Electricity: measuring and testing – Magnetic – Displacement
Patent
1990-12-10
1992-06-30
Strecker, Gerard R.
Electricity: measuring and testing
Magnetic
Displacement
30420722, 30420725, G01B 730, G01B 714
Patent
active
051266652
DESCRIPTION:
BRIEF SUMMARY
BACKGROUND OF THE INVENTION
The invention relates to a device for measuring the angle of rotation and including two bodies having areas of electrically conductive and/or ferromagnetic material, and sensor coils whose resistance changes as a function of change in the magnitude of area of one of the bodies assigned to sensor coils. In a known measuring device the rotation of a shaft is determined by two concentrically arranged sleeves which are moved relative to one another. One of the sleeves comprises two rows of slots which are offset relative to one another and form the electrically nonconductive area. In the other sleeve, a row of continuous slots is formed which likewise extend in the direction of the sleeve axis. At least one coil, through which a high-frequency alternating current flows, is arranged in the area of the two slot rows of the first sleeve. The electrically nonconductive surface of the sleeves, i.e. the opening surface of the slots, is changed by relative tangential displacement of the two sleeves relative to one another, so that the damping of the coils is varied. The measuring device has the disadvantage that only small angles of rotation are measurable.
SUMMARY OF THE INVENTION
The object of the invention in a measuring device, having a relatively small size and able to measure angles of up to 180.degree.. The object of the invention is achieved by dividing one body into a number of areas corresponding to the number of coils with a coil arranged on each area and by location the second body in a recess of the one body. Because of the semicircular construction of the coil body, the diameter of the sensor can be small. The coil body is constructed with consideration to manufacturing, so that the coil can be wound relatively simply, and a simple overall assembly of the sensor is possible. Coils with an overall width of 1 to 2 mm already deliver a relatively high measurement signal. The measurement errors caused by the axial play of the coil body and the measurement part do not occur or are only negligibly small. Since the coils are comprised in a compensating circuit, the temperature-dependent transmitteroffset drift is low.
The present invention both as to its construction so to its method of operation, together with additional objects and advantages thereof, will be best understood from the following detailed description of the preferred embodiments when read with reference the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 shows an exploded view of the measuring device according to the invention;
FIG. 2 shows a perspective view of the measuring part;
FIG. 3 shows a cross-sectional view of another embodiment of the measuring device according to the invention;
FIG. 4 shows a side view in the direction IV--IV according to FIG. 3; and FIG. 5 shows an electrical circuit of the device.
DESCRIPTION OF THE PREFERRED EMBODIMENTS
A sensor comprising a cylindrical coil body 11 is designated by 10 in FIG. 1. The latter is produced from a solid cylinder of material which is preferably electrically nonconductive. The cylinder has a central longitudinal groove 12 proceeding from a front end surface. Two cores 13, 14 which are semicircular in cross-section are accordingly formed, a coil 15, 16 being wound on each of the cores. They are connected in a Wheatstone bridge as shown in FIG. 5. The coils 15, 16 are wound in the circumferential direction of the coil body 11. A measuring part 17 comprising metallic, electrically conductor and/or ferromagnetic material is arranged at a slight distance around the coil body 11 and is constructed as a sleeve segment and overlaps half of the circumference of the coil body as seen approximately in the circumferential direction. The length of the measuring part 17 should preferably be equal at least to the width of the coils 15 and 16, respectively. The measuring part 17 is connectable with a structural component part, not shown, whose rotational movement is to be determined.
In the initial position, the measuring part 17 is aligned in such
REFERENCES:
patent: 2949576 (1960-08-01), Bolton
patent: 3020527 (1962-02-01), MacLaren
patent: 3439256 (1969-04-01), Kahne
patent: 4013911 (1977-03-01), Fujiwara et al.
patent: 4764767 (1988-08-01), Ichikawa et al.
patent: 5027067 (1991-06-01), Witzig et al.
Dobler Klaus
Hachtel Hansjorg
Robert & Bosch GmbH
Strecker Gerard R.
Striker Michael J.
LandOfFree
Device for measuring an angle of rotation of a rotatable structu does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Device for measuring an angle of rotation of a rotatable structu, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Device for measuring an angle of rotation of a rotatable structu will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1866368