across a certain distance with bar, parallel slot of two mutual diametrically contrapositions (45) or circular groove take shape in the piston rod, and they define the width that is approximately equal to groove (45) inner width, the bar end abuts against on the groove as engaged element (48), constitute at least one outwards outstanding drivening piece, this drivening piece snaps among the side recessed (46) that takes shape in the recess sidewall.

10. differential pistonpump according to claim 9 is characterized in that, the tangent line that side recessed (46) is parallel on the eccentric wheel (13,14) extends, and is longer than drivening piece in this direction.

11. differential pistonpump according to claim 2, it is characterized in that, be used for to the eccentric wheel (14) of the valve control device (18) that sets discharge opeing and feed liquor control valve unit (A) of stepped piston (K) with respect to the eccentric wheel that is used for this stepped piston (K) (13) around nearly 90 ° of axis (38) biasings of live axle (12), and leading in rotary driving direction (4).

12. differential pistonpump according to claim 2, it is characterized in that, three or three above stepped pistons (K) star ground distributes along the axis (38) of live axle (12), and sets a common eccentric wheel (13) and a common towed body (44) for stepped piston (K).

13. differential pistonpump according to claim 12, it is characterized in that, the axis (38) that the valve control device (18) that is used for discharge opeing and feed liquor control valve device (A) of stepped piston (K) is distributed in live axle (12) regularly with star on every side, preferably setover respectively nearly 90 °, and set a common eccentric wheel (14) and a common towed body (44) for valve control device (18) with respect to stepped piston (K).

14. differential pistonpump according to claim 2, it is characterized in that, discharge opeing and feed liquor control valve unit (A) have a feed liquor valve seat (27) and a discharge opeing valve seat (28) regularly with housing, and these valve seats are radially towards the axis (38) of live axle (12) alignment and coaxial, discharge opeing valve seat (28) is than the close more live axle (12) of feed liquor valve seat (27), and discharge opeing valve seat (28) points to towards live axle (12), and feed liquor valve seat (27) points to the direction that deviates from live axle (12).

15. differential pistonpump according to claim 14, it is characterized in that, valve control device (18) extends through discharge opeing valve seat (28) until in the feed liquor valve seat (27) with radial spacing respectively, with respect to live axle (12) and at valve seat (27,28) sealing between, and have and be used for first convex shoulder (23) that a draining valve is lifted, this draining valve is arranged in movable mode on the side of sensing live axle (12) of discharge opeing valve seat (28), and have and be used for second convex shoulder (24) that a feed liquor valve body is lifted, this feed liquor valve body is arranged on the side that deviates from live axle (12) of feed liquor valve seat in movable mode.

16. differential pistonpump according to claim 15 is characterized in that, described convex shoulder (23,24) is by being fixed on the end formation that preferably is fixed on the pipe (22) on the valve control device (18) with screw thread.

17. differential pistonpump according to claim 15 is characterized in that, feed liquor valve body (32) be one by spring (33) towards feed liquor valve seat (27) load, the best disk by spring (33) centering; Draining valve (29) is one and passes through spring (31) towards the annular disc that discharge opeing valve seat (28) loads and guides movingly on valve control device (18), preferably has a bearing ring seal (30) that is arranged between valve control device (18) and the annular disc.

18. differential pistonpump according to claim 17 is characterized in that, annular disc and disk have taper or spherical fitting surface, and valve seat (27,28) preferably constitutes taper or spherical.

19. differential pistonpump according to claim 15, it is characterized in that, at convex shoulder (23,24) between along the spacing of vertically seeing of valve control device (18) less than being installed on valve seat (27,28) spacing between the valve body on, and preferably make two valve bodies be on the top dead center and lower dead center of the stepped piston (K) that sets to discharge opeing and feed liquor control valve unit (A), and make and have the gap that is preferably about 0.1～0.4mm with respect to corresponding convex shoulder (23,24).

20. differential pistonpump according to claim 15 is characterized in that, valve control device (18) moves by the guiding device (21,37) that is fixed on the housing between discharge opeing valve seat (28) and live axle (12) and between valve seat (27,28).

21. differential pistonpump according to claim 14, it is characterized in that, valve seat (27,28) and guiding device (21) be arranged on sleeve body (25,26) in, in this sleeve body the is clamped in shell wall (10) and the housing inner chamber between the cap (9) adjacent, and have a liquid entering hole (5) and two liquid ports (34 with live axle (12), 6), another liquid entering hole is arranged in the shell wall (10).

22. according to each described differential pistonpump in the aforesaid right requirement, it is characterized in that the eccentric wheel (14) that is used for the eccentric wheel (13) of stepped piston (K) and is used for valve control device has essentially identical at least size and has identical eccentricity (C).

23., it is characterized in that the size of the eccentricity (C) of eccentric wheel (13,14) can be adjusted and/or eccentric wheel (13,14) can be installed on the live axle with changing according to each described differential pistonpump in the aforesaid right requirement.