Turbine wheel meter

A turbine wheel meter with a meter housing having a lateral opening, with a measuring insert including an impeller, and a flow regulator being inserted in a duct of the meter housing. The measuring devices can, without removing the same from a length of conduit, be installed, exchanged, and calibrated outside of the meter housing by a corresponding structure of the flow regulator in relation to a discontinuity or gap in the duct, by a plug-in and centering arrangement provided on opposed end faces of the measuring device and the flow regulator device, by a flaring portion of the duct in conjunction with a counter shoulder of the flow regulator, as well as by the use of a clamping element.

BACKGROUND OF THE INVENTION 
The invention relates to a turbine wheel meter for measuring a volume of a 
flowing medium, with a meter housing having a lateral opening, being 
penetrated by a duct having a discontinuity in a zone of the lateral 
opening, and with a tubular measuring insert disposed in the discontinuity 
and comprising an impeller and a reversing gear, as well as a flow 
regulator, arranged on the inlet side in the duct, upstream of the 
measuring insert, and being in the shape of a displacement member seated 
in a cylinder sleeve and provided with guide ribs, with a housing lid 
sealing the opening and carrying a counting mechanism on the outside. 
The invention is utilized, in particular, with turbine wheel meters for gas 
supply systems wherein pipe diameters of four inches and more are used, 
and large volumes are to be measured at high pressures with great 
accuracy. 
Turbine wheel meters with a straight flow channel have been proposed 
wherein surrounded by the flow of the medium a measuring insert, with an 
impeller, is arranged, with a flow regulator being disposed forwardly of 
the measuring insert. In a number of these meters, such as, for example, 
the type proposed in DOS No. 2,702,319 the flow divider or regulator and 
the measuring insert are placed into the flow channel in the longitudinal 
direction; however, a disadvantage of this arrangement resides in the fact 
that the turbine wheel meter must be removed from the length of conduit 
when exchanging those parts due to damage or for maintenance purposes, 
thereby resulting in a time consuming assembly work which is also rather 
cumbersome due to the considerable weight of the meter intended for large 
nominal cross sections. 
In, for example, DOS No. 2,066,055, another turbine wheel meter is proposed 
which includes a meter housing having a lateral access to the flow channel 
through which the measuring insert with the impeller is introduced; 
however, a disadvantage of this proposed arrangement resides in the fact 
that an assembly of the flow divider or regulator takes place by insertion 
from the front into the flow channel. Consequently, for exchanging a 
damaged flow regulator, the entire meter housing must be removed from the 
conduit. 
The aim underlying the present invention essentially resides in providing a 
turbine wheel meter constructed so that not only a measuring insert 
thereof but also the flow regulator can be removed from the meter housing 
without disassembly of the entire meter thereby enabling a calibration of 
the turbine wheel meter and flow regulator outside of the meter housing. 
In accordance with advantageous features of the present invention, a 
turbine wheel meter of the aforementioned type is proposed wherein a 
length of a cylindrical sleeve of the turbine wheel meter is smaller than 
an inside diameter of a discontinuity or interruption of a duct of the 
meter, and the cylindrical sleeve of the flow regulator and measuring 
insert include plug-in and centering means having neutrally opposed end 
faces. The duct includes a cylindrical flaring portion emanating from the 
discontinuity or interruption, with a shoulder, the radial bearing surface 
of which, extends toward the discontinuity, and the cylindrical sleeve of 
the flow regulator seated in the flaring portion abuts, with a counter 
shoulder, the aforementioned shoulder. A circular ring-shaped clamping 
element is disposed between the measuring insert and the edge of the duct 
discontinuity or interruption on the discharge side. 
By virtue of the above noted features of the present invention, it is 
possible to remove the measuring insert as well as the flow regulator from 
the lateral opening of the meter housing in the proposed turbine wheel 
meter without having to disassemble the entire meter from the length of 
the conduit. As can readily be appreciated, this means not only a simple 
assembly at the manufacturing plant but also a ready exchange of these 
essential components without any problems. 
The plug in and centering means proposed by the present invention for 
releasably joining the two components makes it possible to calibrate or 
recalibrate the entire measuring device of the meter outside of the meter 
housing and insert the same only after completion of the calibration 
operation thereby saving expenses in manufacturing and servicing of the 
turbine wheel meter. 
Advantageously, an end web having the shape of a circular ring which 
engages into the measuring insert is provided as the plug-in and centering 
means at the cylinder sleeve. This simple arrangement reliably ensures the 
position of the measuring insert and the flow regulator with respect to 
each other inside and outside of the meter housing. 
A circular-ring-shaped end groove wherein a sealing ring is seated is 
suitably located beside the end web. This feature effects sealing of the 
junction point between the measuring insert and the flow regulator. 
According to another feature of the invention, guide means for the 
measuring insert are provided in the meter housing in the zone of the duct 
discontinuity, with the guide means imparting to the measuring insert its 
prescribed location in the radial direction within the duct, and 
facilitating insertion and removal, respectively, of the flow regulator 
into and out of the duct. 
Suitably, transverse ribs integrally formed in the interior of the meter 
housing serve as the guide means. 
It is advantageous to fashion the clamping element to be spring-elastic. 
This clamping element, which thus can be utilized under tension, ensures 
the correct position of the measuring insert and the flow regulator in the 
axial direction. 
The clamping element can carry along its edge a projecting fishplate as 
well as at least one tang attached at a right angle, with the fishplate 
facilitating the pulling out of the clamping element, and the aiding in 
attaching the element either to the meter housing or to the measuring 
insert.

DETAILED DESCRIPTION 
The turbine wheel meter as illustrated in the Single FIGURE of the drawing 
comprises a capped metal meter housing generally designated by the 
reference numeral 1 provided with two end-positioned mounting flanges 2, 3 
containing mounting bores 4. The turbine wheel meter is inserted into a 
length of a gas supply conduit by way of the mounting flanges 2, 3. 
The meter housing 1 has, in a center area thereof, a lateral opening 
generally designated by the reference numeral 5 constituted by an 
integrally formed pipe connection 6, with the opening 5 being sealed by a 
housing lid 7 by cap screws 8 and a gasket 10 inserted in a groove 9. The 
housing lid 7 carries at an outer top side thereof a mechanical counting 
mechanism with, for example, six counting positions. 
A cylindrical straight duct 12 extends through the meter housing 1, with 
the duct 12 having a discontinuity, interruption, or gap generally 
designated by the reference numeral 13 formed in a zone or area of the 
lateral opening 5. A gas, the volume of which is to be measured with the 
turbine wheel meter, flows through the duct 12 in a direction of the four 
arrows. The discontinuity or gap 13 divides the ducts 12 into two halves, 
with one half of the duct 12 being disposed on an inlet side and the other 
half being disposed on an outlet side of the meter housing 1. 
A tubular measuring insert generally designated by the reference numeral 14 
is inserted in the discontinuity 13 of the duct 12 with the measuring 
insert 14 comprising a cylindrical wall 15 and a cylindrical gearbox 16, 
attached with radial holding webs 17 at the cylindrical wall 15, with 
formation of an annular duct 18. An impeller 20 is arranged on an end face 
19 of the measuring insert 14 on the inlet side, with the impeller being 
rotatable on a shaft 21 supported in the gearbox 16, and with the shaft 21 
actuating a reversing and reducing gear accommodated in the gearbox 16. 
A rotary shaft 23, with an annular magnet 24 positioned at an end thereof, 
is mounted in an extension 22 of the measuring insert 14, with the rotary 
shaft 23 extending out of the gearbox 16 through a web. The annular magnet 
24 is disposed in opposition to a second annular magnet 25 and separated 
thereform by a gastight diaphragm 26, with the drive shaft 27 of the 
second annular magnet 24 driving the counting mechanism 11. 
Guides for the measuring insert 14 are formed in the shape of two 
transverse ribs 28 integrally formed in the meter housing 1 in a zone or 
area of the discontinuity 13 of the duct 12. The measuring insert 14 rests 
with the cylindrical wall 15 on the two transverse ribs 28, with the 
transverse ribs 28 being fashioned as two narrow bearing blocks with an 
approximately semicircular bearing surface. 
A flow regulator generally designated by the reference numeral 29 is placed 
in the duct 12 on the inlet side upstream of the measuring insert 14, with 
flow regulator 29 including a cylindrical sleeve 30 housing in its 
interior centrally a hollow displacement member 31 provided with a 
hemispherical head at one end and open on the discharge side. The 
displacement member is studded with a circular array of radial guide ribs 
32, with the ends of the guide ribs 32 being joined by a ring 33 inserted 
from the front into the cylindrical sleeve 30. 
The length 1 of the cylindrical sleeve 30 is smaller than the inside 
diameter w of the discontinuity 13 of the duct 12 so that the flow 
regulator 29, once the husing lid 7 has been removed and the measuring 
insert 14 has been lifted out, can be removed, after lateral shifting to a 
place previously occupied by the measuring insert 14, through the opening 
5 of the meter housing 1. During the displacement of the flow regulator 
29, the latter slides along the transverse ribs 28. 
The cylindrical sleeve 30 of the flow regulator 29, as well as the 
cylindrical wall 15 of the measuring insert 14, exhibit on their end faces 
mutually opposed plug-in and centering means generally designated by the 
reference numeral 34. To serve in this capacity, an annular end web 35 is 
provided in the cylindrical sleeve 30, with the end web 35 extending for 
some distance with tight fit into the cylindrical wall 15 of the measuring 
insert 14. An end groove 36, having the shape of a circular ring, is 
arranged in the cylindrical sleeve 30 beside the end web 35, with a 
sealing ring 37 being inserted in the end groove 36 and sealingly 
contacting the end face of the cylindrical wall 15. 
The portion of the duct 12 of the meter housing 1 on the inlet side 
exhibits a cylindrical, flaring portion 38 emanating from the 
discontinuity 13 and has a shoulder generally designated by the reference 
numeral 39, the radial, annular bearing surface 40 of which points toward 
the discontinuity 13. The cylindrical sleeve 30 includes a counter 
shoulder 41 in the form of its circular end face. The flow regulator 29 is 
fittingly seated in the flaring portion 38 of the meter housing 1, and the 
counter shoulder 41 abuts against the shoulder 39. In this way, the 
position of the flow regulator 29 is accurately fixed in both the axial 
and radial directions. 
A flat, circular-ring-shaped clamping element 43 is inserted between the 
measuring insert 14 and/or the cylindrical wall 15 and the annular edge 42 
of the discontinuity 13 of the duct 12 on the discharge side. The width of 
the ring of the clamping element 43 coincides with the thickness of the 
cylindrical wall 15 of the measuring insert 14. The clamping element 43 is 
designed to be spring-elastic and is preshaped so that it is seated like a 
spring washer under tension in the interspace between the cylindrical wall 
15 and the edge 42 of the duct 12 and urges the flow regulator 29 by way 
of the measuring insert 14 against the shoulder 39 of the flaring portion 
38. Thereby the position of these two parts with respect to the meter 
housing 1 is clearly fixed in the axial direction. 
The clamping element 43, swordlike in cross section, carries at its edge a 
fishplate 44 with a hole 45 into which can be introduced, for example, a 
hook-shaped tool for pulling out the clamping element 43. Two short tangs 
46 and 47 are attached at a right angle at the base of the fishplate 44, 
and with the aid of these tangs, the clamping element 43 is releasably 
attached by screws 48 to the measuring insert 14 as well as to the meter 
housing 1. 
In order to prevent the measuring insert 14 from twisting, a longitudinal 
groove 49 is arranged in the cylindrical wall 15. A hexagonal screw 50 
with a trunnion at the end, penetrating the wall of the meter housing 1, 
engages into the longitudinal groove 49. The cylindrical sleeve 30 of the 
flow regulator 29 carries a blind bore 51 engaged by a headless screw 52 
seated in the wall of the pipe connection 6, and this retains the flow 
regulator 29 during its dismounting for the purpose of facilitating 
separation from the measuring insert 14. 
The cylindrical sleeve 30 of the flow regulator 29 carries on its outer 
wall, close to the discontinuity 13, a radial annular groove 53 
accommodating a ring seal 54 so as to prevent the formation of an 
undesirable bypass of the flow along the outside of the cylindrical sleeve 
30.