DE102009000303A1 - Slide bearing shell for use as lower slide bearing shell in crankshaft main bearing or as upper slide bearing shell in connecting rod bearing, has sliding surface at shaft or cam pin and oil pressure case inserted in sliding surface - Google Patents

Abstract

The slide bearing shell (100) has a sliding surface (110) for a system at a shaft or a cam pin, an oil pressure case (112) inserted in the sliding surface and an oil supply channel flowing in the oil pressure case. The oil pressure case is dimensioned as functions of system oil pressure such that a pressure is produced, with which the crankshaft and the connecting rod are lifted. Independent claims are also included for the following: (1) a slide bearing system with an oil supply unit; and (2) a method for supplying a slide bearing shell in a crankshaft main bearing or a connecting rod bearing of a combustion engine with oil.

Description

The The invention relates to a plain bearing shell and a plain bearing for a crankshaft main bearing or a connecting rod bearing with a sliding surface for engagement with a shaft or crankpin, an oil pressure pocket embedded in the sliding surface and one in the oil pressure bag opening oil feed. The The invention further relates to the use of such a plain bearing shell in a crankshaft main bearing or connecting rod bearing. Further concerns the invention is a sliding bearing system with at least one such Slide bearing and an oil supply device. After all The invention relates to a method for supplying the sliding bearing shell with oil.

The Invention relates in particular to applications in diesel and gasoline engines, the above have a start-stop system, the one for that ensures that the engine is stopped when the vehicle is stationary and at Power demand by the driver, for example, via actuation of Engine ignition, the accelerator pedal and / or the clutch is started. The invention but also affects so-called hybrid drives, which consist of a combination an internal combustion engine (petrol or diesel) and an electric motor consist. Even with the hybrid drives are more frequent start and stop operations of Internal combustion engine, possibly also while driving under electric drive required, for example, if the power of the electric motor is not sufficient or the battery charge is too low.

The aforementioned applications are characterized in comparison with conventional pure engine drives in that they turn off the combustion process to increase the efficiency and / or CO ₂ reduction as soon as the power of the internal combustion engine is no longer needed. In particular, the environmental aspect of CO ₂ reduction is becoming increasingly important and makes new demands on the drive technology. Due to the comparatively large number of start and stop operations, especially in city traffic, an increased bearing wear in the engine is observed. This is due to the fact that during the start and stop operations no hydrodynamic bearing lubrication is present, so the bearing is exposed to increasingly mixed friction conditions. The increasing bearing wear can be compensated to some extent by choosing wear-resistant bearing materials in part. In principle, however, such engines can not achieve the mileage of conventionally powered engines.

task It is therefore the object of the invention to provide a plain bearing shell and its use, to provide a sliding bearing, a sliding bearing system and a method their use in the aforementioned engines with start-stop automatic one higher Mileage of the engines causes.

The Invention is characterized by a plain bearing shell with the features of Patent claim 1, a plain bearing having the features of the claim 8, a plain bearing system with the features of claim 10 or of claim 12, the use of the plain bearing shell with the features of claim 22 and by a method solved with the features of claim 25. Advantageous developments The invention are the subject of the dependent claims.

The sliding bearing according to the invention for a Crankshaft main bearing or a connecting rod bearing is with an upper and a lower sliding bearing shell, wherein in the case of the crankshaft main bearing the lower plain bearing shell or in the case of the connecting rod bearing the upper one Slide bearing shell a sliding surface for engagement with a shaft or crankpin of the crankshaft, a in the sliding surface recessed oil pressure pocket and one in the oil pressure bag has opening oil supply.

The inventive method provides that to supply a plain bearing shell in a crankshaft main bearing or in a connecting rod bearing of an internal combustion engine with oil, in which the sliding bearing shell has a sliding surface for engagement with a shaft or crank pin, an inserted into the sliding oil pressure bag and one in the oil pressure bag has an opening oil feed, When starting or stopping the engine, the oil pressure bag with a hydrostatic oil pressure is charged.

to execution This method comprises the invention at least one of the above described sliding bearing according to the invention and an oil supply device on, the oil supply device an oil reservoir and an oil line having, which with the oil supply of the Slide bearing shell communicates.

The oil supply is preferably in the form of an oil well through the plain bearing shell or an inner circumference, at least up to one subarea circumferential oil groove educated.

The aforementioned aspects of the invention is based on the idea that the oil pressure pocket in the an oil pressure can be applied to the lower bearing shell so that even without the rotation of the crankshaft required for the formation of a hydrodynamic oil film, an oil cushion can form between the shaft or crank pin and the lower bearing shell, in order to achieve the aforementioned mixed friction conditions even at start-stop. Avoid operations.

Accordingly, the sliding bearing shell according to the invention adapted for use as a lower plain bearing shell in one Crankshaft main bearing or as upper plain bearing shell in one Connecting rod bearing, with a sliding surface for engagement with a shaft or crankpin, an in the sliding surface recessed oil pressure pocket and one in the oil pressure bag opening oil supply, wherein the oil pressure bag dependent on from a system oil pressure is dimensioned so that a compressive force can be generated with the the crankshaft or the connecting rod can be raised.

When lower plain bearing shell in the context of the invention is the plain bearing shell understood that in the bearing seat of a crankcase or Pleuels is installable so that they are in accordance with the intended orientation of the crankshaft housing or the connecting rod is oriented in the direction of gravity. Corresponding is the upper one of the gravity built opposite slide bearing shell. According to the invention is in the lower plain bearing shell in the bearing seat of the crankshaft housing the oil pressure pocket aligned in the direction of gravity, while at the upper plain bearing shell in the bearing seat of the connecting rod against the oil pressure pocket the direction of gravity is aligned.

This make sure the oil always from there to the shaft or crankpin and the sliding surface is brought, where the shaft journal at standstill of the engine on the bearing surface of the Main bearing or the connecting rod bearing rest on the crankpin. in this connection like all the following considerations Simplified assumes that gravity at standstill the engine the predominantly is on the crankshaft or the connecting rod engaging force. Of course finds the invention also there application, where more static forces in particular in other directions, eg. B. by tensile forces of belt drives to the Attack components. In this case, instead of the direction of gravity the direction of the sum vector of all forces for the alignment of the oil pressure pocket authoritative so that the total power can be hydrostatically compensated.

Especially Preferably, the plain bearing shell is used so that the oil pressure pocket the plain bearing shell in the circumferential direction from the solder to both Pages about extends at an angle of at least 10 °.

This ensures that even with slight inclination of the crankshaft housing or of connecting rod oil directly to the bearing point of the bearing shell and the counter-rotor (shaft or crankpin) passes.

The oil pressure bag the sliding bearing shell preferably has an average depth of 0.05 to 0.7 mm, preferably 0.1 to 0.5 mm. The oil pressure bag is preferably drilled in the form of an eccentric to the central axis or milled Recess of smaller radius than the inner diameter of the Sliding surface incorporated into the plain bearing shell. This results in a Depth gradient increasing towards the center of the bag. The mean groove depth is preferably 60-80% and more preferably 65-75% the maximum groove depth.

In This depth range is a sufficient flow of oil and thus a uniform and rapid distribution of the oil film under the wave or Crankpin guaranteed.

Around at the same time a sufficient strength of the plain bearing shell guarantee has the oil pressure bag a minimum residual wall thickness of 0.4 mm, preferably 0.6 mm.

According to one advantageous development of the method is the crankshaft or the connecting rod when starting or stopping the internal combustion engine through the hydrostatic oil pressure raised.

A corresponding advantageous development of the sliding bearing system provides that the oil supply device an oil pressure generating device which is set, the oil pressure bag with oil under to supply sufficient hydrostatic pressure to the crankshaft to raise.

Prefers the crankshaft or the connecting rod at least when starting or stopping by 0.5 to 4 microns raised.

In This area typically moves the surface roughness of the shaft and crank pin of the Crankshaft so that a corresponding increase the wear through Material contact between the pin and the corresponding sliding surface of the Sliding bearing shell efficiently reduced.

A preferred development of the method provides that the crankshaft or the connecting rod when starting or stopping for at least 0.1 to 4, preferably 1 to 2 seconds is raised.

critical is that the crankshaft or the connecting rod when starting at least until the internal combustion engine reaches at least 60%, preferably has reached 100% of its idle speed, or at Stopping the engine is raised as long as this at the most still has 20% of its idle speed, preferably to a standstill has come. These conditions are in the claimed time window usually fulfilled.

Around ensure that the crankshaft or connecting rod is sufficiently Dimensions raised can be, is the oil pressure generating device preferably set up, an overpressure of at least 2 bar, more preferably at least 5 bar.

With a lower hydrostatic pressure, the shaft or the connecting rod only to be raised, by the lateral dimensions of the oil pressure bag be chosen very large in the circumferential direction and in the width direction of the bearing shell. However, this has a very high oil drain, an undesirably high increase the specific load through the oil pressure bag and one too big restriction the bearing portion of the sliding surface result. on the other hand is the hydrostatic oil pressure preferably not more than 40 bar, more preferably not more than 20 bar limit. Excessive pressures are too high namely technically impractical, since the requirements for the oil pressure generating device and the oil supply very increase sharply and thus increased Costs associated.

Farther Preferably, the plain bearing shell is designed so that the length of the oil pressure pocket in the circumferential direction an angle of at least 10 °, preferably at least 20 ° and more preferably at least 30 ° to at the most 110 °, especially preferably at most 90 °, and most preferably at most 70 °, overstretched.

With increasing restriction the aforementioned limits will be at a still moderate increase in the specific Load of the bearing shell by the pressure oil pocket on the one hand the required hydrostatic Pressure maintained in a workable area and at the same time the stationary oil flow through lateral oil drain limited to a practicable level. Not insignificant in this case is the requirement that the solder on the the central axis of the stored shaft section approximately with the middle of the oil pressure bag coincides in the circumferential direction, because the force required to lift the crankshaft is proportional to in the direction of gravity projected area of the oil pressure pocket is. In opposite Direction applies this also for the geometry of the connecting rod bearing.

In an advantageous development, the oil pressure pocket has a width in Axial direction of not more than 75%, preferably at most 60%, more preferably at most 50% and most preferably at most 40% of the effective Width of the plain bearing shell. The minimum width of the oil pressure bag in the axial direction at least 10%, preferably at least 20% of the effective width the sliding bearing shell.

When effective width of the plain bearing shell is the width of the sliding surface of the Sliding bearing shell understood that is in contact with the counter-rotor. The Selection of the relative width of the oil pressure pocket causes with increasing restriction on the above values a cheaper relationship from the needed hydrostatic pressure, the increase of the specific load of the bearing shell and the needed stationary oil flow due the lateral oil drain.

In an advantageous embodiment of the sliding bearing system, the oil pressure generating device a pressure accumulator or an oil pump on.

The pressure accumulator keeps the pressure independent of the operating condition of the engine, especially when the engine is at a standstill. The volume of the pressure accumulator is to be at least dimensioned such that the oil pressure necessary for lifting the shaft or the connecting rod can be maintained at least until the hydrodynamic pressure generated by the shaft rotation carries the load from mass forces and / or forces from the engine fuel combustion can. This typically happens when the engine idling speed is reached. The same applies to the dimensioning of the oil pump, which must be swept so that the necessary oil pressure and the necessary to increase the shaft or the connecting rod delivery capacity ready stand.

Of the Pressure accumulator, preferably with a membrane or a spring-piston arrangement as elastic elements for energy storage, can advantageously either by means of an oil pump connected to the accumulator or during operation of the internal combustion engine taking advantage of the hydrodynamic Pressure in the plain bearing due to oil backflow be loaded. In the latter case, the oil supply device preferably one in the oil line switched check valve on, which is set, during operation of the internal combustion engine, an oil flow of the oil pressure bag into the oil reservoir, in this case in the accumulator, release. At the oil pump can it is also the engine's rotary lubricating oil pump, if these are over has the required pressure level.

to Realization of a targeted, over a limited period of time raising the crankshaft or the connecting rod when starting or stopping, the oil supply device preferred one in the oil line switched on valve and a valve control device, the is set up, the valve when starting and / or stopping the engine to open.

following the function of the sliding bearing system according to the invention is described: Sufficiently long before the start of the wave rotation by tempering of the engine, the valves leading to the bearings are initiated by a switching signal of the valve control device, thereby opening the pressure from the accumulator over the oil line and the oil supply on the oil pressure bag is switched. The same applies to a pressurization by oil pump. The resulting hydrostatic pressure acts over the entire surface of the oil pressure pocket in the form of a force on the crankshaft or the connecting rod of gravity. The crankshaft, including connecting rods, pistons, rings, Bolts, circlips, flywheel and possibly others with the shaft connected components, it is raised so, that the surface of the Crankshaft and the lower bearing shells through a lubricating film already be separated without rotation of the crankshaft. The same applies to the connecting rods. The valve control device can with the ignition or with be connected to the engine control or be part of the same.

In corresponding way allows the invention described below function for wear-free Stopping the engine: Sufficiently long before stopping the rotation of the crankshaft when stopping the engine are the valves leading to the main bearings or connecting rod bearings by means of the valve control open, whereby the pressure from the pressure accumulator is switched to the oil pressure pocket. The same applies to a pressurization by oil pump. The static pressure in the accumulator is thus over the oil line and the oil supply on the oil pressure bag connected to the lower bearing shell and causes a gravity opposing force to raise the crankshaft or the Connecting rods. Again, the crankshaft and possibly associated Components or connecting rods and their components so far raised that the surfaces of the shaft and the lower Bearing shells by a hydrostatic lubricating film until it stops remain separate from the rotation of the crankshaft.

The for the hydrostatic pressure build-up when starting and / or stopping the Motors in the oil pressure bag necessary throttling effect on the by the pressure difference between the accumulator or the oil pump and the crankcase caused flow of oil is typically through the shaft to be lifted or to be lifted Connecting rod itself generated. Optionally, one or more Throttling points in the oil line be provided so that the oil reservoir or the accumulator does not run uncontrollably empty and ensures a controlled pressure distribution in the piping system becomes.

Further Embodiments and advantages of the invention are described below an embodiment closer with the help of the drawings explained. Show it:

1 an embodiment of the bearing shell according to the invention in axial view and in radial projection;

2 an exemplary circuit diagram of the oil supply in the sliding bearing system according to the invention;

3 a scheme to illustrate the hydrostatic balance of forces;

4 a three-dimensional diagram of the specific load on the bearing shell according to the invention in dependence on the dimensions of the oil pressure pocket;

5 a two - dimensional diagram of the hydrostatic pressure as a function of the dimension of the Oil pressure pocket and a section of it;

6 a two-dimensional diagram of the stationary oil flow as a function of the dimension of the oil pressure pocket;

7 a second embodiment of the bearing shell according to the invention in axial view and in radial projection;

8th a third embodiment of the bearing shell according to the invention in the axial view and in radial projection and

9 another exemplary circuit diagram of the oil supply in the sliding bearing system according to the invention.

The plain bearing shell 100 according to 1 has a hydrodynamic sliding surface 110 and an oil pressure pocket embedded in the sliding surface 112 on. In the center of the oil pressure bag 112 opens as oil supply an oil well 114 , The oil pressure bag 112 is through a depression in the bearing shell 100 on the side of the sliding surface 110 formed in such a way that these in the plane of the sliding surface 110 viewed on all sides of the sliding surface is bordered. The depression of the oil pressure bag 112 in the radial direction, measured from the plane of the sliding surface 110 , is on average between 0.05 and 0.7 mm, preferably 0.1 to 0.5 mm The oil pressure bag 112 is otherwise characterized in the longitudinal direction by the angle phi (φ), which in the embodiment shown symmetrically about the vertex of the bearing shell 100 is arranged. The measure of the angle phi (φ) is preferably at least 10 °, more preferably at least 20 ° and at most 110 °, particularly preferably at most 90 °. Alternatively to the angle phi (φ), the dimension of the oil pressure pocket 112 be characterized in the longitudinal or circumferential direction by the projection length l. In this case, the projection direction coincides with the radial direction through the vertex.

Depending on the application, the direction of projection or the arrangement of the oil pressure pocket in the circumferential direction can also deviate from the symmetrical arrangement shown to the vertex. For example, in a motor configuration in which the cylinder axis of the combustion chambers is arranged in a V-shape, it may also be displaced by a corresponding angle with respect to the vertex. Decisive for the position of the oil pressure pocket or its center is the direction of gravity. It is therefore according to the invention to ensure that the oil pressure bag 112 the sliding bearing shell 100 when installed in the intended bearing seat in the crankshaft housing or connecting rod is aligned with the orientation of the crankshaft housing or the connecting rod in the direction of gravity, in particular that the center of the oil pressure pocket coincides with the direction of gravity.

The dimension of the oil pressure pocket in the axial direction is characterized by its width b. This is preferably at most 75% of the effective width B of the sliding bearing shell, more preferably at most 50% thereof. The maximum width b of the oil pressure bag 112 is primarily by the left and right of the oil pressure pocket remaining supporting portion Bb of the sliding surface 110 limited. Further limiting factors are described below on the basis of 4 to 6 explained.

In 2 is schematically shown an embodiment of the plain bearing system according to the invention. A plain bearing shell of the kind as in 1 shown here as the lower main bearing shell 200 for use. This forms together with the upper main bearing shell 202 the crankshaft main bearing. Overall, the figure shows five main crankshaft bearings in a crankcase 220 outlines in which a crankshaft 222 is rotatably mounted. The sections stored in the main camps 224 the crankshaft 222 are also referred to herein as shaft journal. Between the shaft journal 224 are the crankpins 226 which move on rotation of the crankshaft around the shaft journals in a circular path. On each of the crankpins 226 is each a connecting rod 228 rotatably mounted, which connects the crankshaft with a drive piston. Also, the connecting rod bearing is in a lower bearing shell 230 and an upper bearing cup 232 divided, in which case the upper connecting rod bearing shell 232 in a similar way with a by means of 1 described oil pressure bag 112 can be equipped. For clarity, the 2 However, only one embodiment described in which the crankshaft main bearings are formed according to the invention.

The plain bearing system has an oil supply device in addition to the slide bearings described above 234 on which an oil reservoir and an oil line 236 includes, which with the oil hole in the lower main bearing shell 200 communicated. In the illustrated embodiment of the oil supply device 234 is an oil pressure generating device 238 provided, which is set up, the oil pressure bag in the main bearing shell 200 with oil under sufficient hydrostatic pressure to supply the crankshaft 222 to raise. More specifically, the oil pressure generating means includes 238 a pressure accumulator 240 and an upstream oil pump 242 that the accumulator 240 loaded with oil. The accumulator 240 may alternatively be omitted. It should be noted that a suitably dimensioned oil pump must be swept for acting on the oil pressure pockets with a sufficient oil pressure. The oil pump 242 is over an oil line 244 to the main oil supply of the engine consisting of an oil sump 246 , a low-pressure cooling oil pump 248 and an oil filter 250 connected. About the main oil supply system is primarily the oil gallery 252 in the crankcase 220 as well as other lubrication points in the engine supplied with oil under lower pressure.

Behind the oil pump 242 begins the high pressure area to supply the lower main bearing shells with an overpressure of at least 2, preferably at least 5 bar. With this pressure, the pressure accumulator 240 loaded. A valve system consisting of a controllable inlet valve or check valve 254 and a controllable switching valve 256 , ensures that after loading the pressure accumulator 240 the oil pump 242 can be switched off. Sufficiently long time before starting and / or stopping the engine, the switching valve 256 opened by a switching pulse from a valve control device, not shown, so that the oil under pressure from the pressure accumulator 240 on the oil pressure pockets 212 in the lower bearing shells 200 is switched.

Due to a matched to the available oil pressure dimensioning of the oil pressure pockets, this leads to an increase in the crankshaft 222 to make direct metallic contact thereof with the sliding surface of the lower main bearing shells 200 to prevent at hydrodynamic pressure in the main bearings, which does not exist or which decreases.

Since gravity g in the in 2 shown simplified scheme acts vertically down, the oil supply and the oil pressure pocket in the lower bearing shell 200 vertically under the shaft journal 224 arranged.

The gap and pressure conditions in the hydrostatic lubrication gap between the lower bearing shell 200 and the shaft journal 224 are in 3 shown enlarged. Because of in the oil pressure bag 212 Pending pressure, which corresponds in first approximation to the pressure p _{oil passage} in the oil passage, the crankshaft is raised by a height h _gap . The desired stroke is preferably 0.5 to 5 microns, which ensures that contact between the shaft journal and the plain bearing surface is largely avoided. In order to be able to determine the pressure required for a corresponding stroke, the hydrostatic balance of forces must be considered between the weight force F _G acting on the mass of the crankshaft and associated components and the counteracting lifting force of the oil F _oil . The following applies: F G = (m piston + m bolt + m rings + m pleuel + m crankshaft + m flywheel )G F G = F oil F oil = A bag · (P oil passage - p crankcase ) = n · l · b · (p oil passage - p crankcase )

Herein, with m, the masses of the crankshaft, pistons, bolts, rings, connecting rods and the flywheel, with g gravity, with A _pocket , the surface of the projected oil pressure pocket, with p the pressures in the oil passage on the one hand and in the surrounding crankcase on the other hand and with n the number of bearings designated. For truck engines here m masses of typically 90 to 200 kg, for passenger car engines typically 15 to 50 kg use. If different from 2 only individual (not all) bearing points are equipped with the hydrostatic bearings according to the invention, the proportionate weight of the power tool for F _{G is} to be set.

Furthermore, an estimation for the maximum demand must be made assuming lossless flow and mass conservation of the oil. This happens according to the following approach: p + ρ · g · z + ρ 2 ν 2 = const ṁ = ρ · A · ν = const

In the concrete example according to 3 this means

Here, p _oil denotes the flow density of the oil, v the flow velocity in the gap or in the oil channel, ṁ the mass flow in the gap or in the oil channel and A the cross-sectional area of the gap or the oil channel, respectively perpendicular to the flow direction v.

mit

worin D_Ölkanal den Durchmesser der Ölbohrung und Ölleitung und D_i den Durchmesser des Gleitlagers bezeichnet.By inserting you get

With

wherein D _{oil passage} the diameter of the oil well and oil line and D _i denotes the diameter of the sliding bearing.

With oil as incompressible medium you get the required volume flow of up to V. oil :

The same applies to the stop process.

With a start time .DELTA.t _start and the number z of the hydrostatic bearing points, the _oil volume V _oil to be delivered with p _oil results: V oil = V. oil · .DELTA.t begin (4)

Because friction become the oil stream and the delivered oil volume lower than these formulas. The difference goes for the provision of accumulator volume as a security. But it is the same also the delivery pressure higher interpreted.

In 4 the increase in specific load is indicated by the presence of the oil pressure pocket. By the oil pressure pocket for generating a hydrostatic pressure when starting and stopping the engine at the same time the hydrodynamically active surface (herein also referred to as the bearing portion of the sliding surface) is reduced during engine operation. This results in the in 4 shown increase in the specific load of the remaining hydrodynamically effective area as a function of the relative pocket _width B _rel = b / B and the angle phi (φ). This increase in the specific load must be taken into account in material selection with regard to material strength. It can be seen, for example, that the specific load does not yet double when, at an angle phi (φ) of 110 °, the relative width is not at the same time a value of about 50%. exceeds. Conversely, the specific load does not double, for example, if at a relative width of 75% the angle phi (φ) does not simultaneously exceed a value of about 50 °.

In 5 The hydrostatic oil pressure to achieve the necessary lifting force for lifting the crankshaft assuming the typical mass of a truck crankshaft together with connected parts of about 150 kg, in turn, depending on the surface area of the oil pressure bag. As expected, it can be seen that with a very small area of the oil pressure pocket, a singularity of the necessary oil pressure results. A pressure range of 100 bar or more is certainly of little practical importance. It can be seen that a preferred pressure range of 40 bar or less can be achieved if, at a circumferentially short length corresponding to an angle of 14 °, the relative width does not become less than 30% at the same time.

In 6 the dependency of the stationary oil flow on the relative width _porridge on the one hand and the angle phi (φ) on the other hand is shown. This surprisingly shows that as the relative width decreases, the stationary oil flow increases significantly while decreasing as the length of the oil pressure pocket decreases. After this evaluation, a reasonable steady flow of oil of about 0.15 l / s with a assumed stroke of 5 microns and a total of 5 bearings can be met or exceeded, if at a relative bearing width of about 30% does not exceed an angle of about 90 ° becomes.

From the diagrams according to the 4 to 6 Overall, it can be read that a particularly preferred dimensioning of the lubricating oil bag provides a width between 30 and 60% of the effective width of the bearing shell with simultaneous length expansion corresponding to an angle phi (φ) between 20 ° and 90 °. Very particular preference is given to dimensioning with a relative width in the range between 30 and 45% with simultaneous length expansion corresponding to an angle phi (φ) between 20 ° and 70 °.

In 7 is another embodiment of the sliding bearing shell according to the invention 300 shown. This also has a hydrodynamic sliding surface 310 and an oil pressure pocket embedded in the sliding surface 312 on. For the design and dimensioning of the oil pressure bag 312 that applies to 1 said. As oil supply for the oil pressure bag 112 serves a circumferential oil groove 314 , in this example, on both sides to the subarea 316 the bearing shell revolves. This oil groove is in connection with an oil groove, which also revolves up to the partial surface, in a corresponding upper bearing shell of the assembled plain bearing.

An inventive plain bearing system adapted to this embodiment of the sliding bearing is schematically shown in FIG 9 shown. The plain bearing shell in the manner as in 7 or 8th shown here as the lower main bearing shell 500 for use. This forms together with the upper main bearing shell 502 the main crankshaft bearing, of which in turn five in a crankcase 520 for bearing the crankshaft 522 arranged.

The sliding bearing system has an oil supply device in addition to the main slide bearings described above 534 with an oil pipe 536 on, which initially with an inner circumferential oil groove in the upper main bearing shell 502 and above with the oil groove in the lower main bearing shell 500 the crankshaft main bearing communicates. As an oil line 536 is in this embodiment of the sliding bearing system according to the invention on the already existing main oil supply system in the crankcase 520 resorted.

The oil supply device 534 further comprises an oil pressure generating device 538 which is set up, the oil pressure pocket in the lower main bearing shell 500 with oil under sufficient hydrostatic pressure to supply the crankshaft 522 to raise. The oil pressure generating device 538 includes in detail a pressure accumulator 540 and an upstream oil pump 542 that the accumulator 540 loaded with oil. The oil pump 542 is as in the example according to 2 over an oil line 544 to the main oil supply of the engine, consisting of the oil sump 546 , a low-pressure cooling oil pump 548 , an oil filter 550 and the oil gallery 552 in the crankcase 520 , connected.

Behind the oil pump 542 begins the high pressure area to supply the lower main bearing shells with an overpressure of at least 2, preferably at least 5 bar. With this pressure, the pressure accumulator 540 loaded. A valve system consisting of a controllable inlet valve or check valve 554 and a controllable switching valve 556 , ensures that after loading the pressure accumulator 540 the oil pump 542 can be switched off. Sufficiently long time before starting and / or stopping the engine, the switching valve 556 opened by a switching pulse from a valve control device, not shown, so that the pressurized oil from the accumulator 540 on the oil pressure pockets in the lower bearing shells 500 is switched. At the same time, a check valve ensures 558 that the increased hydrostatic pressure in the oil line 536 not in the low pressure path including filter 550 , Oil pump 548 or lead 544 can get.

Due to an adapted to the available oil pressure dimensioning of the oil pressure pockets a compressive force is exerted, which leads to an increase of the crankshaft 522 leads to a direct metallic contact thereof with the sliding surface of the lower main bearing shells 500 to prevent at hydrodynamic pressure in the main bearings, which does not exist or which decreases. When dimensioning the oil pressure pockets in the lower main bearing shells 500 It should be noted that the same oil pressure also in the oil groove in the upper main bearing shells 502 is present and provides for an opposing acting compressive force. For this plain bearing system, the following formalism results with D _i as the inner diameter of the bearing shells A _{groove, o} A _{groove, u} as the projected area of the upper or lower groove, b _{groove, o} , b _{groove, u} as the width of the upper and lower groove, L _proj the projected length of the pressure _pocket , A _pocket the projected area of the pressure _pocket and b the pocket _width : A Groove o = D i · b Groove o ; A Nut, u = (D i - L proj ) · B Nut, u ; A bag = L proj · B (1)

und schließlich:

Under the proviso that the upper bearing shell has no additional oil pocket, it is to be demanded: A _{groove, o} </! A _{groove, u} + A _pocket , so that the resulting pressure force acts upwards. This follows

and finally:

The resulting hydrostatic pressure force F _{res, stat} corresponds to the difference of the projected areas of the pressure oil-carrying structures (grooves, pressure oil pocket) of the two bearing shells, multiplied by the applied hydrostatic pressure p _oil : F res, stat = (A below - A above ) · P oil = [(D i - L proj ) · B Nut, u + b · L proj - D i · b Groove o ] F res, stat = [D i · (B Nut, u - b Groove o ) + L proj · (B - b Nut, u )] * P oil (3)

A simple special case arises when the groove widths are the same at the top and bottom. The compressive force will then: F res, stat = L proj · (B - b Nut, u ) · P oil (4)

Another simple special case arises when b _{Nut, u} = b is selected. φ (phi) then becomes 180 ° and for the compressive force one obtains: F res, stat = D i · (B Nut, u - b Groove o ) · P oil (5)

In 8th is such an embodiment of the sliding bearing shell according to the invention 400 shown. This also has a hydrodynamic sliding surface 410 and an oil pressure pocket embedded in the sliding surface 412 which, unlike the previous example, together with the oil groove 414 on both sides to the partial surface 416 the bearing shell revolves. It is therefore an oil pressure pocket, in which the angle phi (φ) is 180 °. You can also call this as a stepped oil groove. The greater length of the oil pressure pocket can be compensated by a correspondingly reduced width thereof.

Basically, it is also sufficient if the circumferential oil groove rotates only to one side to the partial surface. In any case, in addition to a corresponding consideration of the modified projected effective areas to note that is provided by the oil groove of the required total cross section for oil supply under high pressure. The above considerations with reference to 3 for the calculation of the oil quantity and oil pressure requirements apply here analogously.

As a further modification of the embodiment according to 8th can be completely dispensed with the oil groove, so that the oil pressure bag itself functionally includes the oil supply, if they are up to at least circumscribes a partial surface and although here it is ensured that sufficient cross-section is provided for the oil flow.

100

plain bearing shell

110

sliding surface

112

Oil pressure pocket

114

oil well

200

lower Main bearing

202

upper Main bearing

220

crankcase

222

crankshaft

224

shaft journal

226

crank pins

228

pleuel

230

lower Connecting rod

232

upper Connecting rod

234

Oil supply

236

oil line

238

Oil pressure generating means

240

accumulator

242

oil pump

244

oil line

246

oil sump

248

Cooling oil pump low pressure

250

oil filter

252

oil gallery

254

inlet valve

256

switching valve

300

plain bearing shell

310

sliding surface

312

Oil pressure pocket

314

oil groove

316

subarea

400

plain bearing shell

410

sliding surface

412

Oil pressure pocket

414

oil groove

416

subarea

500

lower Main bearing

502

upper Main bearing

520

crankcase

522

crankshaft

534

Oil supply

536

oil line

538

Oil pressure generating means

540

accumulator

542

oil pump

544

oil line

546

oil sump

548

Cooling oil pump low pressure

550

oil filter

552

oil gallery

554

inlet valve

556

switching valve

558

check valve

phi (Φ)

angle section the oil pressure bag in the circumferential direction

I, L _proj

projected Length of the oil pressure bag in the circumferential direction

b

width the oil pressure bag

B

effective Width of the bearing shell

b _rel

relative Width of the oil pressure pocket (B / B)

G

The direction of gravity

z

Hubkraftrichtung

F _g

gravity

F _oil

hydrostatic lifting capacity

h _split

Height of the gap, stroke

A _gap

Cross sectional area of the Hubspalts

A _bag

projected area the oil pressure bag

p _{oil channel}

hydrostatic Pressure in the oil hole / oil line

p _crankcase

hydrostatic Pressure in the crankcase

V _gap

flow rate of the oil in the lifting gap

V _{oil channel}

flow rate of the oil in the oil well / oil line

m

Dimensions

m '

mass flow

n

number of the bearings

ρ _oil

flow density of the oil

D _{oil channel}

diameter the oil drilling / oil line

D _i

diameter of the plain bearing

V _oil

oil Capacity

V. _oil

Oil flow

Δt _start

start time

D _i

Inner diameter the bearing shells

A _{groove, o}

projected area the upper groove

A _{groove, u}

projected area the lower groove,

b _{groove, o} ,

width the upper groove

b _{groove, u}

width the lower groove

Claims (31)

Plain bearing shell ( 100 . 300 . 400 ) adapted for use as a lower plain bearing shell in a crankshaft main bearing or as an upper plain bearing shell in a connecting rod bearing, with a sliding surface ( 110 ) for engagement with a shaft or crank pin, one in the sliding surface ( 110 ) in the oil pressure pocket and one in the oil pressure pocket ( 112 ), wherein the oil pressure pocket is dimensioned in response to a system oil pressure so that a pressure force can be generated with which the crankshaft and the connecting rod can be raised. Plain bearing shell ( 100 . 300 . 400 ) according to claim 1, characterized in that the oil pressure bag ( 112 ) has an average depth of 0.05 to 0.7 mm, preferably 0.1 to 0.5 mm. Plain bearing shell ( 100 . 300 . 400 ) according to claim 1 or 2, characterized in that the oil pressure bag ( 112 ) has a minimum residual wall thickness of 0.4 mm, preferably 0.6 mm. Plain bearing shell ( 100 . 300 . 400 ) according to one of claims 1 to 3, characterized in that the length of the oil pressure pocket ( 112 ) in the circumferential direction an angle of at least 10 °, preferably at least 20 ° to at most 110 °, preferably at most 90 ° spans. Plain bearing shell ( 100 . 300 . 400 ) according to one of claims 1 to 4, characterized in that the oil pressure pocket ( 112 ) has a width in the axial direction of at least 10%, preferably at least 30%, up to at most 75%, preferably at most 50% of the effective width of the plain bearing shell ( 100 ) having. Plain bearing shell ( 100 ) according to one of claims 1 to 5, characterized in that the oil supply in the form of an oil well ( 114 ) is formed by the sliding bearing shell. Plain bearing shell ( 300 . 400 ) according to one of claims 1 to 5, characterized in that the oil supply in the form of an inner circumference, at least up to a partial surface circumferential oil groove ( 314 . 414 ) is trained. Plain bearing for a crankshaft main bearing with an upper and a lower plain bearing shell ( 200 . 202 ), wherein the lower plain bearing shell ( 200 ) a sliding surface for engagement with a shaft or crankpin ( 224 . 226 ), characterized in that the lower plain bearing shell ( 200 ) one in the sliding surface ( 110 ) recessed oil pressure bag ( 200 ) and having an opening into the oil pressure pocket oil supply. Plain bearing according to claim 8 with a lower plain bearing shell ( 200 ) according to one of claims 1 to 7. Plain bearing for a connecting rod bearing with an upper and a lower plain bearing shell ( 230 . 232 ), wherein the upper plain bearing shell ( 232 ) a sliding surface for engagement with a shaft or crankpin ( 224 . 226 ), characterized in that the upper plain bearing shell ( 232 ) one in the sliding surface ( 110 ) recessed oil pressure bag ( 112 ) and having an opening into the oil pressure pocket oil supply. Slide bearing according to claim 10 with an upper plain bearing shell ( 202 ) according to one of claims 1 to 7. Sliding bearing system for a crankshaft main bearing or a connecting rod bearing of an internal combustion engine with at least one sliding bearing according to one of claims 8 to 11 and an oil supply device ( 234 ), characterized in that the oil supply device ( 234 ) an oil reservoir and an oil line ( 236 ), which with the oil supply of the plain bearing shell ( 100 . 200 ) communicates. Slide bearing system according to claim 12, characterized in that the oil supply device ( 234 ) into the oil line ( 236 ) has switched on check valve, which is adapted to release an oil flow from the oil pressure pocket in the oil reservoir during operation of the internal combustion engine. Sliding bearing system according to claim 12 or 13, characterized by a bearing seat as part of a crankshaft housing ( 220 ) or connecting rods ( 228 ), wherein the plain bearing shell ( 100 . 200 ) is arranged in the bearing seat so that the oil pressure pocket ( 112 ) of the sliding bearing shell ( 100 . 200 ) at the intended orientation of the crankshaft housing ( 220 ) in the direction of gravity or the connecting rod ( 228 ) is aligned against the direction of gravity (g). Plain bearing system according to claim 14, characterized in that the oil supply device ( 234 ) an oil pressure generating device ( 238 ), which is adapted to the oil pressure bag ( 112 ) with oil under sufficient hydrostatic pressure to the crankshaft ( 222 ) or the connecting rod ( 228 ). Plain bearing system according to claim 15, characterized in that the oil pressure generating device ( 238 ) is arranged to provide an overpressure of at least 2.5 bar, preferably at least 5 bar. Plain bearing system according to claim 15 or 16, characterized in that the oil pressure generating device ( 238 ) has a sufficient delivery capacity to the crankshaft ( 222 ) or the connecting rod ( 228 ) when starting and / or stopping the internal combustion engine for at least 0.1 to 4 seconds, preferably 1 to 2 seconds to raise. Plain bearing system according to one of claims 15 to 17, characterized in that the oil pressure generating device ( 238 ) an accumulator ( 240 ) or an oil pump. Slide bearing system according to claim 18, characterized in that the pressure accumulator ( 240 ) has a membrane or a spring-piston arrangement. Sliding bearing system according to claim 18 or 19, characterized in that the oil pressure generating device ( 238 ) one to the accumulator ( 240 ) connected oil pump ( 242 ) for charging the pressure accumulator ( 240 ) with oil. Sliding bearing system according to one of claims 12 to 20, characterized in that the oil supply device ( 234 ) into the oil line ( 236 ) switched on valve ( 256 ) and a valve control device which is set up, the valve ( 256 ) when starting and / or stopping the internal combustion engine to open. Use of a sliding bearing shell ( 100 . 200 ) in a crankshaft main bearing, wherein the plain bearing shell ( 100 . 200 ) a sliding surface ( 110 ) for engagement with a shaft journal ( 224 ), one in the sliding surface ( 110 ) recessed oil pressure bag ( 112 ) and one in the oil pressure bag ( 112 ) has opening oil supply and so in the bearing seat of a crankcase ( 220 ) can be installed, that the oil pressure bag ( 112 ) the sliding bearing cup ( 100 . 200 ) at the intended orientation of the crankshaft housing ( 220 ) is oriented in the direction of gravity. Use of a plain bearing shell in a connecting rod bearing, wherein the plain bearing shell ( 100 . 200 ) a sliding surface ( 110 ) for engagement with a crankpin ( 226 ), one in the sliding surface ( 110 ) recessed oil pressure bag ( 112 ) and one in the oil pressure bag ( 112 ) has opening oil supply and so in the bearing seat of a connecting rod can be installed that the oil pressure bag ( 112 ) of the sliding bearing shell ( 100 . 200 ) is aligned against the direction of gravity at the intended orientation of the connecting rod. Use according to claim 22 or 23, characterized in that the oil pressure pocket ( 112 ) of the sliding bearing shell ( 100 . 200 ) extending in the circumferential direction from the solder to both sides over an angle of at least 10 °. Method for supplying a sliding bearing shell in a crankshaft main bearing or a connecting rod bearing of an internal combustion engine with oil, wherein the sliding bearing shell ( 100 . 200 ) a sliding surface ( 110 ) for engagement with a shaft or crankpin ( 224 . 226 ), one in the sliding surface ( 110 ) recessed oil pressure bag ( 112 ) and one in the oil pressure bag ( 112 ) has an opening oil feed, characterized in that when starting or stopping the internal combustion engine, the oil pressure bag ( 112 ) is subjected to a hydrostatic oil pressure. Method according to claim 25, characterized in that that the crankshaft or the connecting rod when starting or stopping by the hydrostatic oil pressure is raised. Method according to claim 26, characterized in that that the crankshaft or connecting rod when starting or stopping at least by 0.5 to 4 microns is raised. Method according to one of claims 26 or 27, characterized that the crankshaft or the connecting rod when starting or stopping for at least 0.1 to 4 seconds, preferably 1 to 2 seconds is raised. Method according to one of claims 25 to 28, characterized in that the oil pressure bag ( 112 ) from an accumulator ( 240 ) is subjected to the oil pressure. A method according to claim 29, characterized in that the pressure accumulator ( 240 ) by means of an oil pump ( 242 ) is loaded with oil. A method according to claim 29, characterized in that the pressure accumulator ( 240 ) is loaded in the operation of the internal combustion engine by utilizing the hydrodynamic pressure with oil.