1. A rolling bearing device with a sensor comprising:
a first raceway member including a peripheral surface having a raceway surface;
a second raceway member including a peripheral surface having a raceway surface and an annular displacement-detected portion;
rolling elements arranged between the raceway surfaces of the first and second raceway members;
a sensor unit that detects radial displacement and axial displacement of the displacement-detected portion; and
a calculator,
wherein the sensor unit includes:
a first displacement detector including a detection surface that radially faces the displacement-detected portion;
a second displacement detector located at a distance axially from the first displacement detector, and including a detection surface that radially faces the displacement-detected portion,
wherein the first displacement detector and the second displacement detector substantially axially overlap each other, and each of the first displacement detector and the second displacement detector includes four displacement sensors arranged at substantially regular intervals in a circumferential direction,
wherein the calculator calculates translational loads that act on the displacement-detected portion, and moment loads that act on the displacement-detected portion on the basis of
fi\u2212ri,
ti\u2212bi,
fo\u2212ro,
to\u2212ro, and
a value that is obtained by subtracting from an output of one sensor of the first displacement detector an output of one sensor of the second displacement detector that substantially overlaps the one sensor axially, or a value that is obtained by subtracting from the sum of outputs of a plurality of sensors of the first displacement detector the sum of outputs of a plurality of sensors of the second displacement detector that substantially overlap the plurality of sensors axially,
where outputs of the four sensors of the first displacement detector are represented by fi, ri, ti, and bi, respectively, and outputs of the four sensors of the second displacement detector are represented by fo, ro, to, and bo, respectively, and
where fi and ri are outputs of two sensors of the first displacement detector located substantially line-symmetrically with respect to a central axis of the second raceway member, ti and bi are outputs of the other two sensors of the first displacement detector located substantially line-symmetrically with respect to the central axis of the second raceway member, fo is an output of a sensor that substantially overlaps the sensor outputting fi axially, ro is an output of a sensor that substantially overlaps the sensor outputting ri axially, to is an output of a sensor that substantially overlaps the sensor outputting ti axially, and bo is an output of a sensor that substantially overlaps the sensor outputting bi axially.
2. The rolling bearing device according to claim 1,
wherein the second raceway member includes a wheel-attaching flange for attaching a wheel of a vehicle, and the first raceway member includes a body-attaching flange for attaching a body of the vehicle,
wherein the raceway surface of the first raceway member is located radially outside the raceway surface of the second raceway member,
wherein, in a state where the second raceway member is arranged in a predetermined position,
a detection surface of the sensor outputting fi radially faces a portion of the displacement-detected portion that is located substantially on a front side of the vehicle,
a detection surface of the sensor outputting ri radially faces a portion of the displacement-detected portion that is located substantially on a rear side of the vehicle,
a detection surface of the sensor outputting ti radially faces a portion of the displacement-detected portion that is located substantially on a vertical top side of the vehicle, and
a detection surface of the sensor outputting bi radially faces a portion of the displacement-detected portion that is located substantially on a vertical bottom side of the vehicle, and
wherein the calculator calculates a translational load in a vertical direction of the vehicle, a translational load in a traveling direction of the vehicle, a translational load in an axial direction of the wheel, a moment load around the vertical direction of the vehicle, and a moment load around the traveling direction of the vehicle, based on fi\u2212ri, ti\u2212bi, fo \u2212ro, to\u2212ro, (fi+ri+ti+bi\u2212(fo+ro+to+bo)) and twenty-five constants.
3. The rolling bearing device according to claim 1,
wherein the second raceway member includes a wheel-attaching flange for attaching a wheel of a vehicle, and the first raceway member includes a body-attaching flange for attaching a body of the vehicle,
wherein the raceway surface of the first raceway member is located radially outside the raceway surface of the second raceway member,
wherein, in a state where the second raceway member is arranged in a predetermined position,
a detection surface of the sensor outputting fi radially faces a portion of the displacement-detected portion that is located substantially on the front side of the vehicle,
a detection surface of the sensor outputting ri radially faces a portion of the displacement-detected portion that is located substantially on the rear side of the vehicle,
a detection surface of the sensor outputting ti radially faces a portion of the displacement-detected portion that is located substantially on the vertical top side of the vehicle, and
a detection surface of the sensor outputting bi radially faces a portion of the displacement-detected portion that is located substantially on the vertical bottom side of the vehicle, and
wherein the calculator calculates Fx, Fy, Fz, Mz and Mx based on (i) four values selected from fi\u2212ri, ti\u2212bi, fo\u2212ro, to\u2212ro and (fi+ri+ti+bi\u2212(fo+ro+to+bo)), (ii) sixteen constants, and (iii) a relational expression Fy=MxR,
where a radius of the wheel is represented by Rm, a translational load in a vertical direction of the vehicle is represented by FzN, a translational load in a traveling direction of the vehicle is represented by FxN, a translational load in an axial direction of the wheel is represented by FyN, a moment load around the vertical direction of the vehicle is represented by MzN\xb7m, and a moment load around the traveling direction of the vehicle is represented by MxN\xb7m.
4. The rolling bearing device according to claim 1,
wherein the sensor unit includes:
a rotation-signal extractor that extracts a rotational synchronization component included in the rotation of the second raceway member relative to the first raceway member based on each of a signal output by the first displacement detector and a signal output by the second displacement detector; and
a displacement signal calculator that calculates a signal associated with the displacement of the displacement-detected portion based on an output of the first displacement detector, an output of the second displacement detector, and an output of the rotation-signal extractor.
5. The rolling bearing device according to claim 4,
wherein the first displacement detector and the second displacement detector substantially axially overlap each other, and each of the first displacement detector and the second displacement detector includes four displacement sensors arranged at substantially regular intervals in the circumferential direction,
wherein the sensor unit includes an orthogonal component calculator that calculates, based on a signal of the first displacement detector and a signal of the second displacement detector, a first displacement signal representing the displacement of the displacement-detected portion on a first axis that extends radially, and a second displacement signal representing the displacement of the displacement-detected portion on a second axis that is orthogonal to the first axis and extends radially, and
wherein the rotation-signal extractor includes:
a first calculator that converts the first displacement signal and the second displacement signal into two signals in a first rotating coordinate system that rotates at the same rotational speed as the rotational speed of the second raceway member relative to the first raceway member, and that is composed of two axes that extend radially and are orthogonal to each other;
a second calculator that performs time integration on each of the two signals output by the first calculator to output two signals; and
a third calculator that converts the two signals output by the second calculator into two signals in a second rotating coordinate system that rotates in a direction opposite to the first rotating coordinate system at same rotational speed as the first rotating coordinate system and that is composed of two axes that extend radially and are orthogonal to each other.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A three-phase motor having a stator formed by sequentially inserting winding coils of three phases of U-phase, V-phase and W-phase into slots provided on an inner circumferential surface of a stator core,
wherein the winding coil of each phase is formed by connecting plural unipolar coils formed by winding electric wires in plural turns, and each of the unipolar coils includes a pair of insertion parts to be inserted into the slots and a pair of coil end parts connecting the pair of insertion parts, and
the winding coils of the three phases have the relationships of CvCu <1.0 and CwCv <1.0, where Cu represents an average length of the electric wires forming the coil end parts of each of the unipolar coils in the winding coil of U-phase, Cv represents an average length of the electric wires forming the coil end parts of each of the unipolar coils in the winding coil of V-phase, and Cw represents an average length of the electric wires forming the coil end parts of each of the unipolar coils in the winding coil of W-phase.
2. The three-phase motor as claimed in claim 1, wherein the pair of insertion parts of each unipolar coil of U-phase is inserted in the slots, with an insertion part of the pair of insertion parts inserted into an appropriate slot, and the pair of coil end parts of the each unipolar coil of U-phase protrudes from the end parts in the axial direction of the stator core, and
the pair of insertion parts of the each unipolar coil of V-phase is offset from a corresponding unipolar coil of U-phase by a predetermined number of slots in one circumferential direction of the stator core as the pair of insertion parts are inserted in the slots, and the pair of coil end parts of the unipolar coils of V-phase are partly superposed on the inner circumferential side of the pair of coil end parts of the unipolar coils of U-phase, and
the pair of insertion parts of the each unipolar coil of W-phase is offset from a corresponding unipolar coil of V-phase by a predetermined number of slots in the one circumferential direction of the stator core as the pair of insertion parts are inserted in the slots, and the pair of coil end parts of the unipolar coils of W-phase are partly superposed on the inner circumferential side of the pair of coil end parts of the unipolar coils of V-phase.
3. The three-phase motor as claimed in claim 2, wherein the ratio CvCu and the ratio CwCv are substantially equal.
4. The three-phase motor as claimed in claim 3, wherein the circumferential length of the electric wires forming the unipolar coils of at least one of the winding coils of the three phases becomes shorter toward the outer circumferential side of the stator core.
5. The three-phase motor as claimed in claim 4, wherein with respect to the rate of change of the circumferential length of the unipolar coils, the rate of change in the unipolar coils of U-phase is higher than the rate of change in the unipolar coils of V-phase, and that the rate of change in the unipolar coils of V-phase is higher than the rate of change in the unipolar coils of W-phase.
6. The three-phase motor as claimed in claim 2, wherein the circumferential length of the electric wires forming the unipolar coils of at least one of the winding coils of the three phases becomes shorter toward the outer circumferential side of the stator core.
7. The three-phase motor as claimed in claim 6, wherein with respect to the rate of change of the circumferential length of the electric wires, the rate of change in the unipolar coils of U-phase is higher than the rate of change in the unipolar coils of V-phase, and that the rate of change in the unipolar coils of V-phase is higher than the rate of change in the unipolar coils of W-phase.
8. The three-phase motor as claimed in claim 1, wherein the ratio CvCu and the ratio CwCv are substantially equal.
9. The three-phase motor as claimed in claim 8, wherein the circumferential length of the electric wires forming the unipolar coils of at least one of the winding coils of the three phases becomes shorter toward the outer circumferential side of the stator core.
10. The three-phase motor as claimed in claim 9, wherein, with respect to the rate of change of the circumferential length of the electric wires, the rate of change in the unipolar coils of U-phase is higher than the rate of change in the unipolar coils of V-phase, and that the rate of change in the unipolar coils of V-phase is higher than the rate of change in the unipolar coils of W-phase.
11. The three-phase motor as claimed in claim 1, wherein the circumferential length of the electric wires forming the unipolar coils of at least one of the winding coils of the three phases becomes shorter toward the outer circumferential side of the stator core.
12. The three-phase motor as claimed in claim 1, wherein CvCu=0.88 to 0.98 and CwCv=0.88 to 0.98.
13. The three-phase motor as claimed in claim 12, wherein CvCu=0.90 to 0.95 and CwCv=0.90 to 0.95.
14. A three-phase motor having a stator formed by inserting winding coils of three phases of U-phase, V-phase and W-phase into slots provided on an inner circumferential surface of a stator core,
wherein the winding coil of each phase has plural unipolar coils formed by winding electric wires in plural turns, a connecting wire for connecting the unipolar coils, and a pair of lead parts formed by leading out the electric wires from unipolar coils situated at both ends of each of the plurality of winding coils, and each of the unipolar coils includes a pair of insertion parts to be inserted into the slots and a pair of coil end parts connecting the pair of insertion parts, and
with respect to average circumferential lengths of the unipolar coils in the winding coils of the three phases, the average circumferential length in the unipolar coils of V-phase is shorter than the average circumferential length in the unipolar coils of U-phase, and the average circumferential length in the unipolar coils of W-phase is shorter than the average circumferential length in the unipolar coils of V-phase, and
the pair of insertion parts of the unipolar coils of U-phase are inserted in the slots and the pair of coil end parts of the winding coils of U-phase protrude from end parts in an axial direction of the stator core, and
the pair of insertion parts of the unipolar coils of V-phase are offset from the unipolar coils of U-phase by a predetermined number of slots in a first direction, which is one circumferential direction of the stator core, as they are inserted in the slots, and the pair of coil end parts of the unipolar coils of V-phase are partly superposed on an inner circumferential side of the pair of coil end parts of the unipolar coils of U-phase, and
the pair of insertion parts of the unipolar coils coil of W-phase are offset from the unipolar coils of V-phase by a predetermined number of slots in the first direction of the stator core as they are inserted in the slots, and the pair of coil end parts of the unipolar coils of W-phase are partly superposed on an inner circumferential side of the pair of coil end parts of the unipolar coils of V-phase.
15. The three-phase motor as claimed in claim 14, wherein, of the pair of lead parts of the winding coil of each phase, the lead part situated at an end part in a second direction, which is opposite to the first direction of the stator core, is used as a neutral point side lead part, and the neutral point side lead parts of the winding coils of the three phases are bundled to form a neutral point at a position where an offset from the winding coil of U-phase by a predetermined angle in the second direction is made, so that the neutral point side lead part of the winding coil of V-phase is longer than the neutral point side lead part of the winding coil of U-phase, and the neutral point side lead part of the winding coil of W-phase is longer than the neutral point side lead part of the winding coil of V-phase.
16. The three-phase motor as claimed in claim 14, wherein an average circumferential length Lv of the unipolar coils in the winding coil of V-phase and an average circumferential length Lw of the unipolar coils in the winding coil of W-phase satisfy the following relational equations:
Lv=(S*Lu*n*m\u22122*\u03c0*R*Sv)(S*n*m) and
Lw=(S*Lu*n*m\u22122*\u03c0*R*Sw)(S*n*m)
where Lu represents the average circumferential length of the unipolar coils in the winding coil of U-phase,
n represents the number of turns of each unipolar coil in the winding coil of each phase,
m represents the number of poles of the unipolar coils in the winding coil of each phase,
\u03c0(pi) represents the ratio of the circumference of a circle to its diameter,
R represents the radius from the center of the stator core to the center in the radial direction of the slot,
S represents the total number of slots in the stator core,
Sv represents the number of slots by which the unipolar coils of V-phase are offset from the unipolar coils of U-phase in the first direction of the stator core, and
Sw represents the number of slots by which the unipolar coils of W-phase are offset from the unipolar coils of U-phase in the first direction of the stator core.
17. The three-phase motor as claimed in claim 16, wherein the circumferential length of the electric wires forming the unipolar coils in the winding coils of U-phase and V-phase becomes shorter toward the outer circumferential side of the stator core.
18. The three-phase motor as claimed in claim 17, wherein with respect to the rates of change of the circumferential length of the electric wires, the rate of change in the unipolar coils of U-phase is higher than the rate of change in the unipolar coils of V-phase.
19. The three-phase motor as claimed in claim 14, wherein the circumferential length of the electric wires forming the unipolar coils in the winding coils of U-phase and V-phase becomes shorter toward the outer circumferential side of the stator core.
20. The three-phase motor as claimed in claim 19, wherein with respect to the rates of change of the circumferential length of the electric wires, the rate of change in the unipolar coils of U-phase is higher than the rate of change in the unipolar coils of V-phase.