DE1235031B - Rod guide for a precision pressure measuring device designed as a piston balance - Google Patents

Description

GERMAN #IW PATENT OFFICE

EDITORIAL DEVELOPMENT German class: 42 k -14/10

Number: 1235 031

File number: M 45105IX b / 42 k

1235031 Filing date: April 23, 1960

Opened on: February 23, 1967

An earlier right, the German patent 1205 731, relates to a rod guide for a piston scale trained precision pressure measuring device, in which the weight bar in the axial direction of three in 120 ° - Division on the rod circumference within the inner ring of a deep groove ball bearing arranged miniature ball bearings is guided, characterized in that the lateral pressure component through the middle the miniature ball bearing and the center of the balls of the deep groove ball bearing shows and that in itself known Way, the point of application of the weight bar on the piston below the center of gravity of the displaced barrier fluid lies. This resulted in such a substantial improvement in the measurement sensitivity compared to known designs achieved that there is the possibility of using the device as a calibration standard to be able to use.

Only in the lower measuring range, approximately below 2 kp / cm ² , can the frictional component be so great that the value of the measurement uncertainty permissible for calibration purposes is exceeded and the weight bar, which is set in rotation, comes to a standstill in such a short time that the measuring marks are set is impossible at this time.

The cause of the still excessive friction is mainly in the deep groove ball bearing there, its Friction value is too large, due to the result of the attachment of the miniature ball bearings in the Inner ring relatively large rolling radius of the balls of the deep groove bearing. Especially with a small print run the lateral pressure component on the bearings is so small that the weight bar rotates between the three miniature ball bearings in the inner ring of the deep groove ball bearing without the inner ring in To offset rotation. This means that a friction that slows the rotary motion is unfavorable affects the measurement accuracy occurs.

This error is eliminated by the invention.

The rod guide for a precision pressure measuring device designed as a piston balance by means of a deep groove ball bearing and with this connected three miniature ball bearings arranged at 120 °, with the lateral pressure component through the center of the grooved bearing balls and through the centers the miniature ball bearing shows is characterized according to the invention in that the deep groove ball bearing on the rod and the miniature ball bearings are mounted in the outer ring of the deep groove ball bearing.

By this measure according to the invention it is achieved that the frictional torque of the deep groove ball bearing is reduced to a minimum and the low coefficient of friction of the rod guide moved up and down for a piston scale
trained precision pressure measuring device

Applicant:

H. Maihak Aktiengesellschaft,
Hamburg 39, Semperstr. 26-38

Named as inventor:
Hans Stüben, moor rain over Ütersen

Rod in the three miniature ball bearings does not experience any change. With that the possibility is given, too to be able to measure properly with low loads.

The drawings show:
Fig. 1 a longitudinal section through the rod guide,

A b b. 2 a section through the ball bearings.
On the floating ZylinderC in the pressure vessel £ oil piston B the pressure of the ballast weights D is transmitted by the weight bar N. The small deep groove ball bearing P ^{r is} attached to the end of the weight rod N which is offset for the purpose of reducing the diameter. In the socket Q for the outer ring of the bearing P ', the three miniature ball bearings O are attached in 120 ° divisions. The support takes place in the bore of the bush R, the surface of which is hardened, ground and polished to reduce the friction for the up and down movement of the miniature ball bearings.

Claims (1)

Claim: Rod guide for a precision pressure measuring device designed as a piston balance by means of a Deep groove ball bearing and with this in connection, arranged in 120 ° division three Miniature ball bearings, with the lateral pressure 709 510/263