EP2201584B1 - Coupling device - Google Patents

Description

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

From the DE 199 32 504 A1 is a realization of a contactless energy and data transmission of two mutually rotatable parts is known in which two or more coils are rotatably mounted, wherein at least one of the coils is in a half, which has an L-shaped cross-section. From the DE4125143 a device for contactless transmission of alternating signals is known. The device discloses (column 4, lines 18-42, Fig. 10-12) transmitters and receivers which are driven to rotate concentrically to each other. Both parts include both flat conductor loops which act as coils for the inductive coupling and coupling capacitors in the form of metal foils. Both coupling devices are housed together within a shielding housing. 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, dass das induktive Koppelelement von einer magnetischen Abschirmung umgeben ist und dass die kapazitiven Koppelelemente außerhalb der magnetischen Abschirmung des induktiven Koppelelements angeordnet sind. Somit ist die Induktion von Wirbelströmen durch die induktive Übertragung in die kapazitiven Koppelelemente weiter vermindert und sind Störquellen für die Datenübertragung vom Übertragungsbereich ferngehalten. Bei einer vorteilhaften Ausgestaltung ist am ersten Gehäuseteil ein erstes Paar von Koppelflächen und am zweiten Gehäuseteile ein zweites Paar von Köppelflächen ausgebildet, wobei je eine Kontaktfläche des ersten Paars mit einer Kontaktfläche des zweiten Paars ein kapazitives Koppelelement bilden.
  Von Vorteil ist dabei, dass das Signal der Leistungsübertragung nicht auf das Signal der Datenübertragung übersprechen kann. Somit sind die Übertragungsfehler verringert. Von Vorteil ist weiter, dass mit dem induktiven Koppelelement große Stromstärken übertragbar sind und somit eine Leistungsversorgung möglich ist, während mit den kapazitiven Koppelelementen Datensignale mit kleiner Stromstärke verzerrungsarm übertragen werden. Vorzugsweise ist die magnetische Abschirmung zwischen induktivem Koppelelement und kapazitiven Koppelelementen angeordnet.

Important features of the invention in the coupling device are that a first housing part and a second housing part are provided which are rotatably mounted 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 concentrically with the axis on the first housing part and the secondary winding is arranged on the second housing part concentric with the axis,
• an electrically conductive coupling surface is formed on the first housing part and an electrically conductive coupling surface is formed on the second housing part, which together form a capacitive coupling element, that the inductive coupling element is surrounded by a magnetic shield and that the capacitive coupling elements outside the magnetic shield of the inductive coupling element are. Thus, the induction of eddy currents is further reduced by the inductive transmission in the capacitive coupling elements and sources of interference for data transmission are kept away from the transmission area. In an advantageous embodiment, a first pair of coupling surfaces is formed on the first housing part and a second pair of Köppelflächen on the second housing parts, 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 the capacitive coupling elements data signals are transmitted with low amperage distortion. Preferably, the magnetic shield between inductive coupling element and capacitive coupling elements is arranged.

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 claims define the subject matter of the protection claim by indicating the technical features of the invention.

LIST OF REFERENCE NUMBERS

• 1 rotary transformer
• 2 housing part
• 3 housing part
• 4 connecting ring
• 5 connection box
• 6 plugs
• 7 Excerpt from arrears
• 8 BNC connector
• 9 screw
• 10 wave
• 20 primary winding
• 21 secondary winding
• 22 connection
• 23 shielding
• 24 air gap
• 25 ring insert
• 26, 27, 28, 29 copper band
• 30 labyrinth seal
• 31 axis of rotation
• 32 primary winding
• 33 trough
• 34 secondary winding
• 35 carriers
• 36 lids
• 37 gap
• 38 area
• 40 copper strips
• 41 longitudinal stripes
• 42 horizontal stripes
• 43 gap
• 44 end of the strip
• 45 incision
• 50, 51 modem
• 52, 53 transceivers
• 54 generator
• 55 AC / DC converters
• 56 primary side
• 57 secondary side
• 58, 59 capacitor
• 60 consumers
• 61 Rotary transformer

• Es zeigt
  • Figur 1 einen erfindungsgemäßen Drehübertrager,
  • Figur 2 eine Schnittansicht durch den Drehübertrager nach Figur 1,
  • Figur 3 eine Schnittansicht durch einen weiteren Drehübertrager,
  • Figur 4a eine Kupferband für ein Koppelelement eines Drehübertragers,
  • Figur 4b ein weiteres Kupferband für ein Koppelelement eines Drehübertragers und
  • Figur 5 das elektronische Prinzipschaltbild eines Drehübertragers.

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

• It shows
  • FIG. 1 a rotary transformer according to the invention,
  • FIG. 2 a sectional view through the rotary transformer after FIG. 1 .
  • FIG. 3 a sectional view through another rotary transformer,
  • FIG. 4a a copper strip for a coupling element of a rotary transformer,
  • FIG. 4b another copper strip for a coupling element of a rotary transformer and
  • FIG. 5 the electronic schematic diagram of a rotary transformer.

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

On the first housing part 2 and the second housing part 3, a terminal box 5 is formed. At each terminal box 5 is a plug 6 for high current, that is for more than 10A, formed and a BNC connector 8 for connecting a high-frequency line.

A hinged bracket on the plug 6 forms a pull-out fuse 7 for the plug of the power line.

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

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

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

The plug 6 is connected by leads, not shown, with terminals 22, which in turn are connected to the two ends of a primary winding 20. The windings of the primary winding 20 extend around the axis of rotation of the rotary transformer. Thus, an alternating current which is impressed on the plug 6 in the primary winding 20 generates Magnetic field, which passes through a ring-shaped extending around the axis of rotation secondary winding 21 and induces a current in the secondary winding 21. The secondary winding 21 is fixedly connected to the second housing part and via terminals and not shown conductors with an in FIG. 2 not apparent plug 6 connected. Primary winding 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, an air gap 24 is arranged, which allows the relative rotatability of the first and second housing part.

Primary winding 20 and secondary winding 21 are each of U-shaped in cross-section, annular-trough-shaped shields 23, whose openings are facing each other. Thus, the magnetic field generated by the primary winding and the secondary winding is included and substantially does not come out of the annular region enclosed by the shields 23.

Outside the shields 23, a ring insert 25 extending concentrically with the axis of rotation is formed on the first housing part 2, on the inside of which a pair of annular copper bands 26, 27 are attached. The copper strips 26, 27 are electrically connected to the two terminals of the BNC terminal 8 in the terminal box 5 of the first housing part 2.

Between the ring insert 25 and the shields 23, a second concentrically extending annular insert 31 is formed on the second housing part 3, on the outside of a further pair of annular copper bands 28, 29 is arranged. The copper strips 28, 29 are electrically connected to the two terminals of the BNC terminal 8 in the terminal box 5 of the second housing part 3.

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

The copper strips 26, 27, 28, 29 are radially aligned, that is, the normal of the surface points in the radial direction with respect to the axis of rotation. The copper strips 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 capacitive coupling elements operated in parallel, a transmission of RF signals from the BNC connection 8 of the first housing part 2 to the BNC connection 8 of the second housing part 3 is possible without contact, irrespective of the rotational position of the rotary transformer.

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

FIG. 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 axis of rotation 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, an annular trough 33 made of ferromagnetic material is embedded. In this trough 33, the primary winding 32 is wound. In the space enclosed by the trough 33 engages an annular support 35 with the secondary winding 34 a. The primary winding 32 is thus arranged radially within the secondary winding 35.

The annular support 35 is fixed to the second housing part 3. In the second housing part 3, a lid 36 made of ferromagnetic material is incorporated, which closes the trough 33 in an annular manner. Thus, the interior of the trough 33 receiving the primary winding 32 and the secondary winding 34 is magnetically sealed against the outside.

First housing part 2 and second housing part 3 are rotatably mounted about the axis of rotation 31 against each other. Between the housing parts, a gap 37 is formed, which has an axially extending, rotationally symmetrical region 38 and terminates in a labyrinth seal 30.

In the side walls of the area 38, a first pair of copper strips 26, 27 are embedded and opposite the pair of copper strips 26, 27 a second pair of Copper bands 28, 29. The copper bands 26, 27, 28, 29 are mounted on an electrically non-conductive substrate and electrically isolated from each other and against the environment.

A first copper strip 26 of the first pair thus forms, together with a first copper strip 28 of the second pair, a capacitor and thus a first capacitive coupling element. Likewise, the second copper strip 27 of the first pair together with the second copper strip 29 of the second pair forms 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, the copper strips 26, 27, 28, 29 of the rotary transformer are designed such that the smallest possible eddy currents are induced by the inductive coupling element.

FIG. 4a shows a first example of such training. On a longitudinal strip 41 made of copper, transverse strips 42 made of copper are arranged to form a copper strip 40 and electrically connected thereto, so that gaps 43 are formed between the transverse strips 42. These gaps reduce induced eddy currents in the copper strip 40.

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

FIG. 4b shows a second example of a development of the copper strips 26, 27, 28, 29th

In a copper strip 30 side incisions 45 are laterally introduced in the longitudinal direction, so that there is a total of a meandering extending conductor. The copper strip 40 is assembled at the ends 44 to form an annular copper strip. In an alternative embodiment, the ends 44 are assembled to a gap so that no circulating currents can flow along the copper strip 40.

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

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

A trained as a transducer head rotary transformer 61 comprises a primary side 56 and a secondary side 57 of 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 is fed from a generator 54 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 passed through the transformer to a rectifier 55. 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 load 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 passes these as signals to the transceiver 52. The transceiver 52 amplifies the signals.

The rotary transformer 61 comprises 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 mutually movable.

Via the capacitors 58, 59 arranged in parallel, signals from the transceiver 52 can be transmitted to the transceiver 53 and vice versa. A return via a ground line is not necessary. Thus, the susceptibility is reduced.

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

Conversely, the modem 51 may send data to the transceiver 53 received in the modem 50.

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

Claims (14)

1. A coupling device
   having a first housing part and a second housing part which are mounted rotatable relative to one another 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 in a manner concentric to the axis and the secondary winding is arranged on the second housing part in a manner concentric to the axis,

   - in that at the first housing part there is an electrically conductive surface as a first coupling surface,
   and at the second housing parts there is formed an electrically conductive surface as a second coupling surface,
   which coupling surfaces together form a capacitive coupling element,
   wherein

   - the inductive coupling element is surrounded by a magnetic shield, characterised in that

   - the capacitive coupling elements are arranged exterior to the magnetic shield of the inductive coupling element.
2. A coupling device according to claim 1,
   characterised in that

   - electrically conductive surfaces form a first pair of coupling surfaces at the first housing part and electrically conductive surfaces form a second pair of coupling surfaces at the second housing part
   wherein each electrically conductive surface, in particular coupling surface, of the first pair forms a capacitive coupling element with a respective electrically conductive surface, in particular coupling surface, of the second pair.
3. A coupling device according to any one of the preceding claims,
   characterised in that
   the housing parts are manufactured from plastics material or
   an electrically insulating material is provided between the housing parts and the respective electrically conductive surfaces.
4. A coupling device according to any one of the preceding claims,
   characterised in that
   the magnetic shield is arranged between inductive coupling element and capacitive coupling elements.
5. A coupling device according to any one of the preceding claims,
   characterised in that
   the coupling surfaces are formed by metallic, annular bands whose surface is in each case arranged radially to the rotational axis.
6. A coupling device according to any one of the preceding claims,
   characterised in that
   the coupling surfaces of each pair are arranged on a common, notional cylinder.
7. A coupling device according to any one of the preceding claims,
   characterised in that
   the windings of the primary winding and the secondary winding each run around the rotational axis.
8. A coupling device according to at least one of the preceding claims,
   characterised in that
   the primary winding and the secondary winding are each connected to a connector which has an anti pull out device.
9. A coupling device according to at least one of the preceding claims,
   characterised in that the inductive coupling element is arranged radially within the capacitive coupling elements.
10. A coupling device according to at least one of the preceding claims,
    characterised in that
    each contact surface has a ring width from 1 cm to 3 cm, in particular 2 cm.
11. A coupling device according to at least one of the preceding claims,
    characterised in that
    the coupling surfaces of each capacitive coupling device are 0.5 cm to 2 cm apart, in particular 1 cm.
12. A coupling device according to at least one of the preceding claims,
    characterised in that
    the coupling surfaces of the capacitive coupling devices are each in the form of an electrically conductive ring which is electrically severed at one site.
13. A coupling device according to the preceding claim,
    characterised in that
    in the centre and between the ends formed by the severing, the coupling surfaces of the capacitive coupling devices are each connected to connection means.
14. A coupling device according to at least one of the preceding claims,
    characterised in that
    in a circumferential direction, the coupling surfaces of the capacitive coupling devices have gaps or incisions running transversely,
    and/or in that
    the coupling surfaces are each secured on an electrically insulating base.

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