Abstract:
A sensor bearing assembly having a rolling element bearing and at least one sensor is provided. The rolling element bearing includes an inner ring, an outer ring, and rolling elements arranged between the inner ring and the outer ring. The at least one sensor is arranged to convert one or more physical magnitudes to electrical sensor signals. The sensor is attached directly or indirectly to the rolling element bearing. The assembly further comprises a converter unit. The converter unit is arranged to convert the electrical sensor signals to output signals, the output signals are different to in type, form and/or amplitude in relation to the electrical sensor signals. The converter unit is also disposed in a separate enclosure that does not share the same enclosure with the sensor.

Description:
TECHNICAL FIELD 
       [0001]    The invention concerns sensor bearing assemblies and is more particularly directed to rolling element bearings comprising one or more sensors and their interface. 
       BACKGROUND 
       [0002]    A rolling element bearing comprises an inner ring, an outer ring and several rolling elements or bodies installed between these two rings. These rolling elements can be balls, rollers or needles. In the meaning of the invention, a rolling bearing and a rolling element bearing can be, for instance, a ball bearing, a roller bearing or a needle bearing. 
         [0003]    In the field of rolling element bearings, it is known to attach one or more sensors to measure one or more physical parameters and transduce these physical parameters into electrical signals. One such example is the use of a tachometer in order to determine the rotation speed of a member supported by a rolling bearing. For instance, truck lifts are equipped with electric motors to move upwardly of downwardly the forks of the truck. The position and speed of the forks can be controlled for safety reasons. In this context, it is known to use an instrumented rolling element bearing assembly in order to support a rotating shaft of an electric motor with respect to a frame and to provide a variable-voltage regulator with some information with respect to a rotation parameter of the rotating shaft. Such an instrumented rolling bearing assembly includes a sensor, in the form of an electronic component such as a Hall-effect cell, and possibly some other electronic components for the treatment of the output signal of such a sensor. There is still room for improvements. 
       SUMMARY 
       [0004]    An object of the invention is to define a manner to create a flexible sensor bearing assembly. 
         [0005]    The aforementioned object is achieved according to the invention by a converter unit. The converter unit is arranged to convert electrical sensor signals to output signals, the output signals are different to form, type and/or amplitude in relation to the electrical sensor signals. The converter unit is also enclosed in a separate enclosure, that is the converter unit does not share a housing/enclosure with the sensor, the converter unit is housed in its own enclosure. 
         [0006]    In some embodiments for the electrical sensor signals, the converter unit is electrically coupled with the sensor by means of an electrical cable. In other embodiments for the electrical sensor signals, the converter unit is electrically coupled with the sensor by means of matching coded detachable connectors, a sensor side coded connector and a converter unit input side coded connector. The coding being a physical coding, such as matching male/female connectors. The coded connectors can be coded as to what type of signals are delivered and expected, that is different physical characteristics in dependence on the type of signal. For the electrical sensor signals, the converter unit can further be electrically coupled with the sensor by means of an electrical cable between sensor and sensor side coded connector and/or between the converter unit and the converter unit input side coded connector. In some embodiments the converter unit side coded connector is integrated with the separate enclosure of the converter unit. The enclosure itself can then in some embodiments be part of the coding, that is the physical shape of the enclosure allowing only matching connectors. 
         [0007]    Sometimes for the output signals the, converter unit is electrically coupled with other equipment by means of an electrical cable. In other embodiments for the output signals, the converter unit is electrically coupled with other equipment by means of matching coded detachable connectors, an other equipment side coded connector and a converter unit output side coded connector. The converter unit can further be electrically coupled with the other equipment by means of an electrical cable between the other equipment and other equipment side coded connector and/or between the converter unit and the converter unit output side coded connector. Or the converter unit side coded connector can be integrated with the separate enclosure of the converter unit. In such cases it can be advantageous that also the enclosure shape is part of the coding. 
         [0008]    Suitably the converter unit further comprised power supply conditioning means. Such conditioning means can comprise power supply conversion and/or electrical interference filtering means. 
         [0009]    In some embodiments the converter of the converter unit converts analog sensor signals to digital sensor signals or converts digital sensor signals to other digital sensor signals. In other embodiment the converter of the converter unit converts digital sensor signals to analog output signals. 
         [0010]    In some versions the converter of the converter unit linearizes the sensor signals, that is goes from a non-linear sensor output to a linear output signal. The linearization can then be done by means of a transfer function and/or look-up table. Likewise in some versions of the converter can de-linearize a linear signal if the sensor signals are linear and a non-linear output is desired, this can also according to the invention be by means of a transfer function and/or look-up table. 
         [0011]    The different additional enhancements of the converter unit/dongle according to the invention can be combined in any desired manner as long as no conflicting features are combined. 
         [0012]    The aforementioned object is also achieved according to the invention by a power supply conditioning/converter unit/dongle. The power converter unit is arranged to convert/condition an available power supply to a power supply suitable for a sensor unit of a sensor bearing unit. The power supply conditioning/converter unit/dongle comprises power supply conversion and/or electrical interference filtering means. The power supply converter unit is enclosed in a separate enclosure, that is the power supply converter unit does not share a housing/enclosure with the sensor, the power supply converter unit is housed in its own enclosure. 
         [0013]    In some embodiments for the power supply to the sensor, the power supply converter unit is electrically coupled with the sensor by means of an electrical cable. In other embodiments for the power supply to the sensor, the converter unit is electrically coupled with the sensor by means of matching coded detachable connectors, a sensor side coded connector and a power supply converter unit input side coded connector. The coding being a physical coding, such as matching male/female connectors. The coded connectors can be coded as to what type of power supply is delivered and expected, that is different physical characteristics in dependence on the type of power supply. The power supply unit can further be electrically coupled with the sensor by means of an electrical cable between sensor and sensor side coded connector and/or between the power supply converter unit and the power supply converter unit input side coded connector. In some embodiments the power supply converter unit side coded connector is integrated with the separate enclosure of the power supply converter unit. The enclosure itself can then in some embodiments be part of the coding, that is the physical shape of the enclosure allowing only matching connectors. 
         [0014]    Suitably the power supply converter unit also provides pass through for the sensor signals. Sometimes the power supply converter unit is electrically coupled with other equipment by means of an electrical cable. In other embodiments the power supply converter unit is electrically coupled with other equipment by means of matching coded detachable connectors, an other equipment side coded connector and a power supply converter unit side coded connector. The power supply converter unit can further be electrically coupled with the other equipment by means of an electrical cable between the other equipment and other equipment side coded connector and/or between the power supply converter unit and the power supply converter unit side coded connector. Or the power supply converter unit side coded connector can be integrated with the separate enclosure of the power supply converter unit. In such cases it can be advantageous that also the enclosure shape is part of the coding. 
         [0015]    The different additional enhancements of the power supply converter unit according to the invention can be combined in any desired manner as long as no conflicting features are combined. 
         [0016]    The aforementioned object is also achieved according to the invention by a sensor bearing assembly comprising a rolling element bearing and at least one sensor. The rolling element bearing comprises an inner ring, an outer ring, and rolling elements arranged between the inner ring and the outer ring. The at least one sensor is arranged to convert one or more physical magnitudes to electrical sensor signals. The sensor is attached directly or indirectly to the rolling element bearing. According to the invention the assembly further comprises a converter unit. The converter unit is arranged to convert the electrical sensor signals to output signals, the output signals are different to form, type and/or amplitude in relation to the electrical sensor signals. The converter unit is also enclosed in a separate enclosure, that is the converter unit does not share a housing/enclosure with the sensor, the converter unit is housed in its own enclosure. 
         [0017]    In some embodiments for the electrical sensor signals, the converter unit is electrically coupled with the sensor by means of an electrical cable. In other embodiments for the electrical sensor signals, the converter unit is electrically coupled with the sensor by means of matching coded detachable connectors, a sensor side coded connector and a converter unit input side coded connector. The coding being a physical coding, such as matching male/female connectors. The coded connectors can be coded as to what type of signals are delivered and expected, that is different physical characteristics in dependence on the type of signal. For the electrical sensor signals, the converter unit can further be electrically coupled with the sensor by means of an electrical cable between sensor and sensor side coded connector and/or between the converter unit and the converter unit input side coded connector. In some embodiments the converter unit side coded connector is integrated with the separate enclosure of the converter unit. The enclosure itself can then in some embodiments be part of the coding, that is the physical shape of the enclosure allowing only matching connectors. 
         [0018]    Sometimes for the output signals the, converter unit is electrically coupled with other equipment by means of an electrical cable. In other embodiments for the output signals, the converter unit is electrically coupled with other equipment by means of matching coded detachable connectors, an other equipment side coded connector and a converter unit output side coded connector. The converter unit can further be electrically coupled with the other equipment by means of an electrical cable between the other equipment and other equipment side coded connector and/or between the converter unit and the converter unit output side coded connector. Or the converter unit side coded connector can be integrated with the separate enclosure of the converter unit. In such cases it can be advantageous that also the enclosure shape is part of the coding. 
         [0019]    Suitably the converter unit further comprised power supply conditioning means. Such conditioning means can comprise power supply conversion and/or electrical interference filtering means. 
         [0020]    In some embodiments the converter of the converter unit converts analog sensor signals to digital sensor signals. In other embodiment the converter of the converter unit converts digital sensor signals to analog output signals. 
         [0021]    In some versions the converter of the converter unit linearizes the sensor signals, that is goes from a non-linear sensor output to a linear output signal. The linearization can then be done by means of a transfer function and/or look-up table. Likewise in some versions of the converter can de-linearize a linear signal if the sensor signals are linear and a non-linear output is desired, this can also according to the invention be by means of a transfer function and/or look-up table. 
         [0022]    The different additional enhancements of the sensor bearing assembly according to the invention can be combined in any desired manner as long as no conflicting features are combined. 
         [0023]    A primary purpose of the invention is to provide a means to be able to adapt a sensor bearing assembly to different requirements as to what is delivered as output signals and also to be able to adapt to different requirements as to what connectors are used and for example what type of power is delivered. This is obtained according to the invention by having a converter unit in a separate enclosure, in a dongle. And to ensure that the correct dongle is used to be able to code the connector of the dongle to only match connectors that match the electrical characteristics of the dongle/converter unit, the sensor, and the environment/other equipment that the sensor bearing assembly is intended to be connected to. In some embodiments the signal conversion and power are separated into two different dongles, each with their own enclosure, and suitably their own coded connections. Other advantages of this invention will become apparent from the detailed description. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0024]    The invention will now be described in more detail for explanatory, and in no sense limiting, purposes, with reference to the following figures, in which 
           [0025]      FIG. 1  illustrates an instrumented rolling element bearing, 
           [0026]      FIG. 2  illustrates an instrumented rolling element bearing according to the invention, 
           [0027]      FIG. 3A-3C  illustrate further embodiments of instrumented bearings according to the invention, 
           [0028]      FIG. 4  illustrates an example of an output of a temperature sensor, 
           [0029]      FIG. 5A-5B  illustrate examples of different outputs of an instrumented rolling element bearing with a converter according to the invention, instrumented with for example a temperature sensor according to  FIG. 4 , 
           [0030]      FIG. 6  illustrates an example of an output of a non-linear temperature sensor 
           [0031]      FIG. 7  illustrates an example of a linear output of an instrumented rolling element bearing according to the invention, instrumented with for example a non-linear temperature sensor according to  FIG. 6 , 
           [0032]      FIG. 8  illustrates a basic example of a block diagram of a dongle according to the invention, 
           [0033]      FIG. 9  illustrates a further example of a block diagram of a dongle according to the invention, 
           [0034]      FIG. 10  illustrates a block diagram of a converter unit/dongle and power converter unit/dongle according to the invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0035]    In order to clarify the method and device according to the invention, some examples of its use will now be described in connection with  FIGS. 1 to 10 . 
         [0036]      FIG. 1  illustrates an instrumented rolling element bearing  100  with an outer ring  102 , rolling elements  104 , an inner ring  106  and a sensor arrangement  120 . The sensor arrangement  120  will comprise at least one sensor unit  12  that will deliver its output through a connector  124  via a cable  126 . If the sensor unit  122  is active then it will most likely receive any necessary required power through the connector  124  as well. The sensor output through connector  124  will be supplied to other equipment/units that will use this output/information for determining one or more parameters of the bearing  100 . These parameters may be one or more of temperature, speed, acceleration, vibration, load, strain of different parts of the bearing  100  or unit/parts connected to the bearing  100 . Interfacing an instrumented bearing  100  to other equipment/units requires careful attention. For example, if it is a question of rotational speed of an attached shaft, then the sensor might deliver a number of pulses per rotation. The other equipment/units that the instrumented bearing  100  is intended to be coupled  124  with might for example in some cases expect a 4 to 20 mA linear signal and in other cases a pulse width modulated 12 Volt signal. This would require two different sensor units  122 , one that comprises electronics to generate the 4 to 20 mA linear signal and another that comprises electronics to generate the pulse width modulated 12 Volt signal. As the sensor unit  122  is closely integrated with the bearing, this means that two different instrumented bearings need to be manufactured and stocked. Not optimal. 
         [0037]      FIG. 2  illustrates an instrumented rolling element bearing  200  according to the invention. The instrumented bearing  200  according to the invention also comprises an outer ring  202 , rolling elements  204 , an inner ring  206 , a sensor unit  222  and a connector  224  to other equipment/units. According to the invention a novel converter  230  is coupled between the sensor unit  222  and the connector  224  to the other equipment/units. The converter  230  converts/transforms the electrical sensor signals from the sensor to electrical signals suitable for whatever the connector is intended to be connected to. In accordance with the example above, according to the invention one type of instrumented bearing needs to be stocked, comprising a sensor unit for speed but without the connector. Depending on customer need a suitable converter that will generate the desired output signals is attached to the sensor unit before delivery. In the example of  FIG. 2  the converter  230  is attached to both the sensor unit  222  and the connector  224  to other equipment/units by means of a cable. 
         [0038]      FIGS. 3A ,  3 B and  3 C illustrate further embodiments of instrumented rolling element bearings  300  according to the invention comprising further enhancements.  FIG. 3A  illustrates a rolling element bearing  300  with a sensor unit  343  with an integrated coded connector according to an alternative embodiment. The coded connector is adapted to cooperate with a coded connector  344  of a converter  332  according to a first alternative embodiment of the invention. As is illustrated in  FIG. 3A  the coded connector  344  is integrated with the converter  322 . Another version of this embodiment is having the coded connector  344  being coupled with the converter  322  by means of a cable. Also the coded connector of the sensor unit  342  can be extended with a cable. 
         [0039]    The coding might take the form of being matching electrical connectors, as in number and shape/size. The coding might also take the form of the connector housing encapsulating the connector having different physical sizes and shapes such as round, rectangular, triangular, or heart shaped. In some embodiments there might be a combination of the physical coding as to both connector and housing. As an aid other types of visual coding, such as color, can be used to aid in matching the two ends. 
         [0040]    The coding is important to avoid human error in that there will be a match to both ends as to what is at least electrically expected. For example the sensor unit  342  expects to be fed with 12V regulated DC and the converter  332  expects the sensor unit  342  to deliver 5 V pulses as an indication of rotational speed of an attached shaft. Thus the sensor unit  442  coding can for example indicate one or more of what kind of sensor it is, what the output signals are and what type of power requirement, if any, is required. The physical coding of the converter  332  has to match this. 
         [0041]      FIG. 3B  illustrates using physical coding of a converter unit  334  according to the invention to avoid any human error in coupling the instrumented rolling element bearing  300  to other equipment/units, where the other equipment/units expect and/or require certain input and provide an expected type of power as to levels and quality. In this embodiment the converter  334  comprises a coded connector  354  adapted to cooperate with a matching coded connector  352  which in turn is coupled to other equipment/units. As described above the coding might take the form of being matching electrical connectors, as in number and shape/size. The coding might also take the form of the connector housing encapsulating the connector having different physical sizes and shapes such as round, rectangular, triangular, or heart shaped. In some embodiments there might be a combination of the physical coding as to both connector and housing. As an aid other types of visual coding, such as color, can be used to aid matching the two ends. 
         [0042]    Also in this embodiment it is important for the converter  334  to know what it can expect to be fed with as to power, for example 12V regulated DC. Likewise it is important that the other equipment/units that are coupled to the matching coded connector  352  receives the expected type and range of electrical signals and delivers the correct power. Thus the coded connector  352  of the converter  334  coding can for example indicate one or more of what kind of output signals will be generated and what type of power, if any, is required. The physical coding of the coded connector  352  of the other equipment/units has to match this. As is illustrated in  FIG. 3B  the coded connector  354  is integrated with the converter  334 . Another version of this embodiment is having the coded connector  354  being coupled with the converter  324  by means of a cable. 
         [0043]      FIG. 3C  illustrates an embodiment essentially combining the embodiments as illustrated in relation to  FIGS. 3A and 3B  by a converter  336  comprising both a coded connector  344  adapted to cooperate with a matching coded connector of a sensor unit  342 , and a coded connector  354  adapted to cooperate with a matching coded connector  352  coupled to other equipment/units. Other versions of this embodiment are either one or both of the coded connector  354  being coupled with the converter  336  by means of a cable and the coded connector  344  being coupled with the converter  336  by means of a cable. Also the coded connector of the sensor unit  342  can be extended with a cable. 
         [0044]      FIG. 4  illustrates an example of an output  470  of a temperature sensor with regard to output voltage  492  in relation to measured temperature  490 . As can be seen, the output  470  is linear with an offset. The desired output from such a temperature sensor might be Voltage but with a different relationship between temperature and output Voltage than what the sensor gives, or the desired output might be a standard 4 to 20 mA between some predefined temperatures.  FIGS. 5A and 5B  illustrate examples of different outputs  575 ,  577  of an instrumented rolling element bearing according to the invention, instrumented with for example a temperature sensor according to  FIG. 4 .  FIG. 5A  illustrates the use of a converter according to the invention that will generate a relationship/curve  575  that is normalized between Volts  592  and temperature  590  with a predetermined slope.  FIG. 5B  illustrates the use of a converter according to the invention when the desired output is a relationship/curve  577  in the range of 4-20 mA  594  in relation to temperature  590 . 
         [0045]    As a further example  FIG. 6  illustrates a voltage  692  output  672  based on the temperature  690  measured by a non-linear temperature sensor. This is usually not a desired behavior of a temperature sensor and will in most cases only make it practical to use within narrow temperature ranges where the temperature sensor shows some linearity. According to the invention, the output of a non-linear sensor can be linearized by means of a converter to a desired output. This can for example be done by a formula or a look-up table.  FIG. 7  illustrates an example of a linear voltage  792  output  779  in relation to measured temperature  790  of an instrumented rolling element bearing according to the invention, instrumented with for example a non-linear temperature sensor according to  FIG. 6 . 
         [0046]      FIG. 8  illustrates a basic example of a block diagram of a converter unit/dongle  830  according to one embodiment of the invention. As is illustrated in  FIGS. 2 and 3A  to  3 C, the converter unit is separated from the sensor unit. There is thus sensor side coupling/connection means  861  to couple the converter unit  830  to the sensor unit. The sensor side connection means  961  can for example be a coded connector as illustrated in  FIGS. 3A and 3C , or it can be connecting means for attaching a cable that couples the converter  830  to the sensor unit, as is illustrated in  FIGS. 2 and 3B . The sensor side connector means  861  will transfer power  810  as received from the other equipment/units side coupling/connector means  862  to the sensor unit. The sensor side connector means will also transfer sensor signal 2   815  received from the sensor unit to the converter electronics  863 . The converter electronics  863  will convert/transform the sensor signals  815  to converted output signals  816  which are of a type and range that is expected at the other equipment/units side coupling/connector means  862 . This can for example comprise transforming an analog sensor signal  815  into a digital output signal  816 . In some embodiments it can be simply to change the levels of the analog sensor signal  815  by either dampening them or amplifying them to get a desired output signal  816 . Alone or in combination, the converter electronics can also just change the output impedance. The other equipment/units side coupling/connector means  862  will couple/connect an instrumented bearing according to the invention with a converter unit  830  to other equipment/units such as measurement equipment or condition monitoring equipment. 
         [0047]      FIG. 9  illustrates a further example of a block diagram of a converter unit/dongle  930  according to the invention. This version/embodiment of a converter unit/dongle  930  according to the invention comprises in addition to a sensor side coupling  961 , an equipment/unit side coupling  962 , converter electronics  964  that will take sensor signal(s)  915  and create converted output signals  916 , also a power conditioner/regulator/protector unit  965  that will create conditioned power line(s)  912  from received unconditioned power line(s)  910 . The power conditioner/regulator/protector unit  965  can for example have active or passive protection/filtering, and/or have means for up or down conversion, and/or creation of multiple voltages, such as for example creating plus and minus 12 Volts from a 5 Volt input. Suitably there will be an internal power connection  911  to the converter electronics  964  from the power conditioner/regulator/protector unit  965 . The specific requirements of both the sensor unit and the application as such and in what environment the instrumented bearing is to operate in will dictate what the power conditioner/regulator/protector unit  965  will comprise. Is the sensor unit sensitive to electrical noise, is the environment for the specific application electrically noisy, what are the poser requirements of the sensor unit, what kind of power can/will the specific application deliver? A big advantage of the invention is the possibility to change the converter unit  930  without having to change the sensor unit/the instrumented bearing as such. This means that if an application turns out to be electrically noisier than what was predicted, then the converter unit  930  can be exchanged with another one with more electrical noise filtering/protection. 
         [0048]    A further embodiment is attained by separating the converter electronics and the power conditioner/regulator/protector unit into separate enclosures/dongles.  FIG. 10  illustrates a block diagram of such an embodiment where the converter electronics and power/conditioner/regulator/protector unit are in separate enclosures/dongles  1030 ,  1031 . The converter unit/dongle  1030  is similar to the converter unit/dongle as described in relation to  FIG. 8 . There is thus a sensor side coupling/connection means  1061  to couple the converter unit  1030  to a sensor unit. The sensor side connection means  1061  can be a physically coded connector to only match/connect with appropriate sensor units or it can be connecting means for attaching a cable that couples the converter  1030  to the sensor unit. The sensor side connector means  1061  will transfer power  1011  as received from a coupling/connector means  1082  to the sensor unit. The sensor side connector means  1061  will additionally transfer sensor signals  1015  received from the sensor unit to the converter electronics  1063 . The converter electronics  1063  will convert/transform the sensor signals  1015  to converted output signals  1016  which are of a type and range that is expected at the other end at the coupling/connector means  1082 . This can for example comprise transforming an analog sensor signal  1015  into a digital output signal  1016  or digital to analog. In some embodiments it can be changing the levels of the analog sensor signal  1015  by either dampening the sensor signal  1015 , shifting the sensor signal  1015  or amplifying the sensor signal  1015  to get a desired output signal  1016 . Alone or in combination, the converter electronics  1063  can also change the output impedance. The coupling/connector means  1082  will allow an instrumented bearing via the converter unit  1030  to be correctly connected/coupled to other equipment/units such as measurement equipment or condition monitoring equipment, or as depicted in  FIG. 10 , also via a power converter unit/dongle  1031  suitably comprising a power conditioner/regulator/protector  1066 . According to one embodiment of the invention the converter unit/dongle  1030  is coupled to the power converter unit/dongle  1031  by means of matching couplings/connectors  1081 ,  1082 . Suitably an other equipment/units side coupling/connector  1066  of the power converter unit/dongle  1031  is the same as the other equipment/units side coupling, and/or coupling to power converter unit/dongle  1082  of the converter unit/dongle  1030 . In this type of embodiments the power converter unit/dongle  1031  is optional and can be added if there is a need to condition the supply power available. The power converter unit/dongle  1031  according to the invention comprises in addition to a sensor side coupling and/or converter unit/dongle coupling  1081 , and equipment/unit side coupling  1062 , a power conditioner/regulator/protector unit  1066  that will create conditioned power line(s)  1012  from received unconditioned power line(s)  1010 . The power conditioner/regulator/protector unit  1066  can for example have active or passive protection/filtering, and/or have means for up or down conversion, and/or creation of multiple voltages, such as for example creating plus 5 Volts from a 12 Volt input. The specific requirements of both the sensor unit and the application as such and in what environment the instrumented bearing is to operate in will dictate what the power conditioner/regulator/protector unit  1066  will comprise. Is the sensor unit sensitive to electrical noise, is the environment for the specific application electrically noisy, what are the poser requirements of the sensor unit, what kind of power can/will the specific application deliver? A big advantage of the invention according to this embodiment is the possibility to change only the power converter unit/dongle  1031  without having to change even the converter unit/dongle  1030 . This means that if an application turns out to be electrically noisier than what was predicted, then the power converter unit/dongle  1031  can be added or be exchanged with another one with more electrical noise filtering/protection. The power converter unit/dongle  1031  can also be used without the converter unit  1030 , in this case the power converter unit is directly coupled to an instrumented bearing in any manner as previously described. All of the connectors/couplings can be coded as previously described. 
         [0049]    The invention is based on the basic inventive idea of one easily interchangeable part, the converter/dongle that adapts an instrumented bearing to many different applications/environments/requirements. The invention is not restricted to the above-described embodiments, but may be varied within the scope of the following claims. 
         [0050]      FIG. 1  illustrates an instrumented rolling element bearing:
     100  Rolling element bearing,     102  Outer ring,     104  Rolling elements,     106  Inner ring,     120  Sensor arrangement,     122  Sensor unit,     124  Connector to other equipment/units,     126  Cable/conductor between sensor and connector   
 
         [0059]      FIG. 2  illustrates an instrumented rolling element bearing according to the invention:
     200  Rolling element bearing,     202  Outer ring,     204  Rolling elements,     206  Inner ring,     222  Sensor unit,     224  Connector to other equipment/units,     230  Converter according to the invention comprising a converter converting the electrical sensor signals from the sensor to electrical signals suitable for whatever the connector is intended to be connected to.   
 
         [0067]      FIGS. 3A-3C  illustrate further embodiments of instrumented bearings according to the invention:
     300  Rolling element bearing,     322  Sensor unit with included cable embodiment, coupled to a converter according to the invention,     324  Connector to other equipment/units,     332  Converter according to a first alternative embodiment, the converter comprising a coded connector adapted to cooperate with a matching coded connector of a sensor unit,     334  Converter according to a second alternative embodiment, the converter comprising a coded connector adapted to cooperate with a matching coded connector coupled to other equipment/units,     336  Converter according to a third alternative embodiment, the converter comprising two coded connectors, one coded connector adapted to cooperate with a matching coded connector of a sensor unit, and one coded connector adapted to cooperate with a matching coded connector coupled to other equipment/units,     342  Sensor unit with integrated coded connector according to an alternative embodiment, the coded connector is adapted to cooperate with a coded connector of a converter according to the invention,     344  Coded connector on a converter according to the invention, the coded connector is adapted to cooperate with a matching coded connector of a sensor unit,     352  Coded connector coupled to other equipment/units, the coded connector is adapted to cooperate with a matching coded connector of a converter,     354  Coded connector on a converted according to the invention, the coded connector is adapted to cooperate with a matching coded connector coupled to other equipment/units.   
 
         [0078]      FIG. 4  illustrates an example of an output of a temperature sensor:
     470  Relationship/curve of a sensor output, in Volts for illustration, in relation to temperature,     490  Temperature axis,     492  Sensor output axis in Volts   
 
         [0082]      FIGS. 5A-5B  illustrate examples of different outputs of an instrumented rolling element bearing according to the invention, instrumented with for example a temperature sensor according to  FIG. 4 :
     575  Relationship/curve of converter output in normalized Volts in relation to temperature,     577  Relationship/curve of converter output in 4-20 mA in relation to temperature,     590  Temperature axis,     592  Converter output axis in Volts     594  Converter output axis in mA.   
 
         [0088]      FIG. 6  illustrates an example of an output of a non-linear temperature sensor:
     672  Relationship/curve of sensor output, in Volts, in relation to temperature,     690  Temperature axis,     692  Sensor output axis in Volts   
 
         [0092]      FIG. 7  illustrates an example of a linear output of an instrumented rolling element bearing according to the invention, instrumented with for example a non-linear temperature sensor according to  FIG. 6 :
     779  Relationship/curve of converter output in linearized Volts in relation to temperature,     790  Temperature axis,     792  Converter output axis in Volts   
 
         [0096]      FIG. 8  illustrates a basic example of a block diagram of a converter unit/dongle according to the invention:
     810  Power line(s),     815  Sensor signal(s)     816  Converted output signals     830  Converter according to one embodiment of the invention     861  Sensor side coupling     862  Other equipment/units side coupling     863  Converter electronics   
 
         [0104]      FIG. 9  illustrates a further example of a block diagram of a converter unit/dongle according to the invention:
     910  Unconditioned power line(s)     911  Power to the converter electronics     912  Conditioned power line(s)     915  Sensor signal(s)     916  Converted output signals     930  Converter according to a further embodiment of the invention,     961  Sensor side coupling     962  Other equipment/units side coupling     964  Converter electronics     965  Power conditioner/regulator/protector   
 
         [0115]      FIG. 10  illustrates a block diagram of a converter unit/dongle and power converter unit/dongle according to the invention:
     1010  Unconditioned power line(s)     1011  Power line(s),     1012  Conditioned power line(s)     1015  Sensor signal(s)     1016  Converted output signals     1017  Sensor signal(s) pass through     1030  Converter unit/dongle according to the invention     1031  Power Converter unit/dongle according to the invention     1061  Sensor side coupling     1062  Other equipment/units side coupling     1063  Converter electronics     1066  Power conditioner/regulator/protector     1081  Either sensor side coupling and/or converter unit/dongle coupling     1082  Either other equipment/units side coupling, and/or coupling to power converter unit/dongle