DE1155336B - Piston head guide in a fluid radial piston machine - Google Patents

Description

GERMAN

PATENT OFFICE

Sch 28084 Ic / 59a

REGISTRATION DATE: JUNE 28, 1960

NOTICE
THE REGISTRATION
AND ISSUE OF
EDITORIAL: OCTOBER 3, 1963

The invention relates to a piston head guide in a liquid radial piston machine (Pump, motor or clutch) whose cylinder star, without being relative to the one that absorbs the piston pressures To rotate the housing, executes an eccentric circular rolling movement and its internally acted upon Pistons, each consisting of a jacket piston and a core piston that can be moved and rotated in this exist, with their two outer conical heads on oblique eccentric guideways roll off.

In radial piston machines of this type, it is advantageous in terms of running that the pistons and can roll backward movement on the eccentric guideway with a rotating movement run around their own axis. The problem arises here, the piston heads and guideways to be arranged so that the orbital forces interact with that acting on the piston from the inside Fluid pressure during the pressure phase no component directed parallel to the machine shaft that try to tilt the cylinder star and therefore edge pressures on its bearing would evoke. In addition, if the housing and the cylinder star are arranged to rotate, then would this undesirable effect even increases as a result of the centrifugal forces acting on the pistons.

A number of radial piston pumps of this type are already known.

In a known arrangement, for. B. the cylinders in two different, normal to the axis of rotation The machine-oriented planes are arranged, the radially outer piston ends being conical and interact with suitably shaped guideways. The guideways are in With respect to the plane of symmetry of the entire piston arrangement arranged in an angular mirror image. This ensures that the bevel of the guide surfaces required for a rolling movement and the radially outer piston ends generate opposing axial forces that can cancel each other out.

In another known radial piston pump, the arrangement is made in a similar manner, with the difference, however, that they cooperate with the radially outer, conically shaped piston ends Guide surfaces in the vicinity of the plane of symmetry of the two planes containing the pistons lie. However, the effect is the same.

These devices have the disadvantage that production is more difficult due to the cylinder chambers and pistons arranged in two different planes. Such a pump also has a piston head guide
in a liquid radial piston machine

Applicant:

Swiss locomotive
and machine factory,
Winterthur (Switzerland)

Representative: Dipl.-Ing. R. Beetz, patent attorney,
Munich 22, Steinsdorfstr. 10

Claimed priority:
Switzerland of June 14, 1960 (No. 6774)

Dipl.-Masch.-Ing. Theodor Müller,

Winterthur (Switzerland),
has been named as the inventor

greater weight and a larger longitudinal dimension.

In another known pump, the piston bores are at an oblique angle with respect to the axis of rotation arranged in the cylinder star, namely in two different ones, with respect to the axis of rotation normal plane mirror-image angular positions. The radially outer piston end faces are truncated Ball segments formed and interact with a cylindrical surface as a guide track, whose axis is parallel to the axis of rotation. Here, tilting moments are still exerted on the shaft, which results from the angular displacement of the individual cylinders. This arrangement has the rest has the same drawbacks as the above-mentioned known arrangements, namely a difficult one Manufacture of the cylinder star and large dimensions in the axial direction of the shaft.

The invention is based on the object of creating a radial piston pump in which there is no tilting moment is exerted on the shaft and which has small longitudinal dimensions.

This object is achieved in that the guide track for the outer head of the jacket piston on one side of the central plane of the piston and the guideway for the outer head of the Core piston is arranged on the other side of the transverse center plane.

309 690/175

All pistons are thus arranged in one plane, so that there are very small longitudinal dimensions result. The manufacture of a cylinder star suitable for such a pump is also very difficult simple.

The conical piston heads of the two sub-pistons advantageously roll along on guide tracks a roof-like cross-section.

It is the aspect ratio of the two KoI-Zur The piston on the jacket serves to secure the pistons against being lifted too far from the guideways 15 seated disc 21 and attached to the housing 1 mating guide track 22, while for the The core piston 14 has its own head 19 protruding beyond the head of the jacket piston 15 as a backup serves against sliding back into the jacket piston 15.

The radial fluid acts on the jacket piston 15

bent parts and the inclination of the guideways against io sigkeitsdruck P ₂ and the contact pressure P ₂ '= P ₂ / cos a ₂ , the transverse center plane selected so that the resultant as FIG. 3 shows. Let yourself be at the intersection of these forces

all forces acting on the piston parts during operation of the liquid and the guideways as well as the dynamic forces has no axial component parallel to the machine shaft.

In order to secure the pistons against lifting off the guideways, a mating guideway belonging to the jacket piston is preferably provided on the housing, while for the core piston its own are composed of the resulting axial force P ₂ · tg « ₂ . This axial force is counteracted by the forces P ₁ and P ^ = P ₁ ZcOSa ₁ acting on the core piston 14, the resultant of which is equal to P ₁ · tg Ct 1 and which also acts on the jacket piston 15. If one chooses in particular the cross-sectional ratio of the two piston parts, the points of application of the forces P ₁ 'and P ₂ ' and the inclinations of the guideways

ner head as a safeguard against sliding back in the? <o 17 and 20 against the transverse center plane in such a way that the Jacketed piston is used.

The generatrices of the guideways can be arranged offset from one another in such a way that the conical tips of the core pistons lie further outside than those the jacketed piston.

The invention is explained in more detail on the basis of schematic drawings of an exemplary embodiment. It shows

Fig. 1 shows a longitudinal I-I of Fig. 2

section through a piston machine working as a pump according to the invention,

FIG. 2 shows a cross section through the pump according to the section line II-II in FIG. 1,

3 shows a longitudinal section through a cylinder on a larger scale and with details of the operation occurring forces.

In the two-part housing 1, the drive shaft 3 is rotatably mounted by means of the two bearings 2. The cylinder star 5, which has six cylinders, for example, is rotatably mounted on the crank 4 of the shaft 1. In this sits the control sleeve 6, which has a flow opening 8 for each cylinder 7. The cylinder star 5 leads in the machine housing 1 as a result of the rotary movement axial forces P ₂ · tga ₂ and P ₁ · IgO ₁ attack at the same point on the cylinder axis and are of the same size, these axial forces cancel each other out completely, and it then acts from the jacket piston 15 no axial force on the cylinder wall. For this purpose, as already mentioned _{, the condition P 2 -IgO 2} = P ₁ -tgCt ₁ must be fulfilled. This is possible despite the fact that TgCi _{1 is} not equal to tga ₂ if the cross-sectional area of the jacket piston _{15 is selected in the ratio tg Ct 1 AgOi 2} to that of the core piston 14.

Instead of arranging the shaft in a rotating manner as in the exemplary embodiment, the housing could also vice versa and the cylinder star be designed to rotate and the shaft fixed. Should the machine be used as a Working shaft coupling, the pressure line must be able to be closed by a closing element, since the Otherwise the machine cannot transmit any torque. This device is not shown in the drawing.

The weight of the pistons can also be adjusted in such a way that the cylinder star when the cylinder star is rotating Axial forces arising as a result of the centrifugal forces of the pistons cancel each other out completely.

It is also obvious that the invention

tion of the eccentric 4 from a circular rolling movement, whereby it is guided by the two auxiliary cranks 9 45 can also be used on radial piston machines and does not rotate relative to the housing. To can, in which the eccentricity of the crank 4 lead to cranking 4 which is adjustable for the supply and discharge of the and therefore necessary channels 10, 11 instead of the auxiliary cranks 9 ver-working fluid. They open out adjustable guide members occur. Since the design of this in the suction slot 12 or the pressure slot 13. With members for the application of the invention without Bedem suction slot 12 is one half of the cylinder 7 50 is meaning, is on their representation and description through openings 8 in connection, while the other exercise waived.
Half of the cylinder with the one on the back
the crank 4 located pressure slot 13 is in communication. It is assumed that the
Turn drive shaft 3 counterclockwise (arrow w). 55

In the cylinders? two-part pistons are arranged, each consisting of a core piston 14 and a jacket piston 15. The latter has one conical head 16, which is held on the left eccentric guide track 17 of the housing 2

Claims (5)

PATENT SAYS: NEN plate 18 is applied. The core piston 14 is guided and supported longitudinally displaceably in the jacket piston 15 and is pressed with its likewise conical head 19 by the pressure of the liquid against the right-hand eccentric guide track 20 of the plate 18. The two guide tracks 17 and 20 are roof-like with respect to the central cross-sectional plane. 1.Piston head guide in a liquid radial piston machine (pump, motor or clutch), the cylinder star of which, without rotating relative to the housing that absorbs the piston pressures, executes an eccentric circular rolling movement and its internally loaded piston, each consisting of a jacket piston and one in this move - and rotatable core piston exist, roll with their two outer conical heads on inclined eccentric guide tracks, characterized in that the guide track (17) for the outer head (16) of the jacket piston (15) on one side of the transverse center plane of the piston (14, 15) and the guide way (20) for the outer head (19) of the core piston (14) arranged on the other side of the transverse center plane is. 2. piston head guide according to claim 1, characterized in that the guide tracks (17, 20) have a roof-like cross-section. 3. piston head guide according to claim 1 or 2, characterized in that the generators of the Guide tracks (17, 20) are arranged offset from one another that the imaginary cone tip of the Guide track (20) of the core piston (14) is further out than that of the guide track (17) the jacket piston (15). 4. piston head guide according to claim 1 to 3, characterized in that the cross-sectional ratio of the two piston parts (14,15) and the inclination of the guide track (17, 20) against the Transverse center plane are chosen so that the resultant of all acting on the piston parts during operation Forces of the liquid and the guideways as well as the dynamic forces no axial component having parallel to the machine shaft. 5. piston head guide according to claim 1 to 4, characterized in that to secure the piston against lifting off the guide rails (17, 20) a mating guide track (22) on the jacket piston (15) cooperating with the Housing is provided, while for the core piston (14) its head (19) as a safeguard against Serves sliding back into the jacket piston (15). Considered publications:
German Patent No. 812 620;
U.S. Patent Nos. 2,074,068, 2,383,059. 1 sheet of drawings © 309 690/175 9.63