FR2763652A1 - Hydraulic pump and electro-pump group fitted with this pump - Google Patents

Abstract

The pump (P) has a body (2) having an end base plate (1) which is used as interface with a motor group (M). At the opposite end of the body (2) is a cover (10). A casing (14) covers the pumps body so as to define between them a fluid space (R). The casing is pressed onto an end of the base plate and grip seals the cover (10). A part (22) is designed to be screw fixed on the cover (14) so as to press it against the base plate (1). The part (22) is used for connection of the high and low pressure pipes (12,19). The part (22) has an hole in it which is designed to aligned itself with a fluid passage (11) in the cover.

Description

The present invention relates to a hydraulic pump and an electro-pump unit comprising an engine block connected to this pump.

Such an electro-pump group is already known, the motor unit of which is connected to the pump body by means of an interface plate serving both as a front flange for the motor and as a support for the mobile assembly of the pump. This assembly has a great compactness because the electric motor is placed in an envelope to define between them a fluid reservoir. This envelope is held tightly on the engine block by two half-flanges fixed by several screws on the engine / pump interface plate. Two fittings are also mounted laterally on the interface plate for the high pressure and low pressure pipes.

However, due to the various motor / pump support and tank / pump support interfaces, this assembly presents an increased risk of leakage. In addition, to achieve good compactness, the structure of this assembly is complex and requires many flanges, screws and fittings, which increases the overall cost and complicates assembly.

The present invention therefore aims to provide a new hydraulic pump having a high compactness while minimizing the risk of leaks.

To this end, the subject of the invention is a hydraulic pump comprising a pump body having at one end a base serving as an interface with a motor unit and at its opposite end a cover, a jacket peripherally enveloping the pump body to define between them a fluid reservoir, said jacket being supported at one end on said base and fitted at its opposite end on said cover, and a separate part intended to be fixed on the aforementioned cover and to come to bear on said opposite end of the jacket to hold it against the base of the pump body. It can thus be seen that the reservoir is no longer directly fixed to the pump body but simply held by tightening thereon.

In a first embodiment, the separate part is a counter plate provided with at least one hole for fixing it to the cover. This counter plate can also ensure the connection of the high pressure and low pressure pipes to the pump. In particular, the counterplate may include a hole for a fixing screw intended to be screwed into the cover of the pump. This eliminates the need for fittings for low pressure and high pressure pipes.

In a particular form of connection, the plywood has at least one hole which is intended to align with a passage of fluid in the cover and / or the jacket for fixing therein a high pressure or low pressure pipe respectively.

In another form of connection, the counterplate extends to the vicinity of a fluid passage in the jacket and / or the cover in order to tighten a flange, formed radially projecting from a low pressure or high pressure pipe. , between the counterplate and the jacket or the cover respectively.

In another embodiment, the hole in the counterplate is adapted to receive a base fitting intended to be screwed into a passage of high pressure fluid tapped in the cover, so that said base comes to bear on the backing plate. plate.

In another embodiment, the separate part is a connector with a large base which is intended to be screwed into a passage of high pressure fluid tapped in the cover and whose large base is intended to come into abutment on said opposite end of the shirt.

The invention also relates to an electric pump group in which an engine block is mounted on the interface plate with the above-mentioned hydraulic pump.

The invention will be better understood, and other objects, characteristics, details and advantages thereof will appear more clearly during the detailed explanatory description which will follow of several particular presently preferred embodiments of the invention, given only. by way of illustration and not limitation, with reference to the appended schematic drawings, in which - FIG. 1 is a schematic view partially in section on line II of FIG. 6, of the motor-pump unit according to the invention; - Figure 2 is a top view of Figure 1, the reservoir and the backplate having been omitted - Figure 3 is a top view of Figure 1, the backplate having been omitted alone - Figure 4 is a broken sectional view with parallel planes along the line IV-IV of Figure 2, with the tank in addition - Figure 5 is a broken sectional view with parallel planes along the line VV in Figure 2, with the tank in addition - Figure 6 is a top view of Figure 1; and - Figure 7 is a partial view similar to Figure 1 and showing another embodiment of the clamping of the reservoir on the pump body.

According to the embodiment shown in FIGS. 1 to 6, the motor-pump unit of the invention comprises an engine block M connected to a pump P by an interface plate 1 serving both as a front flange for the engine M and support for the mobile pump assembly P.

The pump P comprises, in addition to its interface plate 1, a central block forming the pump body 2 in which are housed bearings 3 supporting shafts 4 and 5 on which are pinions 6 of the hydraulic gear pump. One of these shafts 4 is integral in rotation with a drive shaft 7 passing through the interface plate 1 from the engine M. Centering pins 8 are provided between the central block 2 and the interface plate 1 for ensure the correct positioning of the pump. Opposite the interface plate 1, the pump body 2 is closed by an upper plate 5 which is itself surmounted by a cover 10 in the shape of a bell. This cover 10 has an outlet passage 11 for the high pressure fluid to a high pressure pipe 12.

As shown in FIG. 4, the interface plate 1, pump body 2, plate 9 and cover 10 assembly are connected together by means of tie rods 13 passing through the stack of these components.

The general internal structure of the motor-pump unit and its operation will not be described here in detail and are similar to the electric motor and hydraulic pump assembly with high compactness described in French patent application No 95 07 132 filed on June 15 1995 in the name of the plaintiff.

An outer jacket 14 is mounted at one end on the interface plate 1, in leaktight support by means of a seal 15 interposed between the jacket 14 and an axially projecting circumferential rib 16 from the plate 1 This rib 16 is also used for positioning and fitting the jacket 14 around the pump P. The body of the jacket 14 extends along the pump P and at a distance from it so as to wrap and define a low pressure fluid reservoir R between the jacket 14 and the pump P. The opposite end of the jacket 14 is fitted peripherally around the cover 10 of the pump P, with a seal 17 interposed between them. An inlet passage 18 for low pressure fluid is also provided through the jacket 14 at said end opposite the interface plate 1, to receive a low pressure pipe 19.

It will be noted that here the connections of both the low pressure 19 and high pressure pipes 12 are provided at the head of the pump P, and not laterally at the level of the interface plate 1.

The cover 10 may also have an axial blind tapping 20 intended to receive a clamping screw 21 serving to fix a flange or counter-plate 22 at the head of the pump P. This counter-plate 22 is intended to come to bear on the free end of the jacket 14 to come and tighten the latter on the interface plate 1.

Thus, the jacket 14 is maintained on the pump unit without any direct attachment.

As visible in FIG. 6, the fixing flange 22 has an elongated shape ending at a fork end, the two lateral arms 23 of which enclose the low pressure pipe 19. The jacket 14 has a counterbore 18a at the low pressure passage 18 intended to receive a radially projecting flange 19a from the low pressure pipe 19 which can be obtained by deformation with the press. This flange 19a is intended to be sandwiched between the aforementioned counterbore 18a and the fork 23 of the fixing flange 22.

The high pressure hose 12 is meanwhile expanded or inflated hydraulically through the fixing flange 22 and the high pressure passage 11 as can be seen in FIG. 1. It is also possible to weld the high pressure hose to the fixing flange 22.

Of course, in the embodiment of Figures 1 to 6, one could alternatively provide a flange 22 with double fork 23 to retain the two pipes 12 and 19 or a flange with three holes to retain the two pipes in the manner of the pipe 12, or even reverse the connection of pipes 12 and 19.

In FIG. 7, an alternative embodiment is shown, also comprising a fixing flange 122 generally similar to the flange 22 and a hydraulic connection 24 with base 24a. The flange 122 here has a single bore intended to be aligned with the passage 11 of the cover 10, which passage 11 is tapped to receive the lower threaded portion of the connection 24 by screwing. Thus, the flange 122 is tightened against the cover 10 by through the base 24a, when the fitting 24 is tightened in the threaded passage 11.

In the variant of Figure 7 we note that the thread 20 and the fixing screw 21 are deleted.

However, it is here necessary to thread the passage 11 of the cover 10 and to use a hydraulic connection.

Finally, purely by way of illustration, we note in FIGS. 2 and 5 a fluid intake tube 25 between the reservoir R and the pump P. The other structural details of the pump P, such as the compensation chambers, are not not described here in more detail and are generally known in the art.

Although the invention has been described in connection with particular embodiments, it is obvious that it is in no way limited thereto and that it includes all the technical equivalents of the means described as well as their combinations if these are within the scope of the invention.

Of course, seals 17 are also provided between the casing 14 and the pipes 19 or 12 (see FIG. 1). The counterplate 22 also includes housings for seals 17 in order to ensure sealing with the base 24a and the threaded position of the connector 24.

Claims (8)

1 - Hydraulic pump (P) comprising a pump body (2) having at one end a base plate (1) serving as an interface with a motor unit  (M) and at its opposite end a cover (10), a jacket (14) enveloping the pump body peripherally to define between them a fluid reservoir  (R), said jacket being supported at one end on said base plate and fitted at its opposite end on said cover, and a separate part (22, 122, 124a) intended to be fixed on the aforementioned cover and to come in pressing on said opposite end of the shirt to hold it against the base plate. 2 - Pump according to claim 1, characterized in that the separate part is against a plate (22, 122) provided with at least one bore for its attachment to the cover. 3 - Pump according to claim 2, characterized in that the counterplate completely ensures the connection of the high pressure (12) and low pressure (19) pipes on the pump. 4 - Pump according to claim 3, characterized in that the counterplate comprises a bore for a fixing screw (21) intended to be screwed into the cover. 5. Pump according to claim 3 or 4, characterized in that the counterplate comprises at least one bore intended to align with a passage of fluid (11) in the cover and / or the jacket to fix there by inflation a high pressure or low pressure hose respectively. 6 - Pump according to one of claims 3 to 5, characterized in that the against-plate is adapted to come and clamp a projecting collar (19a) on a low pressure and / or high pressure pipe against the jacket or the cover respectively. 7 - Pump according to claim 2 or 3, characterized by a connector (24) with base (24a) intended to pass through the bore of the counter-plate and to be screwed into a passage of high pressure fluid (11) tapped in the cover. , so that said base (24a) is in abutment on the counter-plate and provides sealing by seals (17). 8 - Electro-pump group in which an engine block (M) is mounted on the interface plate (1) with the pump according to one of the preceding claims.