DE584850C - Device for determining or compensating for the difference in position of two spatially separated shafts - Google Patents

Description

GERMAN EMPIRE

ISSUED ON
SEPTEMBER 25, 1933

REICH PATENT OFFICE

PATENT LETTERING

CLASS 74 c GROUP 8 oi

74c G 36.

separate waves

Patented in the German Empire on May 11, 1930

To determine and compensate for the difference in position of two spatially separated In particular, shafts are electrical remote display and control devices with systems of a type similar to that of a motor Design known, which are usually connected so that they are like an electric differential gear works. For example, there are two with the to. comparative waves

ίο. coupled sensors to an electrical differential receiver switched, which receives no relative adjustment as long as the positions of the two shafts match, within certain limits it does not matter whether both waves stand still or rotate at the same speed. All based on this differential principle electrical display or control devices adhere to several basic principles Errors which in most cases do not guarantee a sufficiently precise setting. The types of construction often require relatively heavy donors, which are still needed by the receiver are influenced retrospectively and the waves, which are often only very lightly resilient, are very much brake strongly. Engine-like receivers also tend to oscillate due to their armature flywheels, which they, especially in the case of sudden movements that change abruptly, for example and make control unusable. Furthermore, it is very annoying that in the encoder anchors, especially in higher speeds, not just for setting the receiver or for other purposes Purposes effective transformer voltage is induced, but also still a rotational tension which causes undesirable tension shifts and consequently incorrect measurement and control results.

The invention aims to avoid the disadvantages of the known devices and in particular to eliminate the influence of the rotational stress. To determine and to compensate for the difference in position of two spatially separated shafts is according to the invention a rotary transformer connected to each of the two shafts; both functional Dtehtransformers built in the same way each carry one in a bridge circuit arranged winding, in particular on the in a fixed pole housing arranged pole pairs of the rotary

*) The patent seeker indicated the following as the inventors:

Dipl.-Ing. Johannes Vopel in Berlin-Zehlendorf and Dipl.-Ing. Rudolf Oetker in Berlin-Mariendorf.

transformers can be arranged. The windings of the rotatable with the shafts Anchors are short-circuited with one another. The whole arrangement is made in such a way that in the case of misalignments between the two waves, the balance of both bridges is disturbed and then between corresponding zero points of the bridges occurring voltage difference or the bridge compensation current to display and register the difference in position or to control the difference in position of the two shafts compensating drive member is used. To register, you can use the connection line corresponding bridge zero points an oscilloscope must be switched on, while to compensate for the position differences of the shafts an adjusting motor connected to one of the two shafts is connected to the corresponding bridge zero points can be, wherein the bridge compensation current is expediently fed to the motor via an amplifier arrangement.

In the drawing, the invention is illustrated using three exemplary embodiments.

In Fig. 1, 1 and 2 denote the two spatially separated waves, the differences in position of which are to be measured. The armatures% and a _{s of} two completely identically built rotary transformers are attached to these shafts. The triangular windings of armature Ct ₁ and a ₂ are short-circuited by lines b, c and ti. The armature% (a ₂ ) can be rotated in the pole housing C ₁ (e ") equipped with four pole pieces. The pole shoes offset by 90 ⁰ have windings of equal value f _± , g _lt Pi ₁ , I ₁ (U, is. &2> is), which are in groups ^ ₁ , If ₁ (f ₂ , g ₂ ) and Pi ₁ , I ₁ Qi ₂ , i ₂ ) are connected in parallel to the alternating current source k , in that the current is fed to the bridge feed points A ₁ (A ₂ ) and B ₁ (B ₂ ) through the lines ni and η . The zero points D ₁ and D _{2 of} the two electromagnetic bridges are connected by the line 0 , while the current or voltage-sensitive measuring device £ is connected to the zero points C ₁ and C _{2 of this bridge.}

In the position shown, the power flows of the pole pairs f _v I ₁ (f ₂ , i ₂ ) and g _ls Pi ₁ (Sz> h ₂ ) close evenly across the armature (Z ₁ (a ₂ )) in both rotary transformers Fig. 2 shows that the fields generated in the individual pole pieces are added geometrically to the common field HT . This field penetrates the armature and causes voltages in the triangular windings, but these do not result in equalizing currents, since the voltages induced in the triangular windings If the systems are symmetrical, all poles have the same inductive resistance, so that the voltage drop from A ₁ (A ₂ ) to C ₁ (C ₂ ) is just as great as the voltage drop from A ₁ (A ₂ ) to D ₁ (D ₂ ), The bridge zero points C ₁ , C ₂ and D ₁ and D ₂ therefore have the same potential, so that the display instrument p does not make a deflection er speed, because the rotational stresses generated in the latter case cancel each other out. The particular advantage of this arrangement is that, even at the highest speeds, the rotational voltages do not result in equalizing currents in the connecting lines 0 and q .

If there are differences in position between shafts 1 and 2, the fields of armatures O ₁ and a _{2 are} shifted, changing the magnetic resistance of the pole shoe pairs and consequently disturbing the equilibrium of the two electromagnetic bridges. As a result, equalizing currents corresponding to the magnitude of this misalignment will now occur in the connecting lines 0 and q of the bridge zero points _{C 1} and C ₂ or D ₁ and D ₂ . The size of this misalignment can be read from the correspondingly calibrated display instrument p.

In order to reduce the number of long-distance lines in cases where there are large distances between the two shafts, without giving up the advantages of the arrangement described, the bridge zero points of one rotary transformer according to Fig. 3 or the windings of two opposite pole shoes according to Fig. 4 of a rotary transformer are short-circuited. The equalizing currents corresponding to the difference in position between the two shafts 1 and 2 are then _{picked up at the bridge zero points C 2} and D _{2 of} the second rotary transformer and used for registration in the device according to Fig. 4, whereas in the device according to Fig. 3 they are used to compensate for these misalignments .

The design of the rotary transformers arranged on the two shafts 1 and 2 in Fig. 3 corresponds completely to that of Fig. 1. The bridge zero points C ₁ and D _{1 of} the first rotary transformer, which serves as a transmitter in this device, are short-circuited by the line /, while at the bridge zero points C ₂ , D _{2 of} the second rotary transformer acting as a receiver, an amplifier device j is used to readjust the receiver and the heavy object t coupled with it

Drive motor r is connected. "The arrangement is again made so that as long as the position between the encoder and the object to be set t matches, the bridge zero points C ₁ and D ₁ or C ₂ and D _{2 have the} same voltage and the motor r as a result As soon as misalignments occur, the balance of the bridges is disturbed, and

The motor receives current until it has rotated the shaft 2 and the object t coupled to it into the position corresponding to the encoder shaft ι and thus restored the bridge balance.

With this device, a current or voltage sensitive could in the bridge compensation line ι The measuring instrument must be switched on, which will continuously detect the misalignment with the corresponding re-calibration on the encoder point of the item to be adjusted. -The rash of this instrument However, compared to the one according to Fig. ι with the same misalignment, it would only be approximately be half as large, since in this case the voltage difference of only one Bridge is measured.

In Fig. 4, the magnet windings J ₁ and I ₁ of the rotary transformer arranged on the shaft 1 are short-circuited _{by the lines W 1} and W _2. The bridge compensation current of the rotary transformer arranged on the shaft 2 is used here to record the misalignments between the two shafts, in that the oscilloscope loop χ is switched on _{between the two bridge zero points C 2} and D _2. A synchronously oscillating relay z, which is connected to an alternating current source y of the same frequency and phase as the bridge compensation current, is used to rectify the compensation current in a manner known per se, so that the oscilloscope continuously records the misalignments according to size and direction. This results, for example, in a vibration pattern as shown in Fig. 5. The envelope H is then the error curve plotted as a function of time.

It is of course easily possible, including those obtained with the device according to Fig. 1 To use bridge compensation currents for photographic registration or for readjustment. Likewise could a recording or readjusting device other than the one shown is used be, for example, a sequential pointer arrangement with manual operation.

Of course, it is also possible with these rotary transformers to use the roles to swap the stator and armature. So it can also be used in the bridge circuit Relocated the armature of the rotary transformers and the excitation windings of the two transformers can be short-circuited together.

Claims (6)

Patent claims: 1. A device for determining or compensating for the difference in position of two spatially separated shafts, characterized in that with each of the two spatially separated shafts, a rotary transformer of preferably the same design, each with a winding connected in a bridge (f _lt g _v Ji ₁ , 1 ₁ or / 2; S2. ' ^ 2> h) is connected, the windings (a _± or a ₂ ) of the parts rotatable with the shafts are short-circuited with one another, and that the faulty. position between the two shafts by disturbing the equilibrium of the two bridges between the zero points of each bridge or between the corresponding zero points of both bridges, the voltage difference that occurs is used to display or register or to control a drive element that compensates for the difference in position of the two shafts. 2. Device according to claim 1, characterized characterized in that the fixed pole housing arranged in a go Pairs of poles of the rotary transformers in bridge circuit carry magnet windings and the windings of the in these pole housings arranged and attached to the shafts to be compared Anchors are short-circuited together. 3. Device according to claim 1 and 2, characterized in that the zero points one electromagnetic bridge with the zero points of the other electromagnetic bridge through compensating lines are connected, in which a current or voltage sensitive instrument for the purpose of displaying the respective Misalignment is turned on between the two shafts. 4. Device according to claim 1 and 2, characterized in that in the connecting line the zero points of a no electromagnetic bridge a current- or voltage-sensitive display element for the respective misalignment between the two waves is switched on, while the zero points of the other bridge or two opposite pole windings of the other rotary transformer are short-circuited. 5. Device according to claim 3 or 4, characterized in that in the connecting line two corresponding zero points of the two bridges or in the Connecting line of the zero points of a bridge an oscilloscope is switched on, expediently with the interposition of a synchronously oscillating relay, that the differences in position between the two waves are recorded in terms of size and direction. 6. Device according to claim 3 or 4, in which on one with the second shaft connected object the respective position and movement of the first shaft is transmitted, characterized in that the two corresponding zero points both bridges or at the zero points of a bridge, expediently via an amplifier arrangement a drive motor for the item to be set is connected is. 1 sheet of drawings