Rotation angle sensor

A Rotation angle sensor includes the following elements:

BACKGROUND OF THE INVENTION

The invention relates to a rotation angle sensor device that includes at leasta rotor unit,a stator unit,a housing unit that is at least partially positioned around the rotor unit and the stator unit, anda bearing-shaft unit by means of which at least the rotor unit may be moved with respect to the stator unit.

A rotation path sensor to recognize the position and the path of a rotatable drive shaft is known from the German Patent Publication No. DE 198 57 017 A1. The sensor includes a stator and a rotor that is provided with connecting elements to connect it to the drive shaft and to a moveable measuring disk. Between the stator and the rotor a rocker bearing is positioned at a prestated distance from the axis of the rotor and is limited by the moveable measurement disk. The rotor has two elastic flaps as connecting elements that are loaded away from each other by an elastic link in order to ensure the connection with the drive shaft at a point distant from the rocker bearing. The sensor also includes means to have it built into the drive shaft.

A disadvantage in this device lies in the fact that the rotation path sensor is mounted in an enclosed housing that must also be placed onto a throttle plate housing that is also enclosed, even if the sensor housing is partitioned. Even if the rotor shaft can be placed onto the drive shaft, the sensor housing must always be connected with the throttle plate housing separately. Also, the shaft must have separate bearings, and a return spring must be provided for the rotation path sensor.

A rotational angle sensor device consisting of a stationary and a rotating unit with a rotor axis is known from the German Patent Publication No. DE 199 03 490 A1. Along with an actuation unit, the pre-mounted units are coupled to an end of the throttle plate element.

The European Patent Publication No. EP 10 24 267 A2 describes a positioning device for a throttle plate unit in which a throttle plate is positioned within a housing unit by a throttle plate shaft so that it may be adjusted. This positioning device includes at least:A Hall-effect rotational angle sensor device mounted on a throttle plate shaft, consisting of a stationary unit and a moveable unit that may be displaced with respect to the stationary unit, a drive unit (109), andA transmission positioned between the moveable unit and the drive unit.

The housing unit at least partially surrounds the stationary and moveable unit, whereby the stationary unit consists of a first and a second stator ring arc segment that provides a stator separation recess in which at least one Hall integrated circuit is positioned and at least partially retained in the housing unit. The moveable unit consists of a ring magnet arc segment that is at least partially separated by an air gap from the first and the second stator arc segment and that, together with a third stator ring arc segment, is at least partially held together in a toothed-wheel segment of the transmission, positioned across from the air gap.

A rotational angle sensor device, particularly for a throttle plate adjustment device, is also known from the European Patent Publication No. EP 10 54 237 A2. This sensor device includes at least:a stator unit with at least two stator segment elements that are positioned together to form a separation recesswhereby at least one Hall sensor is positioned in the separation recess,a rotor unit with at least one ring magnet segment element moveable with respect to the stator unit,a plug unit, anda housing unit in which at least the stator unit is at least partially held,whereby the ring magnet segment element includes a link element andwhereby the link element of the ring magnet segment element is shaped into the rotor unit.

For the latter known devices, the shaft must have separate bearings, and a return spring must be provided for the rotor unit.

SUMMARY OF THE INVENTION

A principal object of the present invention is to provide a rotational angle sensor device which is simpler than the corresponding devices known in the art.

This object, as well as other objects which will become apparent from the discussion that follows, are achieved, in accordance with the present invention, by providing a rotation angle sensor device which comprises:(a) a rotor unit;(b) a stator unit;(c) a housing unit that is positioned at least partially around the rotor unit and the stator unit; and(d) a bearing shaft unit, with which at least the rotor unit is moveable with respect to the stator unit.

According to the invention, the rotor unit includes at least one segment magnet that is so held by a magnet receiver unit that it is positioned at least partially within a cylindrical jacket of a rotor element.

The advantages achieved via the invention particularly consist of the fact that the segment magnet is held tangential to the cylinder jacket. This ensures that, on the one hand, exact measurement values are transmitted, and on the other hand, expensive magnetic material is not required.

Further objects of the present invention are achieved by providing a rotation angle sensor device of the type described above wherein the rotary unit includes at least one rotor element, the bearing shaft unit is constructed as at least one shaft receiver recess mounted in the rotor element, and the mount of the rotor element is taken along with the mounted shaft of a rotor actuation unit inserted into the shaft receiver recess.

The advantages achieved by the invention particularly consist of the fact that the rotor element is mounted on its own bearing, and, like a parasite, the rotational angle sensor device uses the bearing mount of its “host”, thus creating a so-called flying bearing. This flying bearing may be very easily and quickly installed in that the shaft of the “host”, i.e., the shaft of the rotor actuation unit may be simply inserted into the shaft receiver recess.

The rotor and the stator units may be based on a potentiometric, Hall electronic, or resistive magnetic principle. The flying bearing may thus be used for all sensors intended to detect rotational angle or rotational movements.

The rotor unit may include at least one rotor element. A first bearing shaft unit may be formed as at least one shaft receiver recess mounted in the rotor element so that the bearing of the rotor element may be taken over with a shaft mounted in the shaft receiver recess of a rotor actuation unit.

The rotor actuation unit may be a throttle plate unit, a throttle plate adjusting unit, or the like.

It is possible for the bearing shell to be connected with the rotor unit. However, the shaft element may also be connected with the rotor unit. This ensures intentional and controlled power transfer to the rotor unit. It further ensures that the bearing shell and/or the shaft element is/are held together, along with the rotor unit.

The rotor unit my include at least one segment magnet that is held by a magnet receiver unit so that it is held at least partially within a cylindrical jacket of a rotor unit.

The rotor unit may be of a magnetic non-conducting material into which the segment magnet and the magnetic receiver unit may at least partially be formed.

The stator unit may include a stator element that allows a free space at least between its stator segment elements into which at least an application-specific integrated circuit may be positioned. Preferably two application-specific integrated circuits are positioned in the free space that may be connected with a circuit board element. This provides a rotational angle sensor that operates on the Hall electronic principle, providing sensitive detection of changing rotational angle.

The shaft element may be connected with a lever. This lever is suitable for the transfer of angular movements to the shaft element.

The housing unit may consist of a sensor housing that may be closed with a covering element. This design of the housing allows simple mounting of the stator and rotor units with their partial elements. After mounting, the housing may be closed by the covering element and correspondingly sealed.

The sensor housing may at least partially surround plug elements that are connected with at least one circuit board element. The sensor housing simultaneously forms the parts of the plug by means of which the sensor may be connected.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The preferred embodiments of the present invention will now be described with reference toFIGS. 1–4of the drawings. Identical elements in the various figures are designated with the same reference numerals.

FIGS. 1 through 4show a rotation angle sensor with a magnetic segment.

The rotation angle sensor consists ofa rotor unit4,5,17,19,20,21,22.1,22.2,22.3,23a stator unit2,3,6, anda housing unit1,7,8,16.

The rotor unit surrounds the segment magnets4that are held by a magnet receiver unit5. The magnet receiver unit5is shaped as a rotational cylinder element with a recess. The magnet segment4is positioned on the periphery of the magnet receiver unit5. The magnet receiver unit5with the segment magnet4is held by a rotational cylinder element19of a rotor element17(see particularlyFIGS. 3 & 4). The magnet receiver unit5and the magnet segment4are at least partially shaped or inserted in a cylinder jacket23of the rotational cylinder element19made of plastic.

The stator unit surrounds a stator element6that includes two stator segment elements separated by a gap. Two application-specific integrated circuits3are positioned in the space of the essentially horseshoe-shaped stator element6. The two application-specific integrated circuits3are connected with a circuit board element2. The described rotor and stator units are positioned within a sensor housing7, asFIGS. 3 & 4show. The housing7also receives a plug element16connected with the circuit board element2. Two securing sockets8are included to fasten the sensor housing7.

When these parts are mounted within the sensor housing7, it is closed with a covering element1. A cast seal18ensures that any gaps between the covering element7and the sensor housing8are sealed against liquids and dust.

A conventional bearing is provided to mount a shaft element13connected with a lever14in which a socket15is positioned.

The main elements of this mount are:A bearing shell9that looks essentially like a bobbin, andA radial shaft seal12shaped like a hollow cylinder.

The radial shaft seal is placed onto the shaft element13. A securing ring11is placed into a recess of the shaft element, and an adapter washer10is placed before it. Subsequently, the bearing shell9is pressed onto the shaft element, and this unit is inserted with the bearing shell9into a bearing opening of the sensor housing7to the point that the shaft element13is held by the rotor element17.

It is also possible that the bearing shell9is at least partially formed when the sensor housing7is formed. The bearing shell and the radial shaft seal may be made either of plastic or of metal. The material used depends on the application conditions.

Instead of the conventional bearing, a flying bearing is used in an otherwise conventionally-designed rotation angle sensor. The essence of the flying bearing consists of the use of the bearing as a “host”. This “host” may be a bearing-mounted shaft of a throttle valve or similar device.

For this, the rotor element17is provided with a shaft receiver recess20, and is divided into two clamp jaws22.1,22.2. Both clamp jaws22.1,22.2are provided with a clamp ring recess21. A spring ring may be placed into the clamp ring recess21.

A rotation angle sensor with a rotor element17so shaped is mounted as a unit, and needs only to be mounted onto the mounted shaft of the “host” e.g., a throttle valve. The rotor element17is thus also mounted using the bearing mount of the “host.” The conventional bearing described above is no longer necessary, allowing savings both in materials and assembly costs.