DE102004049864B4 - Hydrostatic displacement machine with mutually phase-displaceable displacement movements of displacers - Google Patents

Abstract

The invention relates to a hydrostatic displacement machine with a rotor (R) and a stator (S) and with a plurality of displacement chambers, which are arranged in the rotor (R) or in the stator (S) and in which in each case a displacement body (K1, K2 ) which performs a plurality of displacement movements during one complete revolution of the rotor (R), following a periodic function. In order to adjust the displacement volume continuously and to achieve a simple and space-saving design, according to the invention at least two Verdrängerräume each connected to a Verdrängerraumeinheit (V) and are the displacement movements of the therein arranged Verdrängerkörper (K1, K2) phase-shifted against each other.

Description

The invention relates to a hydrostatic displacement machine having a rotor and a stator and having a plurality of displacement chambers which are arranged in the rotor or in the stator and in each of which a displacement body is located, which carries out a plurality of displacement movements during a complete revolution of the rotor, the follow a periodic function, in each case at least two displacement chambers are connected to one another to a Verdrängerraumeinheit and the displacement movements of the displacer arranged therein are mutually phase-shifted.

Such displacement machines, which are also referred to as "multi-stroke" displacement machines, have the advantage over "single-stroke" displacement machines that the space is drastically reduced. Such displacement machines are z. As known from the prior art in many embodiments radial piston machines, for example, with external support of the piston on a cam track by means of one roller.

Single-stroke displacement machine, however, can be relatively easily adjusted in the displacement and are known, for example, as swash plate, oblique axis or swash plate machines.

In the DE 102 44 262 A1 discloses a multi-stroke displacement machine, in which each displacer is pivotally coupled to a yoke having two, each supported on a cam lever arms. During operation of the displacement machine, movements of the lever arms are generated by the two cam tracks, which overlap and are combined to form a displacement movement of the displacement body.

By phase shifting the cam tracks, which are impressed with the same periodic functions, it is possible to steplessly control the displacement movement of the displacement between a "maximum stroke" and "zero stroke". In the latter case (zero stroke) performs the displacement during a complete revolution of the rotor not a single displacement movement, while the two lever arms of the articulated yoke move in each case with the largest possible deflections pendulum.

The displacement machine described combines the two features "Mehrhubigkeit" and "adjustability". This makes it possible, on the one hand to provide a very compact displacement machine available and on the other hand to achieve large speed changes by controlling the displacement volume. However, a relatively large number of components is required by the described operative connection of the displacement body with the cam tracks via a yoke with two lever arms and supporting rollers.

From the GB 327 016 A a generic multi-stroke positive displacement machine with variable displacement volume is known, which is designed as an axial piston machine. In a rotating cylinder drum continuous piston bores are arranged, in which two pistons are arranged, which form a common displacement unit. The pistons are each supported on a multi-stroke cam. By turning the two cams, the displacer volume of the displacement machine can be changed.

The DE 24 37 139 A discloses a radial piston engine, in each of which two pistons are arranged in each piston bore of a rotating cylinder drum, which form a common displacement chamber unit. An outer piston is supported on an outer fixed outer cam track. An inner piston is supported on a rotating inner cam.

From the DE 952 402 B a double-row radial piston machine with variable displacement volume is known, which has two mutually parallel cam tracks, on each of which a set of pistons is supported, which are arranged in cylinder bores of a rotating cylinder drum. Two axially successive cylinder bores are interconnected to form a Verdrängerraumeinheit. The cam tracks are phase-shifted relative to each other and generate one pressure stroke and one suction stroke of the working pistons per revolution of the cylinder block.

From the DE 101 57 672 A1 a hydrostatic multi-stroke displacement machine designed as a cell machine is known in which the displacement body perform several pivoting movements in one revolution of a rotor. The cell machine has a constant displacement volume.

The present invention is based on the object to provide a multi-stroke positive displacement machine of the type mentioned above, the displacement volume is infinitely adjustable and has a simplified and space-saving design.

This object is achieved in that in each case the displacer of a Verdrängerraumeinheit be supported on a common cam and an assembly of the positive displacement machine, in which the Verdrängerraumeinheiten are included, a plurality of stator segments in which in each case one of the mutually connected displacement chambers of the displacement unit is arranged, wherein the stator segments are adjustable relative to each other in the sense of a phase shift of the displacement movements generated by the cam track.

The idea essential to the invention therefore consists of combining a plurality of displacement chambers (at least two) to form a displacement unit for the purpose of stepless adjustment of the displacement volume of the displacement machine and to control the total volume by superposition of the individual volumes. In this case, the volumes displaced by the individual displacement bodies of the combined displacement chambers are added or subtracted, depending on the phase displacement of the displacement movements, whereby the displacement volume of a single displacement body can be adjusted between a maximum and a minimum (in the extreme case zero) while the displacement movements of the individual displacement bodies are always constant.

In other words, z. B. in the case of "zero stroke" a compression movement of the displacement body are summarized by phase shift with an expansion movement of the other displacement body, so that there is no total volume change in Verdrängerraumeinheit.

The displacement machine is designed according to an advantageous embodiment of the invention as a cell machine.

In this case, the cell machine advantageously has an inner rotor provided with a cam track and an outer stator with at least two stator segments, in each of which at least one displacement body arranged radially between the stator and the rotor is mounted and the periodic force impressed with respect to one of the cam tracks Function are mutually phase-displaceable, wherein between the displacer and the cam trajectory variable displacement chambers are formed, of which in each case a displacement chamber of the first stator segment is connected to a displacement chamber of the second stator segment.

In a further development of the invention, the displacer are each pivotable in a receptacle and have two spaced circumferentially of the cam path, provided for abutment against the cam track engagement zones, between each of which a displacer is formed, wherein the tappable on a straight line section distance of the engagement zones from each other essentially corresponds to half the period length of the periodic function of the cam track.

The change in volume of the displacement is thus generated by space-saving pivotal movements of the displacer in the direction of rotation. The displacement machine can therefore be made very compact.

All embodiments of the positive displacement machine according to the invention are well suited as a direct drive, in particular as a wheel drive, and are therefore preferably provided for this use.

Further advantages and details of the invention will be explained in more detail with reference to the embodiment shown in the schematic figures. It shows

1 a longitudinal section through an axial piston machine designed as a displacement machine of the prior art,

2 a section through the displacement machine according to line II-II in 1 .

3 a development of the rotor and the cam tracks along the line BB in 2 at maximum displacement,

4 a development of the rotor and the cam tracks along the line BB in 2 with minimal displacement,

5 a development of the rotor and the cam tracks along the line BB in 2 at a displacement volume in intermediate position,

6 a cross section through a formed as a radial piston machine displacement machine of the prior art at maximum flow,

7 a cross section through a formed as a radial piston machine displacement machine of the prior art with minimal delivery volume,

8th a settlement of a section 6 .

9 a settlement of a section 7 .

10 a cross section through a variant of a designed as a radial piston machine displacement machine of the prior art at maximum displacement volume,

11 a section along the line XI-XI in 10 .

12 a cross-section through the variant of the designed as a radial piston machine displacement machine of the prior art with minimal displacement volume,

13 a section along the line XIII-XIII in 12 .

14 a schematic representation of the effect context of in 10 illustrated displacement machine,

15 a schematic representation of the effect context of in 12 illustrated displacement machine,

16 a section through a trained as a cell machine according to the invention Verdrängermaschine at maximum displacement and

17 a section through the cell machine according to 16 with minimal displacement.

The in the 1 and 2 illustrated hydrostatic displacement machine is designed as a swash plate axial piston machine. This has a cylinder drum designed as a rotor R, which is connected to a drive shaft T. A plurality of parallel and concentric with a central axis M of the rotor R and the drive shaft T on a common pitch circle and axially continuous cylinder bores are incorporated into the rotor R. Two piston-shaped displacement bodies K1 and K2, which are supported by means of a rolling element W1 or W2 on a cam track N1 or N2, which are adjacent in a rotor S surrounding the rotor R, emerge from both end faces of the rotor R the end faces of the cylinder drum (rotor R) is attached.

The axial cylinder bores incorporated in the cylinder drum (rotor R) form in each case common displacement units V for the two displacement bodies K1 and K2. In other words, each displacement body K1 and K2 is associated with a (partial) displacement chamber, wherein both (partial) displacement chambers are combined to form a common displacement chamber unit V. The supply and removal of pressure medium to and from the Verdrängerraumeinheiten V by means of circumferential recesses A in the cylinder drum (rotor R), which slide past at rotation of the cylinder drum at peripheral control openings O in the stator S.

The two cam tracks N1 and N2 are imprinted with the same periodic functions, which are sinusoidal or modified from the sinusoidal shape. Upon rotation of the rotor R about the central axis M, each displacement body K1 or K2 per revolution performs a number of displacement movements. The displacement machine is thus formed mehrhubig. By preferably oppositely rotating the two cam tracks N1 and N2 relative to each other in the stator S, the two impressed functions are phase-shifted relative to one another and thus also the displacement movements (strokes) of the displacer K1 and K2.

An opposite rotation of the cam tracks N1 and N2 away from a starting position has the advantage that the phase position of the displacement chamber unit V to the control openings O does not change. The control for filling and emptying the displacer unit V can therefore remain unchanged at the same position as seen over the circumference.

This will be in the 3 . 4 and 5 shown, each of which shows a settlement of the nine cylinder bores (Verdrängerraumeinheiten V) provided rotor R and the cam tracks N1 and N2 and below the curves 1 and 2 the displacement movements (strokes) of the displacement body K1 and K2 and the curve 3 the summarized displacement movements. In the cam tracks N1 and N2 five strokes per revolution are housed, so five periods T of the impressed sinusoidal function.

In 3 is the displacement machine in a position of the cam tracks N1 and N2 to each other with maximum displacement volume of the positive displacement machine. In this case, the displacer movements of the displacement bodies K1 and K2 take place in each case without a phase shift relative to each other. Both arranged in a common displacement V displacement body K1 and K2 thus move simultaneously outwards and at the same time to the inside. The individual strokes (curves 1 and 2 ) add up to a displacement-effective total stroke h (lower curve 3 = Cumulative curve) with maximum displacement volume of the displacement machine.

In 4 is the displacement machine in a position of the cam tracks N1 and N2 to each other with a minimum displacement volume of the positive displacement machine, namely in a position in which no total volume is displaced. Here, the two cam tracks N1 and N2 are phase-shifted by half a period T / 2 against each other. The lifting curves 1 and 2 therefore run in the same direction. As the displacer K1 moves outward, the displacer becomes K2 moves inward by the same amount and vice versa. The displacement flow of the (partial) displacement chamber of the volume-promoting displacement body K2 thus flows completely into the (partial) displacement chamber of the volume-sucking displacement body K2. The superimposed total stroke h (curve 3 ) is therefore not displacement effective, the displacement volume of the positive displacement machine equal to zero.

In 5 is the displacement machine in a position of the cam tracks N1 and N2 to each other with a displacement volume between the maximum value and the minimum value (zero). This results in a displacement-effective total stroke h between the maximum displacement volume and the minimum displacement volume (zero).

The in the 6 to 9 illustrated displacement machine is designed as a radial piston engine with external and internal support. Components that are identical in function to components in the 1 to 5 are shown swash plate machine, are provided with the same reference numerals.

The rotor R of the radial piston machine has radial bores, which are provided as displacement unit units V and extend through the rotor R from the outside to a central recess Z. In each radial bore emerges from both sides in each case designed as a piston displacer K1 or K2. On the outside of the rotor R is a surrounding outer cam track N1 for supporting the outer displacement body K1. Within the central recess of the rotor R is an inner cam track N2 for supporting the inner displacement body K2. Both cam tracks N1 and N2 are imprinted with the same sinusoidal or sinusoidal derived function. The cam tracks N1, N2 are rotatable relative to each other, wherein a phase shift of the impressed functions and thus the displacement movements (strokes) of the displacer K1, K2 occurs.

The 6 and 8th show a position of the displacement machine in which the maximum displacement volume is set. This is done - analogous to the representation in 3 - Each of the displacer movements of the displacer K1 and K2 without phase shift to each other: both arranged in a displacement V displacement body K1 and K2 move simultaneously outward and at the same time inward, the individual strokes are added to a displacement-effective total stroke, the maximum displacement volume of the displacement machine causes.

Is in accordance with the 7 and 9 the outer cam track N1 is rotated so far (for example 30 degrees) that a phase shift of T / 2 occurs, then - analogous to the representation in FIG 5 - The combined total stroke not displacement effective, so that the displacement volume of the displacement machine is equal to zero.

The in the 10 to 15 illustrated displacement machine is also designed as a radial piston machine.

The rotor R of this radial piston machine has two parallel rows PR1, PR2 of radial bores (blind bores) RB1 and RB2, in each of which a displacement body K1 or K2 designed as a piston supported on the outside protrudes. Radial holes RB1 of series PR1 have the same diameter as radial bores RB2 of series PR2.

Each row PR1, PR2 of radial bores RB1 and RB2 is associated with a designed as a cam outer cam N1 or N2, where the same sinusoidal or derived from the sinusoidal periodic functions are impressed. Two parallel radial bores RB1 and RB2 are connected to each other and form a common displacement chamber unit V.

In the 10 . 11 and 14 a position of the displacement machine is shown in which it is in the setting with maximum displacement volume. The cam tracks N1 and N2 are set in phase with each other (see also the curves 1 . 2 and 3 in 3 ), both cam tracks N1 and N2 are thus in the same position, so that the strokes of the displacement body K1, K2 are added to a displacement-effective total stroke, the maximum displacement volume of the displacement machine causes.

In the 12 . 13 and 15 the two cam tracks N1, N2 are rotated so far relative to each other that a phase shift by T / 2 has occurred. In this case, the volumes displaced by the displacement movements of the displacement bodies K1, K2 cancel each other out.

In the 16 and 17 a Verdrängerkaschine invention is shown, which is designed as a cell machine. The basic structure of such a cell machine is from the DE 101 57 672 A1 known.

The cell machine has a plurality of radially arranged between an inner rotor R with molded cam N and an outer stator S displacement bodies K, which are each mounted pivotably in a part-cylindrical receptacle L.

Each displacer K has two engagement zones E1 and E2 spaced apart from one another in the circumferential direction of the cam track N and designed to rest against the cam track N, between which a respective displacement space (cell) is formed. The distance of the engagement zones E1 and E2, which can be tapped off on a straight line section, corresponds essentially to half the period length T / 2 of a periodic function impressed on the cam track N.

The partially cylindrical receptacles L, in which the displacement bodies K are pivotally mounted, are located in one of two stator segments S1, S2, which are arranged on opposite sides of the rotor R and are rotatable relative to one another. In the present representation, each stator segment S1 or S2 has three receptacles L with displacers K pivotable therein. Between the displacers K of the stator segment S1 and the cam path N of the rotor R, three displacer spaces a, b and c are formed accordingly. Similarly, three positive displacement chambers a ', b' and c 'are formed between the displacement bodies K of the stator segment S2 and the cam track N.

The respective opposite displacement chambers a and a ', b and b' and c and c 'are interconnected by channels not shown in the figures and each form a Verdrängerraumeinheit.

In the in 16 shown position of the displacement machine each promote the opposite displacement chambers in the same direction, so that there is the maximum displacement volume. Shifts now the two stator segments S1 and S2 by half a period length T / 2 to each other, as in 17 shown, the displacement volume is zero, because the delivery stroke of the displacement chamber a is equal to the suction stroke of the associated displacement chamber a '. In this case, only liquid flows back and forth between the respectively opposite, connected to a Verdrängerraumeinheit Verdrängerräumen.

Claims (5)

Hydrostatic Verdrängermaschine with a rotor and a stator and having a plurality of Verdrängerräumen disposed in the rotor or in the stator and in each of which is a displacement body which performs a plurality of displacement movements during a complete revolution of the rotor, which follow a periodic function , wherein in each case at least two displacement chambers are connected to one another to a displacement unit and the displacement movements of the displacer arranged therein are mutually phase-shifted, characterized in that in each case the displacer (K) a Verdrängerraumeinheit are supported on a common cam track (N) and an assembly of the positive displacement machine, in which the displacement chambers (a, b, c, a ', b', c ') are contained, a plurality of stator segments (S1, S2), in each of which one of the interconnected displacement chambers (a and a', b and b ' , c and c ') of the displacer Aumeinheit is arranged, wherein the stator segments (S1, S2) relative to each other in the sense of a phase shift of the cam track (N) generated displacement movements are adjustable. Hydrostatic displacement machine according to claim 1, characterized in that the displacement machine is designed as a cell machine. Hydrostatic displacement machine according to claim 2, characterized in that the cell machine has an inner, provided with a cam track (N) rotor (R) and an outer stator (S) with at least two stator segments (S1, S2), in each of which at least one radially between the stator (S) and the rotor (R) arranged displacer (K) is mounted and in relation to one of the cam track (N) impressed periodic function are mutually phase-shifted, wherein between the displacer (K) and the cam track (N) volume-displaceable displacement chambers (a, b, c, a ', b', c ') are formed, of which in each case a displacement space (a or b or c) of the first stator segment (S1) with a displacement space (a' or b 'or c') of the second stator segment (S2) is connected. Hydrostatic displacement machine according to claim 3, characterized in that the displacement bodies (K) in each case in a receptacle (L) are pivotable and two circumferentially of the cam track (N) spaced from each other, for abutment against the cam track (N) provided engagement zones (E1, E2 ), between each of which a displacement space (a, b, c, a ', b', c ') is formed, wherein the tapped on a straight line section distance of the engagement zones (E1, E2) from each other substantially half the period length (T / 2) corresponds to the periodic function of the cam track (N). Hydrostatic displacement machine according to one of claims 1 to 4, characterized by the use as a direct drive, in particular as a wheel drive.

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