Bearing lubrication arrangement, procedure for relubricating a bearing and procedure for constructing a bearing lubrication arrangement

Abstract

15 Abstract The invention starts from a bearing lubrication arrangement (10) comprising a lubrication unit (12), which is constructed for emitting grease into a space (14) between a first ring (16) and a second ring (18) of a bearing (20), and at least one temperature sensor (22), which is capable of measuring a temperature T of a component (34) of the bearing, and at least one control unit (24), which is programmed for inducing the lubrication unit to emit grease when a relubrication time span has passed. It is proposed that the relubrication time span depends on (I) and / or (II), wherein t is the time, P is the power needed to compensate the friction in the bearing or an approximation of this power, PEHL is either the sum of the power needed to compensate the friction between the rolling elements (26) of the bearing and all rings (16, 18) of the bearing and the power needed to compensate the friction caused by the seals (28, 30) of the bearing or an approximation of this sum, T ∞ is the ambient temperature, C(t) and D(t) are functions, and 0 ≤ t 1 ≤ t chur and 0 ≤ t 2 ≤ t chur and 0 ≤ t 3 ≤ t chur and 0 ≤ t 4 ≤ t chur and t 1 < t 2 and t 3 ≠ t 4 and holds, wherein E ≠ 0 and E ≠ 0, wherein tchur is the point in time, when after the bearing starts running for the first time at t=0 the churning phase of the running bearing ends.

Description

[0001]  Bearing lubrication arrangement, procedure for relubricating a bearing and procedure for constructing a bearing lubrication arrangement The invention concerns a bearing lubrication arrangement, a procedure for relubricating a bearing and a procedure for constructing a bearing lubrication arrangement. Relubrication in lubrication systems is now often done by applying intermittent dosing: small quantities every few hours. In order to make sure that aged grease is properly replaced, much more grease than 30% of the free volume inside a bearing is dosed during relubrication intervals. Too much grease is used to avoid failures. Relubrication therefore leads to an almost continuous state of grease churning, leading to high friction, energy losses, thermo-mechanical degradation of grease and reduces grease life / relubrication intervals. Knowledge on grease life is normally hardly ever used in lubrication systems (it is time based in practice). Grease life is given by chemical and thermo-mechanical degradation. Chemical degradation (oxidation) is deterministic. Mechanical degradation is given by the stresses on the grease, which are determined by flow and the flow properties of the grease. This flow is very non-linear. Grease life is therefore also determined by how the bearing grease is `run-in’. The run-in phase is called the `churning phase’. After this churning phase the grease is stationary and lubrication takes place primarily by oil bleed from the grease towards the contacts. The phase during which the grease is stationary and the lubrication primarily takes place by oil bleed from the grease is called `bleeding phase’. As explained the bleeding phase starts when the churning phase ends. The point in time when the bleeding phase starts can be found by the temperature behavior of the bearing. Known is also condition-based dosing, where the relubrication intervals are calculated by using a grease life model (based on (real time measured) speed, temperature and load or on its “best guess”). Grease in the context of churning hast been studied for example in “Impact of grease churning on grease leakage, oil bleeding and grease rheology”, Tribology International 176 (2022) 107926 (this will be called “reference 1” in the following) and “Thermo-mechanical aging during churning in grease lubricated bearings and its impact on grease life”, Tribology International Volume 181, March 2023, 108248 (this will be called “reference 2” in the following).     The problem of the invention is in particular to increase the efficiency of bearing lubrication. The task is solved according to the invention by the features of claim 1, by the features of claim 9 and by the features of claim 10, while advantageous embodiments and further embodiments of the invention can be taken from the subclaims. The invention proceeds from a bearing lubrication arrangement comprising a lubrication unit, which is constructed for emitting grease into a space between a first ring and a second ring of a bearing, and at least one temperature sensor, which is capable of measuring a temperature T of a component of the bearing, and at least one control unit, which is programmed for inducing the lubrication unit to emit grease when a relubrication time span has passed. It is proposed that the relubrication time span depends on ^^ ൌ ^௧మ௧భ^^^ ^^^^ ^^ െ ^^^ ^^^ ^^ாு^^ ^^ ^^ and / or ^^ ൌ , wherein t is the time, P is the power needed to compensate the friction in the bearing or an approximation of this power, PEHLis either the sum of the power needed to compensate the friction between the rolling elements of the bearing and all rings of the bearing and the power needed to compensate the friction caused by the seals of the bearing or an approximation of this sum, is the ambient temperature, C(t) and D(t) are functions , and 0 ^ ^^^^ ^^^^௨^and 0 ^ ^^ଶ^ ^^^^௨^and 0 ^ ^^ଷ^ ^^^^௨^and 0 ^ ^^ସ^ ^^^^௨^and ^^^^ ^^ଶand ^^ଷ് ^^ସand holds, wherein ^^ ് 0 and ^^ ് 0, wherein tchuris the point in time, when after the bearing starts running for the first time at t=0 the churning phase of the running bearing ends. Through this an increased efficiency of bearing lubrication can be achieved. In particular, the control unit is programmed to determine the relubrication time span, preferably the control unit is programmed to calculate the relubrication time span. Moreover, it is suggested that the bigger E and / or S is, the smaller the relubrication time span is. Hereby a bigger amount of grease is only used for lubrication if needed. Furthermore, an increase in bearing reliability and reduced bearing friction can be achieved. ^ష^బWith advantage, ^^^^^^ൌ 2^ಲ, wherein T0is a first constant temperature value and TAis a second constant temperature value. Through this an adjustment for thermal effects can be achieved. In particular, ^^^ ^^^ ൌ 1 or ^^^ ^^^ ൌ 0 can hold. 2        Furthermore, it is proposed that ^^ଶെ ^^^^ 0.2 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.2 ^^^^௨^, preferably that ^^ଶെ ^^^^ 0.6 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.6 ^^^^௨^, more preferably that ^^ଶെ ^^^^ 0.9 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.9 ^^^^௨^and most preferably that ^^ଶെ ^^^ൌ ^^^^௨^and / or ^^ସെ ^^ଷൌ ^^^^௨^. Through this a good precision of the relubrication time span can be realized. Advantageously the control unit is programmed to calculate the length of the relubrication time span, wherein the control unit is programmed to use a grease life model to calculate an approximation for the relubrication time span and multiply this approximation with a factor, which is a function of E and / or S. Thereby a simple and effective determination of the relubrication time span can be reached. Moreover, it is proposed that the bearing lubrication arrangement comprises at least one measuring unit, which is constructed for measuring the friction torque of the bearing, and / or at least one measuring unit, which is constructed for measuring the load of the bearing. Through this measured input for the calculation of E can be reached. With advantage is the control unit programmed to calculate an approximation of the power needed to compensate the friction between the rolling elements of the bearing and all rings of the bearing via a bearing friction model. Thereby an important contribution to a calculation of E can be achieved relatively easily. In particular, the control unit is programmed to calculate the approximation of the power needed to compensate the friction caused by the seals of the bearing. Moreover, it is proposed that the control unit is programmed to calculate P with the help of an average cooling factor. Through this torque measurement can be omitted. Moreover, a device is suggested which comprises the bearing lubrication arrangement and the bearing. Furthermore, a procedure for relubricating a bearing is suggested, wherein grease is emitted into a space between a first ring and a second ring of the bearing during a relubrication time span, wherein during the time span ^^^ ^^^ ൌ is calculated in real time, and the emitting of grease is stopped at the point in time ts, when ^^^ ^^^^ ൌ ^^^^^௧^^^^and / or ^^^ ^^^^ ൌ ^^^^^௧^^^^holds, wherein the predetermined number Ecriticaland / or the predetermined number Scriticalare respectively is saved in a control unit, wherein t is the time, T is the temperature of a component of the bearing, P is the power needed to compensate the 3        friction in the bearing or an approximation of this power, PEHLis either the sum of the power needed to compensate the friction between the rolling elements of the bearing and all rings of the bearing and the power needed to compensate the friction caused by the seals of the bearing or an approximation of this sum, ^^^is the ambient temperature, C(t) and D(t) are functions, wherein tbis the point in time, when the time span begins. Through this an increased efficiency of bearing lubrication can be achieved. In particular, a long bearing life together with a low consumption of grease can be reached. ^ష^బWith advantage, ^^^^^^ൌ 2^ಲ, wherein T0is a first constant temperature value and TAis a second constant temperature value. Through this an adjustment for thermal effects can be achieved. In particular, ^^^ ^^^ ൌ 1 or ^^^ ^^^ ൌ 0 can hold. Furthermore, a procedure for constructing a bearing lubrication arrangement is proposed, wherein a set of experiments is done, wherein in each of the experiments a different strategy for dosing grease to a bearing is applied and for each of the experiments a number E and / or a number S is calculated, and one strategy for dosing of the strategies, for which a certain function F, which depends at least on E and / or S, has a minimal value compared to the remaining strategies, is implemented in the bearing lubrication arrangement, wherein ^^ ൌ ^௧మ௧భ^^^ ^^^^ ^^ െ ^^^ ^^^ ^^ாு^^ ^^ ^^ and / or ^^ ൌ wherein t is the time, T is the temperature of a component of the bearing, P is the power needed to compensate the friction in the bearing or an approximation of this power, PEHLis either the sum of the power needed to compensate the friction between the rolling elements of the bearing and all rings of the bearing and the power needed to compensate the friction caused by the seals of the bearing or an approximation of this sum, ^^^is the ambient temperature, C(t) and D(t) are functions, and 0 ^ ^^^^ ^^^^௨^and 0 ^ ^^ଶ^ ^^^^௨^and 0 ^ ^^ଷ^ ^^^^௨^and 0 ^ ^^ସ^ ^^^^௨^and ^^^^ ^^ଶand ^^ଷ് ^^ସholds, wherein ^^ ് 0 and ^^ ് 0, wherein tchuris the point in time, when after the bearing starts running for the first time at t=0 the churning phase of the running bearing ends. Through this an increased efficiency of bearing lubrication can be achieved. In particular, the strategy is implemented in the bearing lubrication arrangement by programming a control unit to execute the strategy. In particular, the strategy can be to relubricate after a certain time interval has passed. 4        ^ష^బWith advantage, ^^^^^^ൌ 2^ಲ, wherein T0is a first constant temperature value and TAis a second constant temperature value. Through this an adjustment for thermal effects can be achieved. In particular, ^^^ ^^^ ൌ 1 or ^^^ ^^^ ൌ 0 can hold. Furthermore, it is proposed that ^^ଶെ ^^^^ 0.2 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.2 ^^^^௨^, preferably that ^^ଶെ ^^^^ 0.6 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.6 ^^^^௨^, more preferably that ^^ଶെ ^^^^ 0.9 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.9 ^^^^௨^and most preferably that ^^ଶെ ^^^ൌ ^^^^௨^and / or ^^ସെ ^^ଷൌ ^^^^௨^. Through this a good precision of the strategy can be realized. Further advantages can be seen in the following description of the drawings. An example of an embodiment of the invention is shown in the drawings. The drawings, the description and the claims contain numerous features in combination. The skilled person will expediently also consider the features individually and combine them to form useful further combinations. Fig.1 shows a schematic half section through a device with a bearing lubrication arrangement according to the invention and with a bearing, Fig.2 shows a diagram of a normalized grease life, and Fig.3 shows a further diagram of a normalized grease life. Figure 1 shows a half section through a device with a bearing lubrication arrangement 10 and with a bearing 20. The bearing is a ball bearing. The bearing could also be a different kind of rolling bearing. The bearing lubrication arrangement comprises a lubrication unit 12, which is constructed for emitting grease into a space 14 between a first ring 16 and a second ring 18 of the bearing 20. The first ring 16 is an outer ring and the second ring 18 is an inner ring. In order to emit grease into the space 14 the lubrication unit 12 comprises a pump (not shown) which can pump grease of the lubrication unit 12 through a through boring 36 of the ring 16 into the space 14. This lubricates a movement of the rolling elements 26 of the bearing 20 relative to the rings 16, 18. Moreover, the bearing 20 comprises a first seal 28, which seals the space 14 at a first axial end of the bearing 20. Furthermore, the bearing 20 comprises a second seal 30, which seals the space 14 at a second axial end of the bearing 20. 5        The bearing lubrication arrangement 10 comprises a temperature sensor 22 which can measure the temperature T of a component 34 of the bearing. The component 34 is the first ring 16. Moreover, the bearing lubrication arrangement 10 comprises a control unit 24, which is programmed for inducing the lubrication unit 12 to emit grease through the through boring 36 into the space 14 when a relubrication time span has passed. At the point in time t=0 the bearing starts running for the first time. This means that a churning phase of the running bearing starts also at t=0. In this phase grease of the bearing is churned by the rolling elements 26. The churning phase ends at ^^^^௨^^. The relubrication time span depends on ^^ Here t is the time, P is the power needed to compensate the friction in the bearing or an approximation of this power, PEHLis either the sum of the power needed to compensate the friction between the rolling elements 26 of the bearing and all rings 16, 18 of the bearing and the power needed to compensate the friction caused by the seals 28, 30 of the bearing or an approximation of this sum, is the ambient temperature of the surroundings of the device, C(t) and D(t) are functions , and 0 ^ ^^^^ ^^^^௨^and 0 ^ ^^ଶ^ ^^^^௨^and 0 ^ ^^ଷ^ ^^^^௨^and 0 ^ ^^ସ^ ^^^^௨^and ^^^^ ^^ଶand ^^ଷ് ^^ସholds, wherein ^^ ് 0 and ^^ ് 0. Furthermore, it can be the case that ^^ଶെ ^^^^ 0.2 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.2 ^^^^௨^, preferably that ^^ଶെ ^^^^ 0.6 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.6 ^^^^௨^, more preferably that ^^ଶെ ^^^^ 0.9 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.9 ^^^^௨^and most preferably that ^^ଶെ ^^^ൌ ^ష^బ^^^^௨^ and / or ^^ସ െ ^^ଷ ൌ ^^^^௨^ . ^^^^^^ൌ 2^ಲand / or ^^^^^^ൌ 1 can hold. T0 is a referencetemperature and can be 40°C. TAis the so-called Arrhenius temperature and can be 15°C. ^ష^బ^^^ ^^^ ൌ 2^ಲcan be chosen to include the thermal aspects of mechanical degradation. Moreover, the bearing lubrication arrangement comprises a measuring unit 32, which is constructed for measuring the friction torque of the bearing. The measuring unit 32 is also constructed for measuring the load of the bearing and the rotational speed of the bearing. The control unit 24 is programmed to calculate the length of the relubrication time span. The bigger E and / or S is, the smaller the determined relubrication time span is. The control unit is programmed to use a grease life model (cf. for example the SKF catalogue “Rolling bearings” of October 2018, pages 112-113, publication number PUB BU / P117000 / 1 EN) to calculate an approximation for the relubrication time span and multiply this approximation with a factor, which is a function of E and / or S, which gives the final result for the relubrication time span. The 6       approximation for the relubrication time span is ^^ହ^ൗ6.3. L50is the amount of time, after which thegrease no longer lubricates the bearing with a probability ^ 50% of failure. The factor is asalready stated determined by E and / or S. At first the energy density ^^^ൌ ^^ൗ ^^^is calculated,wherein Vgis the volume of the grease of the bearing. Figure 2 is gained by experiments, wherein the grease life is measured and at the same time EVis calculated for the bearing of the respective experiment. The normalized grease life of figure 2 is the measured grease life divided by the calculated L50. Figure 2 is figure 5(a) of reference 2: how it was exactly obtained by experiments is described in reference 2. The dashed line in figure 2 represents a function, which can be obtained by a fit to the shown experimental data: Normalized grease life depending on EV. This function is saved in the control unit. For the bearing 20 the calculated EVis put into thisfunction: Through this a value is obtained: This value is multiplied with ^^ହ^ൗ6.3(here L50is thecalculated value), which yields the final result for the relubrication time span which is used for the bearing 20. The described calculations are done by the control unit 24. The control unit 24 is programmed to calculate PEHLvia a bearing friction model. Such a bearing friction model can be found in the SKF catalogue “Rolling bearings” of August 2013, publication number PUB BU / P110000 / 2 EN. Equations for this calculation are also contained in section 2.7 in reference 1. With these equations and the load of the bearing, which is measured by the measuring unit 32, a friction torque needed for the calculation of PEHLcan be calculated. Afterwards this friction torque is multiplied with the rotational speed, which is measured by the measuring unit 32: This yields PEHL. Multiplication of the measured friction torque with the measured rotational speed yields P. With P and PEHLavailable E is calculated via time integration, cf. the mentioned equation. In some cases the friction torque cannot be measured. Then P can be calculated with the help of the average cooling factor Ws, cf. section 2.7 of reference 1, which is saved in the control unit 24 and which was obtained as described in section 2.7 of reference 1. Wsdescribes the cooling of the bearing via thermal energy balance with the surroundings of the bearing. P can be calculated from the measured temperature in the churning phase, cf. equation (5) in reference 1: ^^ ൌ Δ ^^ ^^^, wherein Δ ^^ ൌ ^^ െ ^^^. Wscan be calculated from data in the bleeding phase of the bearing: ^^^ൌ is the ambient temperature, i. e. the temperature of the surroundings of the bearing (the sensor for measuring ^^^is not shown). 7        The control unit is programmed to calculate S with the measured temperature T and with themeasured ^^^. With S the control unit calculates ^^ொ^ൌ ^^ൗ ^^^ ^^, wherein ^^ ൌ , whereinr0is the outer ring radius of the bearing, B is the bearing width and hcris the combined (convective and radiative) heat transfer coefficient (cf. (4) of reference 2). The normalized grease life of figure 3 is the measured grease life divided by the calculated L50. Figure 3 is figure 5(b) of reference 2. Figure 3 is gained by experiments, wherein the grease life is measured and at the same time SQVis calculated for the bearing of the respective experiment. How figure 3 was exactly obtained by experiments is described in reference 2. The dashed line in figure 3 represents a function, which can be obtained by a fit to the shown experimental data: Normalized grease life depending on SQV. This function is saved in the control unit. For the bearing 20 the calculated SQVis put into this function: Through this a value is obtained: Thisvalue is multiplied with ^^ହ^ൗ6.3(here L50is the calculated value), which yields the final result forthe relubrication time span which is used for the bearing 20 in case the relubrication time span is not calculated with E and only S is used for the calculation. The relubrication time span starts at the end of the churning phase. Then relubrication is repeated periodically after further relubrication time spans of the same length have passed. The temperature T is logged by the control unit at least during the running-in phase and preferably for ^^ ^ 0. All the described calculations are done by the control unit 24. In figure 2 and figure 3 the measured grease life is the amount of time, after which the grease no longer lubricates the bearing with a probability ^ 50% of failure. Figures 2 and 3 show the effect of churning. Here many bearings have been running under exactly the same conditions. However, every bearing showed different running-in due to the “chaotic nature” of grease lubrication. It should be noted that choosing D(t)= 0 also works in the spirit of the invention. With the device shown in Figure 1 a procedure for relubricating a bearing can be executed which is different from the one described above and a further embodiment of the invention. The procedure is executed by the control unit. During the procedure grease is emitted into the space 14 between the first ring 16 and the second ring 18 of the bearing during a relubrication timeinterval, wherein during the relubrication time interval ^^^ ^^^ ൌ െ ^^^^^ᇱ^^^ாு^^^^ ^^′ and / or8       ^^^ ^^^ ൌ is calculated in real time, and the emitting of grease is stopped at the point in time ts, when ^^^ ^^^^ ൌ ^^^^^௧^^^^and / or ^^^ ^^^^ ൌ ^^^^^௧^^^^holds, wherein the predetermined number Ecriticaland / or the predetermined number Scriticalare respectively is saved in the control unit 24, wherein tbis the point in time, when the relubrication time interval begins. A length of a time span, which is between two relubrication time intervals, can be saved in the control unit. A further embodiment of the invention, which is a procedure, can also be illustrated with the device in Figure 1, wherein for this embodiment of the invention the programming of the control unit 24 is different from the one in the first embodiment of the invention. The procedure is a procedure for constructing the bearing lubrication arrangement 10, wherein a set of experiments is done, wherein in each of the experiments a different strategy for dosing grease to the bearing 20 is applied and for each of the experiments the number E and / or the number S is calculated, and one strategy for dosing of the strategies, for which a certain function F, which depends at least on E and / or S, has a minimal value compared to the remaining strategies, is implemented in the bearing lubrication arrangement. The numbers E and S are the ones described above. The function F can for example be F(E)=E or F(S)=S. In another example F can depend on E and S. One of the strategies to dose grease to the bearing can be to dose a certain amount of grease to the bearing each time when a certain time span tlubhas passed. The different strategies can for example differ from each other through different values of tluband / or through different values of the dosed amount of grease. The implementation of the best strategy is done by programming the control unit 24. With all of the described embodiments of the invention it is possible to prevent bearings from failing early by dosing more grease than other bearings of the same type need in the same situation and with the same history. Furthermore, with the invention and the described embodiments less grease can be dosed to those bearings which need less grease than other bearings of the same type need in the same situation and with the same history. Therefore, also grease can be saved, which reduces friction and therefore energy consumption. The dosing in the invention and in all the embodiments reduces the mechanical degradation of the grease in the bearing, leads to a reduced time between dosing and reduced required grease volumes. Dosing is done such that the degradation of the grease is minimized. The reliability of bearings is increased. 9        This invention is both a condition monitoring tool and also a relubrication strategy tool for lubrication systems. 5        List of reference numerals: 10 Bearing lubrication arrangement 12 lubrication unit 14 space 16 ring 18 ring 20 bearing 22 temperature sensor 24 control unit 26 rolling element 28 seal 30 seal 32 measuring unit 34 component 36 through boring

Claims

Claims:

1. Bearing lubrication arrangement (10) comprising a lubrication unit (12), which is constructed for emitting grease into a space (14) between a first ring (16) and a second ring (18) of a bearing (20), and at least one temperature sensor (22), which is capable of measuring a temperature T of a component (34) of the bearing, and at least one control unit (24), which is programmed for inducing the lubrication unit to emit grease when a relubrication time span has passed, characterized in that the relubrication time span depends on ^^ ൌ^௧మ௧భ^^^ ^^^^ ^^ െ ^^^ ^^^ ^^ாு^^ ^^ ^^ and / or ^^ ൌ, wherein t is the time, P is the power needed to compensate the friction in the bearing or an approximation of this power, PEHLis either the sum of the power needed to compensate the friction between the rolling elements (26) of the bearing and all rings (16, 18) of the bearing and the power needed to compensate the friction caused by the seals (28, 30) of the bearing or an approximation of this sum, ^^^is the ambient temperature, C(t) and D(t) are functions , and 0 ^ ^^^^ ^^^^௨^and 0 ^ ^^ଶ^ ^^^^௨^and 0 ^ ^^ଷ^ ^^^^௨^and 0 ^ ^^ସ^ ^^^^௨^and ^^^^ ^^ଶand ^^ଷ് ^^ସand holds, wherein ^^ ് 0 and ^^ ് 0, wherein tchur is the point in time, when after the bearing starts running for the first time at t=0 the churning phase of the running bearing ends.

2. Bearing lubrication arrangement according to claim 1, characterized in that the control unit (24) is programmed to determine the relubrication time span, wherein the bigger E and / or S is, the smaller the determined relubrication time span is.

3. Bearing lubrication arrangement according to claim 1 or claim 2, ^ష^బ^^^^^^ൌ 2^ಲand / or ^^^^^^ൌ 1 , wherein T0is a first constant temperature value and TAis a second constant temperature value.

4. Bearing lubrication arrangement according to at least one of the preceding claims, characterized in that ^^ଶെ ^^^^ 0.2 ^^^^௨^and / or ^^ସെ ^^ଷ^ 0.2 ^^^^௨^.

5. Bearing lubrication arrangement according to at least one of the preceding claims, characterized in that  the control unit (24) is programmed to calculate the length of the relubrication time span, wherein the control unit is programmed to use a grease life model to calculate an approximation for the relubrication time span and multiply this approximation with a factor, which is a function of E and / or S.

6. Bearing lubrication arrangement according to at least one of the preceding claims, characterized by at least one measuring unit (32), which is constructed for measuring the friction torque of the bearing, and / or at least one measuring unit (32), which measures the load of the bearing.

7. Bearing lubrication arrangement according to at least one of the preceding claims, characterized in that the control unit (24) is programmed to calculate an approximation of the power needed to compensate the friction between the rolling elements (26) of the bearing and all rings (16, 18) of the bearing via a bearing friction model.

8. Bearing lubrication arrangement according to at least one of the preceding claims, characterized in that the control unit (24) is programmed to calculate P with the help of an average cooling factor.

9. Procedure for relubricating a bearing (20), wherein grease is emitted into a space (14) between a first ring (16) and a second ring (18) of the bearing during a relubrication time span, wherein during the time span ^^^ ^^^ ^ᇱ^ ^െ ^^ ^^ ^^ாு^^^ ^^′ and / or ^^^ ^^^ ൌis calculated in real time, and the emitting of grease is stopped at the point in time ts, when ^^^^^^^ൌ ^^^^^௧^^^^ and / or ^^^^^^^ൌ ^^^^^௧^^^^ holds, wherein the predeterminednumber Ecriticaland / or the predetermined number Scriticalare respectively is saved in a control unit (24), wherein t is the time, T is the temperature of a component (34) of the bearing, P is the power needed to compensate the friction in the bearing or an approximation of this power, PEHLis either the sum of the power needed to compensate the friction between the rolling elements (26) of the bearing and all rings (16, 18) of the bearing and the power needed to compensate the friction caused by the seals (28, 30) of the bearing or an approximation of this sum, is the ambient temperature, C(t) and D(t) are functions, wherein tbis the point in time, when the time span begins.

10. Procedure for constructing a bearing lubrication arrangement (10), wherein a set of experiments is done, wherein in each of the experiments a different strategy for dosing grease to a bearing (20) is applied and for each of the experiments a number E and / or a number S is calculated, and one strategy for dosing of the strategies, for which a certain function F, which depends at least on E and / or S, has a minimal value compared to the remaining strategies, is implemented in the bearing lubrication arrangement, wherein wherein t is the time, T is thetemperature of a component of the bearing, P is the power needed to compensate the friction in the bearing or an approximation of this power, PEHLis either the sum of the power needed to compensate the friction between the rolling elements (26) of the bearing and all rings (16, 18) of the bearing and the power needed to compensate the friction caused by the seals (28, 30) of the bearing or an approximation of this sum,is the ambient temperature, C(t) and D(t) are functions, and 0 ^ ^^^^ ^^^^௨^and 0 ^ ^^ଶ^holds, wherein ^^ ് 0 and ^^ ് 0, wherein tchuris the point in time, when after the bearing starts running for the first time at t=0 the churning phase of the running bearing ends.

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