EP1783371A1 - Electric pump unit - Google Patents

Abstract

The pump has hydraulic pumps (8, 9) driven in rotation by electric motors (1, 2), respectively. The hydraulic pumps and the motors are arranged in a manner that the power of the hydraulic pumps are obtained by adding the power of the motors. The hydraulic pumps are integrated to a common pump body. A discharge manifold has a discharge channel common to the hydraulic pumps and a suction manifold has a suction channel common to the hydraulic pumps.

Description

The invention relates to an electropump, of the type comprising at least one hydraulic pump, in particular gear, driven in rotation by a motor device.

Electro-pumps of this type, which are known and in particular used by the power steering of a motor vehicle, have the major disadvantage that the power of the group is limited although the vehicles to be equipped with a power steering are becoming heavier and the powers necessary to ensure the power steering are higher and higher. However, currently the power of the electric pump units is limited for technological reasons, in particular because the power supply and the connectors do not accept a sufficient intensity, as the technology of high power engines (> 1.5 kW ) is almost non-existent for a voltage of 12V and that the development of such motors is limited to low series and has a high cost.

The invention aims to overcome the drawback of known systems.

To achieve this goal, the electro-pump unit according to the invention is characterized in that it comprises two hydraulic pumps and two electric motors which are arranged so that the power of the group can be obtained by adding the powers of the two. engines.

According to a characteristic of the invention, the electropump is characterized in that it comprises a discharge manifold which comprises a discharge channel common to both pumps.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the two pumps are integrated in a common pump body.

According to yet another characteristic of the invention, the electro-pump unit is characterized in that comprises a suction manifold having a suction channel common to both pumps.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the drive motors of the two pumps are arranged on either side of the common pump body.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the pump body is sandwiched between the suction manifold and the discharge manifold, each manifold bearing on its outer face one of the two engines.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the pump body comprises, inside an outer casing wall, a high pressure volume common to both pumps, which communicates with the working chambers of the two pumps and a common high pressure volume provided in the discharge manifold, which is in communication with the common discharge channel.

According to yet another characteristic of the invention, the electro-pump unit is characterized in that it comprises a common support sole which comprises, inside, the common discharge channel and on one side of which are mounted the two pumps and on the other two engines.

According to yet another characteristic of the invention, the electropump is characterized in that the two pumps are enclosed in a common liner capable of constituting a low pressure liquid reservoir.

According to yet another characteristic of the invention, the electro-pump unit is characterized in that at least one of the pumps comprises, in its discharge path a non-return valve so that this pump can be selectively stopped.

According to yet another characteristic of the invention, the electric pump unit is characterized in that it comprises an engine control device adapted to control one engine from the outside and that engine controls the speed of the other.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the two motors rotate in the same direction or in opposite directions.

According to yet another characteristic of the invention, the electro-pump unit is characterized in that the two pumps are adapted to rotate with an angular offset of a few degrees to provide a decrease in the pressure pulsations produced by the electro-pump unit.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the two pumps are capable of operating in phase opposition.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the pumps operate at different speeds of rotation.

According to yet another characteristic of the invention, the electric pump unit is characterized in that the presence of two motors constitutes a redundancy security means.

• la figure 1 est une vue en perspective d'un premier mode de réalisation d'un système de groupe électro-pompe selon l'invention ;
• la figure 2 est une vue latérale du système représenté sur la figure 1,
• la figure 3 est une vue en perspective du manifold d'aspiration indiqué en A sur la figure 1 du système selon l'invention, certaines parties du module pompe étant représentés supplémentairement ;
• la figure 4 est une vue en perspective du corps de pompe B de la figure 1, disposé sur le module d'aspiration A ;
• la figure 5 est une vue en perspective du manifold de refoulement indiqué en C sur la figure 1 ;
• la figure 6 est une vue en coupe le long de la ligne VI-VI de la figure 2 ;
• la figure 7 est une vue en coupe le long de la ligne VII-VII de la figure 2 ;
• la figure 8 est une vue en coupe selon la ligne VIII-VIII de la figure 2 ;
• la figure 9 est une vue en coupe selon la ligne IX-IX de la figure 2 ;
• la figure 10 est une vue en coupe selon la ligne X-X de la figure 2 ;
• la figure 11 est une vue en coupe selon la ligne XI-XI de la figure 2 ;
• la figure 12 est une vue en coupe de l'ensemble formé par le corps de pompe B et des manifolds A et C à l'état assemblé selon la ligne XII-XII de la figure 8 ;
• la figure 13 est une vue en coupe de cet ensemble selon la ligne XIII-XIII des figures 8 et 9 ;
• la figure 14 est une vue en coupe de cet même ensemble selon la ligne XIV-XIV des figures 5 et 9 ;
• la figure 15 est une vue latérale d'un second mode de réalisation du système groupe électro-pompe selon l'invention ;
• la figure 16 est une vue de dessus de la figure 15 ;
• la figure 17 est une vue en coupe le long de la ligne XVII-XVII de la figure 16 ;
• la figure 18 est une vue en coupe le long de la ligne XVIII-XVIII de la figure 16 ; et
• la figure 19 donne le schéma synoptique du système selon l'invention, comportant deux moteurs électriques d'entraînement de deux pompes hydrauliques.

The invention will be better understood, and other objects, features, details and advantages thereof will appear more clearly in the explanatory description which follows, with reference to the appended schematic drawings given solely by way of example illustrating two modes of embodiment of the invention and in which:

• Figure 1 is a perspective view of a first embodiment of an electro-pump system according to the invention;
• FIG. 2 is a side view of the system represented in FIG. 1,
• FIG. 3 is a perspective view of the suction manifold indicated at A in FIG. 1 of the system according to the invention, some parts of the pump module being represented additionally;
• Figure 4 is a perspective view of the pump body B of Figure 1, disposed on the suction module A;
• Figure 5 is a perspective view of the discharge manifold indicated at C in Figure 1;
• Figure 6 is a sectional view along the line VI-VI of Figure 2;
• Figure 7 is a sectional view along the line VII-VII of Figure 2;
• Figure 8 is a sectional view along the line VIII-VIII of Figure 2;
• Figure 9 is a sectional view along the line IX-IX of Figure 2;
• Figure 10 is a sectional view along the line XX of Figure 2;
• Figure 11 is a sectional view along the line XI-XI of Figure 2;
• Figure 12 is a sectional view of the assembly formed by the pump body B and manifolds A and C in the assembled state along the line XII-XII of Figure 8;
• Figure 13 is a sectional view of this assembly along the line XIII-XIII of Figures 8 and 9;
• Figure 14 is a sectional view of the same set along the line XIV-XIV of Figures 5 and 9;
• Figure 15 is a side view of a second embodiment of the electro-pump system according to the invention;
• Figure 16 is a top view of Figure 15;
• Fig. 17 is a sectional view along the line XVII-XVII of Fig. 16;
• Figure 18 is a sectional view along the line XVIII-XVIII of Figure 16; and
• Figure 19 gives the block diagram of the system according to the invention, comprising two electric motors for driving two hydraulic pumps.

Figure 1 is an overview of an electric pump unit according to the invention, which comprises two electric motors and two hydraulic pumps, each driven by one of the two motors. In FIG. 1, the references 1 and 2 designate the two electric motors, the reference B the pump body which encloses two hydraulic gear pumps, the inlet or suction manifold of the pumps and C the outlet manifold or of repression. As shown in the figures, the pump body B is sandwiched between the inlet manifolds A and outlet C. These parts thus form a compact block disposed between the two motors. Each motor has a base portion respectively 4 and 5 which carries the electrical connections 6 of the motors and encloses the electrical circuits.

FIG. 19 gives the block diagram of the system according to FIG. 1. It can be seen that the motor 1 drives a first pump designated by the reference 8 and the second the motor 2 a second pump 9. The two pumps 8 and 9 suck up the hydraulic fluid in a tank 10. The discharge paths of the two pumps are joined at the junction point 14 and thus supply the user in high pressure hydraulic fluid, generally in oil. In the discharge line of each pump upstream of the junction point 14 is provided a check valve 12. A pressure limiter 11 and a feed valve 13 are mounted in parallel between the junction point 14 and the reservoir.

Referring to Figures 3 to 11 will be described hereinafter the structure of the pump body B and suction manifolds A and discharge C of a first embodiment of the invention.

FIG. 3 illustrates the structure of the suction manifold A and also shows the pinions of the gear trains of the two pumps 8 and 9, noted for the pump 8 and 16 for the pump 9, the pinions being shown with their lower bearings. 17 and above 18. The presentation of the manifold or suction support A is completed by the two sectional views 6 and 7 which are taken along the lines VI-VI and VII-VII shown in FIG.

The suction manifold A comprises a suction channel 20 which opens outwards into the lateral face 21. This channel 20, which is rectilinear as can be seen in FIGS. 6 and 7, communicates with low-pressure capacitive cavities 23, 24 of the manifold from the inner face 25 for receiving the pump body B. This suction channel 20 is connected to a reservoir 10 according to Figure 19, outside the electropump.

It can be seen that the cavity 23 near the pinions 16 of the pump 9 is wider and deeper than the cavity 24 on the side of the other pump, which is in the form of an arcuate groove. The cavity 23 has a raised bottom intermediate zone 23 'which delimits a cavity 26 for receiving the spring 27 of the pressure limiter 11 (FIG. 19). The suction channel 20 opens directly into the cavity 23 and communicates with the cavity 24 by a vertical channel 28, that is to say perpendicular to the section plane. Figure 7 further shows at 30 grooves in which are placed unrepresented seals. The reference 25 designates the installation face of the pump body B.

It is apparent from FIGS. 3, 6 and 7 that the hydraulic fluid, that is to say the oil, after having been sucked from the tank fills the low pressure cavities 23, 24 to independently feed the two gear trains 15, 16 as shown in the perspective figure of the pump body B and the sectional views 8 and 9.

Figures 4, 8 and 9 show that the pump body B has a bottom wall 32 which rests on the installation face 25 of the suction manifold A and on which rises an outer casing wall 33, and the interior of this envelope of peninsulas 35, 36 which delimit chambers 37, 38 housing the gear trains 15, 16 and bearings 17, 18, parts in the form of peduncles 39 of attachment of presqu'Ilots at the envelope wall 33 configured for producing two cylindrical housings 40, 41 of the two check valves 12 (Figure 19) and the housing 39 in alignment with the cavity 26 for receiving the pressure limiter 11 (Figure 19). The envelope wall 33 has a boss which delimits a cavity 43 intended to receive the feedback valve 13 (FIG. 19). The remainder of the space inside the envelope wall 33 constitutes a capacitive volume comprising four cavities 45, 46, 47, 48 separated from each other only by the peduncle-shaped portions and two narrow ribs 49 of attachment of the penlets to the envelope wall. The front face and the surfaces of the presqu'Ilots, peduncles and ribs constitute the exposure face 34 for manifold C.

The sectional views parallel to the plane of the pump body of FIGS. 8 and 9 show the inlet channels 50 and 51 of the chambers 37 and 38 for housing the gear trains with the bearings of the two pumps and the outlet channels 53 and 54. As seen in the sectional view perpendicular to the plane of the body B of Figure 12, the inlet channel 51 communicates with the low pressure cavity 23 in which the suction channel 20 opens. The channel input 50 is connected to the suction channel 20 in a corresponding manner, not shown specifically.

Figure 12 also shows that the outlet channel 54 communicates with the housing 41 of one of the two check valves 12, through the orifice 52 of the seat of the ball 55 of the valve. The ball 55 is pushed back onto its seat by a return spring 57 resting at its other end on a bearing base 58 being guided by a member in the form of a rod 59 of the valve, disposed in the center of the housing 41. The outlet channel 53 communicates in the same way with the housing 40 of the other non-return valve 12.

The perspective figure 5 and sectional views of FIGS. 10 and 11 illustrate the structure of the manifold or pressure support C.

The discharge manifold C comprises a bottom wall 60 on which is raised perpendicularly an outer casing wall 61 which encloses a common capacitive volume 63. The front face 62 of this wall is intended to bear on the front face of installation of the pump body 34. The volume 63 surrounds two islands 65, 66 for supporting the upper bearings 18 of the two gear trains, these islands are connected to each other by a relatively thin bar 67 and, at the of this bar, to the casing wall 61 by a raised area 68. This area has two circular projections 69 to the level of the laying plane of the manifold. These zones 69 are intended to serve as a bearing surface, each at the base of a base 58 of spring support of a nonreturn valve 12. These are isolated so that these portions and the raised area 68 shrink, but do not prevent the oil filling the cavity can pass over the area 68 by flowing around the projections 69. There are still 70 grooves in the free face of the islands 65, 66 for the receiving core compensating gaskets surrounding the bearing regions 18 of the gear trains, the recessed portions 73 being filled with the low pressure lubricating oil. In the assembled state of the pump body B and the manifolds A and C, the islands 65 and 66 of the manifold C rest on the presqu'Ilots 35, 36 of the pump body B.

With reference to the perpendicular sectional views, FIGS. 13 and 14, it can be seen that the housing cavities 40, 41 of the pump body B communicate with the volume 63 of the discharge manifold C, by passages indicated at 72 on the part of and other and around the projections 69 of support of the check valves.

The sectional view of FIG. 10 shows that the capacitive volume 63 is in communication with a high-pressure outlet channel 75 which opens out into the side wall 76 of the discharge manifold C. In FIG. opening towards the outside of the outlet channel, that is to say of repression, is not visible, but one recognizes at the bottom of the volume 63 in 77 the opening of the channel 75 in the volume 63.

Since the discharge outlet manifold C comes, in the assembled state, by its upper face 62 bearing on the upper face 34 of the pump body B, the cavities 45, 46, 47 and 48 of the body B and the volume 63 of the discharge manifold C constitute a single volume filled with the high-pressure oil discharged by the pumps 8 and 9 through the discharge channels 53 and 54 (FIG. 9) via the non-return valves 12 arranged in the chambers 40, 41.

Concerning the pressure limiter 11 (FIG. 19) it is placed in the cavity 26 of the suction manifold A (FIGS. 3, 6, 7) and the cavity 39 of the pump body B (FIGS. 4, 8, 9). The bottom of the cavity 26 is in communication with the low pressure suction space 23, by a not shown channel and the cavity 39 of the pump body B communicates via a channel 75 visible in FIGS. 8 and 9 with the high pressure cavity. 48 and thus with the discharge channel 75 via the volume 63 of the discharge manifold C.

Regarding the refilling valve 13, it is housed in the cavity 43 of the pump body B (FIGS. 4, 8, 9) which communicates, as can be seen in FIG. 13, with the low-pressure groove 24 of the manifold. on the one hand, and on the other hand, the volume 63 of the discharge manifold C.

In this first embodiment, the two motors 1 and 2 are arranged on either side of the assembly formed by the two pumps and comprising the suction manifolds A and discharge C and sandwiched between these two manifolds, the pump body B. In Figure 3 there is shown at 80 the drive shaft of the motor 2, which is intended to pass through the bore 81 visible in the island 66 of the discharge manifold C. Regarding the drive of the gear train 15 of the pump 8, it is driven by the motor 1 whose shaft will then cross the bottom wall of the suction manifold A.

Figures 15 to 18 illustrate a second embodiment of the electro-pump system system according to the invention. This embodiment also comprises two motors denoted 1 and 2, each intended for driving a hydraulic gear pump, for example of the type described in the patent application. European EP 1 026 392 . These two pumps designated by the references 8 and 9, as in the first embodiment, are mounted on one side of a common support sole 83 and enclosed in a jacket 84 which delimits a low pressure liquid reservoir. The two motors 1, 2 are mounted on the other side of the support sole 83. FIG. 17 shows at 86 the motor shafts of the motors 1 and 2, at 87 the driving shafts driven in rotation by the motor shafts 86.

As can be seen in FIG. 18, the common support 83 for pumps and motors comprises a channel 89 which opens outwards into the lateral face 90 of the support and extends inside the support, passing under the pump 8 to the pump 9. The discharge channels of the high pressure liquid, designated by the reference 92, of the two pumps open into the channel 89 which is therefore the common discharge channel of the two pumps and thus the system according to the invention. 'invention.

It is apparent from the description of the invention and the figures, that it solves the problem of increasing the power of an electro-pump system while using the known technologies. The invention therefore consists in using two motors which are controlled to be able to add the available powers of the two pumps. The invention also makes it possible to drive two different and uncoupled pumps to increase the difference between the minimum and maximum flow of the electropump. Pumps are generally limited in minimum flow because it is necessary to operate them at a minimum speed, the use of two pumps and two motors allows during low flow requests, not operate a motor and reduce power consumption. Thanks to the presence of a non-return valve at the outlet of the pumps, one of the two pumps can be stopped. The invention makes it possible to use engines that are widely used in series and to provide redundancy between the two motors, which makes it possible to avoid stopping power assistance in the event of a failure of one of the engines.

Regarding the engine control, it is performed from the instructions of the vehicle that the electro-pump group team. The steering could be provided by one of the two engines which would then drive the speed of the second.

To the advantage indicated above of the reduction of the noise and the hydraulic pulsations thanks to the large volume of the high-pressure space, is added that the noise and the pulsations can be further reduced thanks to the cooperation of the two pumps. Indeed, each pump generates pulsations of a frequency equal to the number of teeth multiplied by the rotation frequency of the pump. By making the two pumps turn with a setting of a few degrees, there is a decrease in the pressure pulsations, at the same time as an increase in the frequency. According to the invention the motor control could be carried out to obtain a functioning of the pumps in opposition of phase. We could also drive the engines at different speeds.

It emerges from the description of the two embodiments of the invention, which have been given by way of example only, that the invention makes it possible, by integrating the functions of the two pumps into a common pump body, to reduce the bulk of the group, while providing a large common high pressure volume, which provides, despite the presence of two pump units, a considerable improvement in the damping pulsations produced by these pumps.

Claims (13)

Electro-pump unit, of the type comprising at least one hydraulic pump, in particular a gear pump, driven in rotation by an electric motor, characterized in that it comprises two hydraulic pumps (8, 9) and two electric motors (1, 2) which are arranged in such a way that the power of the group can be obtained by adding the powers of the two motors, that the two pumps (8, 9) are integrated in a common pump body (B) and that the electric pump unit comprises a discharge manifold (C, 83) provided with a discharge channel (75, 89) common to both pumps (8, 9) and a suction manifold (A) having a common suction channel (20) at both pumps .. Electro-pump unit according to Claim 1, characterized in that the drive motors (1, 2) of the two pumps (8, 9) are arranged on either side of the common pump body (B). Electro-pump unit according to Claim 2, characterized in that the pump body (B) is sandwiched between the suction manifold (A) and the discharge manifold (C), each manifold bearing on its outer face a two engines. Electro-pump unit according to one of claims 2 or 3, characterized in that the pump body (B) comprises, inside an outer casing wall (33) a high pressure volume common to both pumps which communicates with the working chambers of both pumps and a common high pressure volume provided in the discharge manifold (C), which is in communication with the common discharge channel (75). Electro-pump unit according to Claim 1, characterized in that it comprises a common support sole (83) which has, on the inside, the common discharge channel (89) and on one side of which both are mounted. pumps (8, 9) and on the other the two motors (1, 2). Electric pump unit according to claim 5, characterized in that the two pumps (1, 2) are enclosed in a common jacket (84) capable of constituting a low pressure liquid reservoir. Electro-pump unit according to one of Claims 1 to 6, characterized in that at least one of the pumps has a non-return valve (12) in its discharge path, so that this pump can be selectively switched off. Electro-pump unit according to one of claims 1 to 7, characterized in that it comprises a motor control device (1, 2) adapted to control an engine from the outside and in that this engine drives the speed of the other. Electro-pump unit according to one of claims 1 to 8, characterized in that the two motors rotate in the same direction or in opposite directions. Electro-pump unit according to one of Claims 1 to 9, characterized in that the two pumps (8, 9) are adapted to rotate with an angular offset of a few degrees to provide a reduction of the pressure pulsations produced by the electro-electric unit. -pump. Electro-pump unit according to one of Claims 1 to 10, characterized in that the two pumps (8, 9) are likely to operate in opposite phases. Electro-pump unit according to one of Claims 1 to 11, characterized in that the pumps operate at different speeds of rotation. Electro-pump unit according to one of Claims 1 to 12, characterized in that the presence of two motors (1, 2) constitutes a redundant safety means.

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