Wheel arrangement having a pressure sensor
View Patent ↗A wheel arrangement includes a wheel having a sensor for measuring pressure in the tyre; a spindle, about which the wheel is rotatably mounted with the aid of bearings around the spindle, and of communication elements between the sensor and elements for using measures, which are associated with the spindle. Communication elements are adapted to a transmission system with a frequency higher than 50 kHz comprising a rotating antenna which is supported by the wheel and a fixed antenna. The two antennae do not have their own rotational guiding element. The antennae are generally annular and disposed in a concentric manner on the same level around the wheel axis (X-X) of rotation, the average radial distance between the antennae exceeding 2 mm.
1. Wheel arrangement ( 10 ) comprising:
a wheel ( 14 ) provided with a rim ( 23 ) which is suitable for receiving a tyre, the wheel ( 14 ) carrying a sensor ( 60 ) for measuring the pressure in the tyre;
a spindle ( 12 ) about which the wheel ( 14 ) is rotatably mounted by means of bearings ( 22 ); and
means ( 70 ) of communication between the sensor ( 60 ) and means ( 86 ), associated with the spindle, for using the measurements carried out by the sensor ( 60 ), characterized in that the communication means ( 70 ) are suitable for radiofrequency transmission at a frequency higher than 50 kHz and comprise a rotating antenna ( 74 ) carried by the wheel ( 14 ) and a fixed antenna ( 78 ) carried by the spindle ( 12 ), the two antennae ( 74 , 78 ) not having their own means of guidance in rotation, and in that the rotating antenna ( 74 ) and the fixed antenna ( 78 ) are generally annular and are located in the same plane in a concentric manner about the axis (X-X) of rotation of the wheel ( 14 ), the average radial distance between the rotating antenna ( 74 ) and the fixed antenna ( 78 ) exceeding 2 mm.
2. Wheel arrangement according to claim 1 , characterized in that the average radial distance between the rotating antenna ( 74 ) and the fixed antenna ( 78 ) is substantially equal to 5 mm.
3. Wheel arrangement according to claim 1 , characterized in that the fixed antenna ( 78 ) extends around the rotating antenna ( 74 ).
4. Wheel arrangement according to claim 1 , characterized in that it comprises an auxiliary device ( 30 ) located inside the wheel spindle.
5. Wheel arrangement according to claim 4 , characterized in that the auxiliary device ( 30 ) comprises a rotary member ( 34 ) and in that it comprises means ( 36 ) for the connection in rotation of the rotary member ( 34 ) and the wheel ( 14 ), which means extend generally along the axis of rotation of the wheel, through the rotating antenna ( 74 ) and the fixed antenna ( 78 ).
6. Wheel arrangement according to claim 5 , characterized in that the means ( 36 ) for connection in rotation comprise a rotating core ( 50 , 54 , 80 ) which is fixedly joined to the wheel ( 14 ) and which is engaged through the spindle ( 12 ), and in that the rotating antenna ( 74 ) is carried by the rotating core ( 50 , 54 , 80 ) and is fixed for rotation therewith.
7. Wheel arrangement according to claim 5 , characterized in that the connecting means ( 36 ) comprise a mechanism ( 56 ) for coupling in rotation the wheel and the rotary member ( 34 ) of the auxiliary device ( 32 ), which coupling means are suitable for compensating for any axial offsetting between the wheel ( 14 ) and the rotary member ( 34 ).
8. Wheel arrangement according to claim 4 , characterized in that the auxiliary device comprises a tachometer ( 32 ).