Classifications

• • 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
  • G01B7/30—Measuring arrangements characterised by the use of electric or magnetic techniques for measuring angles or tapers; for testing the alignment of axes
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
  • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
  • G01D5/204—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the mutual induction between two or more coils
  • G01D5/2053—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature by influencing the mutual induction between two or more coils by a movable non-ferromagnetic conductive element
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
  • G01D5/00—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable
  • G01D5/12—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means
  • G01D5/14—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage
  • G01D5/20—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature
  • G01D5/22—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils
  • G01D5/2208—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils by influencing the self-induction of the coils
  • G01D5/2225—Mechanical means for transferring the output of a sensing member; Means for converting the output of a sensing member to another variable where the form or nature of the sensing member does not constrain the means for converting; Transducers not specially adapted for a specific variable using electric or magnetic means influencing the magnitude of a current or voltage by varying inductance, e.g. by a movable armature differentially influencing two coils by influencing the self-induction of the coils by a movable non-ferromagnetic conductive element

Definitions

• the invention relates to a measuring device for determining the angle of rotation according to the preamble of the main claim.
• the rotation of a shaft is determined with the aid of two disks which are movable relative to one another.
• the disks have slots that form the electrically non-conductive area.
• a coil through which a high-frequency alternating current flows is arranged at least on the end face of a disk in the region of the slots.
• the relative displacement of the disks relative to one another means that the electrically non-conductive surface of the disks, i.e. changes the opening area of the slots, thereby varying the damping of the coil.
• the measuring device has the disadvantage that the axes of the disks have to be centered exactly with respect to one another, so that any axial play can have an effect as a measurement error.
• the measuring device with the characterizing features of claim 1 has the advantage that the device is relatively small. Both the radial play and the axial play of the measuring device are largely compensated for.
• the resolution of the measurement signal is very large and its linearity within the relatively large measurable angular range is very good.
• the coils can be prefabricated using etching technology or thick-film technology and glued to the inner wall of a sleeve. As a result, the distance between the coils and the current conducting piece can be minimized and the measuring sensitivity can thus be improved. With a particularly small design, relatively large angular ranges can be measured.
• the Strom ⁇ Leit published is moved perpendicular to the measuring coil axis, resulting in a particularly good measurement effect.
• FIG. 1 shows a sleeve with coils applied and FIG. 2 shows a current conducting piece.
• a sleeve-shaped support, indicated by 10, made of electrically non-conductive material is indicated, on the inner wall of which four coils 11, 12, 13, 14 are arranged. Two coils 11, 13 and 12, 14 are arranged diametrically opposite one another.
• the measuring angle of the measuring device is determined by the size of the coils 11 to 14.
• the coils 11 to 14 can be arranged in a meandering shape or in the form of a rectangle. They are preferably designed as flat coils and glued in the form of foils to the inner wall of the carrier 10.
• the coils 11 to 14 can be applied in known etching technology or in thick-film technology to a suitably designed flexible film. But it is also possible that To arrange the carrier film on the outer wall of the carrier.
• the coils can also be wound with wire.
• FIG. 2 shows a current-conducting piece 20 which is of mirror-image design and has two regions 21, 22 made of electrically conductive material, which face the coils and are aligned with the radius of the carrier 10. Electrically non-conductive regions 23, 24 are located between the regions 21, 22. This can be achieved by means of a recess and the air gap which results from this, or by a surface made of electrically non-conductive material.
• the angular range of the areas 21, 22 is greater than the angular range of the coils 11 to 14, so that the areas 21, 22 each always at least partially cover two coils.
• the current conducting piece 20 can consist entirely of electrically conductive material, or a layer of electrically conductive material on the surface of the regions 21, 22 facing the coils is sufficient.
• the current conducting piece 20 is connected to a component, not shown here, whose rotational movement is to be detected.
• the measuring device works on the inductive or eddy current measuring principle.
• a high-frequency alternating current flows through the coils.
• the current guide piece 20 is rotated in the carrier 10 for the measurement.
• a magnetic alternating field is created on the coils, which causes 20 eddy currents on the installation surface of the current conducting piece.
• the size of the eddy currents generated depends on the material used for the current conducting piece, in particular its surface, and on the distance of the coils from the surfaces of the current conducting piece.
• the eddy currents generated reduce the coil AC resistance, which causes a reduction in the voltages applied to the coils.
• the respective one becomes Coils associated size of the surface of the areas 21, 22 of the current guide 20 changed.
• the surface of the current conducting piece assigned to the coils is increased by the same amount as it is reduced in the other coil. Since the current conducting piece is mirror-inverted, the change in the eddy current resistance is also effected, as described above, between the opposing coils 12, 14.
• the diametrically opposite coils are connected in such a way that their field directions are rectified, ie that both field directions point away from or point to the sensor axis, but the coils which follow one another on the carrier 10 are wound in such a way that their field directions are opposed.
• the voltages of the opposite coils are added and then the sums are rectified and subtracted from each other. Traps z. If, for example, the axes of the carrier 10 and the current conducting piece 20 are not exactly together during assembly, the measuring device has a certain radial play. As a result of the axially symmetrical arrangement of both the current conducting piece 20 and the coils, the increase in voltage caused on one side is compensated for by the corresponding decrease in voltage on the other side. In addition, if the width of the coils is larger or smaller than the width of the current conducting piece, an axial play caused by the installation can also be compensated for. In this case, too, the diametrically opposed measuring errors compensate each other.

Landscapes

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

Priority Applications (1)

Applications Claiming Priority (2)

Publications (1)

Family

ID=6353539

Family Applications (1)

Country Status (6)

Cited By (1)

Families Citing this family (6)

Citations (3)

Family Cites Families (4)

• 1988
  • 1988-05-04 DE DE3815074A patent/DE3815074A1/de active Granted
• 1989
  • 1989-04-14 JP JP1504059A patent/JPH03504158A/ja active Pending
  • 1989-04-14 EP EP19890904011 patent/EP0414699A1/de not_active Withdrawn
  • 1989-04-14 WO PCT/DE1989/000224 patent/WO1989011077A1/de not_active Application Discontinuation
  • 1989-04-14 KR KR1019890702500A patent/KR900700848A/ko not_active Withdrawn
  • 1989-05-04 ES ES8901535A patent/ES2014077A6/es not_active Expired - Lifetime

Patent Citations (3)

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