Sensor-mounted roller bearing apparatus

1. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring attached to a fixing part, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein the apparatus comprises piezoelectric elements in the form of a film interposed between said fixed bearing ring and said fixing part so as to detect loads applied between said fixed bearing ring and said fixing part, and

wherein said piezoelectric elements are interposed between said fixing part and an outer periphery of said fixed bearing ring and between said fixing part and a flange integrally formed on an outer periphery of said fixed bearing ring to detect both axial loads applied in the axial direction of said bearing and radial loads applied in the radial direction of said bearing, and the fixing part and the fixed bearing ring with the integrally formed flange are separate members from each other.

2. The sensor-mounted roller bearing apparatus according to claim 1 , wherein said fixed bearing ring consists of an outer ring having a flange that is fixed to an annular knuckle included in a suspension of a vehicle; wherein four of said piezoelectric elements are interposed between the axial end surface of said outer ring flange and the axial end surface of said knuckle at intervals of 90° around the axis of said bearing to detect axial loads applied in the axial direction of said bearing; wherein four of said piezoelectric elements are interposed between the outer periphery of said outer ring and the inner periphery of said knuckle at intervals of 90° around the axis of said bearing to detect radial loads applied in the radial direction of said bearing.

3. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein load sensors that detect loads applied between said fixed bearing ring and a fixing part to which said fixed bearing ring is fixed are provided on a fixing means that fixes said fixed bearing ring and said fixing part,

wherein the fixing means extends through a through hole formed in said fixing part and said load sensors are disposed within said through hole, and

wherein said load sensors are piezoelectric elements that are built into said fixing means or attached to the surface of said fixing means in a manner in which they are interposed between said fixing means and said fixing part and supply signals according to the load.

4. The sensor-mounted roller bearing apparatus according to claim 3 , wherein said load sensors consist of two strain gauges connected to each other in series so that said load sensors detect strain generated in said fixing means depending on said load and of flexural and tensile strain components, one strain component is canceled and only the other strain component is detected.

5. The sensor-mounted roller bearing apparatus according to claim 4 , wherein said fixed bearing ring consists of an outer ring having a flange that is fixed to an annular knuckle included in a suspension of a vehicle; and said fixing means consists of multiple fixing bolts that fix said knuckle and said flange at pre-determined positions different from each other around the axis of said bearing, respectively.

6. The sensor-mounted roller bearing apparatus according to claim 3 , wherein said fixed bearing ring consists of an outer ring having a flange that is fixed to an annular knuckle included in a suspension of a vehicle; and said fixing means consists of multiple fixing bolts that fix said knuckle and said flange at pre-determined positions different from each other around the axis of said bearing, respectively.

7. The sensor-mounted roller bearing apparatus according to claim 3 , wherein said fixed bearing ring consists of an outer ring having a flange that is fixed to an annular knuckle included in a suspension of a vehicle; and said fixing means consists of multiple fixing bolts that fix said knuckle and said flange at pre-determined positions different from each other around the axis of said bearing, respectively.

8. The sensor-mounted roller bearing apparatus according to claim 3 , wherein said fixing means extends completely through said though hole.

9. The sensor-mounted roller bearing apparatus according to claim 3 , wherein said through hole extends completely through said fixing part.

10. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring attached to a fixing part and a space formed therebetween, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein the apparatus comprises piezoelectric elements in the form of a film interposed in the space formed between said fixed bearing ring and said fixing part so as to detect loads applied between said fixed bearing ring and said fixing part, and

wherein the space in which the film is located is between said fixing part and an outer periphery of said fixed bearing ring and between said fixing part and a flange integrally formed on an outer periphery of said fixed bearing ring and wherein said piezoelectric elements detect both axial loads applied in the axial direction of said bearing and radial loads applied in the radial direction of said bearing, and the fixing part and the fixed bearing ring with the integrally formed flange are separate members from each other.

11. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein load sensors that detect loads applied between said fixed bearing ring and a fixing part to which said fixed bearing ring is fixed are provided on a fixing means that fixes said fixed bearing ring and said fixing part,

wherein the fixing means extends through a through hole formed in said fixing part and said load sensors are disposed around the fixing means and are disposed within said through hole, and

wherein the fixing means extends through a hole formed in said fixing part and said load sensors are disposed within said through hole for detecting directional load components in the longitudinal, vertical and transverse directions of a vehicle, respectively.

12. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein the apparatus comprises piezoelectric elements in the form of a film interposed between said fixed bearing ring and a fixing part to which said fixed bearing ring is fixed so as to detect loads applied between said fixed bearing ring and said fixing part, and

wherein said piezoelectric elements are interposed between said fixing part and an outer periphery of said fixed bearing ring and between said fixing part and a flange integrally formed on an outer periphery of said fixed bearing ring to detect individually axial load components applied in the axial direction of said bearing and radial load components applied in the radial direction of said bearing, and the fixing part and the fixed bearing ring with the integrally formed flange are separate members from each other.

13. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein load sensors that detect loads applied between said fixed bearing ring and a fixing part to which said fixed bearing ring is fixed are provided on a fixing means that fixes said fixed bearing ring and said fixing part, and

wherein the fixing means extends through a through hole formed in said fixing part and said load sensors are disposed within said through hole for detecting directional load components in the longitudinal, vertical and transverse directions of a vehicle, respectively.

14. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein load sensors that detect loads applied between said fixed bearing ring and a fixing part to which said fixed bearing ring is fixed are provided on a fixing means that fixes said fixed bearing ring and said fixing part,

wherein the fixing means extends through a through hole formed in said fixing part and said load sensors are disposed within said through hole, and

wherein said fixed bearing ring comprises a flange formed on the vehicle inner side and on the diametrically outer side, and a cylindrical part axially extended on the vehicle inner side and integrally formed with said flange, wherein an annular knuckle as said fixing part included in a vehicle suspension is fixed to said flange and cylindrical part, and wherein said piezoelectric elements are interposed between said knuckle and said flange and between said knuckle and said cylindrical part.

15. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein load sensors that detect loads applied between said fixed bearing ring and a fixing part to which said fixed bearing ring is fixed are provided on a fixing means that fixes said fixed bearing ring and said fixing part,

wherein the fixing means extends through a through hole formed in said fixing part and said load sensors are disposed within said through hole, and

wherein said fixed bearing ring comprises a flange formed on the vehicle inner side and on the diametrically outer side, and a cylindrical part axially extended on the vehicle inner side and integrally formed with said flange, wherein a bolt as said fixing means is inserted into said through hole in a manner in which an axial end surface of said flange, and an axial end surface of an annular knuckle as said fixing part included in a vehicle suspension are in area contact, and the outer periphery of said cylindrical part and the inner periphery of said knuckle are in area contact.

16. The sensor-mounted roller bearing apparatus according to claim 15 , wherein on the outer periphery of a bolt shaft inserted in said through hole formed in said knuckle, two flat areas are formed on the bolt shaft by cutting away the outer periphery of a flat surface, and wherein a pair of piezoelectric elements are respectively attached to the flat areas, so as to clamp said bolt shaft.

17. A sensor-mounted roller bearing apparatus including a bearing having a fixed bearing ring, a rotary bearing ring, and rolling elements rollably provided between said bearing rings, wherein load sensors that detect loads applied between said fixed bearing ring and a fixing part to which said fixed bearing ring is fixed are provided on a fixing means that fixes said fixed bearing ring and said fixing part,

wherein the fixing means extends through a through hole formed in said fixing part and said load sensors are disposed within said through hole, and

wherein piezoelectric elements are interposed directly between an outer surface of said fixed bearing and an innermost surface of said fixing part.