Patent Description:
In the event of a failure associated with the wheel end, such as a bearing failure or brake failure, elements of the wheel end can reach high temperatures very quickly. Such high temperatures may cause tires and/or lubricant to ignite, resulting in wheel lock up or fire. Due to the intense heat caused by a wheel end failure, the wheel end may detach from the axle.

There remains a need for a system for monitoring the wheel end assembly temperature and collecting data on the temperature for immediate and long-term evaluation.

<CIT> discloses a wireless sensor for a wheel end assembly of a heavy-duty vehicle. The wheel end assembly includes a wheel hub and a hub cap mounted on the wheel hub. The sensor includes mounting means disposed in the hub cap. Sensing means are mounted on the mounting means to sense at least one condition of the vehicle. A processor is mounted on the mounting means and is electrically connected to the sensing means to process data from the sensing means. Communication means are mounted on the mounting means and are electrically connected to the processor to communicate the processed data to a user. An electrical energy storage device is mounted on the mounting means and is electrically connected to the sensing means, the processor and the communication means, enabling the sensor to be independent from the vehicle power supply. The sensor also accommodates components of a tire inflation system.

<CIT> discloses wheel end assembly rotatable on an axle on a vehicle having a high temperature warning system. An air pressure supply is positioned inside the axle and connected to a pressure source on the vehicle. A normally closed valve is connected to the axle between the inside and outside of the pressure supply. A heat sensitive control is connected to and actuates said valve upon a predetermined temperature. The control is mounted on the axle adjacent to the wheel end assembly for measuring the temperature of the assembly and axle. A warning system is connected to the pressure supply for actuation upon opening of the valves. The heat sensitive control includes a heat sensitive pressure barrier.

Further aspects and preferred embodiments of the invention are defined in the dependent claims. Any aspects, embodiments and examples of the present disclosure which do not fall under the scope of the appended claims are provided for illustrative purposes.

In some embodiments, a wheel end high-temperature warning system for a vehicle having a wheel-end assembly mounted to an axle is described. The system may include a temperature sensor including a sensor head configured for mounting at a spindle section of an axle near or in the wheel end assembly, the sensor head being in a heat exchange relationship with a bearing or other component of the wheel-end assembly. The system may further include a transmitter disposed on the axle to which the wheel-end assembly is mounted, the transmitter being configured to receive a sensor signal from the temperature sensor indicative of a wheel-end temperature and transmit the signal to a receiver. A vehicle data acquisition module may be coupled to the receiver, the data acquisition module being programmed to receive the sensor signal and process the signal to determine a temperature determined at the spindle. The vehicle data acquisition module may further include a display to provide a digital indication of the temperature and identify the particular wheel-end assembly associated with the temperature. The data acquisition module may further be configured to compare the detected temperature to a threshold temperature and to initiate one or more alarms if the temperature exceeds the threshold temperature. For example, the transmitter may be configured to send a high-temperature alert to a driver mobile device or fleet operator computer or other recipient by text message or email when the temperature sensor detects a temperature above a temperature threshold. The temperature threshold may be a temperature past which the wheel end is at risk of fire or failure of components, such as bearing seals.

It is an objective of some embodiments herein to provide diagnostic information pertaining to the temperature of a wheel end assembly to a system user. For example, one or more alerts or alarm faults may be initiated when one or more wheel-end assembly components reach a threshold temperature or other threshold condition. Systems herein may further identify characteristics of wheel end temperature associated with one or more alerts or alarm faults. For example, systems herein may be used to readily identify a particular wheel-end assembly initiating a fault, such as using an in-cab display included in a data acquisition module. Data acquisition modules herein may further provide an accurate digital reading of a measured temperature of the wheel end of a vehicle or component parts thereof. In some embodiments, a plurality of temperature measurements may be made using temperature probes mounted at different positions within a wheel-end assembly of a vehicle. Such information may provide for a reliable warning of a high temperature condition. Additionally, diagnostic information may be accessed by a user and used to help diagnose whether any vehicle components may be damage, should any such damage have occurred.

It is an objective of some embodiments herein to provide for an accurate measurement of temperature of components of a wheel-end assembly of a vehicle. In some of those embodiments, a sensor head of a an electrical temperature sensor may be positioned in contact with a component of a wheel-end assembly of a vehicle. The sensor head may route an electrical signal generated therein to circuitry of the sensor positioned away from or external to the wheel-end assembly. The electrical signal and a reference signal may then be used to generate a digital signal indicative of temperature. In some embodiments, more than one sensing heads may be positioned on or near more than one component or region of a wheel-end assembly of a vehicle. For example, each of a first sensor and a second sensor may be positioned within a wheel-end assembly of a vehicle. At least one of the first and second sensors may include a sensor head in a heat exchange relationship with the bearings of a wheel-end assembly.

As may be seen in <FIG>, a vehicle <NUM> may comprise a truck <NUM> and a trailer <NUM>. The truck <NUM> may include one or more drive axles <NUM> as part of the vehicle's powertrain. The truck <NUM> may further include a steer axle <NUM> having pivoting hubs that provide steering capability for the vehicle <NUM>. The trailer <NUM> may include one or more fixed axles (not shown) and wheel ends. Each axle may have one or more wheels <NUM> mounted thereto with a tire <NUM> mounted to each wheel <NUM>. Of course, other types of steerable vehicles, such as cars and buses may be provided with the high temperature warning system disclosed herein.

The vehicle <NUM> may be provided with a pressurized air supply (not shown) used to provide pressurized air to an optional automatic tire inflation system (indicated with air hoses <NUM>). The high-temperature warning system (shown in more detail in <FIG>) may warn a driver when an axle <NUM> and/or axle wheel-end assembly reaches a predetermined temperature threshold or other threshold. A digital display of one or more measured temperatures, such as for a specific wheel-end assembly, may further be displayed. Such an axle and/or wheel-end assembly may be of a steerable or fixed configuration.

As may be seen in <FIG> and <FIG>, a wheel-end assembly <NUM> (which may also be referred to herein as a wheel end) may be mounted to a spindle section <NUM> of an axle <NUM> and comprise a hub <NUM>, bearings <NUM> on which the hub may rotate around an axle, a brake drum <NUM>, a wheel (not shown) and a tire (not shown). The spindle <NUM> may be unsealed, or may be sealed at the time of manufacture, or may accept a plug <NUM> to seal the spindle. Plug <NUM> may, for example, be a press plug which may sealingly engage the inside of the axle <NUM> or spindle section <NUM> thereof and may be held in place by an interference fit without requiring additional mechanical means for locking the plug <NUM> in place. The plug <NUM> may provide a pressure barrier to contain the pneumatic pressure within the axle and may engage and support a stator of a rotary air connection, such as may be used in an automatic tire inflation system. Such an example of a rotary connection is described in more detail in connection with <FIG>. Alternatively, a wheel-end assembly may include a plug <NUM> that does not seal the axle <NUM>. In this disclosure, a plug <NUM> that is not required to seal an axle may also be referred to as a sensor mounting plate. In some embodiments, a plug <NUM> (or sensor mounting plate) may be positioned within a spindle section <NUM> of an axle <NUM> and made of a material suitable to ensure that a sensor head mounted to the sensor mounting plate is in a heat exchange relationship with one or both of the bearings <NUM>. For example, a plug or mounting plate may be made of a carbon alloy steel or other suitable material and may be positioned approximate the bearings <NUM>. If the bearings <NUM>, brake drum <NUM>, or other wheel end component fail, then such failure may cause a high temperature event such that a tire or the wheel end lubricant may catch fire. In some instances, bearings have been known to reach a high enough temperature that the bearings melt. A wheel end temperature monitoring system may allow an operator to identify the onset of such a situation before such a critical hazard level is achieved at the wheel end.

As may be seen in the embodiment of <FIG>, a wheel end temperature monitoring system <NUM> may comprise a first electrical temperature sensor or temperature transducer <NUM> disposed at or near the wheel end <NUM> and a transmitter <NUM> disposed on the axle <NUM> so as to monitor local temperatures in the wheel end <NUM>. In some embodiments, the wheel end temperature monitoring system <NUM> may also include a receiver <NUM> and a dedicated vehicle data collection system or computer <NUM> coupled thereto. The data collection system or computer <NUM> may be specifically programmed to process one or more temperature signals, initiate one or more alerts or alarms and/or display temperature data. A temperature signal may also be conditioned so that a transmitter <NUM> may send the temperature signal to an otherwise programmable computer of a vehicle data collection system or other data collection system, such as may be external to a vehicle.

In the embodiment shown in <FIG>, the axle <NUM> may be sealed by a plug <NUM> so as to permit pressurization of the axle <NUM> for a tire inflation system. The temperature sensor <NUM> may be a thermocouple that is disposed in the plug <NUM> adjacent to the centerline of an outboard spindle face <NUM> so as to allow the rotary union <NUM> of a tire inflation system to be fitted at the centerline of the spindle face. Advantageously, temperature sensors such as thermocouples used herein may operate at relatively extreme temperatures and over an extended temperature range. For example, the sensors shown in <FIG> may operate over a wide temperature range, such as a temperature range of about -<NUM> degrees Celsius to about <NUM> degrees Celsius.

As shown in <FIG>, a temperature sensor <NUM> may be a thermocouple having a protective sheath <NUM> enclosing a pair of wires <NUM>. The pair of wires <NUM> may terminate at a sensor head <NUM> of the sensor <NUM>. The sensing head comprises dissimilar materials as is known in the thermocouple art. A thermo-electric current or voltage (which may be referred to as a thermo-electric signal) may be generated which depends on the composition of the two dissimilar materials and the temperature. The temperature sensor <NUM> may include also include a reference junction <NUM>, such as may include one or more component sensors for measurement of a reference temperature. A voltmeter <NUM> may be integrally included in the temperature sensor <NUM> or circuitry for voltage measurement may be externally coupled to the temperature sensor <NUM>.

As shown in each of <FIG>, the sensor head <NUM> may include a threaded portion <NUM> to facilitate mounting of the sensor <NUM>. For example, the sensor <NUM> may be attached to the spindle <NUM> or a plug or other wheel end component using a threaded portion <NUM> of the sensor head <NUM>. The protective sheath <NUM> may insulate the pair of wires <NUM> and protect components of the sensor <NUM> from wear. For example, protective sheath <NUM> may be a highly durable and temperature resistant steel-braid to protect the pair of wires <NUM>, which may otherwise be subject to considerable friction and wear, particularly when the sensor head <NUM> is mounted within the spindle section <NUM> of an axle <NUM> and wherein at least a portion of the wires <NUM> may be otherwise be subject to severe conditions during vehicle operation.

As shown in <FIG>, a temperature sensor <NUM> may include a sensor head <NUM> that is configured for mounting by use of a fastener. For example, the sensor head <NUM> may include a ring eyelet <NUM> configured for mounting the sensor <NUM>. A socket head cap screw <NUM> or other suitable screw or fastener may be inserted through the opening of the ring eyelet <NUM> and used for mounting the sensor <NUM>, such as to the spindle <NUM> (e.g., mounted to the spindle face <NUM>) or to another wheel-end structure, such as a plug <NUM> (as also shown and in <FIG>). Other wheel-end locations for mounting a sensor <NUM>, such as may be used to position a sensing head or probe region of the sensor <NUM> on or near a component for temperature monitoring, may include the hub <NUM>, hub lugs, brake system body <NUM>, and a hubcap. For mounting to wheel end components that rotate with respect to the axle, a rotary electrical coupling may be used to connect the sensor head and transmitter by wired connection.

A temperature sensor <NUM> may monitor the local temperature of a component to which the sensor is attached. In some embodiments, a temperature sensor may contain more than one sensing head or probe. Thus, each of a plurality of sensing heads or probes may be inserted into an associated component for temperature monitoring. The temperature sensor may then monitor the internal temperature or adjacent temperature of more than one component or associated regions of a wheel end so as to provide a more accurate temperature profile of a desired region. For example, a difference in temperature between two or more components of a wheel end may provide for sensitive detection of a fault condition or otherwise serve other diagnostic functions, such as to indicate that one or more sensors or probes of a sensor may be damaged and need to be replaced.

The system <NUM> may include a transmitter <NUM> electrically coupled to the temperature sensor <NUM>. Such coupling may be wired or wireless and may permit communication of a temperature signal from the temperature sensor to the transmitter <NUM>. For example, a wired connection between the transmitter <NUM> and the temperature sensor <NUM> may be used when the transmitter <NUM> is attached to the axle <NUM>, or other suitable locations. Where a wireless link is established between the transmitter <NUM> and temperature sensor <NUM>, the transmitter may be located near but outside of a wheel-end assembly, such as on the axle or another suitable location of a vehicle frame. In some embodiments, a transmitter <NUM> may be integrally linked to the temperature sensor <NUM>, such as included in a common housing together with other components of the temperature sensor <NUM>. The transmitter <NUM> may be disposed on the axle <NUM> at a distance from the wheel-end assembly <NUM> such that heat generated therein does not pose a hazard to the electronics or housing of the transmitter <NUM>, thus avoiding potential damage from high wheel-end temperatures, mechanical impact and lubricants. In some embodiments, the pair of wires <NUM> may be sized in length so as to enable positioning of the reference junction <NUM> at a suitable distance from the sensor head <NUM>. For example, either or both of a reference junction <NUM> and voltage measurement circuitry (e.g., voltmeter <NUM>) may be positioned at a distance from the wheel-end assembly <NUM>, such as on axle <NUM>. The transmitter <NUM> may be coupled to the axle <NUM> through a tapped hole in the axle or at or near the mid-point of a non-tapped bore into the axle.

While a threaded connection may be preferred for connecting the sensor <NUM> and transmitter <NUM> to the spindle and axle, other means of mechanically joining the components may be utilized. Welding, gluing, and strapping are some examples of possible coupling methods other than a threaded connection. For example, in some embodiments, a sensor head <NUM> may be attached to a wall of the spindle section <NUM> via a threaded connection and in some situations additionally glued or fixed therein so that a sensing junction of the head <NUM> is in intimate contact with the wall of the spindle section <NUM>. Such a connection may help to ensure that the sensor head <NUM> and thermo-electric junction therein are in a heat exchange relationship with the bearings <NUM> or other component of the wheel-end assembly.

The transmitter <NUM> may be able to send collected signal data to a data acquisition module <NUM> of a wheel end high-temperature warning system. In some embodiments, the data acquisition module <NUM> may be part of another vehicle data collection and/or processing system, such as a processing module for a tire inflation system. By way of nonlimiting example, a data collection module <NUM> may be part of another data processing or collection system such as a tire pressure monitoring system, an anti-lock braking system (ABS), a telematics system, or other onboard or attached vehicle system. Likewise, the transmitter <NUM> may also be shared among two or more different data collection systems. In some embodiments, a transmitter <NUM> may include a processor, such as may include one or more memory buffers. The processor may, at least temporarily, store data from signals received from different vehicle systems and selectively send signals in a desired manner as may be needed for further processing. Such a processor may be programmed to direct transmission of temperature signal data at a predetermined rate or frequency. And, in some embodiments, that rate or frequency of transmission of temperature signal data may be adjusted based on characteristics of one or more input signals. For example, if a temperature signal is received from a temperature sensor <NUM>, and the signal indicates that one or more wheel end components may be near a temperature limit, a rate of data transmission may be adjusted. To that aim, a processor included in the transmitter <NUM> may be capable of performing at least a rudimentary analysis of signals to compare the signals to one or more specification limits. Accordingly, if a wheel-end assembly is within acceptable boundaries (e.g., within normal specification limits for vehicle operation) temperature data may be transmitted to the data acquisition module <NUM> at a low rate. If signal changes to indicate that the temperature of a wheel-end assembly may be closer to an alarm threshold, a rate of data transmission may be increased.

In some embodiments, either or both of receiver <NUM> and/or transmitter <NUM> may be configured for two-way communication. For example, receiver <NUM> may be readily accessed by the data acquisition module <NUM>, which may include a more sophisticated processor for analysis of temperature data. Data acquisition module <NUM> may be configured to send a signal using receiver <NUM> (if appropriately configured for two-way communication) to instruct appropriately configured transmitter <NUM> to increase or decrease a rate of signal transmission. Thus, signal data may be selectively transmitted when one or more fault conditions may be most likely. Accordingly, energy used in transmission of signal data may be conserved.

In some embodiments, the transmitter <NUM> may have an internal power supply. Such a power supply may be a battery, dynamo, or other energy storage or energy producing device. The transmitter may communicate with the data collection system through a wireless protocol and methodology. Alternately, the transmitter may be powered by a separate power source through a wired connection. For example, the transmitter <NUM> may be connected to the vehicle main electrical system or other vehicle sub-system to power the transmitter. Such sub-system may include but not be limited to an ABS, tire pressure monitoring system (TPMS), or other powered subsystem.

An example of such a transmitter <NUM> may be a sensor-transmitter package from a TPMS that is adapted to collect the thermal data from the wheel end temperature sensor <NUM>. The adaptation may include the TPMS sensor package being reconfigured to accept temperature data rather than pressure data or the TPMS transmitter package may be reconfigured to accept both temperature and pressure data. Such a temperature adapted TPMS sensor may collect the temperature data and display the data, transmit the data to another module, or both display and transmit the data. <FIG> illustrates one embodiment of a view of the data display <NUM> of a TPMS sensor package, such as those carried by Truck System Technologies, adapted to collect and display both pressure and temperature data. The displayed data may be related to the particular wheel end and associated tire to which the sensor is mounted. For example, as shown in <FIG>, a display <NUM> may include a diagram or schematic view <NUM> of a trailer. An individual tire or wheel end <NUM> may be emboldened or highlighted in some way, such as using dashed or broken lines or another suitable indicator. A toggle or selector button may be used to switch between tires or wheel ends. A display system may be configured to display an actual measured temperature <NUM>, provide an indication of whether the temperature is within a certain range (e.g., within a specification or normal range) or both. For example, to indicate that a wheel-end assembly is within a certain range digital temperature data may be color coded or another indicator of a temperature range may be provided. A display may further provide a display <NUM> providing an indication of any active alarms or warnings.

The temperature sensor <NUM> and transmitter <NUM> may be in communication with one another by means of a wired connection <NUM>. For example, wired connection <NUM> may comprise the pair of wires <NUM> or another connection may be used. For example, as described above, the wired connection <NUM> may comprise a pair of wires <NUM> protected by a suitable protective sheathe <NUM> and routed through the interior of the spindle <NUM> and to axle <NUM>. The protective sheath may, for example, be a steel-braided protective sheath.

In a further embodiment, as shown in <FIG>, the temperature monitoring system <NUM> may comprise a first temperature sensor <NUM> disposed through the wall of the spindle section <NUM> and a transmitter disposed on an axle <NUM>, such as through the wall of the axle <NUM>. Such a configuration may be utilized in wheel ends containing an unsealed or sealed spindle and axle. The temperature sensor <NUM> may be disposed at the spindle <NUM> such that the sensor <NUM> is located at the interior of the hub <NUM>. The transmitter <NUM> may be disposed on the axle <NUM> such that the transmitter is substantially isolated from elevated temperatures resulting of the wheel end <NUM>.

In other embodiments, multiple temperature sensors may be coupled to a single transmitter. The transmitter may be configured to discriminate among multiple temperature sensor signals. Thus, if one of the multiple temperature sensors detects a high local temperature, the transmitter may transmit just the signal from that temperature sensor. In other embodiments, the transmitter may send signals from all of the multiple temperature sensors, and the receiving system may determine which temperature sensor has provided the high temperature signal. More than one temperature sensor may be placed in a wheel-end assembly. In some embodiments, a temperature fault may further be initiated based on a threshold difference in temperature between two or more sensors, a threshold rate of change of temperature for one or more sensor, or both.

Although not limited to use with fixed axles, the previous embodiments focused on a temperature monitoring system for a fixed axle. However, systems herein may generally be applied to either of a fixed or a steer axle, as described in the following embodiments described in relation to <FIG>.

Referring to <FIG>, a steer axle <NUM> may be comprised of a wheel spindle <NUM> on which the wheel end assembly <NUM> may be mounted. The wheel end assembly <NUM> may include a hub (not shown) which may rotate on inner bearings <NUM> and outer bearings <NUM>. A wheel <NUM>, tire <NUM> (as shown in <FIG>), and hubcap may be mounted to the hub. A brake drum (not shown) may be integrally formed with the hub or otherwise mounted to the hub. A wheel end assembly <NUM> may contain other components, parts, or attachments that are not shown yet still monitored by the temperature monitoring system.

The outer bearings <NUM> may be retained by a spindle nut <NUM>. A washer <NUM> may be mounted may between the spindle nut <NUM> and outer bearing <NUM>. A cotter pin <NUM> may be inserted through a receiving hole in the end of the wheel spindle so as to prevent the spindle nut <NUM> from becoming unscrewed. The spindle <NUM> may be pivotably mounted to the steer axle <NUM> via a knuckle post assembly (not shown). A hub cap (not shown) may be mounted to the hub so as to generally seal the bearings <NUM> and <NUM> from debris and prevent the loss of lubricant.

As shown in <FIG>, in one embodiment of a steer axle temperature monitoring system, a mounting block <NUM> may be disposed at the inboard or interior face <NUM> of the spindle <NUM>. A temperature sensor <NUM>, such as a thermocouple, may be then be mounted at the block <NUM>. For example, a temperature sensor <NUM> or sensing head of a sensor may be threaded and mate to a threaded hole in the block <NUM>. Alternately, the sensor <NUM> may be welded, glued, epoxied, bolted, or otherwise mechanically mated to the block <NUM>. In one example, the block <NUM> may be positioned, sized, constructed, and/or bonded to the interior face <NUM> of the spindle to facilitate heat exchange between the block <NUM> and the bearings <NUM>. For example, the mounting block <NUM> may be made of a material such as steel or brass.

In some embodiments, a temperature sensor <NUM> may be directly disposed at the interior face <NUM> of the spindle <NUM> such as in <FIG>. The sensor may be adhesively bonded to the face or may be threaded into a port that has been tapped into the spindle <NUM>. In some embodiments, the sensor <NUM> may maintain a probe into the body of the spindle. While the centerline of the inner face <NUM> may be an ideal location for disposition of the sensor <NUM> when avoiding routing a wire through the body of the spindle, any location on any exterior face of the spindle may be suitable as allowed by differing wheel end and spindle designs and configurations. With any such exteriorly mounted sensor <NUM>, the wire <NUM> may be routed through the spindle to the axle through a channel cross-drilled in the spindle <NUM>, such as may be seen in <FIG>. In other embodiments, a temperature sensor <NUM> may be disposed at the outboard end of the spindle <NUM> as in <FIG> or through the mid-body wall of the spindle <NUM> as in <FIG>. More than one temperature sensor may be placed in a wheel-end assembly.

The disposition of the temperature sensor <NUM> may allow for the collection of direct thermal data pertaining to the spindle <NUM> and indirect thermal data for adjacent wheel end components. A temperature sensor <NUM> may be in wired communication with a transmitter (not shown) disposed on the axle as in previous embodiments. A wire <NUM> may be routed from the sensor to the transmitter through or around the knuckle post assembly and then the axle or other suitable routing path. In other embodiments, a sensor <NUM> may be in wireless communication with a transmitter or a data collection module elsewhere on the vehicle.

In some embodiments, a steer axle temperature monitoring system may have a plurality of temperature sensors disposed at the spindle as seen in <FIG>. A first sensor 256A may be disposed at or through the outboard end of the spindle <NUM> while a second sensor 256B is disposed at a mounting block <NUM> on the inboard face <NUM> of the spindle <NUM>. The sensors may be in electronical communication with a transmitter (not shown in <FIG>) to communicate collected temperature signal data to a vehicular data acquisition module. As described previously, the vehicular data acquisition module may also collect and process data associated with one or more additional system such as an automatic tire inflation system or anti-lock brakes system. In some embodiments, a wire <NUM> (which, as shown therein may comprise two or more component wires 176A, 176B) may maintain electronic communication between the first sensor 256A and second sensor 256B wherein the wire is disposed through the interior of the spindle body <NUM>. Alternatively, a separate wire may be used to connect each of the first and second sensors to other components of a high temperature warning system. Alternately, the first sensor 256A and second sensor 256B may be in wireless communication with one another and a vehicular data acquisition system.

The transmitter may be configured to send a high-temperature alert to a driver mobile device or fleet operator computer or other recipient by text message or email when the temperature sensor detects a temperature above a temperature threshold. The temperature threshold may be a temperature past which the wheel end might risk fire or melting of components, such as bearing seals. In other embodiments, a high-temperature warning system may receive temperature data from the transmitter, and may send such an alert to a driver or fleet operator. The high-temperature warning system may be configurable to provide more than one temperature threshold, depending on how many and where sensors are used for a wheel-end. In yet other embodiments, the transmitter may trigger an in-cab alert (such as a sound, light, or message) if a dangerously high temperature is detected. The transmitter may be in communication with other components of a high-temperature warning system through wired or wireless connection. Any suitable wireless network may be used to send an alert. In some embodiments, the transmitter may be a client device in a client-server network architecture, or may send temperature data to a client and/or server where such a network architecture is used for a high-temperature warning system. In some embodiments, the transmitter may be configurable to recognize and adopt communication with one or more transducers, and to receive adjustable temperature warning threshold settings for each transducer. Each transducer may be individually coded to permit a high-temperature warning system to identify and depict on a graphical user interface the vehicle location and temperature reading of each transducer.

In further embodiments, a steer axle temperature monitoring system may have a plurality of temperature sensors disposed in the spindle as seen in <FIG>. A first sensor 256A may be disposed at or through the outboard end of the spindle <NUM> while a second sensor 256B is disposed through the mid-body wall of the spindle <NUM>. The sensors may be in electronic communication with a transmitter (not shown) to communicate collected data to vehicular data acquisition systems, such as an automatic tire inflation system or anti-lock brakes. A wire <NUM> may maintain electronic communication between the first and second sensor wherein the wire is disposed through the interior of the spindle body <NUM>. A strain relief sleeve or wire grommet <NUM> may also be provided to help protect the wire <NUM> from wear. The wire may also be connected to a vehicular data collection system. Alternately, the first and second sensors may be in wireless communication with one another and a vehicular data acquisition system.

In yet another embodiment, a steer axle temperature monitoring system may have a plurality of temperature sensors disposed at the spindle as seen in <FIG>. A first sensor 256A may be disposed through the mid-body wall of the spindle <NUM> while a second sensor 256B is disposed at a mounting block <NUM> on the inboard face <NUM> of the spindle. The sensors may be in electronic communication with a transmitter (not shown) to communicate collected data with data acquisition systems, such as an automatic tire inflation system or anti-lock brakes. A wire <NUM> may maintain electronic communication between the first and second sensors wherein the wire is disposed through the interior of the spindle body <NUM>. The wire may also be connected to a vehicular data collection system. Alternately, the first and second sensor may be in wireless communication with one another and a vehicular data acquisition system.

Use of multiple sensors may permit calculation of a temperature gradient between sensors, and allow detection of the location and spread of high temperatures throughout the wheel end assembly.

For embodiments wherein the wire is routed internally through the spindle, the wire may exit the body of the spindle at any point and then access a transmitter on the axle by means of cross-drilling the spindle as in the embodiment of <FIG>.

In some embodiments, as seen in <FIG>, there may be a temperature sensor head <NUM> with a transmitter assembly <NUM> housed separately yet in communication with one another. The sensor head <NUM> and transmitter assembly <NUM> may be electrically linked by means of a wire <NUM> wherein the wire is disposed through the interior of an axle. The sensor head <NUM> may couple to the outboard end of a sealed spindle or a plug in the spindle, for example, as the case may be for a particular spindle design. The sensor head <NUM> may be disposed adjacent to a rotary union in such cases that a rotary union is present in a wheel end. The sensor head <NUM> may be on the exterior or interior face of the spindle such that the sensor resides at the exterior of the spindle or interior space of the spindle respectively.

The transmitter assembly <NUM> may couple to an axle and be so disposed as prevent interference with other wheel end components. For example, the transmitter assembly <NUM> may be located about <NUM> (<NUM> inches) from the temperature sensor <NUM>. In some embodiments, the transmitter assembly <NUM> may be located about <NUM> (<NUM> inches) to about <NUM> (<NUM> inches) from the transmitter or at the axle endpoint, approximately. Such a location may avoid interference with other vehicle components and provide a location sufficiently free from electronical or other interference for wireless communication between the transmitter <NUM> and any data collection systems of the vehicle. Alternately, the transmitter assembly <NUM> may accept a wired connection to vehicle data collection systems. Such a wired connection may be realized through the use of a Deutsch connector(or other connector switchable for automotive use) at the transmitter to provide environmental protection for the wired connection point. Or, the sensor <NUM> may be connected to a vehicle data collection system using a suitably weather tight connector.

The transmitter assembly <NUM> may be an electronic device housed inside a protective body <NUM> with the body maintaining a mating lug <NUM> at the lower face of the body. Such a lug <NUM> may have a central passage through the lug so as to allow a wire <NUM> to pass from the electronic portion of the transmitter assembly <NUM> for connection to the associated sensor head <NUM>. The lug may also have a faceted portion or washer <NUM> integrated into the lug <NUM> at the upper portion of the lug, such as where the lug <NUM> joins the protective body <NUM> of the transmitter assembly <NUM>. Such a washer <NUM> may provide an appropriate section of the overall transmitter assembly <NUM> at which torque may be applied via a tool such as a wrench. Additionally, the protective body <NUM> of the transmitter <NUM> may maintain a circumferential pattern of indentations <NUM>. Such indentations <NUM> may allow a user to readily and adequately apply torque to the transmitter assembly <NUM> without the use of a tool. As in other embodiments, the transmitter assembly <NUM> may house a second temperature sensor or be adapted for use with a plurality of sensor heads.

Both sensor head <NUM> and transmitter assembly <NUM> may be coupled to their respective section of the vehicle by means of a threaded connection. For example, the sensor may be a thermocouple that threads into a port on a plug or spindle face, as the case may be, while the transmitter body maintains a threaded lug that mates to a port in the axle. Additionally, both sensor head <NUM> and transmitter assembly <NUM> may be sealed so as to provide environmental protection for the electronic electrically sensitive components or elements of each.

In another embodiment, the temperature sensor <NUM> may be disposed inside of a hubcap <NUM>. The sensor may be located at the interior face of the hubcap of the outboard wall <NUM> of the hubcap as in <FIG> or at the interior face of the side wall <NUM> of the hubcap as in <FIG>. The sensor <NUM> may be threaded into the wall of the hubcap or may be surface mounted to the wall. A wire <NUM> may be routed through the interior of the hubcap and through the wheel end <NUM> and further through the axle <NUM> to a transmitter (not shown) disposed further down the length of the axle. A rotary electrical connection (not shown), such as a slip ring, may be used to provide an electrical path from a rotating part to a stationary part of the wheel end. The temperature sensor may be utilized in a hubcap and wheel end containing a tire inflation system <NUM>. Such co-usage of the two systems may be realized by routing the wire <NUM> adjacent to a rotary union <NUM> of the inflation system.

In yet another embodiment, as seen in <FIG> and <FIG>, a temperature sensor <NUM> may be mounted to a hubcap <NUM> with an associated transmitter <NUM> also mounted at the hubcap. The sensor <NUM> may be disposed at the interior face of the hubcap <NUM> while the transmitter <NUM> is disposed at the exterior face of the hubcap. In such an embodiment, the transmitter and sensor components may be of a unitary design or the transmitter and sensor may be separate components in electrical communication by means of an interconnecting wire.

As seen in <FIG>, a temperature sensor and a transmitter may be separate components linked by a wire. The temperature sensor may be disposed at the interior face of a hubcap in the vicinity adjacent to the wheel end so as to capture as accurate useful data. The sensor may be threaded into the wall of the hubcap or otherwise mechanically attached to the hubcap. A wire <NUM> may link the sensor to a transmitter <NUM> so as to maintain electrical communication between the components.

A unitary design is illustrated in <FIG>. In such a configuration, a threaded body <NUM> of the temperature sensor <NUM> may be directly attached to a housing <NUM> in which are disposed the electronic components of the transmitter component. A visual display may also be incorporated into the housing to visually communicate the temperature data. As in previous embodiments, the transmitter <NUM> may collect and disseminate temperature data solely or may also collect and disseminate tire pressure data in conjunction with wheel end temperature data. An embodiment that collects both temperature and pressure data may reflect a temperature sensor combined with a TPMS sensor as previously described.

<FIG> shows an embodiment of a method <NUM> of installing a high temperature warning system. In a step <NUM>, a hole may be drilled into an axle. Alternatively, some axles may include one or more existing holes or dedicated access points. For example, as shown <FIG>, some axles may include or be tapped to include a <NUM> (¼ inch) National Standard Pipe Thread (NPT) hole. In a step <NUM>, a wire, such as may be steel braided protective sheath <NUM> may be threaded through the tapped hole and routed through the axle. A sensor head may be attached to the wire (and threaded along with the wire) or the wire may be attached to the sensor head after threading the wire, depending on the particular design of the sensor. As shown in step <NUM>, a sensor head may be inserted into or through either of a plug or sensor mounting plate. Alternatively, the sensor head may be installed into a hole, such as may be drilled into a face of a spindle or other wheel end component. In a step <NUM>, the plug (or mounting plate) may be attached within the spindle (or other wheel end component).

While the preceding embodiments disclose a single or double temperature sensor arrangement, a plurality of sensors may be employed such that any particular area or component of the wheel end, wherein the capture of temperature data is of benefit, may have a sensor disposed at the desired location.

While some embodiments disclosed use of a thermocouple as a temperature sensor, other electrical temperature sensors may also be utilized. Such other types of sensors may include, but not be limited to, thermistors, resistance temperature detectors such as resistance thermometers silicon bandgap temperature sensors, and other temperature detection modalities or methodologies as may be known to one skilled in the art. The temperature sensors may be of contact or non-contact modalities.

In any or all of the above embodiments, the temperature sensor may be combined with or co-located within a rotary union. As many thermocouples have a probe extension on the thermocouple and many rotary unions rely on a stator that passes through the body to which the rotary union is attached, the probe and stator may be unified into a single body or a temperature probe may be attached to the stator. Alternately, a combined thermocouple and rotary union may be interdisposed such that the probe of the thermocouple passes through the center opening of the rotary union.

Claim 1:
A wheel end high-temperature warning system (<NUM>) for a vehicle having a first wheel-end assembly (<NUM>) mounted to a sealed axle (<NUM>) including a first pressure barrier plug (<NUM>) disposed at a first end thereof, the system characterized by:
a first temperature sensor (<NUM>, <NUM>, 256A) including a first sensor head mounted to the first pressure barrier plug (<NUM>), the sensor head (<NUM>, <NUM>) being in a heat exchange relationship with one or more bearings (<NUM>) of the wheel-end assembly (<NUM>), said first temperature sensor (<NUM>) configured to provide a first signal indicative of a wheel-end assembly temperature.