CH716640A2 - Double pump and oil delivery device for pumping oil for an internal combustion engine. - Google Patents

Abstract

The present invention relates to a double pump (1) comprising: a gear arrangement (2) with three gears (3, 4, 5) of which a first (4) of the three gears (3, 4, 5) with the other two gears (3 , 5), a housing (6) which surrounds the gear arrangement (2) in such a way that when the gears (3, 4, 5) of the gear arrangement (2) rotate, a first suction area (7) and a second suction area (8) and a first delivery area (9) and a second delivery area (10) are formed by the gear arrangement (2), the housing (6) having a first suction inlet (11) fluidically connected to the first suction area (7). The pump (1) is characterized in that the housing (6) has a second suction inlet (12) fluidly connected to the second suction area (8), and the first suction inlet (11) and the second suction inlet (12) are fluidically separated from one another .

Description

description

The present invention relates to a double pump and an oil delivery device for pumping oil for an internal combustion engine.

In order to ensure that a lubricating oil pump of an internal combustion engine can suck in oil even at steep inclines, the oil pans generally have a recess in which the oil is sucked in.

The disadvantage here is that the recess requires additional space and leads to a greater engine height. Due to space restrictions, however, the motor height often has to be kept as small as possible, which is why special solutions are sometimes used; for example by using a so-called dry sump oil pan and / or by arranging the cylinders horizontally.

However, if the principle of a dry sump oil pan is followed, in the case of inclines or high accelerations of the vehicle there is the risk that the suction head for sucking in oil in the oil pan is no longer completely enclosed by oil and therefore oil production cannot be carried out .

If an oil pump is equipped with several suction heads, which are arranged appropriately distributed over the dry sump oil pan, so that at least one of the suction heads is always completely surrounded by oil even with strong accelerations or inclines, this does not provide a remedy. Because if a suction head is not partially enclosed with oil, the oil pump delivers air whereas the required oil delivery and thus the required oil circuit comes to a standstill.

In the prior art, two independent oil pumps are sometimes used to provide some remedy for the aforementioned problems.

However, if the state holds that one of the two and here in each case the same oil pump does not deliver any oil for a long period of time, the self-lubrication of the dry-running oil pump does not occur, so that the probability of damage is greatly increased. In construction machines and other mobile work machines such as a snowcat, operations in which the vehicle is inclined towards the same direction over long periods of time and the oil pan is clearly inclined are quite normal.

It is the aim of the present invention to provide a more cost-effective alternative to this, which at the same time saves installation space and can also solve the problem of a lack of self-lubrication of the dry-running pumping station. This is achieved with the double pump according to the invention according to claim 1. Advantageous embodiments are described in the dependent claims. Furthermore, an oil delivery device for pumping oil for an internal combustion engine is also claimed, which uses the double pump according to the invention.

The double pump according to the invention comprises a gear arrangement with three gears, of which a first of the three gears meshes with the other two gears, and a housing which surrounds the gear arrangement in such a way that when the gears of the gear arrangement rotate, a first suction area and a second suction area and a first discharge area and a second discharge area are formed by the gear arrangement, the housing having a first suction inlet fluidically connected to the first suction area. The double pump is characterized in that the housing has a second suction inlet fluidically connected to the second suction region, and the first suction inlet and the second suction inlet are fluidically separated from one another.

For the purposes of the invention, the use of the term "fluidically separated" does not mean 100% fluid separation, since there is a certain unavoidable leakage in every pump, which is typically in the area of the pumping mechanism. This is the case with a normal piston pump The sealing of a piston in its cylinder is also not completely tight under working conditions. The same is also true for gear pumps, in which the housing, which clings to the rotating gearwheels, must also allow a small amount of leakage.

It is clear to the person skilled in the art that, according to an advantageous modification, the expression "fluidically separated" used in the present application can alternatively be read as the separation of the high and low pressure sides of the pump.

For example, the first suction inlet and the second suction inlet are fluidically separated from each other, which accordingly preferably means that a connection of these two inlets is only possible via a path running through the high pressure side. In the case of a pump, however, such a path must always be minimized or completely blocked, since it works against the desired operating principle of the pump.

The advantage of the double pump according to the invention is that it has two suction areas that are fluidically separated from one another and can be connected to independent suction heads by means of a respective suction inlet.

The structure of the double pump according to the invention enables a suction power at one of the suction inlets, although the other of the two suction inlets runs empty, so for example. Conveying no liquid, but only sucks in air. The supply of air through the other intake inlet does not impair the suction generated by the one intake inlet, so that the double pump according to the invention is particularly suitable as an oil pump in an internal combustion engine, in which it is advantageous to provide suction heads that are spaced apart and operate independently.

In the present case, this is possible even though only a single pump with its two pumping stations is used.

According to the invention, the double pump has two independent pumping stations which, on their suction side, have two oil suction connections that are completely spatially or fluidically separate from one another. This separation begins at the different suction heads, the two separate lines leading to the double pump and extends, including inside the double pump, to the high pressure side, where the two suction lines can be combined.

According to the invention it can be provided that the double pump is an oil pump for pumping oil.

The mechanical power for driving the two pumping stations is introduced via a common input. The oil outlet on the high pressure side preferably takes place via a common oil outlet.

Another advantage of the pump according to the invention is that the problem of the lack of self-lubrication when a fluid is continuously sucked in with only one of the two suction inlets is solved. Since the first gearwheel of the gearwheel arrangement meshes with the other two gearwheels and, regardless of whether both or only one of the suction areas of the pump deliver fluid, always comes into contact with fluid, the first (central) gearwheel ensures that a possible, Outer gearwheel not in direct fluid contact, the suction area of which is running dry, is lubricated with fluid via the engagement with the first, central gearwheel. The first gear wheel is in direct fluid contact and, when engaged with the dry-running outer gear wheel, releases enough fluid so that continuous operation in which only one of the two suction areas is filled with fluid can be maintained without damage comes because of insufficient self-lubrication.

Furthermore, it can be provided according to the invention that the housing further has a dispensing outlet, preferably a single dispensing outlet, which is fluidically connected to both the first dispensing area and the second dispensing area.

It can be provided that the two delivery areas are combined into a single outlet through a corresponding design of the pump housing in order to further minimize the dimensions of the double pump.

According to an optional modification of the present invention it can be provided that the second gear and the third gear, preferably all three gears, have an identical outer shape.

This creates a particularly efficient pump, since the teeth of the gears can then be shaped in such a way that they can engage particularly well in the respective tooth valleys of the gears. This prevents fluid from being transported from the high-pressure to the low-pressure area when the gears rotate

The respective axes of rotation of the three gear wheels are preferably parallel to one another, and these can also lie in a common plane.

According to a further optional modification of the double pump it can be provided that the first delivery area and the second delivery area are fluidically separated from each other by the gear arrangement and the housing from both the first suction area and the second suction area, preferably by connecting the housing to the Reaches the outer contour of the three gears of the gear arrangement.

In this case, the housing is guided so close to the outer contour of the gears that no significant amounts of fluid can flow between the outer contour of a respective gear and the side of the housing facing the gear.

According to the invention it can be provided that the first suction area is arranged adjacent to a contact area of the first gear and the second gear, in which the teeth of these two gears move away from each other during operation of the double pump, the first delivery area adjacent to one Contact area of the first gear and the second gear is arranged, in which the teeth of these two gears move towards each other during operation of the double pump, the second suction area is arranged adjacent to a contact area of the first gear and the third gear, in which the teeth of these move the two gears away from each other when the pump is in operation, and the second delivery area is arranged adjacent to a contact area of the first gear and the third gear, in which the teeth of these two gears move towards one another when the pump is in operation.

The fluid is enclosed within the tooth valley formed by two teeth and conveyed from the low pressure side to the high pressure side before the liquid in the tooth valley is forcibly emptied by meshing with the tooth of the adjacent gear.

It can further be provided according to the invention that one of the three gears is a driven gear and the other two gears only rotate when the driven gear rotates. The driven gear is advantageously one of the two externally arranged gearwheels, since the connection to a drive shaft can be configured in the simplest way.

The invention also relates to an oil delivery device for pumping oil for an internal combustion engine, which comprises a double pump according to one of the preceding claims and an oil sump, wherein the first

The suction inlet and the second suction inlet of the double pump are arranged at regions of the oil sump pan which are spaced apart from one another, in order to suck in a lubricant located therein.

This makes it possible by means of only one pumping station of the double pump to suck out the oil from the oil sump pan even if the pan is inclined to one side or the oil in it accumulates on one side due to inertia or centrifugal forces. In such a case, it is irrelevant for the suction performance of the suction inlet immersed in the oil that the other suction inlet is not completely covered by oil.

It can be provided that the oil sump pan is a dry sump oil pan.

The double pump is preferably driven directly by a main gear train of the internal combustion engine.

It can further be provided that a common, preferably the only, delivery outlet of the double pump is designed to deliver oil to a main oil pan.

It can preferably be provided that an air separator for separating air or other gases in the oil is also provided, which is arranged downstream of the discharge outlet of the pump and upstream of the main oil pan.

Alternatively, it can be provided that an air separator for separating air or other gases located in the oil is also provided, which is arranged within the main oil pan (23) and / or integrated into it.

According to a further modification it can be provided that each of the two suction inlets is provided with a respective oil strainer in order to sieve oil delivered by the double pump.

The invention further relates to a vehicle with an internal combustion engine which has an oil delivery device according to one of the preceding variants.

Further features, details and advantages can be seen from the following description of the figures. Show:

1: a schematic sectional view of the double pump according to the invention.

FIG. 2: a structural illustration of an oil delivery device for an internal combustion engine in a

Lean, and

3: a structural representation of an oil delivery device for an internal combustion engine in horizontal direction

zontal alignment.

1 shows a sectional view of the double pump 1 according to the invention.

The central component of the double pump 1 is the gear arrangement 2, which with its three gears 3, 4, 5 forms two pumping stations. If one of the three gears 3, 4, 5 is driven, each of the three gears 3, 4, 5 rotates in its corresponding direction, since the two outer gears 3, 5 mesh with the middle gear 4.

If one now drives the outer gear 5 arranged on the right in FIG. 1 in a clockwise direction, the middle gear 4 moves in the opposite direction and the left gear 3 moves again in a clockwise direction.

Through the engagement of the gears 3, 4, 5 and the sealing approach of the housing 6 to the respective outer contour of the gears 3, 4, 5, the engagement area of the outer left gear 3 with the middle gear 4 is different from the engagement area of the outer right Gear 5 with the middle gear 4 sealingly separated or fluidically separated.

Thus, the housing 6 is not only brought up to the area of the outer gears 3, 5 facing away from the middle gear 4, but also to the two areas of the middle gear 4 in order to seal suction areas 7, 8 of discharge areas 9, 10 separate or fluidically separate.

It is advantageous if the housing 6 follows the maximum outer diameter of a rotating gear over the distance of at least one tooth pitch of the associated gear 3, 4, 5 for a sealing separation or fluidic separation. In other words, it is advantageous if the housing 6 reaches the gearwheel over a section which extends at least from one tip of a tooth at the same time to an immediately adjacent tip of the same tooth.

The first suction area 7 is located on that side of the engagement area of the gears 4, 5 on which these meshing gears move away from one another. The second suction area 8 is located on that side of the engagement area of the gears 3, 4 on which these meshing gears move away from one another. The respective meshing gears 4, 5 and 3, 4 disengage and, with their freed tooth valleys, generate suction which sucks in a conveying fluid, for example oil. The conveying fluid taken up between two tooth tips is then decoupled from the low-pressure side by, through the rotation of the gearwheel, in the section approaching the gearwheel

of the housing 6 is performed. The delivery fluid cannot escape in this area, since the housing 6 interacts with the tooth tips in such a way that no or only a very small amount of delivery fluid can escape.

By further rotation, the conveying fluid received from the low-pressure side is brought to the high-pressure side, that is to say the delivery area 9, 10, where it is pressed out of its tooth valley due to the meshing of the other gearwheel. Only a small part of the delivery fluid can remain in the tooth valley due to the engagement of the corresponding tooth, so that the delivery circuit for the delivery fluid now begins anew.

It can be seen that the double pump 1 has a first and a second suction area 7, 8, which in the present case are connected to a respective suction inlet 11, 12 which are sealingly separated from one another or fluidically separated.

In contrast to the previously known gear pumps, the present double pump has two mutually separate suction inlets 11, 12, each of which leads to its own suction area 7, 8 of the double pump. The advantage here is that each of the two suction inlets 11, 12 draws in delivery fluid independently of the other suction inlet 12, 11. If one of the two suction inlets 11, 12 only sucks air, for example, this does not mean that the other suction inlet 12, 11 would no longer function. Since the suction inlets 11, 12 are each assigned exclusively to one suction area 7, 8, the suction effect can be maintained regardless of the state of the other suction inlet 12, 11.

In order to save installation space, it can be provided that the two delivery areas 9, 10 are combined with one another to form a common delivery outlet (not shown).

In Fig. 1, the flow directions of a sucked through the two suction inlets conveying fluid are shown by arrows, which result when the outer right gear 5 rotates clockwise.

FIG. 2 shows an oil delivery device 20 for an internal combustion engine.

One recognizes a dry sump oil pan 21, which is used to collect oil dripping from an internal combustion engine, so that the oil can be used again for lubrication.

For this purpose, the oil is pumped out of the dry sump oil pan 21 and another oil container, respectively. the main oil tank 23, from where it is conveyed via a main oil pump 25 to the lubrication points of the engine.

The problem here is that with an inclined position as shown in FIG. 2 or with an inertia or centrifugal force acting on the oil, one of the two suction heads 24 is no longer completely enclosed by oil, which may lead to a complete failure of the Oil production can lead. In a conventional oil pump, in such a situation, the oil delivery comes to a standstill, although one of the two suction heads 24 is completely immersed in oil. A second oil pump is therefore often provided in the prior art, so that each of the suction heads has its own pump.

According to the invention, however, the double pump 1 is suitable here for overcoming the disadvantage described, since the first suction inlet 11 and the second suction inlet 12 can each convey a delivery fluid independently of one another. Thus, in the situation shown in Fig. 2, oil can be promoted via the suction inlet 11 via the double pump 1 and the line 22 to the main oil tank 23, from where it is by means of the main oil pump 25, respectively. the oil circulation pump is fed to the lubrication points of the internal combustion engine. The oil is output from the double pump 1 via a common oil outlet of the two output areas 11, 12.

In the prior art, a second oil pump is often provided so that each of the suction heads has its own pump.

If the dry sump oil pan is continuously sloping on one side for a job or the location of the internal combustion engine, and one of the two suction heads 24 is not completely immersed in oil for a longer period of time, the double pump 1 does not remain in use for this either The more gearwheels involved in the oil production receive their own lubrication, because a certain proportion of the oil remaining on the gearwheel of the gearwheel 4 is transferred to its gear rim. With regard to the ability of oil to creep, i.e. for very small amounts of oil, such as are sufficient for the self-lubrication of all gears 3, 4, 5 of the gear arrangement 2, there is always an oil connection between the two pumping stations.

If, on the other hand, the oil delivery from a dry sump oil pan 21 into the main oil tank 23 is to be ensured, even in the case of inclined positions, in that two spatially completely separate oil connections are present and the oil delivery is carried out according to the state of the art via its own oil pump, then in reality there is only a limited readiness for use in sloping positions. As soon as one of the two pumps does not deliver any oil, the oil supply required for self-lubrication is also interrupted. Consequently, such a system is only suitable for short-term use in inclined positions, but not for long-term use in inclined positions in the same direction.

3 shows the oil delivery device 20 in a horizontal orientation. In addition, it is possible that the suction heads 24 are provided with filters or oil sieves that prevent the supply of impurities.

It can also be seen here that the introduction of mechanical power for operating the double pump 1 with its two pumping stations takes place via a common input. When configuring the gear arrangement,

Claims (15)

so only one of the three gears 3, 4, 5 is driven, it being advantageous to drive one of the outer gears 3, 5. Claims 1. Double pump (1) comprising: a gear arrangement (2) with three gears (3, 4, 5), of which a first gear (4) of the three gears (3, 4, 5) meshes with the other two gears (3, 5), a housing (6) which surrounds the gear arrangement (2) in such a way that when the gears (3, 4, 5) of the gear arrangement (2) rotate, a first suction area (7) and a second suction area (8) as well as a first discharge area (9) and a second delivery area (10) is formed by the gear arrangement (2), wherein the housing (6) has a first suction inlet (11) fluidically connected to the first suction region (7), characterized in that the housing (6) has a second suction inlet (12) fluidically connected to the second suction region (8), and the first suction inlet (11) and the second suction inlet (12) are fluidically separated from one another. 2. Pump (1) according to claim 1, wherein the housing (6) further has a dispensing outlet, preferably a single dispensing outlet, which is fluidically connected to both the first dispensing area (9) and the second dispensing area (10). 3. Pump (1) according to one of the preceding claims, wherein the second gear (3) and the third gear (5), preferably all three gears (3, 4, 5) have an identical outer shape or are identical. 4. Pump (1) according to one of the preceding claims, wherein the respective axes of rotation of the three gears (3, 4, 5) are parallel to one another, preferably lie in a common plane. 5. Pump (1) according to one of the preceding claims, wherein the first delivery area (9) and the second delivery area (10) through the gear arrangement (2) and the housing (6) from both the first suction area (7) and the second Suction area (8) are fluidically separated from one another, preferably by the housing (6) each reaching the outer contour of the three gear wheels (3, 4, 5) of the gear wheel arrangement (2). 6. Pump (1) according to any one of the preceding claims, wherein the first suction area (7) is arranged adjacent to a contact area of the first gearwheel (4) and the third gearwheel (5), in which the teeth of these two gearwheels (4, 5) move away from each other when the pump (1) is in operation, the first delivery area (9) is arranged adjacent to a contact area of the first gearwheel (4) and the third gearwheel (5), in which the teeth of these two gearwheels (4, 5) move towards one another when the pump (1) is in operation, the second suction area (8) is arranged adjacent to a contact area of the first gearwheel (4) and the second gearwheel (3), in which the teeth of these two gearwheels (3, 4) move away from each other when the pump (1) is in operation, and the second delivery area (10) is arranged adjacent to a contact area of the first gearwheel (4) and the first gearwheel (3), in which the teeth of these two gearwheels (3, 4) move towards one another when the pump (1) is in operation. 7. Pump (1) according to one of the preceding claims, wherein one of the three gears (3, 4, 5) is a driven gear and the other two gears rotate only when the driven gear rotates. 8. An oil delivery device (20) for pumping oil for an internal combustion engine, comprising: a double pump (1) according to one of the preceding claims, a sump pan (21), wherein the first suction inlet (11) and the second suction inlet (12) of the double pump (1) are arranged in regions of the sump pan (21) which are spaced apart from one another, in order to suck in a lubricant located therein. 9. Apparatus according to claim 8, wherein the sump pan (21) is a dry sump pan. 10. Device according to one of the preceding claims 8 or 9, wherein the pump (1) is driven directly by a main gear train of the internal combustion engine. 11. Device according to one of the preceding claims 8 to 10, wherein a common, preferably the only delivery outlet (22) of the pump (1) is designed to deliver oil to a main oil pan (23). 12. Device according to the preceding claim 11, further comprising an air separator for separating air or other gases located in the oil, which is arranged downstream of the discharge outlet of the pump (1) and upstream of the main oil pan (23). 13. The device according to the preceding claim 11, further comprising an air separator for separating air or other gases located in the oil is provided, which is arranged within the main oil pan (23) and / or integrated into it. 14. Device according to one of the preceding claims 8 to 13, wherein each of the two suction inlets is provided with a respective oil strainer (24) in order to sieve oil delivered by the pump (1). 15. Vehicle with an internal combustion engine, which has an oil delivery device (20) according to one of the preceding claims 8 to 14.