DE102007042659B4 - coupling device - Google Patents

Abstract

coupling device
with a first housing part and a second housing part,
which are mounted rotatably relative to each other about an axis,
in which
- Form a primary winding and a secondary winding, an inductive coupling element, wherein
the primary winding is arranged concentrically with the axis on the first housing part and the secondary winding is arranged on the second housing part concentric with the axis,
- Is formed on the first housing part, an electrically conductive surface as a first coupling surface
and an electrically conductive surface is formed as a second coupling surface on the second housing parts,
which together form a capacitive coupling element,
characterized in that
the inductive coupling element is surrounded by a magnetic shield,
wherein the magnetic shield between the inductive coupling element and capacitive coupling elements is arranged.

Description

The invention relates to a coupling device for a system for contactless energy and data transmission.

From the EP 1 612 633 A1 a coupling device according to the preamble of claim 1 is known.

From the DE 199 32 504 A1 is a realization of a contactless energy and data transmission of two parts rotatable to each other is known, in which two or more coils are rotatably mounted, wherein at least one of the coils is in a half having an L-shaped cross-section.

From the EP 007 39 03 A2 a device for contactless transmission of information between relatively rotating components is known, wherein a first, stationary component has a first conductor arrangement, which is non-contact coupled to a second, arranged on a second component conductor arrangement, wherein the second conductor arrangement of two substantially rotationally symmetrical Parts, which build a toroidal electric and / or magnetic field, consists, and the first conductor arrangement is arranged in the field of the second conductor arrangement.

From the US 424 26 66 A US-A-5 011 031 A discloses a selectable range rotary machine contactless data acquisition system comprising an annular rotary transformer and a disk-shaped rotary capacitor disposed centrally with respect to the rotary transformer, and wherein the rotary capacitor comprises a stationary disk as a capacitor plate and a rotating disk spaced apart by an air gap are.

From the US 652 33 83 B2 For example, a monitoring and control system with connectorless quick-change components is known in which transceivers are placed in mutually opposed, immovable areas to allow replacement of the monitored components in harsh operating conditions without the risk of damage to electrical connectors and cables.

From the WO 98/63507 A1 a device for contactless information and energy transmission is known, wherein a power-supplied control unit in the form of a data reading device and capacitive coupling elements are present and a data transmission is carried out with simultaneous uninterrupted power transmission and wherein the data storage via inductive coupling elements supplied with the necessary energy and at the same time the data transmission is carried out by a frequency modulation to the data memory via the capacitive coupling elements.

From the DE 332 40 41 A1 A device is known for measuring the pressure or temperature in a wheel tire of a wheel of a motor vehicle, which wheel rotates about an axis carried by a fixed vehicle body on which the wheel in the tire or on its plane at least one sensor with associated electronic circuit and the vehicle body carries operating means responsive to signals generated in said circuit, coupling members being adapted to transfer said signals from said sensor circuitry to said fixed structure carried means and wherein said coupling members have two capacitances, each of which has two armatures having one of the amaturations of the two capacitances attached to the wheel and the other fixed to the fixed structure such that the relevant wheel fitting runs from the one fixed to the fixed structure, and the capacitances into the connection with the sensor circuit u nd the resources are designed in differential transmission mode.

From the GB 880 227 A are known coupling means for coupling between a rotating and a fixed part of an electrical signal transmission system, in which purely electrostatically acting coupling elements are formed.

The invention has the object of developing a system with contactless energy and data transmission, the error rate of the transmission is reduced.

According to the invention the object is achieved in the coupling device according to the features indicated in claim 1.

• – eine Primärwicklung und eine Sekundärwicklung ein induktives Koppelelement bilden, wobei die Primärwicklung am ersten Gehäuseteil konzentrisch zur Achse angeordnet ist und die Sekundärwicklung am zweiten Gehäuseteil konzentrisch zur Achse angeordnet ist,
• – am ersten Gehäuseteil eine elektrisch leitfähige Koppelfläche ausgebildet ist und am zweiten Gehäuseteil eine elektrisch leitfähige Koppelfläche ausgebildet ist, die zusammen ein kapazitives Koppelelement bilden.

Von Vorteil ist dabei, dass die induktive Kopplung eine die Energieversorgung mit großen Stromstärken von konstanter Frequenz ermöglicht, während die kapazitive Kopplung eine verzerrungsarme Übertragung von Signalpulsen zur Datenübertragung ermöglicht.Important features of the invention in the coupling device are specified in claim 1. Thus, it is particularly provided that a first housing part and a second housing part are provided, which are mounted rotatably relative to each other about an axis, wherein

• A primary winding and a secondary winding form an inductive coupling element, wherein the primary winding is arranged on the first housing part concentric to the axis and the secondary winding is arranged on the second housing part concentric to the axis,
• - An electrically conductive coupling surface is formed on the first housing part and on the second housing part an electrically conductive coupling surface is formed, which together form a capacitive coupling element.

The advantage here is that the inductive coupling allows the power supply with large currents of constant frequency, while the capacitive coupling allows a low-distortion transmission of signal pulses for data transmission.

In an advantageous embodiment, a first pair of coupling surfaces and on the second housing parts, a second pair of coupling surfaces is formed on the first housing part, wherein each form a contact surface of the first pair with a contact surface of the second pair a capacitive coupling element. The advantage here is that the signal of the power transmission can not crosstalk to the signal of the data transmission. Thus, the transmission errors are reduced. Another advantage is that with the inductive coupling element large currents are transferable and thus a power supply is possible, while with the capacitive coupling elements data signals are transmitted with low amperage distortion.

In an advantageous embodiment, the inductive coupling element is surrounded by a magnetic shield. Preferably, the magnetic shield between inductive coupling element and capacitive coupling elements is arranged. Thus, the induction of eddy currents through the inductive transmission in the capacitive coupling elements is further reduced and there are sources of interference for data transmission away from the transmission range.

In an advantageous embodiment, the coupling surfaces are formed by metallic, annular bands whose surface is arranged in each case radially to the axis of rotation. Thus, the capacitive coupling elements are functional independently of the rotational position, because the electrical coupling surfaces simulate the rotational symmetry of the coupling device.

In an advantageous embodiment, the coupling surfaces of each pair are arranged on a common, imaginary cylinder. Thus, a compact size is provided.

In an advantageous embodiment, the turns of the primary winding and the secondary winding each extend about the axis of rotation. The advantage here is that the power supply is available regardless of the rotational position of the coupling device.

In an advantageous embodiment, the primary winding and the secondary winding are each connected to a plug which has a pull-out protection. Thus, a high current, for example, of more than 10 A, transferable, and the system has increased security.

In an advantageous embodiment, the inductive coupling element is arranged radially within the capacitive coupling elements. The advantage here is that the inductive coupling element with a small footprint is executable, and that the capacitive coupling can be realized inexpensively.

In an advantageous embodiment, each contact surface has a ring width of 1 cm to 3 cm, in particular 2 cm. Preferably, the coupling surfaces of each capacitive coupling device 0.5 cm to 2 cm, in particular 1 cm, spaced. Thus, particularly favorable conditions for data transmission are achieved.

In an advantageous embodiment, the coupling surfaces of the capacitive coupling devices each form an electrically conductive ring, which is electrically severed at one point. Thus, circulating eddy currents that would be induced in the capacitor surfaces of the capacitive coupling elements of the inductive coupling element, interrupted.

In an advantageous embodiment, the coupling surfaces of the capacitive coupling devices are each connected in the middle between the ends formed by the transection with connection means. Thus, a good data coupling is achieved.

In an advantageous embodiment, the coupling surfaces of the capacitive coupling devices in the circumferential direction on transverse gaps or cuts. Thus, eddy currents that would be induced in the capacitor surfaces of the capacitive coupling elements of the inductive coupling element, further reduced.

In an advantageous embodiment, the coupling surfaces are each mounted on an electrically insulating pad. Thus, an undisturbed data transmission over the communication channel formed by the coupling surfaces is made possible.

Further advantages emerge from the subclaims. The invention is not limited to the combination of features of the claims. For the skilled person, further meaningful combination options of claims and / or individual claim features and / or features of the description and / or figures, in particular from the task and / or posing by comparison with the prior art task.

LIST OF REFERENCE NUMBERS

1

Rotary joint

2

housing part

3

housing part

4

connecting ring

5

junction box

6

plug

7

pull-out protection

8th

BNC connector

9

screw

10

wave

20

primary

21

secondary winding

22

connection

23

shielding

24

air gap

25

ring insert

26, 27, 28, 29

copper tape

30

labyrinth seal

31

axis of rotation

32

primary

33

trough

34

secondary winding

35

carrier

36

cover

37

gap

38

Area

40

copper strips

41

vertical stripes

42

tuck

43

gap

44

strip end

45

incision

50, 51

modem

52, 53

transceiver

54

generator

55

AC / DC converter

56

primary

57

secondary side

58, 59

capacitor

60

consumer

61

Rotary joint

The invention will now be explained in more detail with reference to figures:

It shows

1 a rotary transformer according to the invention,

2 a sectional view through the rotary transformer after 1 .

3 a sectional view through another rotary transformer,

4a a copper strip for a coupling element of a rotary transformer,

4b another copper strip for a coupling element of a rotary transformer and

5 the electronic schematic diagram of a rotary transformer.

1 shows a rotary transformer according to the invention 1 , A first housing part 2 is through a connecting ring 4 with a second housing part 3 connected. First housing part 2 and second housing part 3 are around the axis of the connecting ring 4 rotatable against each other.

On the first housing part 2 and on the second housing part 3 is ever a junction box 5 educated. At every junction box 5 is a plug 6 for high voltage, so for more than 10A , formed and a BNC plug 8th for connecting a high-frequency line.

A hinged bracket on the plug 6 forms an extract security 7 for the plug of the power line.

First housing part 2 and second housing part 3 are made of plastic.

2 shows an axial section through the rotary transformer after 1 ,

The connecting ring 4 is by screws 9 with a hollow shaft 10 connected. As a result, a bearing is formed, in which the first housing part 2 and the second housing part 3 are rotatably arranged.

The plug 6 is by lines not shown with connections 22 connected, in turn, with the two ends of a primary winding 20 are connected. The windings of the primary winding 20 run around the axis of rotation of the rotary transformer. Thus, an alternating current generated via the plug 6 into the primary winding 20 is impressed, a magnetic field, a ring extending around the axis of rotation secondary winding 21 interspersed and in the secondary winding 21 induced a current. The secondary winding 21 is firmly connected to the second housing part and via connections and not shown conductors with a in 2 not visible plug 6 connected. primary 20 and secondary winding 21 have a common axis. Thus, the primary winding and the secondary winding form an inductive coupling element, and it is energy contactless inductively transmittable across the hinge. Between primary winding 20 and secondary winding 21 is an air gap 24 set up, which allows the relative rotatability of the first and second housing part.

primary 20 and secondary winding 21 are each of U-shaped in cross-section, annular-trough-shaped shields 23 comprises, whose openings are facing each other. Thus, the magnetic field generated by the primary and secondary windings is trapped and substantially free from that of the shields 23 enclosed ring area out.

Outside the shields 23 is on the first housing part 2 a concentric with the axis of rotation ring insert 25 formed on the inside of a pair of annular copper bands 26 . 27 is appropriate. The copper bands 26 . 27 are with the two connectors of the BNC connector 8th in the connection box 5 of the first housing part 2 electrically connected.

Between the ring insert 25 and the shields 23 is on the second housing part 3 a second concentric ring insert 31 formed on the outside of another pair of annular copper bands 28 . 29 is arranged. The copper bands 28 . 29 are with the two connectors of the BNC connector 8th in the connection box 5 of the second housing part 3 electrically connected.

The ring inserts 25 . 31 are concentric with each other and thus allow unrestricted rotational movement of the rotary connector.

The copper bands 26 . 27 . 28 . 29 are radially aligned, that is, the normal of the surface in each case points in the radial direction with respect to the axis of rotation. The copper bands 26 and 28 are arranged opposite one another at the same axial position and thus form a capacitive coupling element in the form of a capacitor. Likewise, the copper bands 27 and 29 arranged on the same axial position opposite each other and thus form a second capacitive coupling element in the form of a capacitor.

Due to the two parallel operated capacitive coupling elements is a transmission of RF signals from the BNC connector 8th of the first housing part 2 to the BNC connector 8th of the second housing part 3 Non-contact allows independent of the rotational position of the rotary transformer.

The ring width of the copper strips used 26 . 27 . 28 . 29 is 2 cm, the copper bands 26 . 27 . 28 . 29 of each capacitive coupling element are 1 cm apart.

3 showed a further embodiment of a rotary transformer according to the invention. Shown is a sectional view of a side of the rotary transformer. The rotation axis 31 is indicated by a dashed line. The representation of the bearings and the electrical connections has been suppressed to improve the clarity of the drawing.

In a first housing part 2 is an annular trough 33 made of ferromagnetic material. In this trough 33 is the primary winding 32 wound. In the from the trough 33 enclosed space engages an annular support 35 with the secondary winding 34 one. The primary winding 32 is so radially inside the secondary winding 35 arranged.

The annular carrier 35 is on the second housing part 3 attached. In the second housing part 3 is a lid 36 made of ferromagnetic material, the ring the trough 33 concludes. Thus, the interior of the trough 33 who is the primary winding 32 and the secondary winding 34 magnetically locked against the outside area.

First housing part 2 and second housing part 3 are rotatable about the axis of rotation 31 stored against each other. There is a gap between the housing parts 37 formed, which has an axially extending, rotationally symmetric region 38 and in a labyrinth seal 30 expires.

In the sidewalls of the area 38 is a first pair of copper bands 26 . 27 taken in and opposite the pair of copper bands 26 . 27 a second pair of copper bands 28 . 29 , The copper bands 26 . 27 . 28 . 29 are mounted on an electrically non-conductive pad and electrically isolated from each other and against the environment.

A first copper band 26 of the first pair thus forms together with a first copper band 28 of the second pair, a capacitor and thus a first capacitive coupling element. Likewise, the second copper band forms 27 of the first pair together with the second copper band 29 of the second pair, a capacitor and thus a second capacitive coupling element. Thus, a transmission of signals via the capacitive coupling elements in each rotational position of the rotary transformer and independent of a rotational movement feasible.

Air is arranged between the two copper strips belonging to each capacitive coupling element.

First capacitive coupling element and second capacitive coupling element together form a transmission channel for data transmission.

In further developments are the copper bands 26 . 27 . 28 . 29 the rotary transformer designed such that the smallest possible eddy currents are induced by the inductive coupling element.

4a shows a first example of such training. On a vertical strip 41 made of copper are used to form a copper strip 40 tuck 42 arranged from copper and electrically connected to it, so that between the horizontal stripes 42 Gaps 43 be formed. These gaps reduce induced eddy currents in the copper strip 40 ,

The copper strip 40 will be at the ends 44 assembled to form an annular copper band. In an alternative embodiment, the ends become 44 assembled to a gap, so no circular currents along the longitudinal strip 41 can flow.

4b shows a second example of a development of copper bands 26 . 27 . 28 . 29 ,

In a copper strip 30 are longitudinally laterally alternating incisions 45 introduced, so that the overall result is a meandering conductor. The copper strip 40 will be at the ends 44 assembled to form an annular copper band. In an alternative embodiment, the ends become 44 assembled to a gap, so no circular currents along the copper strip 40 can flow.

In further embodiments, instead of copper, another metallic conductor, for example aluminum, is used.

5 shows the block diagram of a contactless energy and data transmission via a freely rotatable coupling.

A trained as a transformer head rotary transformer 61 includes a primary page 56 and a secondary side 57 a transformer, which are arranged rotatable against each other. The transformer forms the inductive coupling element for non-contact power transmission.

The primary side 56 will be from a generator 54 supplied with a constant alternating current with a current of 10 A or 60 A and a frequency of 25 kHz. Other frequencies between 10 kHz and 200 kHz are foreseeable.

This alternating current is transmitted through the transformer to a rectifier 55 passed. To increase the coupling strength of the rectifier comprises a resonant circuit whose resonance frequency is tuned to the frequency of the injected alternating current.

The rectifier 55 supplies a consumer 60 For example, a converter or a motor or an electronic circuit.

The generator 54 also provides a modem 50 and a transceiver 52 , The modem 50 receives data via a line, not shown, and outputs these as signals to the transceiver 52 further. The transceiver 52 amplifies the signals.

The rotary transformer 61 includes a first capacitor 58 and a second capacitor 59 , The capacitors 58 . 59 form the capacitive coupling elements of a transmission channel for data transmission.

The capacitors 58 . 59 are each designed so that the two plates are movable against each other.

About the parallel capacitors 58 . 59 are signals from the transceiver 53 to the transceiver 53 transferable and vice versa. A return via a ground line is not necessary. Thus, the susceptibility is reduced.

The transceiver 53 is from the transmitted via the inductive coupling element AC, in particular from the rectifier 55 fed. From the transceiver 53 the signals reach the modem 51 also from the rectifier 55 is supplied.

The modem 51 can reverse data to the transceiver 53 ship in the modem 50 be received.

Thus, a bidirectional data exchange is provided via a movable coupling device, wherein an inductive coupling for energy is provided parallel to the coupling for data exchange, from which a consumer and the transceiver 52 . 53 and / or the modems 50 . 51 be supplied.

Claims (17)

Coupling device having a first housing part and a second housing part, which are rotatably supported relative to each other about an axis, wherein - form a primary winding and a secondary winding, an inductive coupling element, wherein the primary winding on the first housing part is arranged concentrically to the axis and the secondary winding on the second housing part concentric is arranged to the axis, - on the first housing part, an electrically conductive surface is formed as a first coupling surface and the second housing parts an electrically conductive surface is formed as a second coupling surface, which together form a capacitive coupling element, characterized in that the inductive coupling element of a magnetic shield is surrounded, wherein the magnetic shield between the inductive coupling element and capacitive coupling elements is arranged. Coupling device according to claim 1, characterized in that - On the first housing part electrically conductive surfaces form a first pair of coupling surfaces and electrically conductive surfaces on the second housing parts form a second pair of coupling surfaces wherein each one electrically conductive surface, in particular coupling surface, of the first pair with an electrically conductive surface, in particular coupling surface, of the second pair form a capacitive coupling element. Coupling device according to one of the preceding claims, characterized in that the housing parts are made of plastic or between the housing parts and the respective electrically conductive surfaces an electrically insulating material is provided. Coupling device according to one of the preceding claims, characterized in that the coupling surfaces are formed by metallic, annular bands, the surface of which is aligned in each case radially to the axis of rotation, wherein the normal of the surface of the coupling surfaces respectively in the radial direction with respect to the axis of rotation shows. Coupling device according to one of the preceding claims, characterized in that the coupling surfaces of each pair are arranged on a common, imaginary cylinder. Coupling device according to one of the preceding claims, characterized in that the turns of the primary winding and the secondary winding extend in each case about the axis of rotation. Coupling device according to one of the preceding claims, characterized in that the primary winding and the secondary winding are each connected to a plug which has a pull-out protection. Coupling device according to one of the preceding claims, characterized in that the inductive coupling element is arranged radially within the capacitive coupling elements. Coupling device according to one of the preceding claims, characterized in that the capacitive coupling elements are arranged outside the magnetic shield of the inductive coupling element. Coupling device according to one of the preceding claims, characterized in that each contact surface has a ring width of 1 cm to 3 cm, in particular 2 cm. Coupling device according to one of the preceding claims, characterized in that the coupling surfaces of each capacitive coupling device 0.5 cm to 2 cm, in particular 1 cm, are spaced. Coupling device according to one of the preceding claims, characterized in that the coupling surfaces of the capacitive coupling devices are each formed as an electrically conductive ring, which is electrically severed at one point. Coupling device according to claim 12, characterized in that the coupling surfaces of the capacitive coupling devices are each connected in the middle between the ends formed by the transection with connection means. Coupling device according to one of the preceding claims, characterized in that the coupling surfaces of the capacitive coupling devices in the circumferential direction have transverse gaps or cuts. Coupling device according to one of the preceding claims, characterized in that the coupling surfaces are each mounted on an electrically insulating pad. Coupling device according to one of the preceding claims, characterized in that the capacitive coupling elements are operable in parallel. Coupling device according to one of the preceding claims, characterized in that the windings of the primary winding extend around the axis of rotation of the coupling device and or the secondary winding extends annularly around the axis of rotation and or the primary winding and the secondary winding have a common axis.

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