DE1901757A1 - Double hydrostatic pump with floating control pin - Google Patents

Description

ap / A 29II Voith gearbox KO

Password 1 "control pin relief" Heidenheim (Brenz)

Double hydrostatic pump with floating control spigot

The invention relates to a two-stream hydrostatic Pump with separate supply and discharge of the working medium for each flow and with a rotor which is common for both flows and has the displacement spaces, as well as with a concentric rotor with little play in a bore in the rotor, stationary, with one suction and one pressure channel for each Electricity as well as with one each in the circumferential direction almost over 180 ° extending suction and pressure control slot provided for each stream, radially flexible, but axially and in the circumferential direction fixed and pressure-tight with respect to the channels on the housing Control pin, with the suction and pressure control slots on the control pin for one stream each in approximately the same axial plane and symmetrically arranged on this or on the other side of a stationary plane (eccentric plane) including the axes of rotation are and the control seat for the two streams in different Axial planes are arranged on the control pin and with the purpose of compensating for the on the suction side and pressure side of the control pin acting pressure forces arranged, the suction or pressure control slots of the control pin diametrically opposite, in the Wall of the control pin incorporated from the outside and connected to the associated channels via pressure equalization channels standing hydrostatic relief fields (pressure pockets).

This type of hydrostatic unit with control pin For the radial connection of the displacement spaces with the working fluid connections, a distinction must be made from those with an axial pressure connection with what is known as a control plate. The pressure pockets of the control pin of single-flow units are sized according to this

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and arranged in such a way that the control pin is force-free and No force pair Floats in its control bore.

In the case of double-entry pumps, a balance of forces could only be achieved with the previously known designs, when both floods are exposed to an equally strong pressure. However, it can easily happen that with double pumps e.g. the one flow works against a high resistance and the other against a low one. Because of this unequal load the flow rate comes from the pressure equalization at the control pin Equilibrium and there is a one-sided load on the control pin. Is the asymmetrical load so great that the If the oil film between the control pin and the bore is squeezed off, metallic contact occurs. A bite and a bite the pin in its bore is the result. The whole unit becomes unusable and has to be overhauled.

The object of the invention is to avoid this damage, i.e. a double flow through a suitable type of control pin relief to equip a hydrostatic pump for an independent loading of each flow rate. This object is achieved in that the control pin relief is carried out separately for each flow rate, that is, that of the center of gravity of the surface of each control slot projected onto the eccentric plane the opposite side of the control pin projected point at least two axially projected on both sides of this Point arranged, worked into the wall from the outside with the pressure applied to the associated control slot pressure relief fields are assigned according to size and position in such a way that the proportion of the surface area projected onto the eccentric plane of the relief fields belonging to a control slot, approximately equal to the proportion also projected onto the eccentric plane of the area of the control slot and that the sum of the static to be determined in the projection on the eccentric plane

ORiQtNAL INSPECTED 00983Λ / 0759

Moments of the axial on this side and on the other side of the projected Point arranged relief fields is at least approximately equal to zero.

As a result of the control pin relief carried out separately for each set of the control slots belonging to a delivery flow, Each conveyor flow can be charged independently of the other, without that the balance of forces on the control pin is impaired.

Due to this separate balance of forces, an increased number of pressure pockets is necessary for each conveying flow. Through this the leakage loss becomes greater, since oil flows out only at the edges of the pressure pockets and the ratio of the area of all printing areas unfavorable to their entire circumference will. In order to compensate for this disadvantage, it is proposed in a further embodiment of the invention that the relief fields each have the smallest possible ratio of circumference to have surface area, are preferably formed in a circular shape. In two ways, one becomes axially this and the other de.5 projected point only a single relief area and at least approximate the centroids of the relief fields assigned to a projected point to one that runs through the projected point and is as steep as possible Lay the helical line lying in the surface of the control pin. The printed pockets should be as close as possible to the circumferential position of the projected one The point where they come to rest, because in this position they can be effective for pressure equalization with almost their full surface. In Circumferential direction further from lying surface point can only with the Portion that lies in the projection direction on the eccentric plane, must be taken into account, even though their actual area share is much larger. The distance between two neighboring ones, too different Control slots belonging to the same side relief pockets can be chosen to be slightly smaller than their spacing to the axially adjacent non-associated control slot, there

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the pressure difference between the two adjacent relief panels is less than that of the adjacent control slot that is not associated with it. So that the leakage loss from the pressure equalization channels between the relief fields and the associated pressure areas is switched off in order to avoid unnecessary open, * leaking areas suggested that the pressure equalization channels exclusively are designed as channels (bores, lines) that are closed on all sides on the circumference.

The invention is illustrated by means of one in the drawings Embodiment explained in more detail below. It show j s ...

1 shows a longitudinal section through the axis of a hydrostatic unit with a floating control pin (rotated by 90 °) and according to the invention Relief fields and pressure equalization channels

2 shows a cross section through the unit at the level of the rotor,

Fig. 3 and 4 each a development of the control pin circumference in the level,

Fig. 5 shows a cross section through the control pin belonging to Fig. 4 and - next to it - the projection of a control slot and its relief fields on the Eccentric plane, and

6 and 7 show half the development of a control tap circular and staggered relief fields and their arcuate extent on the Control pin urafang.

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The hydrostatic unit shown in Figures 1 and 2 can be used as a pump or as a motor, depending on whether its input or output shaft 1 is connected to a power source and driven or whether the inlet connector «2 or 2» des The unit can be connected to a pressure source, but it makes little sense to use it as a motor. With the shaft 1, the radial cylinder 3 or 3 ¹ having and the displacement piston 4 or 4 * receiving and these in the circumferential direction and in the axial direction 'leading rotor 5 is connected, which in the two bearings 6 and 7, carried by the necks 8 and 9 »is mounted in the outer end shields XO and 11. The center of rotation of the rotor and the bearings mentioned above is marked with 12. The radial guide ring 1}, which also rotates with the rotor 5, for the radial guidance of the bulbs 4 and 4 * by means of the bearings 14 and 15 is mounted in the two inner bearing plates 16 and 17 by the fixed dimension eccentric to the axis 12. The ring is aentrieoh mounted in the housing ring 30 and rotates around the Aohee 25, the axes 12 and 25, the Exeenter plane is spanned.

Concentrically Ip inside the rotor 5 and the attached necks δ and 9, the raa3gea # ue control pin bore 27 is attached, which surrounds the control pin 28 with little play. Inside the control pin, the suction * and pressure channels 31 and 32 and 31 * and 32 'are arranged axially; In addition, at the axial height of the plane of the piston 4? $ κβί control sole seats 33 and 34 or 33 ¹ and 34 ^{1 are arranged} on the circumference of the control pin, which are diametrically opposite each other and each extend almost over half the circumference of the control pin. They are separated from each other by in-Exzenterebene webs 35 and 36 in Utafangsrichtung by the cylinders 3, 3 ^1, and the pistons 4 and 4 'limited Verdröngerräuffle are respectively connected to the opposing them SteueraahWZfsn above, be, r radial bores 37 or 37 'in connection. The control strands 33 and 34 or 33 ¹ and 34 ¹ are as wide as the diameter of these bores, and the intermediate webs are somewhat wider than this diameter, so that the hole 37 ^{1 is} well covered by the intermediate web transfer while dta circulation ·. * yqn 3 * u§- §uf | & sekjteuerfishlit * is determined. the

Suction and pressure channels 3I and 32 or 3I ¹ and 32 'are connected to the associated control slots 33 or 34 and 33' or 34 'via short radially extending bores. The channels 3I, 31 ', 32 and 32 ¹ are closed at the front by plugs 38. By means of radial, axially offset bores 39 or 40 and 39 'or 40' in the control pin in the axially outer area facing away from the shaft pin 1, a flow connection of the suction and pressure channels with four axially adjacent, rubber rings against each other and against the pressureless interior of the unit made sealed, annular spaces. These annular spaces are formed between the circumference of the control pin and the inner wall of the connection housing 41 attached to the outer bearing plate 11 facing away from the shaft pin 1. This connection housing surrounds the terminal end of the control pin 28 with a much larger play than the control pin bore 27 whose rotor-side end. The connection housing 41, as well as the control pin 28, are shown in the sectional drawing of FIG. 1 pivoted by 90 ° with respect to the other parts, as can be seen from the section shown in FIG. The channels leading to the connections 2 and 2 'and 42 and 42' are attached in the connection housing wall radially in the extension of the sockets 39 and 40 or 39 'and 40'.

arranged above a between terminal housing 41 and rotor bearing 7, the 3teuerzapfen ring surrounding ψ 43 and via two 90 ° offset from each other fixed to the housing or control peg fixed, sliding in the ring with play in bores pins 44 or 45 of the control pin is gimballed in the housing. It is fixed axially and against rotation within the play of the pins in the radial ring bores.

The control pin is due to the construction just described 28 radially resilient, but fixed axially and in the circumferential direction and attached to the housing in a pressure-tight manner with respect to the channels. This 1st

' . _ ₇ _ 1301757

necessary so that the control pin "floats" in the control bore 27 can and its position exactly according to the location of the hole 27 in the Can align the rotor and also a possible small radial lag or a wobbling movement of the bore axis can follow without constraint.

The compensation of the through the control slots J5j5 and ^ 4 resp. and 34 'on the control pin 26 forces exerted by the laterally and opposite the control slots in the wall of the control pin relief fields come about.

In Figures 3 to 5 relief fields and their arrangement are shown in various forms. The following explanations apply to all three figures. In this case, the consideration is directed only to one control slot and its relief fields, as the calculation rule for the other control slots is repeated in a very analogous manner. As far as the reference numerals with regard to the relief fields are concerned, these, like the associated control slots, are named with the addition of a small letter. It is true that the corresponding control slots in the figures are not differentiated from one another, since they are all designed in the same way. their affiliation to the control slots can be recognized by the preceding number. The explained control slot and the associated relief fields are highlighted by cross hatching. They also have auxiliary lines and dimensions drawn in, which have been omitted from the other control slots or relief fields for the sake of clarity. '' The explanations for one control slot and the arrangement and shape of the relief fields are representative of the other three.

Because the surface exactly opposite a control slot occupied by the other control slot - suction and pressure control slot for one and the same flow rate lie in the same

■ A

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axially aligned plane - are that belong to a control slot * attached to the opposite side of the control pin Relief fields divided into two parts and arranged to the right and left of the opposite control slot. Oa the relief fields are not opposite eyoraetrieoh sum- * can arrange overlying control slot, because although the one Side of the control slot is initially still free, the other "side" However, it is flanked by the adjacent opposite control slot of the other conveyor tube, the discharge must * fields are arranged asymmetrically Eccentric plane projected point S- *, which is usually with the ) corresponding projection of the center of gravity of the opposite control slot coincides, special meaning to » The associated relief fields are to be arranged in such a way that that the common center of gravity of the relief surfaces projected onto the eccentric plane falls on point S *, i.e. the static moments of the surfaces projected into the eccentric plane on the side and on the other side of the control slots must be in relation to the Point S * be the same or, in other words, with regard to the dimensioning and arrangement of the relief fields dl · · - and Beyond the tax rate, the law of leverage must be Last times Last equals force times force arm in relation to the projected pivot point S * and taking into account only the one on the eccentric plane. projected area proportions are applied. That means, among other things, d * J "The two centroids of the relief fields on this and the other side of the control slot and the point S * in the

The eccentric plane must lie on a straight line; on the control pin

On the surface, they must be on a surface line or a approximate helical line. If the helix is very steep, the approximation is good.

In the control pin, the development of which is shown in Fig. J> , rectangular or groove-shaped relief pockets are provided, which extend in the circumferential direction and the length of the

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Tax records. Since all of your pill content is first If the marginal influences are neglected, this is the same associated tax seat 1st, 1st is the overall width of the load fields the same as that of the control slot. The total scope that has relief pockets belonging to a control shift in an apprenticeship according to Flg. 3 and with a length a of the control slots in Itofangsriohtung and a width b in the axial direction Length of U, »4a + 2b. Is according to the example of Figures 1 and 2 assumed for a ο 4.4cm and for b = »0.7 cm (the developments are compared to the ratios in FIGS. 1 and 2 by a factor of 1.5 enlarged), then U becomes, * 19 * 0 cm. That length is responsible for the essential part of the leakage losses of the hydrostatic pump. The smaller the initial length of the relief fields, the shorter is the amount of leakage oil escaping at the edges.

With the control pin, the development of which is shown in Fig. 4, are the relief fields to reduce their circumferential length with the same relief effect after the Durohmessereplane, the perpendicular to the eccentric plane 60, i.e. concentrated in the vicinity of the normal eccentric plane 61.

The surface parts of the relief fields according to Fig. 3 that are further away from this normal plane in the direction of the university take part in the relief only with the very small portion of the cosine of the angle enclosed by the associated tangential plane and the eccentric plane, but their circumferential portion is created with full size the leakage. These two leaking, but ineffective, remote parts of the relief fields according to Flg. 3 are avoided by widening the fields as shown in FIG. The fields are dimensioned such that - as shown in Fig. 5 - the sum of the projected in the Exzenterebene surfaces 34T and 34 * of the relief panels 34 _d and 34 _C gleioh which also per Ji ornamental th surface 34 * of the associated control slot 34 1st . The law of leverage must be observed. This means that the area of 34 * d is three times larger than that of 34 * and the center of gravity of 34 * d must therefore only be 1/3 of the _{distance from the center of gravity of the other projected relief area 34 * O} from the center of gravity S * of the projected tax base 34 *. In addition, the relief fields on the circumference of the control pin must be “arranged” in such a way that the three focal points aw i associated fi & fffl-f & fi areas 34 * »34 * e and *

Lie on a straight line in the eccentric plane. In the arrangement and training of the relief fields according to Flg. 4 and 5 are this « Focal points in the normal eccentric plane 61, i.e. on the Utafang dee control pin on a dumbbell line based on the the aforementioned counters, the circumference of the discharge panel for a control slot is about 9 * 5 cmj due to the arrangement According to FIGS. 4 and 5, compared to the arrangement according to FIG. 3 a reduction in scope of $ 50 is made.

A further shortening of the circumferential length of the relief fields compared to the design according to Flg. 4 and 5 is possible due to the arrangement and design of the pressure pockets according to FIGS. 6 and 7. In the control pin according to FIG. 7, the development of which is partially shown in FIG. 6, the relief pockets are divided into two circular fields, one of which is about (3 ^ 'g) and the other about 2/3 (3 ¹ * ¹ f) of the surface area of the associated control slot 34 ¹ . However, so that the pressure pockets for the pressure equalization of the neighboring control slot can also be arranged approximately in the same axis-perpendicular plane, the center of gravity connecting the two surface centers of the relief fields projected onto the eccentric plane and the projected center of gravity of the control slot must be around the point S * from the axis-parallel position a position inclined with respect to the normal eccentric plane 61 can be pivoted. By moving the center of gravity and the relief fields out of the symmetrical position, space is gained for an arrangement of two relief pockets on each side of the control slots. Of course, with the "inclined ^{arrangement H of} the relief fields, the lever set in relation to the pivot point S * must be taken into account in their arrangement and dimensioning.

As indicated by a dashed contour in the relief field 34'f, it can be extended without any substantial extension the circumferential length the axial space requirement of the large relief fields in that they are designed as ovals or similar, approximating to the circular shape, with the longitudinal axis lying in the direction of the uni.

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The center of gravity of the atrichlierte oval is almost in the same place as that of the full circle.

For the sake of completeness it should be mentioned that for one not only the pressure in the control strokes and the relief "pockets" as well as their respective surface area are to be taken into account "but that a mean pressure and a certain xanda tire area on the force effects of the pressure bags t el In IwMt * The pressure lines are therefore over from the start so much smaller that the stuome of pressure and force Randstrelfenkraft gives the necessary, su ersielende balance strength. In the case of the above-mentioned assessment rules, these are flows of action have not been taken into account and these are therefore only valid subject to a later correction in accordance with the marginal influence of the tax queries and the exemption fields.

The relief feathers are exclusively via bores, i.e. Via channels that are closed on all sides with the associated Zu- bsw. Discharge channels 31,32,31 'bsw. 32 * connected, so that leakage at these connecting channels is excluded. Representing the other fields are in Flg. I and 2 only two pairs of Druckauaglelohkanäle 30 bsw. 51 shown. The holes are drilled straight through the control pin, that the bore leads past the non-associated supply or discharge channel, the affected relief field or the associated Canal but cuts.

Heldenheim (Brenz), January 3rd, 1969 Pö / HKn />

(S 009834/0759

Claims (1)

19Π1 irn ι c υ ι λ ο / ap / A 29II Λ Voith Oetritb XO Keyword "control pin relief" Heidenhein (Brenz) Claims 1. Dual hydrostatic pump with electricity for every ». separate supply and discharge of the working medium and with a "common for both streams" having the displacement role Rotor, as well as with a concentric with little play, arranged in a bore in the rotor, stationary, with One suction and one pressure channel for each stream as well as one suction and pressure control slot each extending in the circumferential direction almost over 180 ° for each stream, radially flexible, but axially and in the circumferential direction control pin firmly and pressure-tightly attached to the housing with respect to the channels, the suction and pressure control slots for one flow each in the same axial plane and symmetrically on this and beyond a stationary plane including the rotation axes (eccentric plane) arranged on the control pin are and the control slots for the two streams are arranged in different axial planes on the control pin, and with the Compensation of the pressure forces acting on the low-pressure side or high-pressure side of the control pin, the supply or Discharge control slots of the control pin are diametrically opposite, worked into the wall of the control pin from the outside and via pressure equalization channels with the associated Channels connected hydrostatic relief fields (pressure pockets), characterized in that the from, 0098 34/0753 ^{# /} " Center of gravity (S) of the area projected onto the eccentric plane of each control slot (33 * 34,33 ', 3 * 1') diametrically projected point on the opposite side of the control pin (28) (3 *) at least two axially on both sides of this projected one Point arranged, worked into the wall from the outside, acted upon by the pressure prevailing at the associated control slot, relief fields are assigned according to size and position in such a way that both the proportion projected onto the eccentric plane of the surface area belonging to a control slot is approximately the same as that on the eccentric plane projected proportion of the area of the control slot, and that the sum of the in the projection on the eccentric plane Static moments to be determined of the relief fields axially on this side and on the other side of the center of gravity projected into the eccentric plane is at least approximately equal to zero. 2. Hydrostatic pump according to claim 1, characterized in that that the relief fields each have the smallest possible ratio of circumference to surface area, preferably are formed in a circular shape. 3 · Hydrostatic unit according to claim 1 or 2, characterized in that axially here and beyond the projected points (S *) only a single relief field is arranged, the centroids of which are at least approximately on one through the projected point (S *) and if possible steep helix lying in the control pin surface. 009834 / 07S9 4. Hydrostatic « unit according to claim Ij 2 or 3, characterized in that the pressure compensation channels between the abovementioned load fields and the pressure space of the associated control slot are designed as closed edges on the circumference (bores, lines, e.g. 50, 51) . Heidenheim, January 3rd, 1968
PÖ / HKn 009834/0759