DE1453493A1 - Hydrostatic axial piston unit with variable stroke volume - Google Patents

Description

. "," Ν Meini & eidiieri: 2342

w'jit July 22nd, 1963

Cologne, Lothringer Str. 81

Dr. Expl.

Applicant's Dr.-Ine. Heinrich Ebert,
HLr th / Bavaria,
In the Weller 2

Hydrostatic axial piston unit with changeable

Stroke volume »

The present invention relates to hydrostatic Axial piston units with variable displacement, as used both as pumps and as motors Find·

The purpose of these improvements is that of such axial piston units, especially at high pressure Working fluency, occurring very intense and high-frequency To eliminate grumbling tears »

In axial piston units of this type, there is generally a relative to a fixed control valve part around! on ends! drum a mostly odd number of cylinders, the longitudinal axis of which, like the corresponding circumferential lines, is coaxial with the drum rotation axis sy 11 Ticiriechen or conical surface as a geometric location,

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«2 ~
evenly distributed around the circumference, arranged sincU

Are in diseen cylinders longitudinally displaceably mounted piston _s kraftschlüssigg under the pressure of the fluid in the respective cylinders or spherical hinged connecting rod to a more or less obliquely to act Troajn.elumlaufaoi3.se disposed support member ·

The cylinders are on the part of the control valve that is standing next to them facing. Slotted end of each cylinder «The slits of all cylinders act on the end face of the drum finally together with corresponding, mostly kidney-shaped Millings as well as sealing surfaces and sealing webs on the fixed control valve part as a whole as a control valve such »that those located in the cylinder drum Cylinder as the drum revolves relative to the nierenf örmigaa Ausfräsungeii on one side of the plane passing through the axis of rotation of the cylinder drum to which the kidney-shaped Discharges are symmetrical and connected with a high pressure line. "

? Altering the stroke volume of the orbiting relative to the control valve cylinder drum, together with this will be pivoted about an axis "In this case, the connection of the control valve for high-pressure or _e low-pressure line generally concentrically about respective pivot connections to said pivot axis * The pistons act: in This is usually done via connecting rods hinged on both sides on a flange of the drive shaft as a support member *; ... . . : -. . . ".. ■■ - ..,

In the case of a cylinder drum arranged centrally and non-rotatably relative to the drive shaft, however, only a swash plate can be used as a support member for the pistons to change the stroke volume

+ / and on the other side of this level with a ~ 3 low pressure line

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be pivoted about a pivot axis, in this case the pistons usually only act positively on the swash plate, be it with a rotatably mounted swashplate directly or with a non-rotatably mounted swashplate via a corresponding one dynamic or hydrostatic sliding shoes

In the case of the two different types of construction, the stroke change takes place in any case by more or less strong pivoting of one component relative to the other about a pivot axis

This swivel axis has generally always been perpendicular to the above-mentioned one in any case. through the drum axis of rotation plane, to which the kidney-shaped millings are symmetrical and furthermore, in particular, always arranged in one plane with the rotational axis of the cylinder drum.

It is generally known that when such axial piston units are in operation, when there is a high brackish difference between High-pressure and low-pressure side and, at high speeds, extremely annoying high-frequency humming tones larger Intensity occur which exclude the application possibilities of these axial roller units for many applications »

Ss is the generally held view that this Humming noises due to the sudden change in pressure of the working fluid that occurs constantly when such units are in operation in the individual cylinders at the transition from the high pressure side to the low pressure seed and vice versa will · We have therefore tried, with more or less success, to increase the intensity of this BrufmtiSne with the help of Blind strokes in connection with corresponding overlaps

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at the control valve, in such a way that the decompression process during the transition from the high pressure side to the low pressure side as well as the compression process during the transition from the low pressure side to the high pressure side are delayed or delayed for the working fluid within the small limits possible for this purpose. more gradually _{o However,} these measures have not fundamentally eliminated these phenomena

The present invention, however, is based on the knowledge that these obnoxious humming tones are not present the ever-present sudden and constant pressure change in the cylinder fluid, but rather only occur if, at the same time, there is also a change in the size of the movement of the respective cylindrical liquid is connected, in other words, if at the same time a more or / less strong inflow of the Working fluids from the high pressure line into the respective Cylinder at the transition from the low-pressure to the high-pressure side or a more or less strong outflow the working fluid from the respective cylinder during the transition from the high pressure side to the low pressure side, i.e. near the dead points. This back and forth pulsation of the liquid under high pressure near the dead center is solely decisive for the intensity of these humming tones o

The invention is based on this basic knowledge the basic task of avoiding the humming tones or strong noises and the associated disadvantages ©

The task set is achieved according to the invention by the design and arrangement of the components of the unit in such a way that that only positive or "only negative swivel torques can be exerted around the swivel axis"

For a better understanding of this according to the invention

Solution Jar principle as well as the particularly advantageous 90980A / 0552

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constructive embodiments are now first. further explanations to the technical "contexts given ·

Based on the above, it has further been found that the change in volume of the liquid in the pressure change due to elasticity or ₀ compressibility of the liquid, as was previously always assumed alone no great change in the movement parameter of the respective cylinders liquid brings with it so that this compressibility the liquid alone cannot be responsible for the intensity of the humming sound that occurs,

It has also been shown that the humming tones z _o B © occur in axial piston units with a pivoting torque that is almost independent / normalized from the respective stroke in the entire stroke range, whereas in axial piston units with a pivoting torque that increases proportionally to the stroke only in the range of small strokes _e

This can be explained according to the invention by the fact that in first case in the whole Hubbereioh around the pivot axis alternating moments occur, de h. that is, moments about the swivel axis occur, which have alternating positive and negative values, while in the broader case these alternating moments are also superimposed by correspondingly larger pivoting moments, especially in the case of larger strokes, so that the remitting moments only with correspondingly smaller strokes or smaller swivel angles in the area are both positive when also negative moments come "

These alternating torques result from the fact that, although the piston is in the symmetrical position on both the high-pressure side, as auoh on the low-pressure side, to which through the pivot axis as auoh duroh the axis of rotation of the cylinder drum imaginary plane, the resulting force of all pistons lies in this plane and thus runs through the pivot axis « When the cylinder drum rotates, however, this plane of symmetry of the piston rotates with the cylinder drum to the previous plane until a piston from the high pressure side €

on the

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Low pressure side or vice versa changes. This is the case for an odd number ζ of pistons, as soon as the drum rotates through an angle of + 9θ £

ζ hato Since the resulting force within this respective rotation remains in the plane rotating with the cylinder drum, continuous rotation of the drum about the pivot axis of the pivotable members results in Weohsel moments JU ^, which are z _e B ₀ for pistons arranged in parallel, which on a Pressure disk act directly as a swash disk, at the maximum the size results in zuj

ζ odd number of pistons in a unit

S ₀ . the center of gravity distance of £ rJ. consecutive

² the piston from the drum rotation axis

F is the piston area of a piston

γ the swivel angle

P ₁ J denFlüssigkeitsdruck mean on the high pressure side P ₁ J the fluid pressure on the low pressure side "*

These alternating moments about the pivot axis ultimately bring about during the rotation of the drum in connection with the always existing play in the adjustment mechanism an oscillating Movement of the pivotally arranged members of the size that in connection with the pressure change of the cylinder fluid now also the above-mentioned inflow of the liquid or the above-mentioned outflow of the liquid from the cylinders under high pressure to the low pressure side

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there, in the vicinity of the dead centers, in sufficient quantities is to avoid the undesirable high-frequency humming tones by pulsing the liquid back and forth in the cylinders

It is already in connection with the design of a piston B for hydraulic axial piston units with pivotable Swash plate proposed to avoid these alternating moments, which there directly on the swash plate Acting piston end face - each designed as a surface of rotation, whose line of intersection with a plane laid through the axis of rotation of a piston B is a mirror image of two Curved lines lying to the axis of rotation results, each at a certain distance from the axis of rotation of the piston tangent to a plane perpendicular to the piston axis of rotation, whereby it is achieved that both in the positive and in the negative Sohwenkwinke above this swashplate these can never act alternating moments about the pivot axis, but either only positive or only negative Total momentsβ,.

However, this measure is not applicable in all cases, especially not when the piston z. Be act via shoes on the swash plate or the piston in mostly pivotally arranged cylinder drum via spherical articulated connecting rods act on the flange of the unit drive shaft _e This measure is especially anwendbarο only tilt resistant executed cylinder barrel storage

According to the present invention is therefore according to an advantageous embodiment of the invention proposed to eliminate these alternating torques by

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that the pivot axis is eccentric to the amount e Drum axis of rotation is arranged, where e at least should be so large that, taking into account the so-called friction circle on the pivot pin on the pivotable members can never act moments that alternately both positive with respect to the pivot axis as well as show negative values «, About the size This value e is given more precise information in the description below

For axial piston units with from the respective stroke almost

-small

independent / mean swivel torque, this eccentric arrangement of the swivel axis is sufficient and also useful to prevent alternating torques in both the positive and negative swivel angle range ₉ if the pivoting member only needs to be pivoted in the positive pivoting angle range or only in the negative pivoting angle range, since otherwise the values for e are too large, so that the size of the maximum adjustment torque is excessively large

In a further embodiment of the invention, however, is in Also within the scope of the following description, an exemplary embodiment for a swivel axis version, with which itself for units with proportional the stroke strongly 'increasing mean swing moment, these Weohsel moments in the entire positive and negative angular range with the same small eccentric distance of the pivot axis can be prevented by the drum rotation axis, as before, and therefore no greater adjustment moments appear",

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The invention is now based on the exemplary embodiments according to,! ig »1 to 11 explained in more detail«

Here shows:

1 shows an arrangement of the pivot axis according to the invention with an axial piston unit to change the stroke • swiveling cylinder drum in which the pistons but connecting rods with ball bearings on both sides act on a flange of the drive shaft,

FIG. 2 shows the swivel body of the arrangement according to FIG. 1, in section and in a view from the section line II-II the Figo 1, especially in view of the situation the associated swivel axis,

Figo 3 cLen swivel body according to FIG. 2, cut according to the Section line IH-III in Fig. 2,

4 shows an arrangement of the pivot axis according to the invention in the case of an axial piston unit with a cylinder drum that is centrically and non-rotatably arranged in relation to the drive shaft and with swiveling swivel plate to change the stroke, on which the pistons act via sliding shoes,

5 shows the position of the pivot axis of the arrangement according to FIG in a section along the section line Y ~ V of FIG. 4,

6 shows an arrangement according to the invention of the pivot axis in the case of an axial piston unit with a cylinder drum arranged centrically and non-rotatably relative to the drive shaft and with pivotable to change the stroke, otherwise rotatably mounted swash plate on which the pistons act directly with their spherical cap end,

FIG. 7 shows the axial piston unit according to FIG. 6, in section according to section line VII-YII,

BAD ORiQiNAL

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an arrangement of the pivot axis according to the invention in an axial piston unit with a cylinder drum arranged centrally and non-rotatably and with a change of pivotable and also rotatably mounted swash plate on which the pistons, as in the Pig. 6, with ball * dome ends act directly, but in which the swivel axis compared to the version naoh fig. 6 is such that, in contrast to all previous arrangements, the mean swivel torque changes sharply in proportion to the piston stroke ₀

9 shows the axial piston unit according to FIG. 8 in section according to section line IX-IX in Fig. 8, ■

FigolO and 11 a Sehwenkachsausführung according to the invention •. For an axial piston unit according to Fig. 8 in an enlarged Appearance as opposed to execution according to Fig. 9 not only in the positive swivel angle range, but also in the negative swivel angle range, so: in the entire swivel angle range, the occurrence of free alternating moments around the pivot axis is prevented and still relatively small Total adjustment torque results,

Figolla or »lib the swivel axis bearing according to Fig» 11 with an oblique disc angle of ψ = + 15 ° or * of

The axial piston units according to Figo 1 to .7 represent Axialkolbena.asführung in which, at constant pressure of the working fluid, the size of the mean pivoting torque, based on the; Pivot axis, not very much changed with the piston stroke; _: ■: - - -

In contrast, represents the Axialkolbenaggregat _a of FIG. 8 " Represent a version in which the middle swivel

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ment, related to the swivel axis, at constant pressure ■ the work flow changes strongly with a change in the piston stroke, in which the mean swiveling torque increases sharply with increasing swivel angle iP and, conversely, decreases sharply with decreasing swivel angle *

The aggregates shown essentially each consist of a rotatably mounted drum 1 'In this drum there is an odd number of cylinders 2 ₉ whose longitudinal axes, like corresponding Uantellinien in a cylindrical surface with the same axis as the axis of rotation of the drum, as a geometric location, evenly distributed around the circumference, are arranged ο The pistons 3 are mounted in the cylinders 2 so that they can be moved back and forth in the direction of the longitudinal axis of the cylinder.

The cylinder 2 is at its the stationary control valve 4 facing end with a Schlitzyversenen ₀ The slits of all the cylinders at the end surface of the respective drum act schlieselich together with the kidney-shaped recesses 6 on the control valve member and the sealing surfaces and "Mchtstegen at the Irennfläohe between 'the cylinder drum 1 and the fixed control valve part 4 as a whole as a control valve in such a way that the cylinders located in the cylinder drum when rotating the drum relative to the kidney-shaped millings are on one side of the plane passing through the drum axis of rotation, to which the kidney-shaped millings lie symmetrically, with the high pressure line 8 and on the other side of this level with the low pressure line 9 are hydraulically connected ₀

This level represents for the execution according to Fig «. I, 41 6 and 8 each represents the image plane, which according to Figo 2 and 3 with I-I, according to Fig. 5 with IV-IV, according to Figo 7 with VI-VI, for Fig «9 with VIlI-VIII and for Fig» 10 with VIIIa-VIIIa

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draws is

In the embodiment according to Pig »1, the cylinder drum is rotatably mounted on the pivot 10, which in turn is fastened in a bore of the control valve part 4 by means of collar 10a and screw 11. The control valve part 4 is pressed conically into the swivel body 12 so that it can be viewed as part of the swivel body _e

The swivel body 12 is provided so that it can be swiveled about the axis AA (-Figo 2 and 3), which in turn, according to the invention, is at the center of the axis of rotation of the drive shaft 13 at a distance e, but otherwise perpendicular to level II, arranged is _e -

For the articulation of the pivoting body at the assembly housing 14 corresponding bores serve the swing body as well as on the unit housing concentric with AA, are inserted through the corresponding to the hinged connection between the pivot body and Aggregatsgehause axle journal 15 _e These pins' are each provided with radial bores 15a and a concentric blind bore 15b provided so that the holes in the swivel body 12 on one side of the high pressure side 8 or ο the holes on the other side of the low pressure side 9 with the help of appropriately provided annular grooves with the further not shown parts of the non-pivotable high pressure or low pressure line hydraulically connected *

The hinge points are of course still corresponding to the outside through seals in the form of sealing rings sealed, which, however, were also not drawn, Since they are known in and of themselves, are of subordinate importance in the context of the present invention. The pistons

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act under the pressure of the working fluid in the Cylinders on both sides of the spherically hinged connecting rod 16, as is known, on the flange of the drive shaft 13, which in turn can be rotated by means of bearings 17 and 18 in the unit housing and cannot be displaced in the longitudinal direction is mounted so that it is rotated under the influence of the piston forces, but not longitudinally displaced regardless of whether it is used as a drive shaft in the case of a pump or as an output in the case of a motor * shaft serves. After all, there is usually not one between the cylinder drum and the drive shaft either Drawn smooth running joint provided, which here only the frictional moments occurring during drum rotation has to overcome and the rest of the synchronism with the swivel body "has to ensure swiveling cylinder drum with the drive shaft"

To "change the stroke or" to change the swivel angle by swiveling the swivel body with the cylinder drum about the swivel axis Α · ~ Α, the hydraulically actuated adjusting piston 20, which is otherwise hydraulically actuated on both sides and is provided longitudinally displaceable in the cylinder 19 of the unit housing, is used, the ZoBe when moving from the position shown to the left via the link 21 causes a reduction in the pivot angle tp and thus the piston stroke and vice versa a position of the piston as ₀ B ₀ is illustrated in Figo 10 for the local version Z, a resultant force on the Triebwellenflansch, which apart from a very small component vernaehlässigbaren umabhängig

909804/0662 ~ ^U ~

of the pivot angle lies essentially in this plane of symmetry and is of the size Σ H if H = pF means the force exerted by the respective fluid pressure .ρ on the area F of each individual piston. Subject to the law of "actio and reactio", the same force also acts in reverse on the swivel body, so that with ecostp as a lever arm, depending on the swivel angle ψ (see Fig. 1), an average swivel moment of the size

M = "Σ H ecos φ results, which can be written more precisely in detail

^ Pw ⁺ ^ ~ * Γ ~ %) ^ eeosi ^ or also

depending on whether of the total odd number ζ of Pistons, as they are normally used in these units is common, the larger number of pistons ^ r- dated Pressure of the high pressure side p ^. and the smaller number of "7-1

Piston - ^ - i- is acted upon by the pressure of the feather pressure side p ", or, conversely, the smaller number of pistons £ ■ £ - by the pressure of the high pressure side P _1x and the larger one

z + 1 η

Number of pistons -yy ~ from the pressure on the feather pressure side

is applied. ■ ■ *

P _1x larger than p, _T is in any case M, like

ü U ^S b

can be seen in general from the two equations, smaller than M, which initially only depends on

^s a

be shown.

When turning the cylinder drum from this symmetry section ~ ment out ^ rotates the plane with the resulting

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Piston force with the drum until a piston changes over from the high pressure side to the low pressure side and vice versa. This is the pail when the drum turns with the resulting piston force

+ 9C ö
Has turned out an angle of ^ -— gps of the plane of symmetry around the drum axis of rotation _e

When this angle is exceeded, the plane of the resulting piston force jumps from this extreme! ^^ into a plane _{e which is a mirror image of the plane of symmetry}

As a result of this, which is always repeated with the constant rotation of the drum in one direction or the other Process 5 becomes the previously derived mean swiveling moment M from an additional moment M via ~ stores that when the drum is rotated by 180 / z, depending on the direction of rotation of the drum, from one negative or positive maximum value changes steadily up to a positive or negative maximum value, then see suddenly to change to the maximum value with the opposite "sign.

The largest M this is both in its size

Max
as well as the alternating torque in the extreme positions, which constantly change with regard to its sign, are, apart from the sign, regardless of whether the greater number of pistons is on the high pressure side or on the low pressure side, in each case completely the same, as is subsequently demonstrated, and are expressed in general terms as follows :

^ ^ _{1 r 2 + 1n} j £

max b

The smaller number of pistons is on the high pressure side

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and on the low pressure side the larger number of Piston is located,

ViTenn, conversely, the larger one on the high pressure side Number of pistons and on the low pressure side the If the number of pistons is smaller, the result is:

Max

ρ -

_Z1 - -κ-

Here means;

ζ the odd number of pistons in a unit

Ϊ ^{1 is} the pressure area of a piston

s _Λ the center of gravity distance from the drive shaft axis of rotation ' ^z ~' z-1 am

from —n— consecutive enj / drive shaft flange

hinged connecting rods! spherical heads ^

^s z + 1 ^ ^en center of gravity from the drive shaft axis of rotation 2 of ^ y- successive, on the drive shaft flange

hinged connecting rod ball heads ψ the .swivel angle
PjT the pressure of the working fluid on the high pressure »-

page
P ₁ yy. the pressure of the working fluid on the low pressure «

According to the laws governing the center of gravity, here ■ Assumed at the same distance from the drive shaft axis of rotation and evenly distributed on the circumference of the drive shaft flange » Ball heads the center of gravity of all ball heads lie on the drive shaft axis of rotation. But then it must be accordingly the center of gravity of the lying on one side, a plane passing through the drive shaft axis of rotation Ball heads, multiplied by the number of these ball heads, equals the center of gravity distance on the other side

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_{Ball heads 9} lying in this plane must be multiplied by their number. It must therefore be expressed in general terms

5 ^s z ~ 1 ⁼ "T" ^s z + 1

Using this relationship; one can then finally for both, above for M

mg -γ

Write expressions ζ.Bo:

=! X ^ T ^s z ~ 1 ^P H ~ ⁵ T " ^s z ~ 1%) ^Fcos f ^sin ^ F" ^{or auc] l} max

ⁱⁿ - ' ^what

ττ z + i% Ψ z ₊ i% f

max —η— —Ir— ζ

according to the above, one and the same maximum values for result in any case, i.e. completely regardless of whether

Max
the larger or smaller number of pistons is located on the high pressure side or on the low pressure side and, in contrast to the values of IL according to the formulas set out above for this purpose,

To now in connection with every ever-present game only positive connections in the swivel mechanism to achieve and thus to avoid a high-frequency movement of the swivel body, which according to the explanations in the introduction, finally, in connection with the change in fluid pressure in the cylinders of the cylinder drum the high-frequency humming tones to be eliminated, especially if there is a high pressure difference between the high - - pressure «and low pressure side and at high speeds the cylinder drum, causes, according to the invention, the out the total moment resulting from the moments 1 / L · and IL

Max

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accept either only positive or only negative values, so it must be M ₀ ⁺ M, either greater than Hull or

less than NuIl ₀ If WU is positive (e positive according to FIG. 1), then 1 / L · + M is positive in all cases, but not

Max

without further ado M ₀ - - M.

^S Vx

If this latter term be positive, so Must IL - M greater than zero, d _o h M ^ M

max max

pur M "is here then the smaller one obtained for this · - ten values, ie M "(see above),"

^b b

If, on the other hand, M is “negative, which would be the jail with the same swivel angle, if the swivel axis at distance e to the drum axis of rotation and to the drive shaft axis of rotation were arranged in a mirror image of the embodiment according to FIG. 1, then“ M _O ~ M, on all cases

^S \ ax

negative, but not without further ado <~ M «+ IL either

max negative

It can be seen that here for both cases, regardless of whether the pivot axis is arranged above or below the drive shaft in FIg ₀ 1, the condition must be met that in general the absolute value of Μ _{σ is} greater than the absolute value must be from M,

' ^{S w} max

i.e., but that according to the expressions derived therefor and deleting Feosa? have to be

(-1 p * ■ s + l _P) β j? f

which finally results from factoring out s -. and dividing through with ^ - p "as a condition for e

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~ 1 "sin

^s z ~ 1

z ~

T "

With a piston unit with, for example, z- 9 pistons, the result depends on the greatest pressure ratio Pn / pw that occurs in each case for the expression

= 0 numerical values according to the following numerical

blackboard:

P _H / p _N = ■ 1.5 10 20 30 co

O = 0.000 0.6400 0.8010 0.895 0.925 1.000

It can be seen from this that e could be equal to zero at p "/ p ^ = 1.0, but otherwise must be greater, the greater the maximum pressure ratio p" / p _w intended for a particular arrangement is to be assumed "

So is the pivot axis like in I ¹ Ig * 1 _? 2 and 3 illustrate at a distance e according to the above condition both from the cylinder drum rotation axis and from the drive shaft "axis of rotation", so with this arrangement, depending on the definition, either only positive or negative resultant torques occur in both the positive and negative swivel angle range so that, in particular in the joints of the swivel mechanism, only non-positive connections are achieved in one direction or the other and thus high-frequency movements of the swivel body are avoided, which would otherwise occur in connection with the liquid

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change in pressure in the cylinders and the in the mowing of the piston dead points take place on and off ** the liquid flows in and out of the cylinder High pressure would cause the humming tones to be eliminated «,

For the sake of completeness it should be noted here * - showed that the size of e taking into account the im Swivel joint existing friction moment JL, which counteracts every moment in its size, nor around'den radius r ,, of the friction circle corresponding to this friction torque

■ ti,

can be reduced, the value of this friction radius results from the pivot pin enr'adius r "and the pivot"

joint underlying coefficient of friction ^ to r-c, ^ = JUr ,,,, so that finally a condition for e ■ total results

From this formula you can finally calculate up to at what pressure ratio Pg / pjT such an axial piston " aggregate "can be driven without oscillating Movements of the swivel body and thus humming noises occur »

In the axial piston embodiment according to FIGS. 4 and 4 is in contrast to the execution according to Figo. 1 to 3 the Drum 101 arranged centrally on the drive shaft 113 and connected to it in a rotationally fixed manner via a spline shaft profile, so that they with their cylinders 102 and pistons 10 3 with this around » runs with the transmission of torque »

The drive shaft 113 is in the bearings 117, 118 in the aggregate, eccentric swivel axis

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housing 114 rotatably mounted ₀

In the same way, that control valve part 104 is fixed in pressed into a hole in the unit housing 114. Its kidney-shaped millings match the one here as well in the unit housing arranged bores of the high pressure line more or less only through their connections recognizable 108 or low pressure line 109 in connection, so that the cylinder here as the drum revolves directly alternately on one side of level IV-IV with the high pressure line 108 and on the other side of level IV-IV hydraulically connected to the Hierder pressure line 10§ been

The pistons 103 are each provided with a ball head and act under the pressure of the liquid in the Cylinders via the sliding shoes hinged to the ball heads onto a pivotably arranged sliding surface of the Swivel body 112 * For changing the stroke volume The swivel body is provided with swivel pins concentric to the axis B-B, which are inserted into corresponding bores of the Unit housing 114 and the screwed-on cover 114a are inserted and stored "

According to the invention, the axis »B-B is at the center of the rotating drum at a distance e perpendicular to the plane IV-IV and in a plane parallel to the sliding surface of the swivel body the centers of the ball heads arranged

This latter measure changes the mean pivoting moment, that is to say the moment that is here in the symmetrical position of the pistons in relation to a plane through the drive shaft axis of rotation and parallel to the swivel axis, the swivel body is again exerted only slightly with the size of the respective

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ligen piston stroke * This mean swivel torque is here

^M s

OOS

When the cylinder drum is turned out of the piston symmetry position, Weohsel moments M arise here again,

d "h _e moments with alternating sign which overlap in the mitt sized Schy / enkmoment, The G-rösstwerte these alternating moments arise additionally look here

5j ^

2 ^

so that the same condition applies to e as to the previous one Embodiment according to Figo 1, results in completeness for the sake of this it should be noted that here s_-

Although it means the center of gravity distance from the drive shaft axis of rotation of ^ zI consecutive pistons, but for which the center of gravity distance from the drive shaft axis of rotation ^{of Ζ} * "Ί consecutive points of intersection is more general

von Kolbendrehaohsen should be understood with the level YV , as this TiTert then also applies to the lall that the pistons in contrast to. The exemplary embodiment is not arranged on a cylindrical surface coaxial with the drum axis of rotation, but on a conical surface coaxial with the drum axis of rotation .

By being arranged at a distance e from the drum axis of rotation The sign of the swivel axis changes in both the positive and the negative swivel angle range resulting moments avoided.

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The elements of the heavy lifting mechanism, which is here from the "hydraulically actuated and actuatable on both sides, in the cylinder 119 of the unit housing arranged longitudinally displaceable piston ^ 120 and on it on the swivel body articulated push rod 121 exists, are thereby clearly frictionally connected to each other, so that no high-frequency Swivel movements of the swivel body can occur as a cause for high-frequency sounds This prevents the joints of the adjustment mechanism from knocking out ο

In the embodiment according to FIGS. 6 and 7, as in the arrangement according to Pigs 4 and 5, the drum 201 is again arranged centrally on the drive shaft 213 and connected to it in a rotationally fixed manner via a splined shaft profile, so that it is here too with its cylinders 202 and pistons 203 rotates with transmission of torque ₀

The drive shaft is rotatably supported in the plain bearings 217 and 218 in the unit housing 214 «'

The groove-shaped millings, sealing surfaces, sealing webs and bores of the control valve part 204 are provided directly on or in the unit housing in such a way that the Cylinder 202 as the drum 201 rotates alternately on one side of the plane VI-VI with the bores of the High pressure line 208 and on the other side of the level VI-VI with the bores of the Mederdruckleitung 209 connected will.

The pistons 203 are here provided with spherical caps at their end facing the swivel body 212, the center of which lies on the respective piston rotation axis. Its radius a is »Under the pressure of the liquid in

-25-

8098CU / 0B52 - ■

The pistons act on the cylinders via their spherical caps directly on a thrust washer 225, which is located opposite in the swivel body 212 by means of rollers 226 and by means of the slide bearing 227 the bearing ring 228 located in the swivel body 212 is rotatably mounted

This thrust washer 225 is used to change the stroke volume together with the swivel body around the inserted into bores on the swivel body and on the unit housing and Pin 229 screwed to the housing can be swiveled »The holes are concentric to the swivel axis G-G ·

According to the invention, the pivot axis is here to the center of the Drum axis of rotation as well as to the center of theDruokBcM.ben Drehaohse arranged at a distance e, perpendicular to the Level YI-YI and otherwise in one aur drum revolver vertical plane YII-VH, in the position shown in * ment (stroke equal to zero or Sohwenkwinkeleiip equal to zero) the centers of the spherical caps are

Duroh this latter measure is the mean pivoting moment Mg, i.e. the Sohwenkmoment, which is here in symmetry the piston to a plane through the drive shaft axis and is exerted on the pivot body 212 parallel to the pivot axis, as in the previous exemplary embodiment

Since the same twisting moments as there are superimposed on this pivoting moment when the drum rotates, the same conditions also apply here for aen distance e, regardless of whether the Sohwenk & ohse at distance e> as shown * above the drive shaft or in

8098/04/0562

In contrast to Mgo 6, the mirror image of it, i.e. below the drive shaft axis of rotation is arranged iato here too appropriately under s_ * the center of gravity distance from the

ζ ** ι

The driving shaft axis of i5zl successive spherical cap centers in plane TII-YII d, _e * h at Hubstelbng lull understood "

Bas Sohwenken the swivel body around the swivel axis takes place only with the help of the handwheel. * 250, with which the threaded spindle / mounted in the unit housing rotate leaves. On the threaded spindle is

'252 252a

the Grewindemuff e /, on which the pins / with the casting blocks are attached, which engage in a corresponding link guide on the swivel body, so that when the handwheel is turned in one or the other direction of rotation, the swivel body is pivoted in one direction or the other » *

The axial piston design according to Pig 8 and 9 corresponds to ! Principle of the arrangement according to FIGS. 6 and 7, do h · the drum Here again, 501 is centric on the drive shaft 515 arranged and connected to the drive shaft via a spline rotatably connected so that they with their cylinders 302 and pistons 505 with the transmission of torque with this runs around * Also the kidney-shaped millings, Sealing surfaces and bores of the high pressure line 508 and lower pressure line 309 directly on the unit housing 314 attached or contained in the unit housing « The pistons 303 are likewise on their joint body 312 facing end * provided with spherical caps, the center of which is on the respective piston rotation aehee and whose radius is a. Under the pressure of the liquid in

909804/0552

The pistons act on the cylinders via their spherical caps

325

also directly to the. Thrust washer / the one in the swivel body

326 ^ 327

en / and means de Gleitlrs ^

by means of the rollers / and by means of the; bearings the bearing ring located in the swivel body is rotatable

stored is © ^i; - ^{v a r?} ■ '·'

Compared to the embodiment according to Figo 6 and 7, however, the Swivel body 312 is provided with pin 330, which is concentric are designed to the pivot axis D-D and which are in corresponding bores on the unit housing 314 and on its' Cover 314a are stored pushed in, so that "the thrust washer can be swiveled together with the swivel housing via an adjusting mechanism which is further drawn «"

The pivot axis D-D is also according to the invention to the center of the drum axis of rotation as well as to the center the thrust washer axis of rotation in turn arranged at a distance e,

'- ■ I-

namely perpendicular to the plane YIlI-YIII and in contrast to the Execution according to Fig. 6 and 7 in the one for the drum hub rotary axis vertical plane IX-IX * in the position shown the pressure disk effective plane is also included "

By this latter measure, in contrast to the embodiment according to FIGS. 6 and 7, the swivel deflection of the swivel body is reduced, so that in this embodiment with the piston end designed as a spherical cap, as in the embodiment according to FIGS drive shaft 313 dureh the pivot body through means of bearings 317 and 318 in the unit housing 314 can be mounted on both sides to §chwenfckörper, which is desirable _for particular & _s ann when such © aggregates sit other aggregates together into @ in © iE g © m © xii © sffi @s ßfeiiSüs ©. © "& wb β, Ί-β steps ! © ® © in ·»

Crstrigb® old b @ 0eii2 äsikt © ji ji Eiafeaiimsss ^_©:: work © it ~ should · © ■ '"". ^: ";',""" * ",

ORI € JNÄL

U53493

In contrast to the "versions described so far This arrangement results in an average pivoting moment Μ «that changes considerably with the pivoting angle, as it turns out to:

Mg * -sS- £ (aay + e)
cosip '

When rotating the cylinder drum out of the symmetry position of the piston to that by the drum drum drum β and parallel. the plane going out to the pivot axis DD results in the same alternating moments as in the previous exemplary embodiment, which are superimposed on the mean pivot moment. M ₁ -

® ^ Vax

always be bigger than Hull "

This results here using and taking into account the Relationships established earlier in this context:

(Ä »l P _H + £ + 1 P _n ) S ₂ (asino? + E)

or

The expression (U, r _z was added later, as was the case with the dejat-preceding derivation

9098CU / Q5S2 ■ '" ²⁸ "

4453493

You can see from this that e can be zero as long as here » so long

asin (p + Ur ₇ · —r_J: __ _e . 'sin -

^P H ^{/ P} N ⁺ iZT 2

is, de h · as long as only pivot angles occur that are Meet condition "

Normally this is the case for units with, for example, nine pistons and a maximum pressure ratio Ptr / pw ■ 30, as long as ψ in the positive or negative pivoting angle range is greater than about 3 $ 8 ° ·

Should, however, 'the aggregate also be operated within this small pivot angle, then an eccentrically close arranged pivot axis required "extends the pivot angle range SiOH this case either a positive pivoting angle or negative ^ ohwenkwinkel only up to the swivel angle is zero, yields verifiable with ASINO ⁰ m Q in the above expression for the same value as before for the embodiment according to FIGS.

However, should the swivel angle range also be set to negative or »positive! Sohwenkwinkel extend, eo increases sioh βφ by the term asiny. If the swivel angle range is to be fully extended from the full positive to the full negative swivel angle, i.e. from γ> «« + 15 ^{0 to} β ψ » -1 | °, then % φ was to be increased by asin15 °

is for normal ratio "e with Jz * Z" ntun piston το

¹ —29-

9 0 9 8 0 4 / as S 2

about Q, 1d to 0 _f 12 &, if d meant the KoIb endurchm.es ser the an. and for sick with this arrangement already very large swivel moments were then, however, compared to the case that only a positive or negative swivel angle was already available. would be required to be almost twice as large with this simply eccentrically arranged swivel axis, which would be nods and desirable *

This arrangement with a simply eccentric pivot axis is therefore for the present embodiment only to recommend if only a swivel angle range is required is that each only differs from a maximum positive or negative swivel angle to a swivel Q extends * For the distance e the eccentric

arranged pivot axis is then sufficient e ■ » e _w · _β

IO

In contrast, should the pivot angle range of a pivot angle ψ "15 ° up to a pivoting angle (p =» - 15 ^O extending, a distance between the pivot axis would be required, the * e ^ + asin 15 ° is given by e _o

If one considers that for this case asinl5 ° with d as the piston diameter is equal to about d / 2, then in the former Fall "into maximum adjustment torque from the hawser

^ ^{2 + e in the latter} case

Adjustment moment of the size

Mg «2h__ ( _a / _{2 + d} / 2 + e} result in tif To

The last adjustment torque would be about $ 1.8 times Size of the former, which is undesirable in many cases *

In order to achieve this undesirably large adjustment torque 909804/0562 “ _n

"» 30 * ·

H53493

to avoid, in the further refinement of the jSrf inding instead of a simply eccentric, Böhwenkachee a. Arrangement according to "Jig> 10, and 11 proposed, in which you see a double eccentric pivot axis at a distance e ^s β from -the Troinmeldrehachse results« Here the pivoting body is in the positive SekwenkbereiGii _; the axis BE ,, in the.. * Negative Scnwenkbereioii .but pivoted about ^ the .-, axis * Fi ^1. ,

each of the two axes _v to the triple axis of rotation in each case only a distance e ^ = βψ _& , have ». - ... ■. ■ - ■. ■, .- ■. .-... -;. ··, ■

This version, instead of the simply eccentric pivot axis bearing, is sloping ·· 9 with the axial piston design ·. use guide according to Figo 8 za «- ■ '

Bei.dieser Schwenkaöhslagerung is the pivot body 41-2 is not provided with the cylindrical pin, whose axis of rotation shown in Wig »8 and 9, are arranged concentrically to the axis DD, but with cones 430, of which the outer bearing surface after lig" IQ and 11 ams two eccentric half-cylinder faces 430a, 430b, which are located in the plane through the thrust washer axis of rotation parallel to the pivot axis EE or ' B ¹ —F cut _ö The upper journal bearing surface corresponds to a cylinder surface, the axis of rotation Mt of which corresponds to the axis- I? - * !? coincides at distance e, whereas the lower journal support surface corresponds to a cylinder surface whose axis of rotation coincides with axis EE at distance e "■" - ■■ "" ■ "-.

In the same manner, the bearing in the unit casing 414 consists of two eccentric to each other situated holes are formed, wherein the upper bearing Iragflache 414a belongs to einer'Bohrung t the center thereof with the axis EE coincides whereas the! Prägfläche 414b belongs lower to a bore, whose center with the axis FI? collapsed

The Badiöh der Halbzyiinde # of the cone bearing surfaces both '9098D4 / 0SS2 - ., ■ , -3α-

all of the "storage areas" in the housing are each of same size, bo that the more frequent support surface of the pin together with the lower bearing surface of the bore in the housing represents a cylindrical surface of the same diameter, whose Axis coincides with axis F-F, and the lower wing of the pin together with the upper wing of the Housing bore a cylinder surface of the same diameter represents} whose axis coincides with the axis E-E, as can be seen in particular from FIG. 11 * The spaces between these pins and bores are finally filled with fillers 431 »432, which dated Cones. 4-30 are guided sideways (see Fig. 10) and the im Section XI-XI (s · Fig * 11) have the shape of crescent circles *

The crescent pieces are on the one facing the drum Side is a mirror image of the drum axis of rotation in the position shown in Fig. 11 (^ «0) cut off, so that

their ends have a central angle of about 120 °

Their ends rest on stops 433 kis 4-36, which are attached to both the pivot pin 430 and the unit housing, so that the filler 431ι 432 clears beyond these stops both relative to the support pin and relative to the eccentric Crehäusebohrungen can move · If, however, the swivel body with its support pin, z. B ₀ according to Fig. 11a, pivoted clockwise, bo the upper filler piece 431 is pivoted from the upper stop of a pin 430, away from the upper stop 433 of the housing bore, while the lower filler piece 432 is held by the stop 436 of the lower housing bore

As a result, in this positive pivoting angle range, pivoting of the pivoting body 412 about the axis EE is effected, that is, at a distance «^ _Q from the plane passing through the drum axis and lying perpendicular to the plane YIIIa-VIIIa.

909804/0552

■ - 32 "

is in order "

As long as the load on the wings of the filler pieces 431 »432 both against the trunnion 430 as auoh limited to one area compared to the housing bores remains, whose end driving rays through the respective cylinder axis not through the friction circle of the other Cylinder axis goes through, there is no self-locking instead, so that when swiveling back the swivel body from a positive pivot angle to Sqhwenkwinkelcp «0 the upper filler piece 431 its stop 434 on the pivot pin 430 follows without further ado, exactly like the lower filler piece 432 at the stop 436 of the exact hole without further remaining

The limitation of the load to the range mentioned can be achieved with a reasonably correct ratio of e to the cylinder radius of both the trunnion and the Bearing bore surfaces by 'corresponding, tolerating the achieve corresponding cylinder radii © This measure is particularly favored by the fact that that the load direction is perpendicular to the thrust washer, d. h · follows the swivel angle in each case «

If, on the other hand, the swivel body with its support pin is pivoted counterclockwise according to Figo 11b z _e Be, the lower filler piece 432 is also pivoted from the lower stop 435 of the pin, namely away from the lower stop 436 of the lower housing bore, while the upper filler piece 431 from the stop of the upper housing bore is held. '

This is a negative pivot angle range in this Swiveling the Sohwenkko'rpere 412 around the Aehee F-F achieved> the mirror image of the drum drenachee to the

9 098 0 4 / OS B2

_ 33 - ■

Axis E-E is arranged

For turning back in this area, there are finally the same conditions as "they were previously for the positive area -has been described- ■ - "<

The described embodiment thus realizes a doubly eccentric journal bearing which, with a distance of only e ^. even for ■■ a pivot angle range extending over the whole positive to negative angular range, in the sense of the invention pivoting moments with alternating positive and negative values verhinderto Compared to an equivalent embodiment according to Figo 8 and 9, the maximum required pitching moment is considerably reduced in this case, which at the in itself comparatively very large Verstellmomenten this embodiment according to Figo 8 and 9 in particular as regards the size of the hydraulic adjusting cylinder of ausserordentiicher importance _o

In the case of axial piston ^{units according to Figo 6 to:} 11 with piston ends in the form of spherical caps, the different speeds in the contact point between the piston and the rotatably mounted pressure disk are in any case the same in the case of larger swivel angles due to the corresponding rolling of the pistons on the rotating pressure disk to ensure down to the pivot angle ML1, the contact point must not lie within the friction circle of the piston in relation to the cylinder bore with the smallest adjustment of the thrust washer, the contact point must never be within a circle concentric to the piston rotation axis, the radius of which is r ^ - « . «Μ,« is * ifA <the coefficient of friction of a piston of diameter ü in its. cylinder

-34-9Ö9804 / 05S2

H53A93

In order to achieve this, pistons are still used according to the invention, the end surface of which consists of a surface of rotation which, at a distance e ^ · from the axis of eotation of the piston, is tangent to a surface perpendicular to the axis of rotation of the piston, where e _v /, ^ «

^K TK2

When using such pistons in axial piston units according to FIGS. 8 to 11, with regard to the distance θ of the pivot axis of the drum axis of rotation or of the drive shaft axis of rotation e compared to the previous values still be reduced by the value e ^ - so that for this Cases applies *

^{P 1} " _sin 90 ° -

909S04 / 0552

Claims (2)

Bettn sign:, 2342 Kö / St. July 22, 1963 U53493 - 35 - Claim 1 · Hydrostatic Acial Piston Unit, on the one hand essentially consisting of a drum with cylinders and pistons rotating around a control member, whose Longitudinal axes distributed uniformly around the circumference in a sur Drum axis of rotation are the same rotational surface and dl · when rotating with the drum relatively sum control member on one side of a sum control member fixed, through dl · Trommeldrehaohse going level each below the Druok of a liquid shoohdruolcleitung, on the other Side of this level, however, are each under the pressure of a Flussigkeltsniederdruokleitung * and the / i on the other hand essentially consists of a stub link for the under The piston is under pressure and is changing the stroke volume of the drum relatively sum Stütsglled bsw « that the support member is arranged so that it can pivot about an axis relative to the drum, which is characterized by the design and arrangement of the components of the unit in such a way that in each case only positive · bsw · in each case only negative «Sohwenkmomente can be exercised around the Sohwenkaohse« -36- 9098CU / 05 52 H53493 ?. «HydroetaU-echee Axialkülbenaggregat according to claim 1, characterized in that the swivel axis (AA, BB, CC, DD) is arranged so far outside the axis of rotation of the drum the rotating pistons in the required pivoting angle range bfci a certain pivoting angle only exert only positive or negative pivoting moments about the pivot axis 3 · Hydrostatic axial piston unit according to claim 1 or r _f characterized in that the rotating drum (1) with the cylinders (2) and pistons (3) and the control member (4) are arranged on a pivoting body / iat, di · K Piston (3) act as a spigot via connecting rods (16) with ball bearings on both sides (16) on a flange of the unit drive shaft (X?) and the swivel body with the revolving drum and the control element is arranged so that it can be swiveled around a swivel pin which is as far as it is centered in the Distance (e) both to the drum rotation axis as well as for the drive shaft rotation is provided that only positive or only negative swivel torques about the swivel axis / foot can be left from the rotating pistons on the swivel body in the entire swivel angle range (generally 1). 4 Hydrostatic axial piston unit according to claim 1 or?, characterized in that the drum (101) with their cylinders (102) and pistons (103) rotates centric and non-rotatably with the unit drive shaft (113), the pistons act on an independent support member (112) that changes the stroke volume by a üchwenkaohee (B-B) pivotable is provided, which is as far out of center cur ' Drum axis of rotation or drive shaft axis of rotation at distance (e) Arranged in a fixed plane parallel to the drum barrel and sum control member (104) that of the rotating pistons in the required pivoting angle range SAD ORiGiNAL 909804/0552 U-53-493 on the support member at a certain pivot angle in each case only positive * or in each case only negative Schwentaoaente, among other things, the pivot axis (B-B) can be exercised (Fig. 4). 5 · Hydrostatic axial piston unit according to claim 4 _f, characterized in that the pivotable support member (412) is provided with two opposing pivot pins (430), the supporting surface of which is formed from two eccentric cylinder surfaces (430a, 430b), the axes of rotation of which when the stroke is zero Distance (s) are arranged in a mirror- inverted manner on a hbeneft fixed to the control member through the axis of rotation _; namely in such a way that the tenon bearing surfaces in relation to the level through the Tromaeldrehaohse are each on the other Ueite of the associated cylinder rotation axis (Ii-E, PF), and that these tenons in aar Troamel are supported by Kreiasiohelstiloken (431 »432) cut off , the outer bearing surfaces of which are old the bearing surfaces in. Ageregets Housing (414) meanwhile formed from the remaining cylinder surfaces of these / eccentrically adjacent cylinder surfaces _. that is, held as a pull-piece between the support pin (430) and the bearing bore la unit housing (414), eeltllch το «support pin or aa housing, are arranged slidably opposite both and old their cut filaments in the zero stroke position of the stub link on stops (C4, A35) and the support pina (430), as well as to aneohllgen (433 »436) of the bearing housing« 14), so that when the actuator is pivoted out of the stroke zero position, depending on the pivot rotation, one circular shaft of each pin is moved old from the pin, while the other Kreiseichelstüok belonging to each pin το «attachment of the bearing housing is held in its position, whereby each of the support pins, fieger- -38- 909804 / 0B52 . - 38 - boiirungen and KreiBsichelstücken overall zylindrise & e sliding bsi Una wing? " The bearing surface is formed in such a way that the support member, depending on the direction of rotation, can be pivoted from the normal zero position around one or the other axis of rotation of the two eccentric cylinder surfaces as the respective pivot axis. 6. Hydrostatic Axialkolbsnag®, in particular with odd Aja.ze.hl you, Fülben and with a pivot axis according to one of claims 1 Me 5 lying in a plane perpendicular to the unit drive shaft »characterized in that the distance e of the respective pivot axis from the drum axis or «Of the drive shaft axis of rotation generally satisfies the following conditions: ι.) ^, - ^ - ^ ₁ _. _νΓ * ₂ 2.) 4-S-SL- ^ ₁ B _{B-> 1} «i * SC + d / 2 ^p s / ^p N ⁺ z3f ~ Pjj / pjj is the maximum number of jerks that occur in the liquid LjU in the high pressure «- bsw _e low pressure line» s the odd number of pistons of the AxialkaLbenaggregatee, e_ ₄ the distance of the intersection of the resultant 2 of ^g "'successive pistons under the same liquid pressure in stroke zero position with the> the pivot axis containing, perpendicular to the drive shaft rotation Bben.®. In this from the Triebwellendrefeechss, (W- den Kibungskoeffiseienteüi in the swivel axle bearing, r "the radius of the trunnion, e ^ the distance from the piston rotation axis at which. Palle of a with a curved rotation plane -39- 909804/0552 H53493 all end face or active face of the piston, this curved surface of rotation touches a plane perpendicular to the surface of rotation of the piston » since the durometer of a piston means " 909804/0552 ^{6AD 0? IkyNAL}