DE1673974A1 - Method and device for damping the rotatable organ of measuring instruments - Google Patents

Description

METRAWATT

NEWS FEUSCHAFT | Tofl Blott

Method and device for damping the rotatable organs of measuring instruments

In addition to air and eddy current damping, measuring instru-. ·

" ^f

ment s for damping the rotating part, so-called oil damping used. Inside is a very or less large one Part of the moving organs, e.g. part of the axis of rotation or the tension band, arranged in a damping fluid

• ■ :. ..- ■ --- ■. ■ - · ■ .. ■ - m

net, preferably as damping fluid, high viscosity ^ Oil is used. . . '

In order to achieve the desired dampening effect, the focus was primarily on the viscosity of the oil used, while the other theological properties were ignored. The damping oils used up to now belong to the so-called Newtonian fluids "in which" the velocity gradient bv (Oy

across the direction of flow the shear stress is Τ'linearly proportional ^. The fluid retention of these Newtonian fluids accordingly has the effect that with a large velocity gradient, ie with a large angular velocity of the movable measuring unit _; the frictional force and thus the damping is high, while- """it is small with small speed gradients.

■. * Of damping oils is rheopex at low sliding speeds, ie they seem to increase their viscosity with increasing speed gradient.

109842/0324 *

; nipl.-lne- Gootg KuHbeum - Dr.jur. H »n« k * rl KM. »En MüHlina — Of. lng. WA linger Vojjiü · «· d« s AuiildittrsiMi OkafclorWllhelm Nubt

BUILDING

These properties are almost without exception undesirable for the intended purpose. Us moving equipment when changing the measurement quantity to th at McDinstrumen as quickly and möglichst.ungedämpft adjust to the actual value, while the damping should be as large in the vicinity of the actual value to overshoot to prevent the set point.

According to the invention, this object is achieved with a method and a device for steaming the rotatable organ of

Measuring instruments of the type mentioned at the beginning, that the damping agent has pseudoplastic and / or thixotropic properties.

A device for carrying out the method is advantageous, inter alia, in that the part fixed to the housing is formed by two strips directed at right angles to the axis of rotation and running on both sides of the latter. J *** ⁰ * "

Further details of the invention are given below with reference to a ger embodiments described in more detail and in the drawing shown.

Fig. 1 shows a fitted with the damping device · " M & Üwerkachse in the Sonitt and in the side view;

Fig. 2 shows an adjusting device for changing the degree of divergence f

Fig. 3 shows a further development of the damping device two different damping effects;

109842/0324 -3 »

BATH ORIGINAL

Fig * 4.-geigt a special design of the steaming device.

According to, Fig. 1 are on de.r axis of rotation 1 that is not shown in detail Meawerkrähmchen, the moving iron or the rotary magnet of an electrical measuring instrument and the pointer 2 attached, the. * the respective measured value compared to the scale indicated at 3 indicates. The axis 1 is eymmetrical by a U-shaped bracket 4 umajit, which is attached to a part 5 fixed to the housing. The damping means is located between the bracket 4 and the axis 1 6, which has pseudoplastic or thixotropic properties. Axis i runs with its tips in bearings 7.

6tl *

Instead of axle bearings, the idea of the invention can also be based on Tension band bearings are used. ·

FIG. 2 shows in a simplified manner how the degree of damping can be changed. For this purpose he leaves Adjust bracket 14 for example with the help of an adjusting screw 15 or by bending in width, so that the Gap between axis 1 and the bracket legs 14a, 14b changed, If the angular speeds of the axis are the same, a different speed gradient then results within the .'Dämpf ungsmit teig 6. The strips 14a, i4b running on both sides and at right angles to axis 1 have the advantage of that regardless of the amount of dampening agent used 6, * " but especially with a changed gap width, always use the

the same length of the axis νο, η damping means surround JL ^ t, because possible excess of the damping agent more or less will distribute far into the depth of the gap formed by the two strips 14a, 14b.

109842/0324 _BAD original

In Pig. 3 is a further development of the inventive concept is shown schematically. There, two damping devices ' 2c and 2i attack the axis 1, each of which raises for itself. aa dampening means of different .theological properties are provided. Thus, for example, in the gap of the damping device 2u, a highly viscous. Means 22 and in the gap of the damping device 21 a low-viscosity means 23 can be used. "■ · -.__

The damping properties can also be used in a known manner by changing the length of the facilities surrounding the axis can be influenced, e.g. by changing the dimensions a

and b in Fig. 5. *. = ..

The dampening agent can have a liquid or paste-like consistency. It is only important that it is structural and / or thixotropic. This theological property largely meets the requirements in the construction of measuring instruments for certain damping properties, because the structurally viscous or thixotropic behavior has such an effect that the damping is comparatively low when the moving part of the measuring mechanism moves at a high angular velocity when the measured variable changes (high velocity gradient within dee damping means) to the actual value adjusts only in the, -. vicinity of the set point (low GeschwindigkeitsgefalleX receives the damping means an apparent hbhere VJ ^ icöeität in this point, the attenuation is much stronger, so that in spite of faster adjustment to the actual value of the measured variable. an overshoot or oscillation of the pointer is avoided.

1098: 42/0324 '^

BATH ORIGINAL

A theological damping agent with a viscosity between 100 and 7000 Stokes has proven to be particularly advantageous. Furthermore, the damping effect desired for electrical measuring instruments is optimally achieved when, with an axis diameter d of 0.5 ... 1.5 mm, the gap width s between axis 1 and the housed part 4, Ik, 2Ό , 21, 24 of the damping device is about 0.5 ... 2.5 mm.

In Pig. h shows a special embodiment of the subject matter of the invention. There the damping device consists of a cylindrical tube piece 24 which is fastened to the housing with the aid of the lugs 5. The axis 1 running through the pipe section is surrounded in the region of the length of the pipe section 1 by the damping means 6, which holds itself in the pipe section due to adhesive forces and the surface tension. With a diameter of the axis 1 d> 0.5 to 1.5 mm and a gap width of 0.5 to 2.5 "mm, the pipe length is made 1 = 3 to 6 mm.

If a damping agent with low surface tension is used, there is a risk of it flowing out or slowly creeping out on the fixed parts of the device. In a sol-, Chen trap are expediently the fixed parts of the damping device at least in the area of the dampening agent or partially provided with a coating that repels the damping agent or made entirely of such a material. Plastics containing fluorine are particularly suitable for this.

109842/0324

Claims (1)

Claims i. Method \ for damping the rotating organ of Measuring instruments in which there is an oil or grease-like element between a fixed part of the housing and the rotating shaft Damping means is used, characterized in that the damping means (6) structurally viscous and / or has thixotropic properties. . 2. The method according to claim 1, characterized in that the damping means (6) has a viscosity between 1000 and has 7000 stokes. - 3. Device for performing the method according to claim or 2, characterized in that the axis of rotation (i) i & e * movable measuring mechanism and / or the part of the device fixed to the housing {k, Ik ₁ 20,21, 24) in the area of the damping means (6 ) is completely or partially provided with a coating that repels the damping agent. Device for performing the method according to claim i or 2, characterized in that the part fixed to the housing ( of two perpendicular to the axis of rotation (1) and directed to both sides of this running strip det - is » formed 109842/0324 -7- OBlGlNAL INSPECTED 5. Apparatus according to claim k, characterized in that the housing-fixed part (4, Ik) comprises the axis of rotation (l) tongs or fork-shaped. «To carry out the procedure ~~ 6. Device * according to claim i or 2, characterized core- shows that two damping devices (20, 21) are provided, in each of which a damping β- ' medium (22, 23} is used with other rheological own juices, - 7. Device according to one of the preceding claims, characterized in that the degree of damping by. ' ' Change in gap width (s) between housings most part (14) and the axis of rotation (l) and / or through Variation of the amount of the damping agent (6) is adjustable. VjEur implementation of the procedure 8. Device) according to claim 1 or 2 _t, characterized in that the axis of rotation (i) of the movable measuring mechanism part of a housing-fixed, cylindrical pipe section (24) is concentrically surrounded, and that in the gap between the axis and Bohrstüok the damping means (6 ) is located. *. ·: 9. The device according to claim 8, dadurob'gekisiert, that with an axle diameter of 0.5 to 1.5 mm · the The width s of the gap between the axis (l) and the part (24) fixed to the housing is 0.5 to 2.5 mm » 109842 / 032A " ⁸ ~ 10. Device according to. Claim 8 or 9, characterized in that the length 1 of the pipe section (2k) is approximately is equal to the diameter. 10984 2/03 2 4