Nsk Corporation

Proterial, Ltd.

Takahiro Odera

Masahiro Kobayashi

Kota Fukuda

Naoki Futakuchi

Hisayoshi Fukui

Teruyuki Nakamura

Junji Ono

Ken Okuyama

Takashi Onimoto

Yoshinori Kubo

Haruhiko Tanno

The torque measuring device includes: a casing made of a magnetic metal; a rotating shaft rotatably arranged inside the casing and having a magnetostrictive effect section whose magnetic permeability changes according to torque to be transmitted; and a torque sensor arranged around the magnetostrictive effect section and supported by the casing, the torque sensor including a coil unit formed in a cylindrical shape using a flexible substrate having a detection coil that changes voltage in response to changes in the magnetic permeability of the magnetostrictive effect section, and a holder made of rubber or synthetic resin, covering an outer peripheral surface of the coil unit, and having a portion that protrudes from the coil unit on both sides in an axial direction; and the torque sensor supported by the casing with an outer peripheral surface of the holder fitted into an inner peripheral surface of the casing.

Torque measuring device

A torque measuring device includes a bridge circuit in which four detection coils arranged around a magnetostrictive effect section of a rotating shaft are arranged on four sides; and the bridge circuit includes a resistance element connected to at least one of the four sides for adjusting a resistance value of the side.

A torque measuring device includes: a coil unit having a detection coil configured to change a voltage in response to a change in magnetic permeability of a magnetostrictive effect section of a rotating shaft; a back yoke arranged coaxially around the coil unit; a holder configured to hold the coil unit and the back yoke; and an electronic circuit including the detection coil and configured to generate an output voltage according to a voltage of the detection coil, a clearance in a radial direction is provided between an outer peripheral surface of the coil unit and an inner peripheral surface of the back yoke, and a range of change in the clearance that accompanies temperature change during use is regulated to a range in which a change in the output voltage is linear with respect to the change in the clearance.

The manufacturing method includes: performing testing of samples having the same configuration as the torque measuring device to be manufactured to find a coil balance Cthat is a ratio (R1×R3)/(R2×R4) of a product R1×R3 of resistance values R1 and R3 of one pair of opposite sides of the four sides of a bridge circuit, and a product R2×R4 of resistance values R2 and R4 of another pair of opposite sides of the four sides, and a temperature change rate Vof output voltage Vo of a sensor portion, and acquiring a relationship X between the coil balance Cand the temperature change rate Vfrom the test results; and measuring the resistance values R1, R2, R3, R4 of the four sides to find the coil balance Cto find the temperature change rate Vfrom the relationship X for the torque measuring device to be manufactured.

Torque measuring device and manufacturing method thereof

A torque measurement device includes a case that does not rotate even during use; a rotating shaft rotatably supported to the case and having a magnetostrictive effect part whose magnetic permeability changes according to a transmitted torque; and a magnetostrictive sensor having a detection part arranged closely adjacent to the magnetostrictive effect part so that a voltage changes according to change of the magnetic permeability of the magnetostrictive effect part, and being supported to the case; and the torque measurement device has a rotation-preventing construction configured to prevent the magnetostrictive sensor from rotating with respect to the case.

Torque measurement device

A torque measuring device includes: a magnetostrictive sensor having a ring-shaped holder arranged around a magnetostrictively affected section of a rotating shaft, a detecting section embedded in the holder and that changing a voltage according to a change in magnetic permeability of the magnetostrictively affected section; and a sensor-side engaging section; and a fixed member having a fixed-side engaging section, the fixed member not rotating even during operation. One of the sensor-side engaging portion and the fixed-side engaging section is a convex section and the other is a concave section. With the sensor-side engaging section and the fixed-side engaging section engaged with a concave-convex engagement, shifting of the position of the magnetostrictive sensor in the direction of rotation and the radial direction with respect to the substrate is prevented.

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Shizuoka, Japan

Takahiro Odera