DE102015000569A1 - Method and device for heating a lubricated wheel bearing for a vehicle wheel - Google Patents

Abstract

The invention relates to a method for heating a lubricated, in particular a grease-lubricated, wheel bearing (1), with a vehicle wheel is rotatably mounted on a vehicle, wherein the wheel bearing (1) as a lubricated rolling bearing with a plurality of bearing side raceways (3, 4) rolling Rolling bodies (7) is formed, between the raceways (3, 4) is provided a rolling body (7) and a lubricant, receiving space as a lubricant receiving space (8), and wherein at least one heating element (12) is provided by means of a designed as a control and / or regulating device heating device (13) for an indirect or immediate heating of defined wheel bearing components, in particular of the lubricant in the receiving space (8) recorded lubricant and / or the air in the lubricant receiving space (8), can be controlled. According to the invention, the heating device (13) and thus the at least one heating element (12) controlled by the latter are activated for a predetermined period of time before or after the start of the journey depending on at least one event characterizing a journey start, in particular immediately before or immediately after Start of journey activated.

Description

The invention relates to a method for heating a lubricated, in particular a grease-lubricated, wheel bearing for a vehicle wheel and an apparatus for carrying out such a method.

Wheel bearings for supporting a vehicle wheel, in particular a wheel hub of a vehicle wheel, are well known. For such wheel bearings are usually single or multi-row bearings, for example tapered roller bearings or ball bearings used, which can also absorb axial forces in addition to radial forces. The rolling bearings regularly have a plurality of bearing-side raceways, in particular between an inner ring and an outer ring, rolling rolling elements, which are regularly kept separated by a cage. In order to further reduce the friction between the rolling elements and the raceways, the roller bearings forming the wheel bearings are lubricated by means of a lubricant, in particular by means of a lubricating grease, in an outwardly sealed space between the two opposing raceways of the outer and inner ring , in which the rolling elements rotate, is recorded. The wheel bearings used in vehicles are designed to be maintenance-free. This is realized with a grease filling, which ensures sufficient lubrication of the rolling elements over the entire life of the wheel bearing. Seals ensure that neither water nor dirt can enter the wheel bearing.

However, for optimal friction reduction by means of the lubricant used, it is necessary that this lubricant has a certain temperature in order to reduce the viscosity of the lubricant so far that the best possible friction reduction is achieved.

For this it is from the JP 2011/058523 A already known to integrate a heating element in a wheel bearing, by means of which the lubricant can be heated. Specifically, for this purpose, a temperature sensor in the lubricant receiving space is arranged as the intermediate space between the two raceways, which adjusts the lubricant temperature to a certain temperature. The energy supply for the electric heating element via the vehicle battery or a positioned on the vehicle roof solar panel. The disadvantage of such a purely temperature-controlled temperature control, however, is that the lubricant, especially in correspondingly cold weather conditions, for a relatively long time after starting the journey does not yet have the optimum lubricant temperature, which has a negative effect on the friction behavior in the wheel bearing.

In contrast, it is an object of the present invention to provide a method for heating a lubricated, in particular a grease-lubricated, wheel bearing for a vehicle available by means of which the aforementioned disadvantages can be avoided and the wheel bearing, in particular the lubricant of the wheel bearing on fast and reliable Can be brought to the desired operating temperature. Furthermore, it is a further object of the invention to propose a suitable device for carrying out such a method.

This object is achieved with the features of the independent claims. Advantageous embodiments are the subject of the dependent claims.

According to claim 1, a method for heating a lubricated, in particular a grease-lubricated, wheel bearing is proposed, with which a vehicle wheel, in particular a wheel hub of a vehicle wheel, is rotatably mounted on a vehicle, wherein the wheel bearing as a lubricated, in particular grease-lubricated, rolling bearing with several between bearing side Runways rolling rolling elements is formed. In the space between the raceways, the rolling elements and a lubricant, in particular a grease, receiving, preferably sealed to the outside, space is provided as a lubricant receiving space. In addition, at least one heating element is provided, for example, on the outer and / or inner ring and / or in the lubricant accommodating space, which by means of a heating device designed as a control and / or regulating device for indirect or direct heating of defined wheel bearing components, in particular of the lubricant accommodated in the lubricant accommodating space and / or the bearing air contained in the lubricant receiving space, can be controlled. According to the invention, the heating device and thus the at least one heating element controlled by the latter are activated as a function of at least one defined event and / or operating parameter characterizing a start of travel for a predetermined period of time before or after the start of the journey, in particular immediately before or immediately after the start of the journey becomes. This ensures that, for example, the lubricant also immediately before or immediately after the start of the journey already has the predetermined target lubricant temperature or the bearing air already has the desired target air temperature. It is understood that of course there is a certain time lag between activation of the heater and the achievement of the respective target temperature. The above formulation "immediately before or immediately after the start of the journey" in connection with both the activation of the heater and in Connection with the attainment of a target temperature thus expressly defines a relatively short period, preferably a period of 1 to 10 minutes before or after the start of the journey, within which both the activation of the heater takes place and also the desired setpoint temperature, in particular a desired lubricant temperature and / or a Target air temperature in the warehouse is reached. In other words, the heating device should be activated shortly before or at the latest immediately after the start of the journey in order to ensure that the optimum target lubricant temperature or the optimum setpoint air temperature in the warehouse is already present at the start of the journey or as short as possible thereafter ,

The start of the journey itself is preferably defined by an engine start.

Unlike in a purely temperature-controlled control thus results in activation of the heater depending on at least one characterizing the start of the journey event or operating parameters the possibility of the heater of the wheel bearing already shortly before or at the latest immediately after the vehicle start or the start of the journey to activate in that the desired preset desired lubricant temperature or desired air temperature in the bearing is also already achieved in the immediate vicinity of this time. Such a measure thus has the effect that the lubricant already at the start of travel or immediately thereafter has the best possible viscosity for the best possible reduction of friction or is reduced by the air heating of the negative pressure in the bearing or in the lubricant receiving space, resulting in a reduced seal friction.

It is understood that the respective predetermined optimum or desired lubricant temperature depends on the geometry of the wheel bearing or rolling bearing, in particular on the materials used, the type of lubricant, etc. depends and is determined accordingly by experiments.

According to a particularly preferred specific first embodiment of the invention, a detection device may be provided on the vehicle side, possibly forming part of the heating device, by means of which a signal of a transmitter unit (preferably a mobile transmitter unit) assigned to the detection unit is detected and transmitted to the heating device, which then transmits the at least a heating element timed before the start of the journey and activated. Such a temperature before starting the vehicle or before the start of the journey can be integrated in a simple and reliable manner in already existing vehicles and their assistance systems. For example, the signal may be an approximation signal of a transmitter unit approaching the vehicle and moving into a reception area of the detection unit. This transmitter unit may preferably be an active or passive transponder, for example an active or passive transponder integrated in a vehicle key. Alternatively, however, the signal may also be a signal of a sender unit to be actively operated by an operator, for example a sender unit designed as a remote control, which in turn may most preferably be a remote control integrated into a vehicle key as a sender unit.

In the measures with a transmitter unit just described, units or assistance systems in a dual function that are already installed on a vehicle are thus regularly used to characterize an imminent start of travel and to generate a trigger signal for activating and activating the heater.

According to an alternative embodiment, the heater but also when deactivating a theft protection device, in particular when unlocking a door lock and / or deactivating an immobilizer and / or deactivating an alarm system, are controlled and activated, in particular controlled and activated by the theft protection device itself. The deactivation of the theft protection device then represents here the event characterizing a start of travel. Again, a unit which is regularly installed on a vehicle in a dual function is thus used to characterize an imminent start of travel and to generate a trigger signal for activating and activating the heating device.

Alternatively, the event characterizing a start of the journey may also be the activation of a parking heater, wherein the activation of the auxiliary heating then simultaneously supplies the trigger signal for the activation of the heating device. Alternatively, however, the event characterizing a start of travel may also be a specific time during a charging process of a traction battery of an at least partially electrically driven vehicle. For example, this may be the end of a recharge that signals an imminent start of travel. The trigger signal for the heater can then be transmitted in this case, for example, from a charging operation monitoring device to the heater.

According to a further alternative embodiment, it is also possible to provide a travel time evaluating device, possibly forming part of the heating device, by means of which, on the basis of the over a defined longer period of time by means of the vehicle trips, at least one usual start of the journey is determined. The heating device is then activated and activated by the travel time evaluation device at a defined point in time before such a customary start of travel.

As an alternative, the heating device can also be activated in a time-controlled manner by means of a time program assigned to the heating device at a defined point in time before a predetermined, intended start of the journey. The event characterizing the start of the journey is here then the intended start of the journey programmed by the driver.

For a conditioning of the wheel bearing after the start of travel, in particular in conjunction with a non-diagnosable wheel bearing, that is, in particular a wheel bearing, in which no storage temperature can be measured, the heater after the start of travel and in dependence on a detected by a detection device driving speed and / or a by means of a detection device detected vehicle acceleration, in particular a lateral acceleration, and / or detected by a detection device steering angle and / or at least one detected by a detection device, the temperature entry via the brake disc defining braking parameters (in particular a brake pressure and / or an ESP intervention) driven and to be activated. In this case, the trigger signal for controlling the heating device supplies either the detection device itself or a device associated therewith, which is, for example, an evaluation device.

As an alternative, the heating device in a vehicle operated in a test bench, in particular in a NEDC (New European Driving Cycle) test, can be activated after the start of the journey if it is detected by means of a detection device, which may be part of the heating device, that the Air conditioning of the vehicle is disabled and / or that no steering movement takes place for a defined period of time after the start of the journey. Here, it is thus concluded via a simplified logic that the vehicle is subjected to a test and accordingly closed to simulate the real driving conditions to a start of the journey, which requires the activation of the heater.

Furthermore, according to a preferred embodiment, at least one temperature-detecting device, in particular at least one temperature sensor, be provided by means of which the ambient temperature and / or a wheel bearing temperature, preferably a lubricant temperature and / or air temperature in the wheel bearing, detected and one, if necessary Part of the heating device forming, evaluation can be supplied. The evaluation device can then enable the activation of the heating device only in the event that the actual ambient temperature is less than a desired ambient temperature associated with the desired lubricant temperature and / or the actual wheel bearing temperature is less than a target wheel bearing temperature assigned to the desired lubricant temperature , Of course, the latter also includes the case that the actual lubricant temperature is less than the desired lubricant temperature or the actual air temperature is less than a desired air temperature. Such a temperature control thus acts only supportive and should prevent that additional heating energy is expended for those cases in which the lubricant or the air in the warehouse already has an optimal operating temperature. Used as redundancy can continue to be avoided with such a temperature detection device and the overheating of the lubricant. If, by means of the evaluation device, it should be ascertained that the lubricant exceeds a certain predetermined critical temperature, then the heating device can also be deactivated by the evaluation device in this case.

While now above all now the activation of the heating element in response to the events or operating parameters that characterize the start of the journey, have been appreciated in detail, and on the one hand with regard to a, preferably immediately before the start of the trip successful activation of the heater as well as in With regard to an activation of the heating device, preferably immediately after the start of the journey, a preferred deactivation possibility of the heating device will now be considered below. Analogously to the activation of the heating device, according to a particularly preferred embodiment, the heating device and thus the at least one heating element controlled by the latter should be deactivated as a function of at least one defined event and / or operating parameter characterizing a travel end. This can be avoided in an energy-saving manner advantageous too long heating the heater, for example, when the end of the journey is already imminent. Thus, for example, according to a particularly preferred embodiment, provision may be made for the heating device to be deactivated at a defined approach to a destination determined, preferably by means of a position and / or navigation data of the vehicle, which detects and evaluates the position determining device. The triggering signal for the deactivation then preferably comes from the position-determining device.

In principle, however, it could also be provided that the heating device is deactivated when a destination is reached, or when the motor is switched off, when a position determining device detects and evaluates, preferably with the aid of a position and / or navigation data of the vehicle.

As an alternative to deactivation in conjunction with an event or operating parameter characterizing a journey end, however, the heating device can also be deactivated in a time-controlled manner in conjunction with a heating program assigned to the heating device, for example the heating device can be deactivated after a defined predetermined heating time. Alternatively or additionally, it can also be provided that the heating device is deactivated when no engine start has taken place within a defined predetermined period of time, for example within 5 to 10 minutes, after activation of the heating device. Further alternatively or optionally additionally, however, the heating device can also be deactivated after a predetermined time interval defined as a function of a detected ambient temperature and / or a travel speed. In the latter case, the time interval is thus calculated variably from existing sensor data.

Alternatively, however, the heating device can also be deactivated when the state of charge of the energy storage device supplying the electrical heating device has reached or falls below a predetermined state of charge threshold value. The trigger signal for the deactivation is then preferably from the energy storage device or a monitoring device associated therewith.

The advantages resulting from the device according to the invention are identical to those of the methodology previously appreciated in detail. In this respect, reference is made to the statements made above.

Although it is mentioned above and in the claims of alternative embodiments and embodiments, it is understood that these can of course be used in any combination with each other, optionally with a corresponding weighting each other, so then, for example, an activation option or a deactivation option takes precedence over another or further activation or deactivation option, which can then form a corresponding redundancy.

The single FIGURE shows schematically and by way of example a half cross section through an arrangement of a rolling bearing designed as a wheel bearing 1 on a wheel hub 2 a vehicle wheel not shown here. Designed as a rolling bearing wheel bearing 1 here includes one of the two bearing-side raceways 3 . 4 forming inner ring 5 and outer ring 6 , Between the raceways 3 . 4 is one of the rolling elements 7 and a not further illustrated lubricant receiving space as a lubricant receiving space 8th provided to the outside with gaskets 9 is sealed.

The wheel bearing 1 is merely exemplary as a double-row roller bearing with two spaced-apart and formed by the rolling elements rows of bearings 10 . 11 educated.

As can further be seen from the single figure, here only by way of example is the lubricant receiving space 8th facing inside of the outer ring 6 a heating element 12 arranged, for example, at least partially or in sections over the outer ring inner circumference extending electrical heating element. This electric heating element 12 is by means of a heater here only schematically illustrated and designed as a control and / or regulating device 13 coupled in such a way (dash-dotted line 14 ) that the heater 13 and thus the controlled by this heating element 12 depending on at least one predefined predetermined and a start of travel characterizing event and / or operating parameters for a predetermined period immediately before or immediately after departure can be activated so that the lubricant immediately after this activation time (for example, 1 to 10 minutes after) and thus after as before immediately before or immediately after the start of the journey has already reached the predetermined target lubricant temperature. Furthermore, the air in the lubricant receiving space or in the bearing can be heated at the desired time immediately before or immediately after the start of the journey, which leads to a reduction of the negative pressure and thus to a reduced seal friction.

An event characterizing the start of the journey may be, for example, a transponder signal derived from a vehicle key 15 be when a person with the vehicle key moves into the receiving area of an associated and not shown vehicle-mounted detection device. The event characterizing the start of the journey may also be the deactivation of an anti-theft device. This can then be a signal 16 to the heater. For further examples, reference is made to the statements made above in the general description part.

For deactivation of the electric heating element 12 For example, an event characterizing a trip end or an operating parameter characterizing a trip end can be used, for example an approach signal determined via a position determination device 17 to a destination. Optionally, alternatively, however, the heating device can also be deactivated in a time-controlled manner, for example, if within a defined predetermined period of time, within for example 5 to 10 minutes, after activation of the heating device 13 no engine start takes place, as with the signal arrow 18 is shown. Again, reference is made to the explanations in the general description part with regard to further alternatives.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• JP 2011/058523 A [0004]

Claims (17)

Method for heating a lubricated wheel bearing ( 1 ), with which a vehicle wheel is rotatably mounted on a vehicle, wherein the wheel bearing ( 1 ) as lubricated rolling bearing with several between bearing side raceways ( 3 . 4 ) rolling rolling elements ( 7 ) is formed, wherein between the raceways ( 3 . 4 ) the rolling elements ( 7 ) and a lubricant receiving space as a lubricant receiving space ( 8th ) is provided, and wherein at least one heating element ( 12 ) is provided, which by means of a designed as a control and / or regulating device heating device ( 13 ) for direct or indirect heating of defined wheel bearing components, in particular of the lubricant accommodating space ( 8th ) received lubricant and / or the air in the lubricant receiving space ( 8th ), is controllable, characterized in that the heating device ( 13 ) and thus controlled by this at least one heating element ( 12 ) is activated as a function of at least one event characterizing a journey start and / or operating parameter for a predetermined period of time before or after the start of the journey, in particular immediately before or immediately after the start of the journey is activated. A method according to claim 1, characterized in that a vehicle-side, possibly part of the heating device ( 13 ), detecting means is provided, by means of which a signal of the detection device associated transmitter unit, in particular a mobile transmitter unit, detected and the heating device ( 13 ), which then sends the at least one heating element ( 12 ) timed before the start of the journey and activated. Method according to Claim 2, characterized in that the signal is an approximation signal of a transmitter unit approaching the vehicle and moving into a reception area of the detection unit, preferably an active or passive transponder as transmitter unit, most preferably an active or passive transponder integrated in a vehicle key as transmitter unit, is. A method according to claim 2, characterized in that the signal is a signal from an operator actively operated transmitter unit, preferably a remote control as a transmitter unit, most preferably a remote control integrated into a vehicle key as a transmitter unit. Method according to claim 1, characterized in that the heating device ( 13 ) when deactivating a theft protection device, in particular when unlocking a door lock and / or deactivating an immobilizer and / or deactivating an alarm system, is activated and activated, in particular controlled and activated by the theft protection device itself. Method according to claim 1, characterized in that the heating device ( 13 ) is activated and activated when activating a parking heater or at a certain time during a charging process of a traction battery of at least partially electrically driven vehicle, in particular in the case of auxiliary heating of the auxiliary heater or in the case of a charging operation of a charging operation monitoring device is controlled and activated. A method according to claim 1, characterized in that one, optionally part of the heating device ( 13 ), driving time evaluation device is provided, by means of which on the basis of over a defined period by the vehicle made trips, at least one usual start of travel is determined, the heater of the travel time evaluation device at a defined predetermined time before such a usual start of driving is activated and activated. Method according to claim 1, characterized in that the heating device ( 13 ) is activated in time-controlled manner by means of a time program assigned to the heating device at a defined point in time before a predetermined, intended start of the journey. Method according to claim 1, characterized in that the heating device ( 13 ) after the start of the journey as a function of a vehicle speed detected by a detection device and / or a vehicle acceleration detected by a detection device, and / or a steering angle detected by a detection device and / or at least one detected by a detection device, the temperature input via the brake disk defining braking parameters, in particular a brake pressure and / or an ESP intervention, is controlled and activated, in particular by the detection device or one of these associated device is activated and activated. Method according to claim 1, characterized in that the heating device ( 13 ) is activated at the start of the journey in a vehicle operated in a test bench, in particular in a NEDC test, when it is detected by means of a detection device, which may be part of the heating device, that the air conditioning system of Vehicle is disabled and / or that no steering movement takes place for a defined period of time after the start of the journey. Method according to one of the preceding claims, characterized in that at least one temperature-detecting device, in particular at least one temperature sensor is provided, by means of the ambient temperature and / or a wheel bearing temperature, preferably a lubricant temperature and / or air temperature in the wheel bearing ( 1 ) and one, possibly part of the heating device ( 13 ), evaluating device is supplied, and that the evaluation device, the activation of the heating device ( 13 ) releases only in the event that the actual ambient temperature is less than a desired ambient temperature associated with the desired lubricant temperature and / or the actual wheel bearing temperature is less than a target wheel bearing temperature associated with the desired lubricant temperature, in particular the actual lubricant temperature is lower is as the target lubricant temperature. Method according to one of the preceding claims, characterized in that the heating device ( 13 ) and thus controlled by this at least one heating element ( 12 ) is deactivated as a function of at least one event and / or operating parameter characterizing a journey end. Method according to claim 12, characterized in that the heating device ( 13 ) is deactivated at a defined, preferably with the help of a position and / or navigation data of the vehicle detecting and evaluating position determining means defined approach to a destination. Method according to claim 12, characterized in that the heating device ( 13 ) is at a, preferably with the aid of a position and / or navigation data of the vehicle detected and evaluated position determining means, reaching a destination or deactivated when stopping the engine. Method according to one of claims 1 to 11, characterized in that the heating device ( 13 ) is deactivated, in particular in connection with a heating program associated with the heating device, and / or that the heating device is deactivated if, within a defined predetermined period of time, in particular within 5 to 10 minutes, after activation of the heating device ( 13 ) no engine start has taken place, and / or that the heating device ( 13 ) is deactivated after a defined predetermined time interval in dependence on a detected ambient temperature and / or a driving speed. Method according to one of claims 1 to 11, characterized in that the heating device ( 13 ) is deactivated when the state of charge of the energy storage device supplying energy to the electric heating device has reached or falls below a predefined state of charge threshold value. Device for carrying out a method for heating a lubricated wheel bearing ( 1 ), in particular a method according to one of the preceding claims, wherein with the wheel bearing ( 1 ) a vehicle wheel is rotatably mounted on a vehicle, wherein the wheel bearing ( 1 ) as lubricated rolling bearing with several between bearing side raceways ( 3 . 4 ) rolling rolling elements ( 7 ) is formed, wherein between the raceways ( 3 . 4 ) the rolling elements ( 7 ) and a lubricant receiving space as a lubricant receiving space ( 8th ) is provided, and wherein at least one heating element ( 12 ) is provided, which by means of a designed as a control and / or regulating device heating device ( 13 ) for direct or indirect heating of defined wheel bearing components, in particular of the lubricant accommodating space ( 8th ) and / or the air in the lubricant receiving space, is controllable, characterized in that the heating device ( 13 ) and thus controlled by this at least one heating element ( 12 ) in response to at least one, a start of travel characterizing event and / or operating parameters for a predetermined period of time before or after driving is activated.

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