Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01L—MEASURING FORCE, STRESS, TORQUE, WORK, MECHANICAL POWER, MECHANICAL EFFICIENCY, OR FLUID PRESSURE
  • G01L3/00—Measuring torque, work, mechanical power, or mechanical efficiency, in general
  • G01L3/02—Rotary-transmission dynamometers
  • G01L3/04—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft
  • G01L3/10—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating
  • G01L3/101—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating involving magnetic or electromagnetic means
  • G01L3/104—Rotary-transmission dynamometers wherein the torque-transmitting element comprises a torsionally-flexible shaft involving electric or magnetic means for indicating involving magnetic or electromagnetic means involving permanent magnets
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01B—MEASURING LENGTH, THICKNESS OR SIMILAR LINEAR DIMENSIONS; MEASURING ANGLES; MEASURING AREAS; MEASURING IRREGULARITIES OF SURFACES OR CONTOURS
  • G01B7/00—Measuring arrangements characterised by the use of electric or magnetic techniques
  • G01B7/16—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge
  • G01B7/24—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring the deformation in a solid, e.g. by resistance strain gauge using change in magnetic properties

Definitions

• the invention relates to a sensor arrangement for detecting changes in angle, in particular for torsion measurement on axes, according to the preamble of the main claim.
• a sensor arrangement is already known from US Pat. No. 5,501,110 in which the torque transmitted to an axis is to be recorded.
• the torque is determined from the torsion or the angle of rotation of the axle ends and a constant that depends on the material and the geometry of the axle.
• the sensor arrangement for detecting small angle changes on moving mechanical components with the generic features of the main claim is further developed with the features according to the invention in an advantageous manner, since a sensor with high sensitivity is used here.
• the magnetoresistive sensor is arranged opposite the one pole of the magnet in such a way that the magnetic field-sensitive layer is tangent to the rotation causing the change in angle. This advantageously takes advantage of the fact that a strong change in the direction of the field lines occurs in a small space (for example> 1 mm) above the pole of the magnet.
• the magnetoresistive sensors according to the invention are linearly controlled due to their pronounced sensitivity to a (here tangential) directional component of the field lines and thus allow a measurement of very small angle changes when the magnet or the sensor rotates.
• a preferred application of the invention results in a sensor arrangement for detecting the torque on an axis, which is known per se from the aforementioned US Pat. No. 5,501,110.
• the magnet and the sensor are each mechanically coupled to different positions of the axis in the axial direction and lie opposite one another in such a way that torsion of the axis can be detected as a change in angle.
• the measuring arrangement can advantageously be implemented by arranging two sensors in the magnetic field of the magnet and interconnecting them in such a way that their differential output can be set to zero without changing the angle.
• the zero point is when the rotating axis is not loaded.
• a relative rotation of the parts with the magnet and the sensors causes a difference in the electrical analog outputs of the two sensors, which can be output directly as torque by electronic signal processing.
• AMR anisotropic magnetoresistive
• GMR giant magnetoresistive
• CMR colossal magnetoresistive
• Figure 1 is a schematic view of a support member for a magnet, the support member being attachable to an axle end
• FIG. 2 shows a view of a magnetoresistive sensor which is arranged in the region of the field lines of the magnet according to FIG. 1.
• a carrier part 1 is shown, which is fastened with a shaft 2 on a rotating axis, not shown here.
• the carrier part 1 rotates with the axis about the coordinate z.
• the magnet 3 with the field lines 4 is shown in detail in FIG.
• a magnetoresistive sensor 5 is arranged opposite the one pole of the magnet 3. For better clarity, a coherent representation of the arrangement of the carrier part 1 with a corresponding carrier part for the sensor 5 has been omitted.
• the sensor 5 must be arranged so that it comes to lie in the area of the field lines 4.
• the carrier part for the sensor 5 is fastened to another axis end as the carrier part 1, so that a relative rotation of the magnet 3 and the sensor 5 relative to one another, caused by a torsion of the axis, can be measured. Since the magnetoresistive sensor 5 has a particular sensitivity with regard to the x component of the field lines 4, a rotation of one of the two components 3 or 5 about the z axis has an effect with a strong change in the output signal of the sensor 5 even with small changes in angle.
• the field line 4.1 has an x component of zero and thus the immediately adjacent field line 4.2 already experiences an easily measurable increase in the x component. In this way, in particular small changes in angle, which occur with the relatively low torsion, can be measured and a precise determination of the torque acting on the axis is possible.

Landscapes

• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Electromagnetism (AREA)
• Transmission And Conversion Of Sensor Element Output (AREA)
• Measurement Of Length, Angles, Or The Like Using Electric Or Magnetic Means (AREA)
• Measuring Magnetic Variables (AREA)

Applications Claiming Priority (3)

Publications (1)

Family

ID=7852827

Family Applications (1)

Country Status (7)

Families Citing this family (9)

Family Cites Families (21)

• 1997
  • 1997-12-20 DE DE19757008A patent/DE19757008A1/de not_active Ceased
• 1998
  • 1998-12-02 US US09/355,042 patent/US6205866B1/en not_active Expired - Fee Related
  • 1998-12-02 WO PCT/DE1998/003539 patent/WO1999032867A1/de not_active Application Discontinuation
  • 1998-12-02 EP EP98966186A patent/EP0975943A1/de not_active Withdrawn
  • 1998-12-02 JP JP53314199A patent/JP2001513901A/ja active Pending
  • 1998-12-02 CZ CZ992916A patent/CZ291699A3/cs unknown
  • 1998-12-07 TW TW087120244A patent/TW406187B/zh not_active IP Right Cessation

Non-Patent Citations (1)

Also Published As

Similar Documents

Legal Events