EP2981720A1

EP2981720A1 - Hydraulic pump with double direction of rotation

Info

Publication number: EP2981720A1
Application number: EP14719055.7A
Authority: EP
Inventors: François POREL
Original assignee: Hydro Leduc SAS
Current assignee: Hydro Leduc SAS
Priority date: 2013-04-04
Filing date: 2014-03-27
Publication date: 2016-02-10
Also published as: WO2014162083A1; FR3004224A1; US20160025081A1

Abstract

A hydraulic pump with double direction of rotation comprises axial pistons bearing against a swash plate, the pump comprising a cylinder head comprising two chambers intended to be connected respectively to a high-pressure circuit and to a low-pressure circuit. The port plate (3) produced in the form of a planar plate arranged between the rotating drum and the cylinder head has two identical openings (22, 23) passing through the thickness of the planar plate. The port plate pivots about an axis (21) in such a way as to be able to occupy two angular positions depending on the direction of rotation of the pump. The pump comprises a device (38, 39) for hydraulically controlling the angular position of the port plate, capable of automatically causing a change in the angular position of the port plate, when the direction of rotation of the pump is reversed, under the effect of the pressure differential between the two chambers of the cylinder head.

Description

The present invention relates to a hydraulic pump with axial pistons bearing against a bias plate, and ice distribution, said pump being rotatable in both directions of rotation, and in particular to a device automatic piloting of the ice cream dispenser.

In known manner axial piston pumps and ice distribution have, at the rear of the pistons, a flat surface, called ice, on which are engraved two curved lights for distribution, one serving for suction the other serving for repression.

Since the construction of a pump with ice-plane distribution, with a double direction of rotation, imposes identical lights in order to be alternately suction or discharge light according to the direction of rotation chosen by the user, it is necessary, so as not to impair the performance of the pump, to wedge the angular position of said distribution window by an angle X to optimize its angular position, which requires means allowing a shift X in both directions around its axis of rotation .

In known pumps of this kind, the change of the angular position of the dispensing ice is operated manually by the user.

Such a mechanism for manually changing the angular position of the dispensing ice is described, for example, in the French patent application FRAI -2965311.

US-A-3227095 discloses in Figure 16 a reversible pump. An inner ring 286 and an outer ring 296 rotate in two mutually opposite directions under the effect of the overpressure present on the discharge side, so as to reduce the suction cavity I and widen the discharge cavity E. The cavity discharge E and the suction cavity I are defined between the two rings 286 and 296 and between the transom segments 288 and 298 carried respectively by these two rings.

The object of the present invention is to provide a pump provided with an automatic device for changing the angular position of the dispensing ice.

For this, the invention proposes a hydraulic pump with two directions of rotation, comprising axial pistons bearing against a bias plate, the pump comprising a rotary barrel rotated by a shaft and carrying cylinders in which the pistons slide, the pump comprising a cylinder head comprising two chambers intended to be respectively connected to a high pressure circuit and a low pressure circuit, the distribution the pump being provided by a distributor window having two identical lumens arranged opposite two chambers of the cylinder head and able to form a suction port and a discharge port in each direction of rotation of the pump, each cylinder being provided with at its base an orifice which passes successively in front of the suction port and the discharge port during the rotation of the cylinder, said dispensing plate being able to pivot about an axis so as to occupy two angular positions according to the direction of rotation of the pump,

characterized by the fact that the pump comprises a device for hydraulically controlling the angular position of the dispensing window capable of automatically causing a change of angular position of the dispensing window, when the direction of rotation of the pump is reversed, under effect of the pressure differential between the two chambers of the cylinder head.

According to embodiments such a pump may comprise all or part of the following provisions.

According to one embodiment, the hydraulic control device comprises a free piston mounted in a cylinder which is connected at each of its ends to one of the two chambers of the cylinder head.

Such a piston may be coupled to the dispensing ice by any appropriate means to drive it about its axis. According to one embodiment, the free piston is provided with a finger whose end is engaged in a housing formed at the periphery of the dispensing ice.

The invention will be better understood, and other objects, details, features and advantages thereof will appear more clearly in the following description of a particular embodiment of the invention, given solely for illustrative purposes and not limiting, with reference to the accompanying drawings. On these drawings:

Figure 1 is a longitudinal sectional view of a pump with two directions of axial piston rotation carried by a rotating barrel and whose rear end rests against a dispensing ice. Figure 2 is an overall perspective view of the pump of Figure 1 mounted for clockwise rotation, seen from the cylinder head side.

Figure 3 is a view similar to Figure 2, the pump being mounted for rotation in the counterclockwise direction.

Figure 4 is a perspective view in section along the line IV-IV of Figure 1, showing an angular control piston of the dispensing glass, said piston being in a first position corresponding to a rotation in the counterclockwise direction.

Figure 5 is a view similar to Figure 4, the control piston being in its second position corresponding to a clockwise rotation.

Figure 6 is an enlarged perspective view in section along the line VI-VI of Figure 4 of the cylinder head of the pump, illustrating the position of the parts when the pump rotates counterclockwise.

Figure 7 is an enlarged perspective view in section along the line VII-VII of Figure 5 of the cylinder head of the pump, illustrating the position of the parts when the pump rotates clockwise.

Referring to Figure 1, which shows schematically an axial section through the body of a variable flow pump, it is seen that the pistons 1 of the pump bear against a bias plate 2 whose inclination relative to the The axis of the pump is variable and controlled by two jacks 5 and 6 which work in opposition. As the pistons 1 of the pump bear against the bias plate 2, the inclination of the latter determines the stroke of the pistons and therefore the displacement of the pump. This type of pump is called a variable flow pump or a variable displacement pump.

Each piston 1 slides in a cylinder la, which bears against the dispensing window 3. The dispensing window 3 is a flat metal plate arranged between the rotary barrel 20 and the yoke 40 and pierced in the thickness direction by two lights 22 and 23 in the form of beans (Fig. 7). The cylinders 1a are carried by a rotating barrel 20, rotated by a shaft 21. Each cylinder is provided at its base with an orifice 4 which, when the barrel rotates, passes successively in front of the slots 22 and 23 (FIG. 7) dispensing ice 3. With reference to FIGS. 2 and 3, the cylinder head 40 of the pump is pierced with two similar ducts serving alternately, one of the discharge duct 41, and the other of the suction duct. A suction flange 43 is mounted on the yoke 40 at the suction duct in FIGS. 2 and 3. The roles of two ducts are permuted when the direction of rotation of the pump is reversed.

We will now describe an automatic control of the angular position of the distribution window, which is illustrated in Figures 4 to 7.

The dispensing glass 3, whose overall shape is that of a ring pierced with a central hole for the passage of the shaft 21 and having a substantially circular outer contour, is freely rotatable about the axis of the shaft 21 of the pump. The distribution window 3, provided with its two identical slots 22 and 23 and rotatably mounted on the shaft 21, has at its periphery 35 a U-shaped housing 36. In this housing 36 is disposed the end of a finger 37, which is carried by a piston 38, which slides freely in its cylinder 39.

When pressurized liquid is introduced to one side of the cylinder 39, the piston 38 is pushed to abut against the opposite end of the cylinder 39 and is held there by the pressure. This movement of the piston 38 causes the ice 3 to rotate. The two opposite stop positions of the piston 38 define the two extreme angular positions of the ice 3 (X and -X), which correspond, one to the rotation in the direction hour (Figures 2, 5 and 7) and the other at counterclockwise rotation (Figures 3, 4 and 6).

Figures 4 and 5 show the cylinder head of the pump, without the ice 3; but with the suction orifices 48 and discharge ports 41, which are alternately the right orifice and the left orifice of the pump yoke 40 according to the connection made in accordance with FIGS. 2 and 3. The cylinder 39 accommodating the free piston 38 is formed in the cylinder head 40, above two symmetrical chambers 49 located respectively in front of the orifices 48 and 41.

Each of the two chambers 49 communicates through a passage 42 with a respective end of the cylinder 39. Thus, by the effect of the hydraulic pressure, the piston 38 is always held in abutment at the end of the cylinder 39 which communicates with the chamber 49 located at low pressure, ie suction side 48, and remote from the end of the cylinder 39 which communicates with the chamber 49 situated at the high pressure, namely the discharge side 41.

In FIG. 5, which corresponds to the rotation of the pump in the clockwise direction, the orifice 48 is the suction orifice, the orifice 41 being that of the discharge. The pressure arrives through the passage 42 on the left side of the cylinder 39 and the piston 38 is pushed to the right until it stops against the right end of the cylinder 39 and is held there by the pressure. This movement of the piston 38 rotates the ice 3 into the position shown in Figure 7 (X angle).

In Figure 4, which corresponds to the rotation of the pump counterclockwise, the orifice 41 is the discharge port, the orifice 48 being that of the suction. The pressure arrives through the passage 42 on the right cylinder side 39 and the piston 38 is pushed to the left until it stops against the left end of the cylinder 39 and is held there by the pressure. This movement of the piston 38 pivots the ice 3 into the position shown in FIG. 6 (angle -X)

Thus the change of the angular setting (X or -X) of the dispensing window 3 is performed without further intervention of the user that the connection of the inlet and outlet ports of the cylinder head 40 of the pump.

Each end of the piston 38 is provided with an internal bent channel 50 connecting the end face of the piston 38 to the lateral face of the piston 38 to the right of the channel 42, so as to be able to transmit the hydraulic pressure coming from the channel 42 until at the corresponding end of the cylinder 39 during a reversal of direction of the pump, and thus initiate the axial displacement of the piston 38.

As can be seen in FIGS. 4 and 5, supply ducts 51 and 52 formed in the cylinder head 40 start from the cylinder 39 opposite the channels 42 in the direction of the control unit of the pump (not shown) to supply this hydraulic pressure control unit. Each of the conduits 51 and 52 is provided with a ball valve 53 which opens only on the side where the discharge pressure of the pump is located.

Although the invention has been described in connection with a particular embodiment, it is obvious that it is not limited thereto and that it comprises all the technical equivalents of the means described and their combinations if they are within the scope of the invention. The use of the verb "to include", "to understand" or "to include" and its conjugated forms does not exclude the presence of other elements or steps other than those set out in a claim. The use of the indefinite article "a" for an element does not exclude, unless otherwise stated, the presence of a plurality of such elements.

In the claims, any reference sign in parentheses can not be interpreted as a limitation of the claim.

Claims

1. Hydraulic pump with two directions of rotation, comprising axial pistons (1) bearing against a bias plate (2), the pump comprising a rotary barrel (20) driven in rotation by a shaft (21) and carrying cylinders ( 1a) in which the pistons (1) slide, the pump comprising a cylinder head (40) comprising two chambers (49) intended to be connected respectively to a high-pressure circuit and to a low-pressure circuit, the distribution of the pump being provided by a dispensing window (3) in the form of a flat plate arranged between the rotating barrel (20) and the yoke (40), the dispensing window (3) having two identical slots (22, 23) passing through the thickness of the flat plate and disposed opposite two chambers (49) of the cylinder head and able to form a suction port and a discharge port in each direction of rotation of the pump, each cylinder (la) being provided at its base of an orific e (4) which passes successively in front of the suction lumen and the discharge lumen during the rotation of the barrel (20), said dispensing crystal (3) being able to pivot about an axis (21) so as to be able to occupy two angular positions in the direction of rotation of the pump, characterized in that the pump comprises a hydraulic control device (38, 39, 42) of the angular position of the dispensing glass (3) capable of automatically causing a changing the angular position of the dispensing ice, when the direction of rotation of the pump is reversed, under the effect of the pressure differential between the two chambers (49) of the cylinder head (40).

2. Device according to claim 1, wherein the hydraulic control device comprises a free piston (38) mounted in a cylinder (39) which is connected at each of its ends to one of the two chambers (49) of the cylinder head (40). ).

3. Device according to claim 2, wherein the free piston (38) is provided with a finger (37) whose end is engaged in a housing (36) formed at the periphery (35) of the dispensing ice ( 3).