Patent Description:
The invention is for instance applicable on working machines within the fields of industrial construction machines or construction equipment, in particular wheel loaders. Although the invention will be described with respect to a wheel loader, the invention is not restricted to this particular machine, but may also be used in other working machines such as articulated haulers, excavators and backhoe loaders.

Nowadays, it may be desired that a vehicle be preconditioned, i.e. set so as to reach a preferred condition when or before the vehicle is intended to be operated. For instance, <CIT> discloses a method for preconditioning various subsystems of an electrified vehicle.

However, there is a need for further improvement relating to vehicle preconditioning.

In view of the above, an object of the present invention is to provide a vehicle comprising a control unit that in an appropriate manner can be used for determining whether or not a vehicle conditioning procedure should be initiated.

This object is achieved by a vehicle according to claim <NUM>.

As such, a first aspect of the present invention relates to a a vehicle. The vehicle comprises a wheel axle fluid circuit adapted to feed wheel axle fluid to one or more wheel axles of the vehicle. The vehicle further comprises a propulsion assembly adapted to propel the vehicle. The vehicle also comprises a control unit.

The control unit is adapted to, on the basis of at least the following:.

determine whether or not a conditioning procedure, during which the temperature of the wheel axle fluid is increased as compared to a present temperature of the wheel axle fluid, should be initiated for the wheel axle fluid.

As used herein, the term "wheel axle fluid" encompasses any fluid that is related to a wheel axle of a vehicle. Purely by way of example, the term "wheel axle fluid" may include one or more of the following: lubricant axel fluid and hydraulic brake fluid.

As such, what the inventors of the present invention have realized is that information associated with a temperature of the wheel axle fluid may be useful information when determining whether or not a conditioning procedure should be initiated. This is since a too cold wheel axle fluid may have an adverse effect on the operation of the vehicle. Purely by way of example, a cold wheel axle fluid, such as a cold lubricant axel fluid, may imply high energy losses when operating the vehicle and such energy losses may be reduced when carrying out the conditioning procedure.

Optionally, the control unit is adapted to determine an energy loss value indicative of energy losses associated with operating the vehicle without initiating the conditioning procedure. The control unit is further adapted to determine a conditioning value indicative of the energy required for the conditioning procedure. The control unit is adapted to determine that the conditioning procedure should be initiated in response to determining that the conditioning value is smaller than the energy loss value.

The conditioning procedure will generally require energy, e.g. energy supplied from a power source of the vehicle. If the vehicle for instance is intended to be operated only a short period after start, it may be unnecessary to initiate the conditioning procedure. As such, the above possibility, in which the conditioning value and the energy loss value are determined and compared, implies a reduced risk in an inappropriate initiation of the conditioning procedure.

Optionally, the control unit is adapted to, in response to determining that the conditioning procedure should be initiated, issue a signal to the vehicle to initiate the conditioning procedure. As such, the control unit may also be adapted to initiate the conditioning procedure.

Optionally, the wheel axle fluid circuit comprises a wheel axle fluid pump arrangement adapted to circulate the wheel axle fluid through the wheel axle fluid circuit. The control unit is adapted to, in response to determining that the conditioning procedure should be initiated, issue a wheel axle fluid pump arrangement control signal to the wheel axle fluid pump arrangement to circulate the wheel axle fluid through the wheel axle fluid circuit to thereby increase the temperature of the wheel axle fluid prior to the expected operation start time of the vehicle.

The temperature of the wheel axle fluid may be increased in a plurality of ways when circulating the same through the wheel axle fluid circuit. Purely by way of example, the temperature may be increased due to friction between the wheel axle fluid and the wheel axle fluid circuit. Other alternatives for increasing the wheel axle fluid temperature are presented hereinbelow.

Optionally, the vehicle comprises a wheel axle fluid heat exchanger. The wheel axle fluid circuit is fluidly connected to the wheel axle fluid heat exchanger such that wheel axle fluid passes through the wheel axle fluid heat exchanger when the wheel axle fluid is circulated through the wheel axle fluid circuit. The control unit is adapted to, in response to determining that the conditioning procedure should be initiated, issue a wheel axle fluid heat exchanger control signal such that the wheel axle fluid heat exchanger adds heat to the wheel axle fluid.

As such, the wheel axle fluid heat exchanger implies an appropriate heating of the wheel axle fluid.

Optionally, the vehicle further comprises a transmission fluid pump as well as a transmission converter, the transmission fluid pump being adapted to feed transmission fluid to the transmission converter, the transmission converter being arranged in relation to the wheel axle fluid heat exchanger such that transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger, the control unit being adapted to, in response to determining that the conditioning procedure should be initiated, issue a transmission fluid pump control signal to the transmission fluid pump such that the transmission fluid pump feeds transmission fluid to the transmission converter as well as to issue a transmission converter control signal to the transmission converter to assume a transmission converter operating condition in which the temperature of the transmission fluid leaving the transmission converter is higher than the temperature of the transmission fluid entering the transmission converter.

As such, the transmission fluid leaving the transmission converter may be used for heating the wheel axle fluid. Moreover, in addition to heating the wheel axle fluid, the increased temperature of the transmission fluid leaving the transmission converter also implies that the transmission converter as such is heated which in turn implies that the transmission converted may operate with reasonable energy losses once the vehicle is operated.

The transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger in a plurality of different ways. Purely by way of example, the transmission fluid leaving the transmission converter may be fed directly to the wheel axle fluid heat exchanger. As such, the transmission fluid leaving the transmission converter can be used directly in the wheel axle fluid heat exchanger.

As another alternative, the vehicle may comprise a transmission fluid heat exchanger being in fluid communication with the transmission converter as well as the wheel axle fluid heat exchanger so as to enable that transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger. As such, heat from the transmission fluid leaving the transmission converter can be used indirectly in the wheel axle fluid heat exchanger.

Optionally, the vehicle comprises a transmission fluid pump power source adapted to power at least the transmission fluid pump. The control unit is adapted to, in response to determining that the conditioning procedure should be initiated, issue a transmission fluid pump power source control signal to the vehicle such that the transmission fluid pump power source feeds energy to the transmission fluid pump.

Optionally, the vehicle comprises an implement fluid circuit with an implement fluid pump. The wheel axle fluid pump arrangement comprises a wheel axle fluid motor and a wheel axle fluid pump. The wheel axle fluid motor is mechanically connected to the wheel axle fluid pump. The implement fluid circuit is connected to the wheel axle fluid pump arrangement such that implement fluid in the implement fluid circuit can power the wheel axle fluid motor. The control unit is adapted to, in response to determining that the conditioning procedure should be initiated, issue an implement fluid pump control signal such that the implement fluid in the implement fluid circuit powers the wheel axle fluid motor.

As such, the implement fluid pump may be used for obtaining a flow in the wheel axle fluid circuit. Moreover, when implement fluid flows in the implement fluid circuit, the temperature thereof increases. The thus heated implement fluid powers the wheel axle fluid motor which implies a heat exchange over the wheel axle fluid pump arrangement, viz from the implement fluid to the wheel axle fluid via the wheel axle fluid motor and the wheel axle fluid pump.

Optionally, the implement fluid circuit comprises a variable implement fluid constriction. The control unit is adapted to, in response to determining that the conditioning procedure should be initiated, issue an implement fluid constriction control signal to the implement fluid constriction such that a flow restriction is imposed on the implement fluid, thereby increasing the temperature of the implement fluid.

The above implies that an appropriate temperature of the implement fluid which in turn implies an appropriate heating of the wheel axle fluid.

Optionally, the vehicle comprises an implement fluid pump power source adapted to power at least the implement fluid pump. The control unit is adapted to, in response to determining that the conditioning procedure should be initiated, issue an implement fluid pump power source control signal to the vehicle such that the implement fluid pump power source feeds energy to the implement fluid pump.

Optionally, a single power source constitutes the transmission fluid pump power source as well as the implement fluid pump power source.

The information associated with the temperature of the wheel axle fluid comprises information as regards a temperature ambient of the vehicle. Information indicative of the ambient temperature may be useful when determining whether or not a conditioning procedure needs to be initiated.

Optionally, the information associated with the temperature of the wheel axle fluid comprises information as regards a temperature of the wheel axle fluid. Information indicative of the temperature of the wheel axle fluid may be useful for determining whether or not a conditioning procedure needs to be initiated. Purely by way of example, information as regards the temperature of the wheel axle fluid may be used for estimating energy losses associated with operating the vehicle without initiating the conditioning procedure as has been discussed hereinabove.

Optionally, the wheel axle fluid circuit comprises a brake fluid circuit adapted to feed brake fluid to one or more brakes of the vehicle.

Optionally, the wheel axle fluid circuit comprises a wheel axle lubricant fluid circuit adapted to feed lubricant fluid to one or more wheel axles of the vehicle.

Optionally, the wheel axle fluid circuit comprises a wheel axle fluid pump arrangement adapted to circulate the wheel axle fluid through the wheel axle fluid circuit.

Optionally, the vehicle comprises a wheel axle fluid heat exchanger. The wheel axle fluid circuit is fluidly connected to the wheel axle fluid heat exchanger such that wheel axle fluid passes through the wheel axle fluid heat exchanger when the wheel axle fluid is circulated through the wheel axle fluid circuit.

Optionally, the vehicle further comprises a transmission fluid pump as well as a transmission converter. The transmission fluid pump is adapted to feed transmission fluid to the transmission converter, the transmission converter being arranged in relation to the wheel axle fluid heat exchanger such that transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger.

Optionally, the vehicle further comprises a transmission fluid heat exchanger being in fluid communication with the transmission converter as well as the wheel axle fluid heat exchanger so as to enable that transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger.

Optionally, the vehicle further comprises a heat exchanger circuit adapted to circulate a heat exchanger fluid between the transmission fluid heat exchanger and the wheel axle fluid heat exchanger.

A second aspect of the present invention relates to a method for controlling a wheel axle fluid circuit of a vehicle. The wheel axle fluid circuit is adapted to feed wheel axle fluid to one or more wheel axles of the vehicle. The vehicle further comprises a propulsion assembly adapted to propel the vehicle, wherein the method comprises, on the basis of at least the following:.

determining whether or not a conditioning procedure, during which the temperature of the wheel axle fluid is increased as compared to a present temperature of the wheel axle fluid, should be initiated for the wheel axle fluid.

Optionally, the method further comprises determining an energy loss value indicative of energy losses associated with operating the vehicle without initiating the conditioning procedure. The method further comprises determining a conditioning value indicative of the energy required for the conditioning procedure. The method comprises determining that the conditioning procedure should be initiated in response to determining that the conditioning value is smaller than the energy loss value.

Optionally, the method further comprises, in response to determining that the conditioning procedure should be initiated, initiating the conditioning procedure.

Optionally, the wheel axle fluid circuit comprises a wheel axle fluid pump arrangement adapted to circulate the wheel axle fluid through the wheel axle fluid circuit. The method comprises, in response to determining that the conditioning procedure should be initiated, circulating the wheel axle fluid through the wheel axle fluid circuit to thereby increase the temperature of the wheel axle fluid prior to the expected operation start time of the vehicle.

Optionally, the vehicle comprises a wheel axle fluid heat exchange. The wheel axle fluid circuit is fluidly connected to the wheel axle fluid heat exchanger such that wheel axle fluid passes through the wheel axle fluid heat exchanger when the wheel axle fluid is circulated through the wheel axle fluid circuit. The method comprises, in response to determining that the conditioning procedure should be initiated, controlling the wheel axle fluid heat exchanger such that the wheel axle fluid heat exchanger adds heat to the wheel axle fluid.

Optionally, the vehicle further comprises a transmission fluid pump as well as a transmission converter. The transmission fluid pump is adapted to feed transmission fluid to the transmission converter. The transmission converter is arranged in relation to the wheel axle fluid heat exchanger such that transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger. The method comprises, in response to determining that the conditioning procedure should be initiated, operating the transmission fluid pump to feed transmission fluid to the transmission converter as well as operating the transmission converter so as to assume an operating condition in which the temperature of the transmission fluid leaving the transmission converter is higher than the temperature of the transmission fluid entering the transmission converter.

Optionally, the vehicle further comprises a transmission fluid heat exchanger being in fluid communication with the transmission converter as well as the wheel axle fluid heat exchanger so as to enable that transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger. The method comprises feeding the transmission fluid leaving the transmission converter to the transmission fluid heat exchanger.

Optionally, the vehicle further comprises a transmission fluid pump power source adapted to power at least the transmission fluid pump. The method comprises, in response to determining that the conditioning procedure should be initiated, operating the transmission fluid pump power source so as to feed energy to the transmission fluid pump.

Optionally, the vehicle comprises an implement fluid circuit with an implement fluid pump. The wheel axle fluid pump arrangement comprises a wheel axle fluid motor and a wheel axle fluid pump. The wheel axle fluid motor is mechanically connected to the wheel axle fluid pump. The implement fluid circuit is connected to the wheel axle fluid pump arrangement such that implement fluid in the implement fluid circuit can power the wheel axle fluid motor. The method comprises, in response to determining that the conditioning procedure should be initiated, operating the implement fluid pump such that the implement fluid in the implement fluid circuit powers the wheel axle fluid motor.

Optionally, the implement fluid circuit comprises a variable implement fluid constriction. The method comprises, in response to determining that the conditioning procedure should be initiated, controlling the variable implement fluid constriction such that a flow restriction is imposed on the implement fluid, thereby increasing the temperature of the implement fluid.

Optionally, the vehicle comprises an implement fluid pump power source adapted to power at least the implement fluid pump. The method comprises, in response to determining that the conditioning procedure should be initiated, operating the implement fluid pump power source so as to feed energy to the implement fluid pump.

The information associated with the temperature of the wheel axle fluid comprises information as regards a temperature ambient of the vehicle.

Optionally, the information associated with the temperature of the wheel axle fluid comprises information as regards a temperature of the wheel axle fluid.

Optionally, the vehicle further comprises a transmission fluid pump as well as a transmission converter, the transmission fluid pump being adapted to feed transmission fluid to the transmission converter. The transmission converter is arranged in relation to the wheel axle fluid heat exchanger such that transmission fluid leaving the transmission converter can be used as a heat source for the wheel axle fluid heat exchanger.

With reference to the appended drawings, below follows a more detailed description of embodiments of the invention cited as examples, wherein:.

The present invention will now be described hereinafter with reference to the accompanying drawings, in which exemplary embodiments of the invention are shown. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiment set forth herein; rather, the embodiment is provided for thoroughness and completeness.

<FIG> illustrates an embodiment of a vehicle <NUM>. In <FIG>, the vehicle <NUM> is exemplified as a working machine. More specifically, the <FIG> vehicle <NUM> is a wheel loader. However, other embodiments of the vehicle are also envisaged. Purely by way of example, the vehicle may an articulated hauler, an excavator and or a backhoe loader (not shown).

The <FIG> vehicle further comprises a set of wheel pairs <NUM>, <NUM>. Each wheel pair <NUM>, <NUM> is connected to a body of the vehicle <NUM> via a wheel axle <NUM>, <NUM>. Moreover, illustrated in <FIG>, the vehicle <NUM> further comprises a control unit <NUM>.

<FIG> schematically illustrates components of a vehicle <NUM>, such as the <FIG> vehicle <NUM>. <FIG> illustrates that that the components comprise the control unit <NUM>. The control unit <NUM> may issue instructions to one or more components of the vehicle <NUM>. However, for the sake of clarity, <FIG> and <FIG> do not illustrate each possible information or instruction connection between the control unit <NUM> and the related component or components of the vehicle <NUM>.

Furthermore, <FIG> illustrates that the vehicle <NUM> comprises a wheel axle fluid circuit <NUM> adapted to feed wheel axle fluid to one or more wheel axles (not shown in <FIG>) of the vehicle <NUM>. For the sake of clarity, the wheel axle fluid circuit <NUM> is illustrated by unbroken lines in <FIG>.

As used herein, the term "wheel axle fluid" encompasses any fluid that is related to a wheel axle of a vehicle. Purely by way of example, the term "wheel axle fluid" may include on or more of the following: lubricant axel fluid and hydraulic brake fluid.

A lubricant axel fluid is used for lubricating one or more components, such as bearings, engaging with the wheel axle. For instance, a lubricant axle fluid may be used for lubricating bearings supporting the wheel axle.

A hydraulic brake fluid may be used for actuating brakes for wheels connected to the wheel axle. Alternatively, a hydraulic brake fluid may be used for braking directly a wheel axle.

Moreover, the vehicle <NUM> further comprises a propulsion assembly <NUM> adapted to propel the vehicle <NUM>. In the <FIG> embodiment, the propulsion assembly comprises a power source <NUM>. Purely by way of example, the power source <NUM> may comprise, or be constituted by, an internal combustion engine, an electric motor, a fuel cell arrangement or the like.

The control unit <NUM> is adapted to use information indicative of the propulsion assembly being inactive <NUM>. Purely by way of example, and as indicated in <FIG>, the control unit <NUM> may be adapted to receive a signal from the power source <NUM>, which signal is indicative of whether or not the power source is running.

Moreover, the control unit <NUM> is adapted to use information indicative of an expected time range until an expected operation start time of the vehicle. To this end, though purely by way of example, the control unit <NUM> may be adapted to receive information from an external transmitter <NUM> indicative of such an expected time range. As a non-limiting example, the external transmitter may be adapted to communicate with the control unit <NUM> via wireless signals. As another non-limiting example, the control unit <NUM> may be adapted to determine the expected time range on the bases of previously planned or previously executed operating schedules performed by the vehicle <NUM>.

Moreover, the control unit <NUM> is adapted to use information associated with a temperature of the wheel axle fluid. As a non-limiting example, the information associated with the temperature of the wheel axle fluid comprises information as regards a temperature ambient of the vehicle. To this end, though purely by way of example, the control unit <NUM> may be adapted to receive information from an ambient temperature information supplier <NUM>. The ambient temperature information supplier <NUM> may for instance comprise a temperature sensor connected to the vehicle <NUM>. As another non-limiting example, the ambient temperature information supplier <NUM> may comprise a link to a weather station, a weather forecast service, or the like.

Instead of, or in addition to, using information as regards a temperature ambient of the vehicle, the information associated with the temperature of the wheel axle fluid may comprise information as regards a temperature of the wheel axle fluid. As such, though purely by way of example, the control unit <NUM> may be adapted to receive information from a wheel axle fluid temperature sensor <NUM>.

The control unit <NUM> is adapted to, on the basis of at least the above information, determine whether or not a conditioning procedure, during which the temperature of the wheel axle fluid is increased as compared to a present temperature of the wheel axle fluid, should be initiated for the wheel axle fluid.

As a non-limiting example, the control unit <NUM> may be adapted to determine an energy loss value indicative of energy losses associated with operating the vehicle <NUM> without initiating the conditioning procedure. Using the above-mentioned lubricant axel fluid as a non-limiting example of the wheel axle fluid, the control unit <NUM> may be adapted to determine the energy loss value indicative of energy losses associated with operating the vehicle <NUM> with relatively cold, and thus less viscous, lubricant axel fluid.

Moreover, the control unit <NUM> may further be adapted to determine a conditioning value indicative of the energy required for the conditioning procedure. Using the lubricant axel fluid again as a non-limiting example, the control unit <NUM> may be adapted to determine a conditioning value indicative of the energy required for heating the lubricant axel fluid to a desired temperature.

Additionally, though purely by way of example, the control unit <NUM> may be adapted to determine that the conditioning procedure should be initiated in response to determining that the conditioning value is smaller than the energy loss value.

Irrespective of how the control unit <NUM> is adapted to determine whether or not a conditioning procedure should be initiated, the control unit <NUM> may be adapted to, in response to determining that the conditioning procedure should be initiated, issue a signal to the vehicle <NUM> to initiate the conditioning procedure. Presented hereinbelow are various examples of how the conditioning procedure could be carried out.

<FIG> illustrates that the wheel axle fluid circuit comprises a wheel axle fluid pump arrangement <NUM> adapted to circulate the wheel axle fluid through the wheel axle fluid circuit <NUM>. As a non-limiting example, the wheel axle fluid pump arrangement <NUM> may be adapted to be powered by an external power source (not shown in <FIG>).

The control unit <NUM> may be adapted to, in response to determining that the conditioning procedure should be initiated, issue a wheel axle fluid pump arrangement control signal to the wheel axle fluid pump arrangement <NUM> to circulate the wheel axle fluid through the wheel axle fluid circuit <NUM> to thereby increase the temperature of the wheel axle fluid prior to the expected operation start time of the vehicle.

The temperature of the wheel axle fluid may increase by the circulation in the wheel axle fluid circuit <NUM> alone. However, as a non-limiting example, the vehicle <NUM> may comprise a wheel axle fluid heat exchanger <NUM>. The wheel axle fluid circuit <NUM> is fluidly connected to the wheel axle fluid heat exchanger <NUM> such that wheel axle fluid passes through the wheel axle fluid heat exchanger <NUM> when the wheel axle fluid is circulated through the wheel axle fluid circuit <NUM>. The control unit <NUM> may adapted to, in response to determining that the conditioning procedure should be initiated, issue a wheel axle fluid heat exchanger control signal <NUM> such that the wheel axle fluid heat exchanger <NUM> adds heat to the wheel axle fluid.

The axle fluid heat exchanger <NUM> may add heat to the wheel axle fluid in a plurality of different ways. To this end, <FIG> illustrates a non-limiting example in which the vehicle <NUM> further comprises a transmission fluid pump <NUM> as well as a transmission converter <NUM>. The transmission fluid pump <NUM> is adapted to feed transmission fluid to the transmission converter <NUM>. Moreover, the transmission converter <NUM> is arranged in relation to the wheel axle fluid heat exchanger <NUM> such that transmission fluid leaving the transmission converter <NUM> can be used as a heat source for the wheel axle fluid heat exchanger <NUM>.

In the <FIG> embodiment, the transmission converter <NUM> is arranged in relation to the wheel axle fluid heat exchanger <NUM> such that fluid leaving the transmission converter <NUM> is fed to the wheel axle fluid heat exchanger <NUM>. As such, in the <FIG> embodiment, the heat in the fluid leaving the transmission converter <NUM> is directly used for heating the wheel axle fluid heat exchanger <NUM>. However, it is also envisaged that the heat in the fluid leaving the transmission converter <NUM> may indirectly be used for heating the wheel axle fluid heat exchanger <NUM>. An example of such an indirect heating is discussed hereinbelow with reference to <FIG>.

Irrespective of whether the leaving the transmission converter <NUM> is directly or indirectly used for heating the wheel axle fluid heat exchanger <NUM>, the control unit <NUM> is adapted to, in response to determining that the conditioning procedure should be initiated, issue a transmission fluid pump control signal to the transmission fluid pump <NUM> such that the transmission fluid pump feeds transmission fluid to the transmission converter as well as to issue a transmission converter control signal to the transmission converter <NUM> to assume a transmission converter operating condition in which the temperature of the transmission fluid leaving the transmission converter is higher than the temperature of the transmission fluid entering the transmission converter.

As such, the transmission fluid leaving the transmission converter <NUM> may be used for heating the wheel axle fluid, e.g. via the wheel axle fluid heat exchanger <NUM>.

Moreover, in the <FIG> embodiment, the vehicle <NUM> comprises a transmission fluid pump power source <NUM> adapted to power at least the transmission fluid pump <NUM>. In fact, the <FIG> embodiment of the vehicle <NUM> comprises a power source <NUM> that is used to power at least the transmission fluid pump <NUM> as well as to power other components, as will be discussed further hereinbelow.

The control unit <NUM> may be adapted to, in response to determining that the conditioning procedure should be initiated, issue a transmission fluid pump power source control signal to the vehicle <NUM> such that the transmission fluid pump power source <NUM> feeds energy to the transmission fluid pump <NUM>.

As also illustrated in <FIG>, the vehicle may comprise an implement fluid circuit <NUM> - indicated by broken lines in <FIG> - with an implement fluid pump <NUM>. Moreover, as exemplified in <FIG>, the wheel axle fluid pump arrangement <NUM> may comprise a wheel axle fluid motor <NUM> and a wheel axle fluid pump <NUM>. The wheel axle fluid motor <NUM> is mechanically connected to the wheel axle fluid pump <NUM>.

The implement fluid circuit <NUM> is connected to the wheel axle fluid pump arrangement <NUM> such that implement fluid in the implement fluid circuit can power the wheel axle fluid motor <NUM>. The control unit <NUM> is adapted to, in response to determining that the conditioning procedure should be initiated, issue an implement fluid pump control signal <NUM> such that the implement fluid in the implement fluid circuit powers the wheel axle fluid motor <NUM>. Thus, the implement fluid pump <NUM> may be used for obtaining a flow in the wheel axle fluid circuit <NUM>. Moreover, when implement fluid flows in the implement fluid circuit <NUM>, the temperature thereof increases. The thus heated implement fluid powers the wheel axle fluid motor <NUM> which implies a heat exchange over the wheel axle fluid pump arrangement <NUM>, viz from the implement fluid to the wheel axle fluid via the wheel axle fluid motor <NUM> and the wheel axle fluid pump <NUM>.

Purely by way of example, the temperature of the implement fluid may be further increased. To this end, though purely by way of example, the implement fluid circuit <NUM> may comprise a variable implement fluid constriction <NUM>. As a non-limiting example, the variable implement fluid constriction <NUM> may be a valve with a variable opening percentage. Moreover, the control unit <NUM> may be adapted to, in response to determining that the conditioning procedure should be initiated, issue an implement fluid constriction control signal to the implement fluid constriction <NUM> such that a flow restriction is imposed on the implement fluid, thereby increasing the temperature of the implement fluid.

Furthermore, as illustrated in <FIG>, the vehicle comprises an implement fluid pump power source adapted to power at least the implement fluid pump <NUM>. In the <FIG> embodiment, a single power source <NUM> constitutes the implement fluid pump power source as well as the previously discussed transmission fluid pump power source. However, it is also envisaged that embodiments of the vehicle <NUM> may comprise a separate implement fluid pump power source (not shown in <FIG>).

Irrespective of the implementation of the implement fluid pump power source, the control unit <NUM> may be adapted to, in response to determining that the conditioning procedure should be initiated, issue an implement fluid pump power source control signal to the vehicle <NUM> such that the implement fluid pump power source <NUM> feeds energy to the implement fluid pump <NUM>.

<FIG> illustrates another embodiment of the vehicle <NUM> according to the present invention. The <FIG> embodiment comprises a plurality of components that are similar to the <FIG> embodiment.

However, as compared to the <FIG> embodiment, the <FIG> vehicle <NUM> further comprises a transmission fluid heat exchanger <NUM> being in fluid communication with the transmission converter <NUM> as well as the wheel axle fluid heat exchanger <NUM> so as to enable that transmission fluid leaving the transmission converter <NUM> can be used as a heat source for the wheel axle fluid heat exchanger <NUM>. Purely by way of example, and as illustrated by broken lines in <FIG>, the vehicle <NUM> may comprise a heat exchanger circuit <NUM> adapted to circulate a heat exchanger fluid between the transmission fluid heat exchanger <NUM> and the wheel axle fluid heat exchanger <NUM>. Moreover, the <FIG> vehicle comprises a transmission fluid circuit <NUM>, illustrated by dashed and dotted lines in <FIG>, fluidly connecting the transmission fluid pump <NUM>, the transmission converter <NUM> and the transmission fluid heat exchanger <NUM>.

While the above description and examples of the present invention relates to the control unit <NUM> and the vehicle <NUM>, it should be noted that the description should also be regarded as a presentation of the method according to the present invention.

As such, the present invention also relates to a method for controlling a wheel axle fluid circuit <NUM> of a vehicle <NUM>. The wheel axle fluid circuit <NUM> is adapted to feed wheel axle fluid to one or more wheel axles <NUM>, <NUM> of the vehicle <NUM>. The vehicle <NUM> further comprises a propulsion assembly <NUM> adapted to propel the vehicle, wherein the method comprises, on the basis of at least the following:.

Claim 1:
A vehicle (<NUM>), preferably a working machine, comprising a wheel axle fluid circuit (<NUM>) adapted to feed wheel axle fluid to one or more wheel axles (<NUM>, <NUM>) of said vehicle (<NUM>), said vehicle (<NUM>) comprising a control unit (<NUM>), said vehicle (<NUM>) comprising a wheel axle fluid circuit (<NUM>) adapted to feed wheel axle fluid to one or more wheel axles (<NUM>, <NUM>) of said vehicle (<NUM>), said vehicle (<NUM>) further comprising a propulsion assembly (<NUM>) adapted to propel said vehicle (<NUM>), said control unit (<NUM>) being adapted to, on the basis of at least the following:
- information indicative of said propulsion assembly (<NUM>) being inactive,
- information indicative of an expected time range until an expected operation start time of said vehicle (<NUM>), and
- information associated with a temperature of said wheel axle fluid,
determine whether or not a conditioning procedure, during which the temperature of said wheel axle fluid is increased as compared to a present temperature of said wheel axle fluid, should be initiated for said wheel axle fluid, characterized in that said information associated with the temperature of said wheel axle fluid comprises information as regards a temperature ambient of said vehicle (<NUM>).