Sensor Arrangement and Method for Joining a Sensor Arrangement of this kind

Abstract

A sensor arrangement for detecting in a contactless manner a movement of a body that is movably mounted within a housing includes the housing, a transducer configured to be non-rotatably connected to the body and move simultaneously with the body, and a measuring apparatus that is fixedly arranged and comprises a measuring element. When the body is movably mounted in the housing, the transducer is configured, in dependence upon the movement of the body, to influence at least one physical variable that is detected by the measuring element, the measuring apparatus is connected to the first housing by way of a connecting adapter that includes, on a side that is facing the first housing, a circumferential receiving contour into which a silicone bead is introduced and pressed in between the receiving contour and the housing, and the silicone bead (fixes and seals the connecting adapter on the housing.

Claims

1. A sensor arrangement for detecting in a contactless manner a movement of a body that is movably mounted within a first housing, comprising: the first housing; a transducer configured to be non-rotatably connected to the body and move simultaneously with the body; and a measuring apparatus that is fixedly arranged and comprises a measuring element, wherein, the sensor arrangement is configured such that when the body is movably mounted in the first housing, the transducer is configured, in dependence upon the movement of the body, to influence at least one physical variable that is detected by the measuring element, the measuring apparatus is connected to the first housing by way of a connecting adapter that comprises, on a side that is facing the first housing, a circumferential receiving contour into which a silicone bead is introduced and pressed in between the receiving contour and the first housing, and the silicone bead that is pressed in fixes and seals the connecting adapter on the first housing.

2. The sensor arrangement as claimed in claim 1, wherein the connecting adaptor 484 comprises, on a side that is facing the first housing: a tube, which is inserted into a corresponding opening in the first housing, in which the transducer that is connected to the moving body is arranged.

3. The sensor arrangement as claimed in claim 2, wherein: the circumferential receiving contour is formed in a rotational symmetrical manner with a cross-section that is curved open on the outer edge of the tube that is defined by a surface of the first housing; and the silicone bead that is pressed in the receiving contour seals the connecting adaptor and the opening in the first housing.

4. The sensor arrangement as claimed in claim 1, wherein the first housing comprises a circumferential annular groove that overlaps the receiving contour on the connecting adaptor at least in part.

5. The sensor arrangement as claimed in claim 1, wherein the sensor arrangement is configured such that when the body is movably mounted in the first housing the receiving contour comprises a receiving space having a first radius that is greater than a cross-section of the silicone bead.

6. The sensor arrangement as claimed in claim 5, wherein the receiving contour comprises a displacement space having a second radius that is smaller than the first radius of the receiving space.

7. The sensor arrangement as claimed in claim 6, wherein the receiving contour comprises, between the receiving space and the displacement space, a tangential and continuously downward route having a curvature that lies opposite with regard to the receiving space and the displacement space and comprises a third radius.

8. The sensor arrangement as claimed in claim 6, wherein the receiving contour comprises at an edge of the displacement space that is remote from the receiving space an outlet.

9. The sensor arrangement as claimed in claim 6, wherein: the first housing comprises a circumferential annular groove that overlaps the receiving contour on the connecting adaptor at least in part; and the circumferential annular groove in the first housing overlaps the receiving contour on the connecting adapter at least in the region of the displacement space.

10. The sensor arrangement as claimed in claim 1, wherein: the transducer comprises a permanent magnet; and the measuring element comprises at least one magnetic variable of a magnetic field of the permanent magnet, said magnetic variable influenced by the movement of the body.

11. The sensor arrangement as claimed in claim 2, wherein at least one press-in rib that extends in the axial direction is formed on an outer wall of the tube and by way of said press-in rib the tube is pressed into in the opening and pre-fixed.

12. The sensor arrangement as claimed in claim 11, wherein: the at least one press-in rib comprises a plurality of press-in ribs; the plurality of press-in ribs are arranged distributed on the outer wall of the tube; and said plurality of press-in ribs center the tube in the opening in the first housing.

13. The sensor arrangement as claimed in claim 1, wherein the connecting adaptor comprises, on the outer periphery, at least one recess configured to engage at least one of positioning tool and gripping tool.

14. The sensor arrangement as claimed in claim 1, the connecting adapter comprising: a plurality of support surfaces on an end side that is facing the measuring apparatus, the plurality of support surfaces configured to engage a press-in tool; and a plurality of contact areas, on an opposite end side that is facing the first housing, against which the connecting adapter is lying on the first housing, wherein the support surfaces and the contact areas are arranged lying opposite one another.

15. The sensor arrangement as claimed in claim 1, further comprising: a metal shielding plate pushed over a second housing of the measuring apparatus and encompasssing the second housing.

16. (canceled)

17. The sensor arrangement as claimed in claim 16, wherein: the measuring element is positioned and fastened on a circuit board; and the connecting adapter comprises, on a side that is facing the measuring apparatus, at least one press-in pin that is pressed into a corresponding opening of the circuit board.

18. The sensor arrangement as claimed in claim 17, wherein: the first housing includes an opening; the at least one press-in pin is one of multiple press-in pins; the multiple press-in pins are formed distributed on the connecting adapter; and said multiple press-in pins position and center the circuit board having the measuring element with regard to the opening in the first housing.

19. The sensor arrangement as claimed in claim 18, wherein the metal shielding plate, the second housing, the circuit board and the at least one press-in pin of the connecting adapter are connected to one another by way of at least one adhesive connection.

20. An ESP system for a vehicle, having an electric motor for driving at least one pressure generator and a sensor arrangement, wherein the sensor arrangement is the sensor arrangement as claimed in claim 1 and is configured to determine at least one of a prevailing rotational position and rotational speed of a shaft of the electric motor.

21. A method for joining the sensor arrangement as claimed in claim 1, said method comprising: providing the first housing with an opening in which the body having the transducer is movably mounted; providing the measuring apparatus that is connected to the connecting adaptor; introducing the silicon bead into the circumferential receiving contour of the connecting adapter, and inserting a tube of the connecting adapter into the opening of the first housing, so that the silicon bead is displaced in the circumferential receiving contour during the insertion procedure and fixes the connecting adapter on the first housing and seals the opening of the first housing.

22. (canceled)

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0025] FIG. 1 illustrates a schematic sectional view of an exemplary embodiment of a measuring apparatus of a sensor arrangement in accordance with the invention for detecting a movement of a body that is movably mounted within a first housing prior to joining to a first housing.

[0026] FIG. 2 illustrates a schematic perspective view of the measuring apparatus shown in FIG. 1 from below.

[0027] FIG. 3 illustrates a schematic plan view of the measuring apparatus shown in FIGS. 1 and 2.

[0028] FIG. 4 illustrates a schematic sectional view of an exemplary embodiment of a sensor arrangement in accordance with the invention for detecting a movement of a body that is movably mounted within a first housing.

[0029] FIG. 5 illustrates a view of a detail V of the measuring apparatus shown in FIG. 4.

[0030] FIG. 6 illustrates a schematic flow diagram of an exemplary embodiment of a method in accordance with the invention for joining the sensor arrangement shown in FIGS. 4 and 5.

EMBODIMENTS OF THE INVENTION

[0031] As is apparent from FIGS. 1 to 5, the illustrated exemplary embodiment of a sensor arrangement 1 in accordance with the invention for the contactless detection of a movement of a body 26 that is movably mounted within a first housing 3 comprises a transducer 20, which is non-rotatably connected to the body 26 and moves simultaneously with the body 26, and a measuring apparatus 10 that is fixedly arranged and comprises a measuring element 16.2. In dependence upon the movement of the body 26, the transducer 20 influences at least one physical variable that is detected by the measuring element 16.2. In so doing, the measuring apparatus 10 is connected to the first housing 3 by way of a connecting adapter 18 that is designed in the illustrated embodiment as a synthetic material injection part 18A. The connecting adapter 18 comprises on a side that is facing the first housing 3 a circumferential receiving contour 18.3 in which a silicone bead 19 is inserted and pressed between the receiving contour 18.3 and the first housing 3, wherein the silicone bead 19A that is pressed in fixes and seals the connecting adapter 18 on the first housing 3.

[0032] As is further apparent from FIGS. 1 to 5, the connecting adapter 18 in the illustrated exemplary embodiment comprises on the side that is facing the first housing 3 a tube 18.1 that can be inserted into a corresponding opening 5 in the first housing 3 and the transducer 20 that is connected to the moving body 26 is arranged in said corresponding opening. The circumferential receiving contour 18.3 is formed in a rotationally symmetrical manner with a cross-section that is curved open on the outer edge of the tube 18.1. As is further apparent from FIGS. 4 and 5, the open cross-section of the receiving contour is defined by a surface of the first housing 3, wherein the silicone bead 19A that is pressed into the receiving contour 18.3 seals the connecting adapter 18 and the opening 5 in the first housing 3.

[0033] As is further apparent from FIG. 4, in the illustrated exemplary embodiment the sensor arrangement 1 in accordance with the invention is used in an ESP system in order to determine a prevailing rotational position and/or rotational speed of a shaft 26A of an electric motor that is used for driving at least one pressure generator. In so doing, the first housing 3 in the illustrated exemplary embodiment is formed by a pump housing 3A of the ESP system which in addition to the electric motor, which is designed by way of example as a rotational speed controlled brushless EC motor (electronically commutated motor), comprises multiple (not further illustrated) fluid pumps, spring pressure storage devices and fluid channels and also solenoid valves and pressure sensors. The moving body 26 in the illustrated exemplary embodiment is therefore designed as a rotationally movably mounted shaft 26A on the free end of which is arranged a permanent magnet 22. As is further apparent from FIG. 4, the shaft 26A of the electric motor is mounted by way of a motor bearing 7 in a rotationally movable manner in the opening 5 that is provided as a motor hole 5A in the pump housing 3A. In so doing, the measuring element 16.2 in the illustrated exemplary embodiment comprises at least one magnetic variable of a magnetic field of the permanent magnet 22 that is influenced by the movement of the body 26. In the case of the body 26 that is designed as the shaft 26A, it is possible to evaluate the influence of the magnetic field that is detected by the measuring elements 16.2 in order to calculate a current angle of rotation and/or a current rotational speed of the shaft 26A. In the case of an alternative (not illustrated) exemplary embodiment, the moving body 26 is designed as a translationally mounted rod. In so doing, in the case of the body 26 that is designed as a rod it is possible to evaluate the influence of the magnetic field that is detected by the measuring element 16.2 in order to calculate a currently covered distance and/or a current displacement speed of the rod.

[0034] As is further apparent from FIG. 4, the permanent magnet 22 is adhered in a retaining vessel 24, which is produced from a non-magnetic material, for fastening to the shaft 26 in the illustrated exemplary embodiment. In so doing, the permanent magnet 22 is positioned and permanently fastened in a very precise manner on the shaft 26A. In so doing, the shaft 26A comprises an end-side hole for receiving a press-in pin of the retaining vessel 24 with the result that the retaining vessel 24 can be permanently fastened to the shaft 26A. The base of the vessel serves as a magnetic isolation layer between the permanent magnet 22 and the soft-magnetic shaft 26A. As a consequence, the amount of useful magnetic field that drains into the shaft 26A is reduced. In the case of an alternative (not illustrated) exemplary embodiment, the permanent magnet is injected in the form of a synthetic material-bonded permanent magnetic material as an extension onto the body 26 with the result that a free end of the body 26 forms the permanent Magnet 22.

[0035] As is further apparent from FIGS. 1 to 5, multiple press-in ribs 18.2 that extend in the axial direction are distributed on an outer wall of the tube 18.1 and this centers the tube 18.1 in the opening 5 in the first housing 3.

[0036] In addition, the tube 18.1 can be pressed into the opening 5 or the motor hole 5A and pre-fixed by way of the multiple press-in ribs 18.2. In order to facilitate the insertion of the tube 18.1 into the opening 5, in the illustrated exemplary embodiments in each case an insertion incline 18.9 is formed at the end of multiple press-in ribs 18.2. In addition, an insertion chamfer 3.3 is formed on the edge of the opening 5.

[0037] As is apparent in particular from FIGS. 2 and 3, the connecting adapter 18 in the illustrated exemplary embodiment comprises on the outer periphery two V-shaped recesses 18.7 for engaging a positioning tool and/or gripping tool. The two V-shaped recesses 18.7 are formed lying opposite one another on the outer periphery of the connecting adapter 18. The recesses 18.7 render it possible during various manufacturing steps to repeatedly and precisely grip the connecting adapter 18 and for the measuring apparatus 10 to be positioned in a very precise rotational manner in the opening 5 of the first housing 3 during the final assembly procedure.

[0038] As is further apparent from FIGS. 1 to 5, the connecting adapter 18 comprises on an end side that is facing the measuring apparatus 10 three support surfaces 18.8 for engaging a press-in tool. The connecting adapter 18 comprises on the end side that is facing the first housing 3 three contact areas 18.6 against which the connecting adapter 18 lies on the first housing 3. In so doing, the support surfaces 18.8 and the contact areas 18.6 are arranged lying opposite one another. It is naturally also possible to provide more than three support surfaces 18.8 or contact areas 18.6.

[0039] In addition, the circumferential receiving contour 18.3 in the illustrated exemplary embodiment comprises for receiving the silicone bead 19 a receiving space A having a first radius R1 that is larger than a cross-section of the silicone bead 19. Furthermore the receiving contour 18.3 for receiving a part of the silicone bead 19A that is pressed in comprises a displacement space B having a second radius R2 that is smaller than the first radius R1 of the receiving space A. In the illustrated exemplary embodiment, the second radius R2 corresponds approximately to half of the first radius R1. As is further apparent in particular from FIGS. 2, 4 and 5, the receiving contour 18.3 comprises between the receiving space A and the displacement space B a tangential and continuously downward route A1 having a curvature that lies opposite with regard to the receiving space A and the displacement space B. In addition, the route A1 comprises a third radius R3 that is equal to the first radius R1. As is further apparent from FIGS. 2, 4 and 5, the receiving contour 18.3 comprises an outlet A2 on an edge of the displacement space B that is remote from the receiving space A. The outlet A2 in the illustrated exemplary embodiment is formed by a gap that is produced by the contact areas 18.6 on the connecting adapter 18 between the connecting adapter 18 and the first housing 3. This renders it possible to perform an additional tolerance compensation and ventilation during the assembly procedure.

[0040] Above all, the geometric design of the receiving contour 18.3 renders it possible by way of multiple radii R1, R2, R3 for the silicone bead 19A that is pressed in to lie cleanly against the surface of the first housing 3 and in the receiving contour 18.3 of the connecting adapter 18. As a consequence, it is possible for example to reduce imperfections and air inclusions within the silicone seal with the aim of completely and uniformly wetting the surface of the first housing 3 and the receiving contour 18.3. Furthermore, the design creates a larger volume and consequently an advantageous tolerance compensation of the quantity of silicone that is applied. In so doing, the silicone bead 19 is introduced into the deeper receiving space A of the receiving contour 18.3. As the tube 18.1 is pressed into the opening 5 of the first housing 3, the silicone bead 19 that is introduced is displaced by way of the route A1 into the flatter displacement space B and the outlet A2 of the receiving contour 18.3 and thus pressed between the receiving contour 18.3 and the surface of the first housing 3.

[0041] As is further apparent from FIGS. 4 and 5, the first housing 3 in the illustrated exemplary embodiment of the sensor arrangement 1 comprises a circumferential annular groove 3.1 which overlaps the receiving contour 18.3 on the connecting adapter 18 at least in part. In the illustrated exemplary embodiment, the circumferential annular groove 3.1 in the first housing 3 overlaps the receiving contour 18.3 on the connecting adapter 18 in the region of the displacement space B and the outlet A2 in order to receive parts of the displaced silicone 19A. By virtue of the circumferential annular groove 3.1, the size of the wetted surface of the first housing 3 is increased. As is further apparent in particular from FIG. 5, the annular groove 3.1 comprises a concave or rounded transition to the flat surface of the first housing 3.

[0042] As is further apparent from FIGS. 1 to 4, the illustrated exemplary embodiment of the measuring apparatus 10 comprises a second housing 12 and a metal shielding plate 14 that encompasses the second housing 12. In so doing, the metal shielding plate 14 is formed in a closed manner and pushed over the second housing 12. The second housing 12 is formed in the illustrated exemplary embodiment as a synthetic material housing. The measuring element 16.2 is formed in the illustrated embodiment as a TMR component 16.2A that is based on the TMR effect (tunnel magneto-resistive effect) and cooperates with the permanent magnet 22 that is arranged on the end of the shaft 26A of the brushless EC motor in order to detect the prevailing rotational position of the shaft 26A. It is naturally also possible to use other measuring elements 16.2 that are suitable to detect the prevailing rotational position of the shaft. In the illustrated exemplary embodiment of the measuring apparatus 10, a sensor electronic system 16 comprises in addition to the measuring element 16.2 a circuit board 16.1 on which is positioned and fastened the measuring element 16.2, and multiple current rails 16.3 are pressed into the circuit board 16 and held in position by the second housing 12. As a consequence, the rotational position signal that is detected by the measuring element 16.2 is transmitted by way of the circuit board 16 and the current rails 16.3 to a (not illustrated) control device.

[0043] As is further apparent from FIGS. 1, 3 and 4, the connecting adapter 18 comprises multiple press-in pins 18.4. In so doing, the circuit board 16.1 is placed on the connecting adapter 18 in such a manner that the press-in pins 18.4 are pressed into corresponding openings of the circuit board 16.1 and position and center the circuit board 16.1 having the measuring element 16.2 with regard to the opening 5 in the first housing 3. As is further apparent from FIG. 4, the tube 18.1 forms a hollow space into which the end of the shaft 26A having the permanent magnet 22 protrudes. In the illustrated exemplary embodiment, the measuring element 16.2 is arranged on a side of the circuit board 16.1 that is facing the shaft 26A or the permanent magnet 22 in a recess of the connecting adapter 18 that is covered by the circuit board 16.1. The (not illustrated) control device can make contact with the current rails 16.3 of the measuring apparatus 10 for example by way of spring contacts.

[0044] As is further apparent from FIGS. 1 to 4, a steel metal plate of the metal shielding plate 14 is bent correspondingly to the geometry of the second housing 12, wherein in order to improve the electro-magnetic shielding effect the metal shielding plate 14 is closed all round. In addition, in each case a bending tab which is embossed and exerts a pre-stressing force on the second housing 12 is formed on two opposite-lying sides of the metal shielding plate 14. So as to position the metal shielding plate 14 precisely with respect to the measuring element 16.2, the second housing 12 comprises two opposite-lying bases (not further described) as a stop for the metal shielding plate 14. As a consequence, it is possible to prevent direct contact of the metal shielding plate 14 with the circuit board 16.1 and as a consequence prevent the metal shielding plate 14 chaffing against the circuit board 16.1. Consequently the risk of a short circuit or interruption in the conductive path is also reduced.

[0045] As is further evident from FIGS. 1, 3 and 4, the metal shielding plate 14, the second housing 12, the circuit board 16.1 and the press-in pins 18.4 of the connecting adapter 18 are connected to one another by way of multiple adhesive connections 16.4.

[0046] As is further evident from FIG. 6, in a step S100 the method 100 in accordance with the invention for joining a sensor arrangement 1 provides the first housing 3 having the opening 5 or motor hole 5A in which the body 26 or the shaft 26A having the transducer 20 is movably mounted. In the step S110, the measuring apparatus 10 that is connected to the connecting adapter 18 is provided. In so doing, the steps S100 and S110 can be performed in the illustrated sequence or simultaneously or in the reverse sequence. In step S120, the silicone bead 19 is introduced into the circumferential receiving contour 18.3 of the connecting adapter 18. In the step S130, the tube 18.1 of the connecting adapter 18 is inserted into the opening 5 of the first housing 3 in such a manner that during the insertion procedure the silicone bead 19A is displaced in the circumferential receiving contour 18.3 and fixes the connecting adapter 18 on the first housing 3.

[0047] After the hardening procedure or activation procedure of the silicone bead 19A that is pressed in, the measuring apparatus 10 is fixed on the housing 3 or the pump housing 3A and seals the opening 5 or the motor hole 5A. The silicone bead 19A that is pressed in can consequently harden for example in the air or in an oven.

[0048] The rotationally symmetrical design of the receiving contour 18.3 renders it possible to apply the silicone bead 19 in a simple and cost-effective manner since a (not illustrated) silicone dispenser, which supplies the silicone bead 19, is stationary and the measuring apparatus 10 having the connecting adapter 18 and the receiving contour 18.3 rotates below the dispenser. The open design of the receiving contour 18.3 renders it possible to apply the silicone in a simple, cost-effective and simultaneously precise manner. In addition, it is rendered possible in a fully automated and optical manner to control the silicone bead that has been applied, for example with respect to quantity, shape, imperfections etc. Since a corresponding surface of the first housing 3 delimits the open receiving contour 18.3 in the downwards direction, as the components are joined together the silicone advantageously displaces in the horizontal direction over the surface of the first housing 3. Consequently, it is possible to avoid the opening 5 in the first housing 3 and the motor bearing 7 that is arranged therein being contaminated by the silicone. By virtue of applying the silicone to the measuring apparatus 10 or the connecting adapter 18 and not to the first housing 3, the costs of rejects in the case of incorrectly applied silicone are reduced. In addition, it is not possible for the silicone to be “stripped off or dragged off” by the tube 18.1 on the connecting adapter 18 into the opening 5.

[0049] In order to pre-fix the tube 18.1 of the connecting adapter 18 during the hardening procedure or activation procedure of the silicone bead 19A that has been pressed in, the tube 18.1 in the illustrated exemplary embodiment is pressed into the opening 5 and centered by way of multiple press-in ribs 18.2 that are arranged on its outer wall.