JPS60209682A - Hydraulically operated variable drain amount rotary pump - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic variable displacement pump of the type with a blade-supporting rotor and a movable stator.

A known pump of this type consists of the following components: (:)
Blade-support rotor; a screw driven into an eccentric position with respect to the rotor, into which a screw is adjustably pushed, and arranged along an axis perpendicular to the axes of said two positions);
(11D Two plates placed facing the stator (
This plate laterally restrains the stator and together with the stator forms a kind of closed box surrounding the rotor, in which openings for suction and discharge of fluid are provided.
;lIψ A casing that encloses all of the above elements and has external suction and exhaust connections.

Such changes in pump displacement are caused by moving the stator, which is eccentric with respect to the rotor.

The construction of such a pump inevitably suffers from several drawbacks, which arise primarily from the instability of the stator restraint, which exists in practice only at the two positions and at the three characteristic points formed by the adjusting screw.

Because of this instability, a shift in the eccentric position of the stator relative to the rotor due to a two-point pressing action is not only a result of the rotation of the stator around the adjustment screw, but also due to the sliding of the stator around this screw. It is also a result of movement. Such sliding components cannot be easily measured and rather vary randomly, resulting in a non-uniform relationship between piston stroke and stator shift.

Therefore, unforeseeable changes in the operating parameters of the pump, such as the position of the minimum and maximum eccentric shaft and therefore the adjustment of the pump, the typical characteristics of the yield point and the noise, and finally the reactions induced during the pump operation. Unpredictable changes in the characteristic seal and angle of fluid displacement with respect to the position of the force axis occur.

Such constrained instability also results in undesirable movement of the stator during rotation of the rotor. The rotor blades may simply stop the stator from rotating because the stator wants to be tightly constrained against rotation.

This results in a sliding movement of the annular circumferential surface of the stator relative to the piston and adjusting screw, and a sliding movement of the side surfaces of the stator relative to the plates, which leads to faster wear of such elements. Moreover, sliding between the stator sides and the plates changes the gap between them, resulting in a decrease in yield point and an increase in noise.

A further drawback observed in the known pumps is always due to the instability of the stator restraint and thus to undesirable changes in the overall geometrical properties of the pump (consisting of a long response time of the stator movement).

The aim of the invention is to eliminate the drawbacks of the known technology mentioned above.

According to the invention, such an object consists of a fuselage, a rotor for supporting the blades rotatably mounted inside one of the cavities of this fuselage, an annular stator surrounding this rotor, and a side sealed off by a plate. It is suitable for shifting into an eccentric position relative to the rotor, and an internal sealed chamber is formed between the stator, the plate and the rotor, into which fluid suction is carried out. To provide a variable delivery capacity rotary pump in which a mouth and a delivery port are in communication; a variable delivery capacity rotary pump is characterized in that a stator is attached to freely vibrate around a pin fixed to a pump body. achieved by.

Pivoting of the stator on the pump body limits the movement of the stator to rotation about the pivot axis only and prevents any other movement that might change the correct position.

The features and advantages of the invention will be described in detail with reference to two embodiments illustrated in the accompanying drawings, which are intended to be illustrative and not limiting.

FIG. 1 is a radial sectional view taken along line II in FIG. 2, showing a first embodiment of the pump of the present invention.

FIG. 2 is a longitudinal cross-sectional view taken along line tr-n of FIG.

FIG. 8 is a radial sectional view similar to FIG. 1 showing a second specific example of the pump of the present invention.

Referring to FIGS. 1 and 2, the pump, generally designated by the reference numeral (10), has a body (11) inside which a cavity (
12), which contains an internal rotor (18) and an external stator (14).

The rotor (18) is fixedly attached to the shirt (15), and this shaft is rotatably attached to the inside of the body (11). A movable set-shaped blade (16) is supported in a corresponding radial cavity (17).

The stator (14) consists of a part (18) where the blades (16) press against the inner wall (19), and a part (20) that projects radially from this part (18), and the part (20) is connected to the body (
11) and is attached to a pin (21) that is slidably fixed to the pin (21) so as to be freely rotatable. The sides of the part (18) are sealed by two plates (22) which are slidingly fixed on the part (18) itself. Part (18
) has a window (28) which opens towards the inside of the blade (16) and towards the outside of the cavity (12). In communication with the window (23), a communication passage (24) is provided in the fuselage (11), which passage connects the cavity (12) with the external environment. In the part (20), in the opposite direction to the window (28), there is a cavity surrounding the annular part of the pin (21).

The cavity (25) faces the blade (16), in which a further radial hole (26) is provided passing through the annular portion of the pin (21). This hole (26) is connected to the pin (21
) is in communication with the common axis groove (27) inside. This groove (27) continues to the duct (28) inside the fuselage and extends to the outside.

The groove (27) connects to a pressure compensation conduit (not shown). Since the pressure compensating conduit is of a type well known to those skilled in the art, the details of its construction will not be described here, only that it exists as a substantial part. In particular, two grooves (29, 80) branch off from the groove (27).

The groove (29) opens into the bottom of the chamber (31) into the cavity (12), in which the piston (32) is freely fixed, and which is connected to the part (18) of the stator (14). It is pressed radially onto the outer wall and its stroke end is adjustable by a screw (83). The groove (30) communicates with the circuit of a pressure regulating valve (85) of known type mounted on the fuselage (11). The chamber (84) opens into a cavity, inside which a piston (86) slides and is pressed by a spring against the inner wall of the part (18) in a position radially opposite to the piston (82), and The two pistons (82, 86) are arranged along a coaxial plane perpendicular to and parallel to the axis of the pin. Body (l
i) is also provided with a duct (88) for the discharge connection of the circuit of the pressure regulating valve (35).

The method of operating the pump (10) will now be described.

When the rotor (18) starts rotating (of course after the shaft (15) is actuated), the stator (14) is in an eccentric position relative to the rotor (18) as shown in FIG. The piston (8) holds the stator (14) shifted towards the bottom (as seen in Figure 1) against the natural stop formed by the piston (82) at the end of the stroke.
This is because elastic suppression occurs due to 6).

In this position, as the rotor (13) turns counterclockwise (see FIG. 1), it is clear that the window (28) acts as a fluid suction opening and the cavity (25) acts as a delivery opening. In this way, fluid is drawn into the receiver from the outside of the fuselage (U), passes through the passage (24), the cavity (12) and the window (28), and from there the variable volume space formed by the blade (16). The fluid is delivered under pressure into the cavity (25) from where it flows through the hole (26) into the groove (27) and then through the duct (28) to be discharged to the outside for its intended use. . Under these conditions, the stator remains stable in the position shown in FIG. 1 until the delivery pressure exceeds a certain maximum value regulated by the pressure regulating valve. This is because the pressure of the fluid extracted from the delivery side through the groove (29) and acting on the piston (82) is
) and the pressure of the fluid extracted from the delivery side via the pressure control valve and the pressure of the spring (37) acting on the piston (86), so the piston (36) with the larger thrust part is the piston. This is because it exerts a higher force than (82).

When the delivery pressure exceeds the predetermined maximum value, the sliding part (89) of the pressure regulating valve (86) moves to the left (see Figure 1), causing the chamber (84) to move as shown in Figure 1. Valve (85
) and a duct (S8) for discharge. In this way, the thrust oil pressure of the piston (86) is reduced and the delivery pressure of the piston (32) is kept constant. Therefore, the force exerted on the piston (82) is
), the stator (14)
1) and move upwards, reducing the eccentricity relative to the rotor, and as a result the pump (lO
) to reduce the delivery pressure even to a value of zero.

As soon as the delivery pressure decreases below the predetermined maximum value, the pressure regulating valve (85) restores the hydraulic loading of the piston (86) and the stator (14) moves to the bottom again.

In this way, adjustment of the delivery rate is obtained as a function of the delivery pressure value and thus to the application requirements.

The pump (lO) described above has many advantages over prior art pumps as mentioned in the introduction.

The stator (14) is moved along a certain predetermined plane because the pin (21) [around which the stator revolves] allows only a single free limb. I can do it. As a result, the geometrical elements (axes, angles, etc.) and the axes on which the reaction forces act can be foreseen and predetermined for all operating steps and for any fixed position, so that all pump components Optimization of the design of the openings, passages, grooves, and vibration-reducing squid elements to achieve the best efficiency (high yield point and low noise) in addition to the optimal dimensioning of the stator position and operating conditions independently (in a relative sense, of course)
enable.

Sliding is prevented by opening the stator and piston. Rotor (1
3) pin (21) is fixed to the stator (14) due to interference caused by
This is because it prevents it from rotating around itself. Sliding is also prevented between the stator and the transverse plates. This is because the play (22) is firmly restrained by the stator (14).

This reduces wear on the pump's components and eliminates the need for precision machining of the contact surfaces of some of the components.

The response time of the stator movement is improved due to the non-variability of the pump geometry and due to the noticeable reduction in friction during the stator movement.

The oscillatory movement of the stator (14) around the pin (21) causes any changes to all suction and delivery passages (window (1B), cavity (25), hole (26)) during movement. do not have. This can be easily deduced by observing the drawings, and is also due to the relative movement between the parts. Optimum operating conditions of the pump are thus obtained in all stator delivery adjustment positions.

This is because the relative movement between stator, rotor and plate leads to undesirable partial shielding of the suction and outlet provided by the stator and into the plate by the rotor, with the result that this The geometry of the aperture changes.

The structure of the pump and the invariance of the geometry of the fluid passages allow the pump to operate as a motor.

This is accomplished by pre-modifying the pistons (82, 86) by changing appropriate end-of-stroke stops and associated drive systems to change the direction of change in stator eccentricity. This important feature, which was not readily available in currently known pumps due to the instability of the points restraining the shifting of the movable stator, is achieved by the present invention, in which the rotor is moved around it in a constant manner. In contrast to the conventional ones, this is immediately achieved in the pump (10) due to the presence of a fixed pin (21) which can be rotated.

Pumps that exhibit this potential are characterized by the fact that, in addition to the possibility of providing fluid delivery when they are combined with other pumps, they also operate in a circuit (a control circuit that operates as a hydraulic motor to power a shaft). ) and thus offer the widest possibilities for adjusting the delivery rate, in that they have wider control characteristics and possibilities than the currently known pumps mentioned in the introduction.

FIG. 3 shows a second specific example of the pump of the present invention.

This pump has a body, rotor, and stator similar to the pump elements shown in FIGS. For simplicity, all elements similar to those of the pump (10) are designated by the same number with the letter A appended. The pump of FIG. 8 is therefore designated by the reference numeral (10A).

This pump (IOA) differs from the pump (10) shown in FIGS. 1 and 2 in that it is intended to move a movable stator about a pin.

In this case a double actuation cylinder (50) is used, the pin (51) of which has the purpose of moving the movable stator (14A).

For this purpose, the screw) y (51) is connected to the stator ( 14A
) extends through a handle (52) which joins an extension (58) of the handle. As can be seen from FIG. 8, the extension (58) protrudes from the portion (18A) of the stator (14A) and is integral with the stator.

A spring (55) is arranged to be elastically pressed against the piston y (51), and this spring holds the piston (51) at its stroke end position, thereby causing the stator (
14/l) is a Jjlii body < 1, similar to the pump in Figure 1.
1A) is shifted downwards relative to the adjustable trade formed by the head of the screw (57) (see FIG. 8).

The movement of / (51) is a well-known type of electronic valve (58
) through 11m1a? No-? °σ) - ↓ 2 A mouth c ++ n mouth C =;
−r+ Connect the drain connections of the two chambers (59, 60) formed by the piston (51) in the sliding seat to the two corresponding chambers (61, 60) by means of operation well known to those skilled in the art.
2).

The source of pressurized fluid may be the delivery side of the pump itself.

The electronic valve (58) can also be controlled by a drive (not shown). This drive is a pulsed electronic valve (58) suitable as a function of several parameters.
to move the piston (51) and therefore the stator (14A) to a desired position.

Regarding the operating parameters, the control device derives a signal from the delivery duct (28A) via the groove (64);
A preferred pressure transducer (68) fixed to the fuselage (IIA)
An electrical signal corresponding to the delivery pressure can be received through. This control device furthermore passes the stator (14A) through a position transducer comprising a sensor element consisting of a small rod (66) which is pressed against the part (18A) of the stator (14A) opposite to the screw (57). ) can receive electrical signals at the location.

Alternatively, the movement of the piston (51) can be controlled by a pressure compensation circuit similar to that found in the pump (10) of FIG. The signal from the surface pressed by the spring (55) passes through a pressure regulating valve similar to the valve shown in FIG.

[Brief explanation of the drawing]

FIG. 1 is a radial cross-sectional view taken along line I and ■ in FIG. 2, showing a first specific example of the pump of the present invention. FIG. 2 is a longitudinal cross-sectional view taken along line 1--H in FIG. FIG. 8 is a radial sectional view similar to FIG. 1 showing a second specific example of the pump of the present invention. In the figure; 1O1IOA...pump; 11. IIA... fuselage;
12.12A...Cavity; 18.13A...Rotor;
14.14A... Stator; 15... Shaft; 16
．． 16A...Blade; 17.17A...Radial cavity; 18.18A120.20A...Stator component; 19.19A...Inner wall; 21, 21A...Pin; 22... Plate; 28.28A... window; 24.
24A...Communication path; 25.25A...Cavity; 26.
26A...Radial hole; 27.27A, 29.80.
・・Groove; 28.28A, 88・・Duct; 81.34・
...Chamber; 82.86 ・Piston; 38...Screw; 85...Pressure control valve; 37 ・ノ(Ne;50
... Cylinder; 51... Zen; 52... Handle, 53.
... Extension part; 54... Connection rod; 55...) (ne; 5
7...Screw; 58...Electronic valve; 59.60.
61, 62...chamber; 63...pressure transducer; 64...
・Groove; 66...Small stick. Procedural amendment (method) February 6, 1985 Manabu Shiga, Commissioner of the Patent Office 1 Display of the case 1988 Patent Application No. 268753 2 Name of the invention Hydraulic operated variable displacement rotary pump 3 Case of person making amendments Relationship Patent applicant name Athos Oleodynamica SpA 4 agent 07 Address Akasaka Taisei Building, 1-1-18 Akasaka, Minato-ku, Tokyo (
Telephone 582-7161) Procedural amendment (method) % formula % 1. Indication of the case, 1982 Patent Application No. 268753 2. Name of the invention Hydraulically operated variable displacement rotary pump 3. Person making the amendment Relationship with the case Patent applicant name Athos Oreodynamica SpA 4, Agent 07 6, Figures 2 and 3 attached to the application subject to amendment

Claims (1)

[Claims] L: a fuselage, comprising a blade-supporting rotor rotatably mounted inside one of the cavities of the fuselage, an annular stator surrounding the rotor, and a side channel sealed by a plate; It is suitable for shifting into an eccentric position relative to the rotor, and an internal sealed chamber is formed between the stator, the plate and the rotor, into which fluid suction and outlet ports are provided. A variable delivery capacity rotary pump that is commonly used in a variable delivery capacity rotary pump, characterized in that a stator is attached to freely oscillate around a pin fixed to the pump body. 2. The pump according to item 1, in which the plate is firmly attached to the stator. 8. A pump according to claim 1, wherein the bottle is internally provided with a hydraulic connection groove between an opening in the pump body and a closed internal chamber leading to the delivery opening. 4. The pump according to claim 8, wherein the hydraulic connection groove is hydraulically connected to the sealed internal chamber via a cavity provided in the stator. 5. Pump according to claim 8, characterized in that in the stator a hydraulic connection window is provided between the second cavity of the pump body through the cavity of this window and the closed internal chamber leading to the suction opening. 6. A pump according to claim 1, wherein the at least one piston is hydraulically actuated and adapted to shift the stator to an eccentric position relative to the rotor. 7. The pump according to claim 6, comprising a pair of pistons that slide within the body and press the stator from positions facing each other in the radial direction. 8. 7. A pump according to claim 6, comprising a single piston dynamically coupled to the stator.