FR2777722A3 - Transmission and reception system using optical links - Google Patents

Abstract

The data and power transmission between the rotating shaft (3) of the machine is carried out using an inductive coupling that does not rely upon mechanical contact . This has a fixed part (4) and a part (2) that moves with the rotor and is optically coupled to the transmitter /receiver (5). Communication with a similar transmitter /receiver is made via the inductive coupling

Description

Optical type transmission-reception arrangement Transmission

  of an electrical signal between a device placed on a rotating structure and a device placed on the ground takes place in a known manner by means of a ring collector, fitted on the shaft of the rotating structure, formed by rings of conductive material such as copper or bronze, and carbon brushes for each ring, one of which is electrically connected to the device mounted on the structure

  rotating and the other connected to the device placed on the ground.

  The conductive ring and the two brushes allow the trans-

  signal mission between the device placed on the rotating unit and the device placed on the ground and vice versa, because it makes an electrical connection between the two units. The ring collector therefore ensures a bidirectional signal transmission of the structure respectively

  rotating to the earth and from the earth to the rotating structure.

  The rubbing contact made between ring and brush does not guarantee

  no good contact over time for spark problems

  lage, micro-crater formation on the ring, wear of

  brooms, incorrect movement of the broom in its own holder

  broom. To overcome the above drawbacks have been developed recently, especially for the transmission of

  low voltage and current value, functional units

  nant differently, in which the signal transmission uses a system not of contact but of a different type such as for example optical, capacitive, electromagnetic, radio frequency, etc. These replacement systems for signal transmission have the following drawbacks: - mounting can only be done at certain points in the

machine; -

  - the signal transmission is not always continuous;

  - signal transmission is not always bidirectional -

  nelle. The main object of the present invention is to provide an arrangement for transmission and reception of optical type signals.

  free from the above mentioned disadvantages.

  To this end, the subject of the invention is an essential arrangement

  so characterized in that it allows transmission-reception

  signal tion without ring collector and without use

  contact brushes, but by means of a device

  optical type tif with infrared rays; the transmission of said signals is of bidirectional type, of the structure

  rotating to the earth and from the earth to the rotating structure.

  Another characteristic of the arrangement comes from the fact that it is provided with a particular transformation unit which, apart from making it completely independent in the management of the signals placed on the rolling structure, provides a power source for the devices placed on the rotating structure, for example the power supply to the bridge

load cells.

  Another characteristic of the arrangement is that it can be applied at any point on the shaft of the rotating structure and that no limitation is provided for

  the speed of rotation of this shaft.

  Another characteristic of the invention consists in that the arrangement can be implemented on demand, thanks to the

  mounting rings and brushes for bidirectional transmission

  power signals, and that it is thus possible to achieve, in the same arrangement, a transmission of ring and brush signals for the power signals and an optical arrangement for the transmission of

low value.

  The invention has the following advantages compared to ring collectors with contact brushes: - absence of brushes and contact rings, condition ensuring absence of handling, absence of limit for the speed of rotation of the machine shaft and operational safety in the transmission of signals; - input and output connection with a cable with four conductors and with as many conductors as there are units to be connected;

  - smaller dimensions, especially in the direction

tion of the length.

  The invention also has the following advantages over more recent replacement systems: - possibility of mounting at any point of the machine; - operation with bidirectional type signals; - continuous signal management; - supply of units placed on the rolling structure; - transmission of analog signals up to a voltage of 200 V and of frequency and phase signals, for example from encoders; - formation of an integrated arrangement with transmission of power signals by the use of rings and brushes and optical type for the transmission of low value signals.

  Other characteristics of the arrangement are described below.

  after with reference to the accompanying drawings only as

illustrative.

  Figure 1 is a sectional view of the ring structure of the arrangement applied to the shaft of the rotating structure

of a machine.

  Figure 2 is an end view of the ring structure

according to figure 1.

  Figure 3 is a diagram of a preferred embodiment of

  the arrangement of connection and transmission / reception of the signals.

  With reference to Figure 3, the emission arrangement

  reception of signals is essentially formed by: - a ring structure 1; a card or several cards 5 placed on the rotating structure 23 of the machine for the connection of the devices fitted on the rotating structure and the signals of which must be transmitted and received; - a card or several cards 6 placed on the ground for the connection of the devices whose signals must be transmitted and received. With reference to Figures 1 and 2, the ring structure 1 is constituted by a rotating part 2 and by a

fixed part 4.

  The fixed part 4 allows the mobile part 2 to rotate thanks to two bearings 7 placed at the two ends of the structure. The mobile part 2 is fitted onto the rotating shaft 3 of the machine and is made integral with the latter by the use

appropriate devices 8.

  Different ring structures are provided for different-

  your ranges of variable shaft diameters from 40 to 400 mm. It is also possible to make ring structures

  for smaller and larger diameters.

  Within the same range, devices are provided

  compensation for a different diameter of the shaft.

  The fixed part 4, concentric with the mobile part 2, is fixed to the ground by means of an anti-torque device 9

  able to overcome the friction of the two bearings 7.

  In the structure is mounted a transformation unit 10, supplied with 24 V / 50 Hz or- at a different frequency from the network, which supplies power to the following consuming units: - rotating cards 24 and 25 of the optical transmission channels - reception of signals; - card or transmission / reception cards 5 for the connection of the devices placed on the rotating structure 23 of the machine; - possible consuming units mounted on the rotating structure 23 of the machine; - possible transformation unit of another ring structure. The power conversion is produced on the transformer principle, that is to say by taking advantage of the variation in concatenated flux between two windings 12, whose particular arrangement ensures the independence of the speed

  of rotation of the machine shaft 3.

  The two windings 12 are housed on two concentric steel rings 13 and 14, the ring 13 being fixed to the part

  fixed and the ring 14 to the movable part of the structure.

  In the ring structure 1 are provided two separate chambers 15 and 16, the chamber 15 for mounting one or more pairs of cards 24 and 26 comprising the optical channels for the transmission-reception of analog, digital signals, serial port , and the chamber 16 for mounting one or more pairs of cards 25 and 27 comprising the optical channels for the transmission of frequency signals

  and phase, for example encoder signals.

  The cards of each pair 24 and 25 are integral with the mobile part 2 of the ring structure 1 and the cards 26

  and 27 are integral with the fixed part 4.

  The data transfer methods between the cards forming each pair may be different depending on the

  type of signals, as described below.

  The ring structure can be supplied in different solutions depending on the type and number of channels to be managed and according to requirements, can be protected against agents

  various atmospheres or be equipped with an anti-resistance

  condensing and arranged to operate in atmospheres

  o explosives are treated.

  The electronic cards 5 and 6, respectively rotating and fixed, have an identical and symmetrical structure and are provided with terminal plates and connection connectors for the following signals: - analog signal input 17; - analog signal output 18; - digital signal input 19; - digital signal output 20; - series 21 consumer unit; - frequency and phase 22 signals (signals from encoders;

  - any on-board units to be supplied.

  Card 5 is connected to revolving cards 24 and 25 and the

  card 6 is linked to cards 26 and 27.

  The connections are made by cable with four conductors, that relating to the cards 5,. 24 and 25 passing through channels 1i and that between cards 6, 26 and 27 by means of a

terminal board.

  The card 5 is supplied by the transformation unit 10 of

the ring structure.

  Between the transceiver card 5 of the rotating structure and the stationary transceiver card 6 are provided means for continuous diagnostic control concerning the transmission and reception of data for

  ensure the proper functioning of the arrangement.

  The variable number and type of signals to be managed, present on the rotating structure and on the structure on the ground, may require the use of additional cards

  connected respectively to revolving cards 5 and fixed cards 6.

  The analog signals 17 and 18 can be in voltage (V) and / or in current (mA), the voltage signals can have an input in transmission up to 200 V corresponding to an output in reception of 10 V. Digital signals 19 can come from clean contacts devoid of voltage and / or 5 + 24 V voltage signals and can intervene with a frequency

maximum of 100 Hz.

  The corresponding signals on reception 20 are available in the clean contact solution with the use of

  relay and / or with "Mosfet" type solid state technology.

  The serial transmit-receive channel 21 is of the asynchronous full duplex type with a transmission speed that can be

  selected between 1200 and 19200 baud.

  The frequency and phase channels, encoder signals, come from commercial devices with transmission frequency typically up to 100 kHz, (it is possible to manage signals of higher frequency up to 300 kHz); the signals are transmitted in unidirectional mode, from the revolving structure to the earth, or from the earth structure to the revolving structure, adapter cards being

  predicted based on signal characteristics.

  As indicated previously, there are two different transmission-reception methodologies for optical channels 24, 25, 26 and 27 depending on the type of signals, whether analog, digital, serial or frequency and

phase (encoder signals). -

  Analog, digital and serial signals have the following characteristics: - the transmission is of the asynchronous simplex or duplex type; - the transmission speed is programmed up to 250

  kbauds but may be higher for special requirements

  lières; - the sampling and transmission speed of analog and digital signals can be programmed according to the

  number and requirements of individual channels.

  For frequency and phase channels (encoder channels), the

  transmission is punctual without treatment.

  The transceiver arrangement object of the invention can be used not only in rotating structures, but also on fixed structures and generally in all cases where it is not possible to make a connection electric cable between devices whose signals must be transmitted and received and even in cases where the

  cable connection could create electromechanical problems

  maintenance over time and good performance.

  The benefits of using the broadcast arrangement

  The above described reception and reception can be summarized as follows: completely transmitting and receiving signals

  autonomous, without the use of contact brushes for emitting

  sion-reception and / or feeding; - arrangement applicable to rotating structures or to fixed structures for which it is not possible to make a cable connection or the cable connection has an operational insecurity; - arrangement usable and mountable on any point of the installation; - transmission and reception of signals of any type, such as continuous transmission of analog signals up to 200 V, transmission-reception of digital signals of frequency up to 100 Hz, frequency signals and phase maintenance between two or more signals, such as encoder signals,

  with a frequency typically of 100 kHz and being able to reach

  at 300 kHz. - serial channels with transmission speed up to 19200 baud; - modularity of the layout, with the possibility of supply with different construction characteristics; - arrangement allowing the mounting of collecting rings and brushes for the transmission-reception of power signals at the same time as the transmission-reception of signals by the arrangement of optical type according to the characteristics

described above.

! 0

Claims (10)

Claims   1. Arrangement for transmitting and receiving optical signals, in particular between a rotating structure and a device placed on the ground, characterized in that it consists of a ring structure (1) comprising a movable part (2) suitable for being fitted on and made integral with the shaft (3) of the rotating structure of the machine and a fixed part (4), a transceiver card (5) connecting the devices to transmit and receive signals and placed on the rotating structure (23) of the machine and a transceiver card (6) connecting the devices in front   send and receive signals and placed on the ground.   2. transceiver arrangement according to claim 1, characterized in that the ring structure (1) is provided with a transformation unit (10) for supplying the various consuming units, including energy conversion is produced by means of the concatenated flow variation between two windings (12) ensuring the independence of the speed   of rotation of the machine shaft (3).   3. transceiver arrangement according to claim 1, characterized in that the ring structure (1) comprises   two separate chambers (15, 16) to contain respective-   one or more pairs of cards (24, 26, 25, 27) for the reception and reception of analog, digital, serial port signals, and frequency and phase signals (encoder signals). 4. transceiver arrangement according to claim 1, characterized in that it comprises one or more cards   transceiver (5) for linking signals from   from devices mounted on the rotating structure (23) of the machine, connected by a four-conductor cable passing in appropriate conduits (11) to the cards   rotating (24, 25) of the ring structure (1).   5. transceiver arrangement according to claim 1, characterized in that it comprises one or more cards   transceiver (6) for linking signals from   from devices placed on the ground and connected by a four-conductor cable via a terminal board and / or connectors.   6. Transmission-reception arrangement according to one of the claims   cations 1, 4 and 5, characterized in that the electro-   rotating and fixed pins (5, 6) have an identical and symmetrical structure and are fitted with terminal plates and connection connectors for signal inputs and outputs   analog (17, 18), digital signal inputs and outputs   ques (19, 20), serial consumer unit (21), signals in   frequency and phase (22) (signals from encoders).   7. Transmission-reception arrangement according to one of the claims   cations 1 and 4 to 6, characterized in that it comprises   means of continuous diagnostic check on the emission   sion and data reception by the cards (5) of the rotating structure (23) of the machine and the cards (6) located on land.   8. Transmission-reception arrangement according to one of the claims   previous cations, characterized in that the structure in   ring (1) can be mounted and used on any point   as the rotating shaft of the structure (23) of the machine.   9. Transmission-reception arrangement according to one of the claims   previous cations, characterized in that it allows the   mounting of collecting rings and brooms for emission-   reception of power signals at the same time as transmission   signal reception with an optical type arrangement.   10. Transmission-reception arrangement according to one of the claims   previous cations, characterized in that it can be used, in addition to rotating structures, also by fixed structures in particular in cases where it is not possible to make an electrical connection by cable between the devices whose signals must be sent and received, or in cases where the cable connection could cause electromechanical problems of resistance over time and good functioning.