SE1451478A1

SE1451478A1 - Lubrication system and a method for controlling the lubrication system

Info

Publication number: SE1451478A1
Application number: SE1451478A
Authority: SE
Inventors: Arnelöf Per; Forsberg Jörgen
Original assignee: Scania Cv Ab
Priority date: 2014-12-04
Filing date: 2014-12-04
Publication date: 2016-06-05
Also published as: US20180087655A1; EP3227584A4; WO2016089287A1; KR20170091120A; EP3227584A1; KR101981727B1; SE538561C2; EP3227584B1; BR112017009695A2; US10451170B2

Description

15 20 25 30 35 gearbox and when certain gears are engaged in the gearbox and especially when a direct-gear is engaged in the gearbox. In the latter case, the torque in the gearbox is directly transmitted from an input shaft to the main shaft of the gearbox. Since the torque is not transmitted via anyone of the gearwheel pairs, the oil supply to the meshing engagements between the primary gearwheels and the secondary gearwheels is redundant. The counter shaft obtains a rotary resistance when the primary gearwheels rotates in contact With oil in the oil sump. Consequently, a constant high oil level in the oil sump results in unnecessary power losses in the gearbox due to the rotary resistance when certain gears are engaged in the gearbox and especially when a direct- gear is engaged.

WO 2008/076061 shows a gearbox with a main shaft and a counter shaft supporting a number of gearwheel pairs. During direct-drive operation in the gearbox, the normal oil level in the gearbox is temporarily lowered such that the gearwheels on the counter shaft rotate without contact with the oil in the oil sump. The oil level is raised back to normal level as soon as the direct drive gear is disengaged. An oil gathering tank is arranged in the gear box. The oil gathering tank comprises an inlet arranged in a position such it receives oil splash ?rom the gearwheels on the counter shaft when they come in contact with the oil. The oil ?ows out from the gathering tank and back to the oil sump via an outlet of the gathering tank regulated by a valve.

SUMMARY OF THE INVENTION The obj ect of the present invention is to provide a lubrication system providing a required lubrication and cooling of including components in a gearbox at the same time as it is possible to reduce power losses in the gearbox.

The above mentioned object is achieved by the lubrication system according to the characterizing part of claim l. The control unit receives information from one or several parameters related to the oil ?ow to the component. In view of this information, the control unit estimates a required oil ?ow to the component. During operating situations when, for example, the component is heavily loaded, the control unit closes the oil ?ow through the bypass line so that the entire oil ?ow is led to the component. During operating situations when the component is less loaded, the control unit leads a suitable part of the oil flow to the bypass line such that a remaining part of the oil ?ow, which corresponds to the estimated required oil ?ow, is led to the 10 15 20 25 30 35 component. The flow losses in the bypass line are consíderably lower than the ?ow losses in the narrow oil passages in the vicinity of the component. When a part of the oil ?ow in the oil line is led to the bypass line, the ?ow losses in the oil line will decrease resulting in less energy consumption of the pump pumping oil through the oil line.

According to an embodiment of the invention, the first valve is arranged in the bypass line. ln this case, the first valve regulates the oil ?ow through the bypass line. The oil ?ow to the component will be the remaining part of the entire oil ?ow through the oil line. The first valve may be positionable in a closed position and in least one open position. Preferably, the ?rst valve is positionable in a plurality of open position in which different large parts of the oil ?ow in the oil line is led through the bypass line.

The ?rst valve may be positionable to different open positions in a step-less manner.

According to an ernbodiment of the invention, the oil line has an extension from the oil sump to a component in the form of a roller bearing in the gearbox. The required oil flow to a roller bearing is, for example, depending on the loading. A too large oil flow to a roller bearing results in rolling losses. In this case, the estimated required oil ?ow will always give the rolling bearing a required lubrication and cooling. Unnecessarily large oil ?ows to the roller bearing is prevented resulting in lower rolling losses in the roller bearings. The roller bearing may be a roller bearing supporting a secondary gearwheel on the main shaft and/or a roller bearing supporting a rotary shaft in the gearbox such as an input shaft or the main shaft.

According to an embodiment of the invention, the bypass line may comprises a reservoir con?gured to store a variable amount of the oil in the gearbox in order to adjust the oil level in the oil sump. The quantity of oil in a gearbox is constant. If an amount of the oil is stored in a reservoir, the amount of oil in the oil sump will decrease in a corresponding manner and thus the oil level in the oil sump. When, for example, a direct-gear is engaged, the torque is not transmitted via the gearwheel pairs in the gearbox. In this case, it is suitable to establish an oil level in the oil sump below all primary gearwheels on the counter shaft in order to reduce the rotary resistance of the primary gearwheel and the counter shaft in an optimally manner. Furthermore the primary gearwheels on the counter sha? are of different sizes. When the torque is transmitted via a gearwheel pair comprising a primary gearwheel of a large size it is possible to establish an oil level in the oil sump located below the smaller sized 10 15 20 25 30 35 primary gearwheels on the counter shaft. Also in this case, the counter shaft obtains a decreased rotary resistance.

According to an embodiment of the invention, the lubrication system comprises a second valve by which the control unit regulates the oil ?ow from the reservoir to the oil sump. It is possible to quickly increase the amount of oil in the reservoir and lowering the oil level in the oil sump by positioning the second valve in a closed position. ln this case, all oil supplied to the reservoir will be maintained in the reservoir. It is possible to decrease the amount of oil in the reservoir and raising the oil level in the oil sump by positioning the second valve in an open position in which the oil ?ow from the reservoir is higher than the oil ?ow to the reservoir. It is possible to accelerate the lowering process of the oil level by positioning the first valve in a closed position. The second valve may be positionable between a closed position and at least one open position. Preferably, the second valve is positionable in a plurality of open position in which varying amounts of the oil in the reservoir is led to the oil sump. The second valve may be movable arranged between different open positions in a step-less mann?f.

According to an embodiment of the invention, the oil line comprises a return line con?gured to lead oil from the reservoir to the oil sump. Preferably, the reservoir is arranged at a higher level than the oil sump. In this case, the oil will ?ow from the reservoir to the oil sump by the gravity. Thus, no pump need to be used for conducting oil from the reservoir to the oil sump. ln this case, the reservoir may comprise an outlet opening at a bottom portion through which the oil leaves the reservoir and ?ows down to the oil sump.

According to an embodiment of the invention, the lubrication system comprises a sensor con?gured to sense the oil level in the oil sump. Such a sensor may include a ?oat or the like sensing the level of the oil in the oil sump. Thereby, it is possible for the control unit to be continuously aware of the actual oil level in the oil sump which facilitate the adjustment of the oil level when, for example, a new gear is to be engaged in the gearbox.

According to an embodiment of the invention, said parameter may be one of the following parameters the gear engaged in the gearbox, the torque transmitted through the gearbox, the temperature of the oil in the gearbox, the inclination of the gearbox, 10 15 20 25 30 35 GPS information, properties of the oil used in the gearbox, properties of the used gearbox, stored data from previous operation of the lubrication system, the temperature of the surrounding, the temperature of a coolant in a cooling system used to cool the oil in the gearbox and information of activation of a brake such as a retarder.

The gear engaged in the gear box is a parameter that can de?ne a suitable oil level in the gearbox in order to reduce the rotary resistance of the counter shaft in an optimal manner. Especially When the direct-gear is engaged in the gearbox, it is possible to reduce the rotary resistance significantly by lowering the oil level in the oil sump. The torque transmitted in the gearbox may define a required oil ?ow to the component. The Cooling properties of the oil are related to the temperature of the oil. Also the lubrication properties of the oil may vary with the temperature. The inclination of the gearbox effects the oil level in relation to the primary gearwheels on the counter shaft.

GPS information about the topography of the road ahead makes it possible to plan in advance the adjustment of the oil flow to the component and the oil level in the oil sump. The properties of the used oil are a relevant parameter in order to provide an oil ?ow resulting in a required lubrication of the component. Stored data from previous operation of the lubrication system can be helpful in order to estimate a required oil flow to the component and a suitable oil level in the oil sump. The temperature of the surrounding and the temperature of a coolant in a cooling system influences on the temperature of the oil in the gearbox. The information of activation of a brake such as a retarder makes it possible to increase the oil level in the oil sump during a braking process in order to provide a rotary resistance in the gearbox adding a complementary braking action to the ordinary brakin g process.

The initially mentioned object is also achieved by the method defined in claim ll.

BRIEF DESCRIPTION OF THE DRAWINGS ln the following a preferred embodiment of the invention is described, as an example, with reference to the attached drawings, in which: Fig. l Fig. 2 shows a gearbox in a vehicle, shows a lubrication system for the gearbox according to the invention and Fig. 3 shows a ?ow chart of a method for controlling the lubrication system. 10 15 20 25 30 35 DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT OF THE IN VENTION Fig. 1 shows a gearbox 2 arranged in a schematically indicated vehicle 1. The vehicle 1 may be a heavy vehicle. The gearbox 2 comprises a housing 2a and an input shaft 3 driven by a not shown combustion engine. The gearbox comprises further a counter shaft 4 provided With a plurality of gearwheels 5-10 of different sizes. In this case, the gearwheels 5-10 are fixedly arranged on the counter shaft 4. The gearbox 2 comprises a main shaft ll provided with a plurality of gearwheels 12- 17 of different sizes. Each gearwheel on 5-10 the counter shaft 4 is in constant engagement With a gearwheel 12- 17 on the main shaft 11 such that they form a number of gearwheel pairs in the gearbox 2. Each gearwheel pair includes a primary gearwheel 5-10 fixedly arranged on the counter shaft 4 and secondary gear Wheel 12-17 rotatably arranged on the main shaft 11 or the input shaft 3.

The gearbox 2 is equipped With a split gear Which in a first split position connects the input shaft 3 With the counter shaft 4 via a ?rst gearwheel pair 5, 12 and Which in a second split position connects the input shaft 3 With the counter shaft 4 via a second gearwheel pair 6, 13. The second gearwheel pair 6, 13 provides a ratio that de?nes a third gear in the gearbox 2, The gearbox 2 further includes a third gearwheel pair 7, 14 which de?nes a second gear in the gearbox 2, a fourth gearwheel pair 8, 15 that de?nes a first gear in the gearbox 2, a ?fth gearwheel pair 9, 16 Which defines a creep gear and a sixth gearwheel pair 10, 17 that define a reverse gear. The sixth gearwheel pair 10, 17 includes an intennediate gearwheel which provides a reverse rotation of the main shaft ll.

The input shaft 3 is rotatably arranged in the gearbox 2 by means of a roller hearing l8a. The secondary gearwheels 12-17 are rotatably arranged on the main shaft 1 1 by means of roller bearings 18b that can be needle bearings. The main shaft 11 is rotatably arranged by means of two roller bearings 18c. Synchronizing units 19-21 are disposed adjacent to the secondary gear Wheels 12-15 of the main shaft 1 1. Each Synchronizing unit 19-21 is con?gured to synchronize and lock at least one of the secondary gear wheels 12-15 on the main shaft 1 l. A first synchronizing unit 19 has the task to establish the different split positions. The first synchronizing unit 19 is able to connect the input shaft 3 With the counter shaft 4 in the gearbox 2, via the first 10 15 20 25 30 35 gearwheels pair 5, 12 in a ?rst split position and, via the second gearwheels pair 6 13, in a second split position. A second synchronization unit 20 is con?gured to synchronize and lock the secondary gearwheels 13, 14 on the main shaft 11. A third synchronizing unit 21 is adapted to synchronize and lock the secondary gearwheel 15 on the main shaft l 1. Furthermore, it is possible by the ?rst synchronizing unit 19 and the second synchronizing unit 20 to provide a direct connection between the input shaft 3 and the main shaft ll and provide a direct-drive gear in the gearbox 2.

The gearbox also includes a range gear 22 which connects the main shaft 11 to an output shaft 23 of the gearbox. The range gear 22 comprises a sun wheel 22a ?xedly arranged on the main shaft ll, planetary wheels 22b, a coupling sleeve 22c and a planetary carrier 22d. By means of the range gear 22, all ordinary gears in the gearbox 2 can be provided with a high range gear or a low range gear. Thus, the range gear 22 provides the gearbox 2 with twice as many gears. A lower portion of the housing 2a comprises an oil sump 24. The oil sump 24 is to be ?lled with gearbox oil. During operation, the primary gearwheel 5-10 of the respective gearwheel pairs distributes oil from the oil sump 24 up to a meshing engagement with the secondary gearwheel 12- 17. The oil provides lubrication and Cooling of the meshing engagement between the primary gearwheel 5-10 and the secondary gearwheels 12-17.

Fig 2 shows a lubrication system in the gearbox 2. The lubrication system comprises an oil line 25. The oil line 25 receives oil, via a suction strainer 26, arranged at a bottom portion of the oil sump 24. The oil line 25 comprises a pump 27 pumping oil through the oil line system 25 and an oil ?lter 28. The oil line 25 is branched at a point 25a in an ordinary portion 25b, 25c and in a bypass line 25d. The ordinary portion comprises an axial oil channel 25b arranged into the main shaft ll and radial oil channels 25c arranged at different axial positions along the axial oil channel 25b. The radial oil channels 25c lead oil to the roller bearing 18a supporting the input shaft 3, the roller bearings 18b supporting the second gear wheels 12-17 on the main shaft 11 and the roller bearings 18c supporting the main shaft 1 1. Furthermore, the axial oil channel 25b leads oil to the sun wheel 22a of the range gear 22. The oil lubricates and cools the roller bearings 18a-18c and the meshing engagement between the sun wheel 22a and the planetary wheels 22b of the range gear 22. The used oil ?ows down into the oil sump 24. The bypass line 25d comprises a first valve 30, an oil reservoir 31 and a return line 32 leading oil from the receiver 31 to the oil sump 24. The oil ?ow through the return line 32 is controlled by a second valve 33. Thus, the oil in the 10 15 20 25 30 35 bypass line 25d is conducted past the components in the form of roller bearings l8a- l8c and the sun Wheel 22a in the ordinary portion of the oil line 25.

A control unit 34 controls the first valve 30 and the second valve 33. When it sets the first valve 30 in a closed position, the oil ?ow through the bypass line 25d is closed. In this case, the entire oil flow is led to the roller bearings l8a-l Sc and the sun Wheel 22a.

When the valve 30 is set in a more or less open position, a part of the oil Will ?ow through the bypass line 25d and a remaining part of the oil Will ?ow to the bearings 18a-18c and the sun Wheel 22a. When the second valve 33 is set in an open position, the oil in the reservoir 31 flows from the reservoir 31, via a return line 32, to the oil sump 24. When the second valve 33 is in a closed position, the return line 32 is blocked and oil Will be maintained in the reservoir 31.

The control unit 34 is able to establish a Variable oil level in the reservoir 31 by means of the first valve 30 and the second valve 33. The control unit 34 receives information from a ?oat 35 about the actual oil level in the gearbox 2. The control unit 34 controls the ?rst valve 30 and the second valve 33 by means of information from a number of operational parameters. In this case, the control unit 34 receives information from a gear change unit about a first parameter 36 related to the gear engaged in the gearbox 2, information about a second parameter 37 about actual torque in the gearbox 2, information from a sensor about a third parameter 38 related to the inclination of the vehicle l, information from a sensor of a fourth parameter 39 related to the temperature of the oil in the gearbox and information from a GPS unit about a fifth parameter 40 regarding the topography of the road ahead.

Fig. 3 shows a ?ow chart of a method for controlling the lubrication system. The method starts at 4l. The control unit 34 receives, at 42, information about the operational parameters 36-40. ln this case, the parameters is the first parameter 36 related to the gear engaged in the gearbox 2, the second parameter 37 about the torque in the gearbox 2, the third parameter 38 about the inclination of the gearbox 2, the fourth parameter 39 about the oil temperature and the fifth parameter 40 about the topography of the road ahead. The control unit 34 may also receive information from other parameters such as properties about the used gearbox and stored data from previous operation of the gearbox 2. Furthermore, a parameter related to the activation of a retarder in the vehicle may also in?uence on the control of the lubrication system. 10 15 20 25 30 35 ln view of said parameters 36-40, the control unit 34 estimates, at 43, a required oil ?ow to the roller bearings lSa-l Sc and the sun wheel 22a. It is important that the oil ?ow to the roller bearings lSa-l Sc and the sun wheel 22a is large enough to ensure a required lubrication and cooling but not too large. The ?ow losses in the oil channels 25b, 25c conducting oil to the roller bearings lSa-l Sc and the sun wheel 22a is much higher than in the bypass line 25d. Thus, a too large oil ?ow to the roller bearings lSa- lSc and the sun wheel 22a results in increased ?ow losses and increased consumption of energy of the pump 27. Furthermore, a too large oil ?ow to the roller bearings lSa- lSc also results in increased rolling losses in the roller bearings lSa-l Sc.

Consequently, a too large oil ?ow to the roller bearings lSa-lSc and the sun wheel 22a results in increased power losses in the gearbox 2 and a higher fuel consumption of the engine of vehicle l connected to the gearbox 2.

The control unit 34 is, at 44, provided with information of the actual oil ?ow in the oil line 25. This information can be based on the stroke volume and the actual speed of the pump 27. The control unit 34 estimates, at 45, the distribution of the oil ?ow to the bypass line 25d and the ordinary portion 25b, 25c of the oil line 25. A part of the oil ?ow is to be led to the bypass line 25d such that a remaining part of the oil ?ow, which corresponds to the estimated required oil ?ow is led to the roller bearing lSa, lSb, lSc and the sun wheel 22a. The control unit regulates, at 46, the first valve 30 such that said remaining part of the oil flow is led to the roller bearing lSa, lSb, lSc and the sun wheel 22a. Advantageously, it is possible to regulate the first valve 30 in a step-less manner in order to regulate the oil ?ow to the bypass line 25d and thereby the oil ?ow to the roller bearings lSa-l Sc and the sun Wheel 22a with a high accuracy.

At 47, the control unit 35 receives information from the float 35 about the actual oil level in the oil sump 24. The control unit 34 estimates, at 48, a suitable oil level in the oil sump 24 in view of information of gear engaged in the gearbox 2. The primary gearwheels 5-10 on the counter shaft 4 are of different sizes and they have different immersion depth in the oil of the oil sump 24. At the suitable oil level, the primary gearwheel 5-10 of a gearwheel pair engaged in the gearbox 2 obtains an immersion depth in the oil at which it supplies oil to its meshing engagement with the secondary gearwheel in a quantity resulting in good lubrication and cooling. The primary gearwheels 5-10 obtain a rotary resistance in the oil which retards the rotary motion of the counter shaft 4. The rotary resistance of the counter shaft 4 results in power losses in the gearbox 2. Due to this fact, it is suitable to have an oil level in the gearbox 2 10 15 20 25 30 35 10 which is as low as possible but with a required lubrication and cooling of the components in the gearbox 2. When the torque in the gearbox 2 is transmitted via a large primary gearwheel 5, 6, it is possible to establish a lower oil level in the oil sump 24 than when the torque is transmitted via a small primary gearwheel 8-10. When the direct-drive gear is engaged in the gearbox 2, the torque is transmitted from the input shaft 3 to the main shaft 11 and thus not via the counter shaft 4 at all. ln this case, it is possible to establísh an oil level in the oil sump 24 below all primary gearwheels 5-10 and reduce the rotary motion of the counter shaft 4 in the oil in an optimal manner.

At 49, the control unit 34 compares the estimated suitable oil level with the actual oil level in the oil sump 24. ln case there is a difference between the estimated suitable oil level and the actual oil level, the control unit 34 regulates primarily the second valve 33 in order to adjust the oil level such the estimated required oil ?ow to the roller bearing 18a-18c Will be unaffected. If the oil level in the oil sump 24 is to be lowered, the first valve 30 is to be in a more or less open position such the reservoir 31 receives an oil ?ow from the oil sump 24. The control unit 34 sets the second valve 33 in a closed position such that all oil entering the reservoir 31 will be maintained. The control unit 34 receives information from the ?oat 35 indicating when the suitable oil level in the oil sump 24 has been reached. lf the ?rst valve 30 is in a closed position, the control unit 34 can perform the lowering of the oil level at a later time when the roller bearings 18a- l 80 do not require the entire oil ?ow in the oil line 25. lf instead the oil level in the oil sump 24 is to be raised, the reservoir 31 is to be drained of oil. In this case, the control unit 34 sets primarily the second valve 33 in a maximum open position. Thereby, the oil ?ows out of the reservoir 31 and back to the oil sump 24 via the return line 32. ln order to accelerate the establishment of the lower oil level, the control unit 34 may set the first valve 30 temporarily in a closed position.

The control unit 34 receives information from the ?oat 35 indicating when the raised suitable oil level in the oil sump 24 has been reached. Then the method restarts at 41.

Thus, the control unit 34 is able adjust the oil ?ow to the roller bearings 18a-l8c and the sun wheel 22a and the oil level in the oil sump 24 in view of a number of parameters. By means of information 35 about the gear engaged in the gearbox 2, it is possible to adjust the oil level in the oil sump 24 in order to reduce the rotary resistance of the counter shaft 4 in the oil in an optimal manner at the same tirne as the roller bearings 18a-18c and the sun wheel 22a obtains a required lubrication and 10 15 20 11 Cooling. By means of information 36 of the torque transmitted via the gearbox 2, it is possible to supply an oil ?ow to the roller bearings l8a-l 8c and the sun wheel 22a providing a required lubrication and cooling at the same time as the ?ow losses and the rolling losses in the roller bearings l8a-c are at a low level. The information 38 about the inclination of the vehicle l, makes it possible to adjust the oil level in the oil sump 24 When the vehicle l drives uphill or downhill. The information 39 about the temperature of the gearbox oil makes it possible to adjust the oil flow to the roller bearings l8a-l 8c and the sun wheel 22 in view of the oil temperature. Especially, the cooling properties of the oil varies with its temperature. The information 40 from a GPS unit about the topography of the road ahead, makes it possible to estimate the ?lture requirement of cooling and lubrication of the roller bearings l8a-l8c and estimate suitable future oil levels in the oil sump 24. ln case the vehicle comprises a retarder, it is possible to raise the oil level in the oil sump 24 when the retarder is activated. The raised oil level in the oil sump 24 results in an increased rotary resistance of the primary gearwheel. The increased rotary resistance adds a brake effect to the vehicle.

The invention is not restricted to the described embodiment but may be varied freely within the scope of the claims.

Claims

Patentkrav

1. Smorj system i en vaxellada, varvid vaxelladan innefattar en huvudaxel (11), en sidoaxel (4) ett flertal kugghjulspar som var och en innefattar ett primart kugghjul (5- 10) som är anordnat pa sidoaxeln (4) och ett sekundart kugghjul (12-15) som är anordnat pa huvudaxeln (11), och varvid smorjsystemet innefattar en oljesump (24), en oljeledning (25) konfigurerad att leda olja fran oljesumpen (24) till atminstone en komponent (18a, 18b, 18c, 22a) i vaxelladan, a pump (27) som pumpar olja genom oljeledningen (25), en bypassledning (25d) genom vilken det är mojligt att leda en del av oljeflodet i oljeledningen (25) forbi namnda komponent (18a, 18b, 18c, 22a) och tillbaka till oljesumpen (24), en forsta ventil (30) som är konfigurerad att reglera oljeflodet genom bypassledningen (25d) och en styrenhet (34) som är konfigurerad att mottaga information fran atminstone en parameter (37-40) som är relaterad till oljeflodet till namnda komponent (18a, 18b, 18c, 22a), att uppskatta ett erforderligt oljeflode till namnda komponent (18a, 18b, 18c, 22a) mot bakgrund av namnda parameter och att reglera den forsta ventilen (30) sa att en del av oljeflodet i oljeledningen (25) leds till bypassledningen (25d) och en aterstaende del av oljeflodet, vilket motsvarar det erforderliga oljeflodet, leds till namnda komponent (18a, 18b, 18c, 22a) kannetecknat av att bypassledningen (25d) innefattar en reservoar (31) som är konfigurerad att lagra en varierbar mangd av oljan i vaxelladan (2) for att justera oljenivan i oljesumpen (24) och att reducera rotationsmotstandet hos det primara kugghjulet (5-10) och sidoaxeln (4) i oljan.

2. Smorj system enligt krav 1, kannetecknat av att den forsta ventilen (30) är anordnad i bypassledningen (25d).

3. Smorj system enligt krav 1 eller 2, kannetecknat av att oljeledningen (25) har en strackning flan oljesumpen (24) till en komponent i form av ett rullager (18a, 18b, 18c) i vaxelladan (2).

4. Smorj system enligt krav 3, kannetecknat av att oljeledningen (25) har en strackning fran oljesumpen (24), via en huvudaxel (11) i vaxelladan (2), till ett rullager (18b) som bar upp ett kugghjul (12-17) pa huvudaxeln (11). 2

5. Smorj system enligt nagot av foregaende krav, kannetecknat av att smorjsystemet innefattar en andra ventil (33) med vilken styrenheten (34) reglerar oljeflodet fran reservoaren (31) till oljesumpen (24).

6. Smorj system enligt krav 5, kannetecknat av att oljeledningen (25) innefattar en returledning (32) som är konfigurerad att leda olja fran reservoaren (31) till oljesumpen (24).

7. Smorj system enligt krav 6, kannetecknat av att reservoaren (31) är anordnad i en position ovanfor oljesumpen (24).

8. Smorj system enligt nagot av foregaende krav, kannetecknat av att smorjsystemet innefattar en sensor (35) som är konfigurerad att avkanna oljenivan i oljesumpen (24).

9. Smorj system enligt krav 1, kannetecknat av att namnda parameter är en av foljande parametrar den ilagda vaxeln (36) i vaxelladan, vridmomentet (37) som overfors via vaxelladan, oljans temperatur (38) i vaxelladan (2), vaxelladans lutning (39), GPS information (40), egenskaper hos den anvanda oljan, egenskaper hos den anvanda vaxelladan (2), lagrad data fran tidigare drift av smorjsystemet, omgivningens temperatur, temperaturen hos en kylvatska i ett kylsystem som anvands for att kyla oljan i vaxelladan (2) och information avseende aktiveringen av en broms sasom en retarder.

10. En metod for att styra ett smorj system i en vaxelada, varvid vaxellklan innefattar en huvudaxel (11), en sidoaxel (4) ett flertal kugghjulspar som var och en innefattar ett primart kugghjul (5-10) som är anordnat pa sidoaxeln (4) och ett sekundart kugghjul (12-15) som är anordnat pa huvudaxeln (11), och varvid smorjsystemet innefattar en oljesump (24), en oljeledning (25) som är konfigurerad att leda olja fran oljesumpen (24) till atminstone en komponent (18a, 18b, 18c, 22a) i vaxelladan, och a pump (27) som pumpar olja genom oljeledningen (25), varvid metoden innefattar stegen att mottaga information fran atminstone en parameter (37-40) som är relaterad till oljeflodet till komponenten (18a, 18b, 18c, 22a) i vaxelladan (2), att uppskatta ett erforderligt oljeflode till namnda komponent (18a, 18b, 18c, 22a) mot bakgrund av namnda parameter och att leda en del av oljeflodet i oljeledningen (25) till en bypassledning (25d) och fOrbi namnda komponent (18a, 18b, 18c, 22a) och att en aterstaende del av oljeflodet, vilket motsvarar det erforderliga oljeflodet, leds till 3 komponenten (18a, 18b, 18c, 22a) kannetecknad av stegen att lagra en varierbar mangd av olja i vaxelladan i en reservoar (31) som är anordnad i bypassledningen (25d) for att justera oljenivan i oljesumpen (24) och att reducera rotationsmotstandet hos det primara kugghjulet (5-10) och sidoaxeln (4) i oljan.

11. En metod enligt krav 10, kannetecknad av steget att reglera oljeflodet till komponenten (18a, 18b, 18c, 22a) med hjalp av en forsta ventil (30) som är anordnad i bypassledningen (25d). 1 0

12. Metod enligt krav eller 11, kannetecknad av steget att leda olja till en komponent i form av ett rullager (18a, 18b, 18c) i vaxelladan (2).

13. En metod enligt krav 12, kannetecknad av steget att leda olja till ett rullager (18b) som bar upp ett kugghjul (12-17) pa huvudaxeln (11).

14. En metod enligt krav 15, kannetecknad av steget att reglera oljeflodet fran reservoaren (31) till oljesumpen (24) med hjalpa av en andra ventil (33).

15. En metod enligt nagot av foregaende krav 14, kannetecknad av steget att leda olja fran reservoaren (24) till oljesumpen (24) via en returledning (32).

16. En metod enligt krav 15, kannetecknad av steget att anordna reservoaren (31) i en position ovanfor oljesumpen (24).

17. Metod enligt nagot av foregaende krav 10-16, kannetecknad av stegen att mottaga information om aktuell oljeniva i oljesumpen (24), att uppskatta en lamplig oljeniva i olja sump (24) med hjalp av namnda parameter (36-40) och att justera den lagrade mangden av olja i reservoaren (31) sa att oljenivan i oljesumpen justeras till den lampliga oljenivan.

18. Metod enligt nagot av foregaende krav 10-17, kannetecknad av steget att mottaga information fran atminstone en av foljande parametrar den ilagda vaxeln (36) i vaxelladan, vridmomentet (37) som overfors via vaxelladan, oljans temperatur (38) i vaxelladan (2), vaxelladans lutning (39), GPS information (40) om den framforvarande vagen, egenskaper hos den anvanda oljan, egenskaper hos den anvanda vaxelladan (2), lagrad data fran tidigare drift av smorjsystemet, omgivningens temperatur, yla oljan i vaxelladan Foregdende krav 1-9. 19 1314 12