JPH0228412Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a support structure for a rotating shaft in a transmitter suitable for application to a liquid level gauge, etc.

The rotating shaft of the level gauge, which converts the vertical movement of the float into degrees of rotation, is normally supported as shown in FIGS. 1 and 2. That is, 1 is a rotating shaft, and one end 1a of this rotating shaft 1 projects outside from the housing 2, and one end of a float lever 3 extending in a direction perpendicular to the shaft 1 is screwed to the projecting end. Fixed. A float 4 floating in the liquid is suspended from the other end of the float lever 3 by a connector 5 and a connecting rod 6. Therefore, a rotational force in the direction of arrow A about the axis is constantly applied to the rotating shaft 1 by the float 4.

The rotating shaft 1 is rotatably held through a torque tube 7 made of a thin flexible film made of stainless steel, Inconel, Monel, Hastelloy, etc. One end of the rotary shaft 7 is fixed by welding to the outer circumferential surface of the protruding end of the rotating shaft 1, and the other end is fixed to the inner wall surface of the housing 2 via a gasket (not shown).
Furthermore, as shown in FIG. 2, the protruding end of the rotating shaft 1 is formed by a substantially inverted V-shaped recess 8 formed on the lower surface of the connecting end of the float lever 3 and a protruding piece 9 having an edge 9A. It is supported. in this case,
The edge portion 9A coincides with the center of the rotating shaft 1.

The housing 2 constitutes a transmitter, and includes an element that expands the rotational displacement of the rotating shaft 1.
A means for detecting an enlarged displacement, an element for transmitting a detected value to a remote location, etc. (all of which are well known and therefore not shown) are built-in. Further, this housing 2 accommodates the float 4 and the like, and is connected to another housing (not shown) constituting a detection section via a flange 11.

By the way, in such a conventional liquid level gauge, when the float 4 moves up and down as the liquid level fluctuates, the float lever 3 rotates around the edge part 9A and rotates the rotating shaft 1, but the edge part 9A and Fluctuations in the liquid level cannot be detected with high precision due to friction loss between the recesses 8, and the protrusion piece 9 needs to be replaced because the edge portion 9A wears out during long-term use, which is a cumbersome task. .

The present invention was developed in view of the above-mentioned points, and by supporting it with wires, frictional parts are eliminated, enabling highly accurate detection and eliminating the need to replace wires even after long-term use. This provides a support structure for a rotating shaft in a transmitter, and its features include at least two through holes each having a small diameter opening at one end of the rotating shaft, which are offset from each other in the axial direction, and the drilling angle is A wire with elasticity and an outer diameter approximately the same as the small diameter portion of the through hole is inserted into each hole, and one end of the wire is inserted into the small diameter portion of each through hole. Each of the two ends is fixed to the opening end, and the other end is fixed to the housing with the other end protruding from the opening end on the large diameter side.

Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings.

FIG. 3 is a partially cutaway perspective view showing an embodiment of the rotating shaft support structure according to the present invention applied to a liquid level gauge, and FIG. 4 is a sectional view of a main part of the same support structure. Components in the drawings that are the same as those in FIGS. 1 and 2 are designated by the same reference numerals, and their explanations will be omitted. In these figures, a connector 20 is fitted onto the outer circumferential surface of the protruding end of the rotating shaft 1 and is fixed with a set screw 21. As shown in FIG. Two diametrical through holes 22 and 23 are bored in the outer peripheral surface of the connector 20, respectively, passing through the axis of the rotating shaft 1. These through holes 22 and 23 are formed at different angles by being shifted at appropriate intervals in the axial direction of the connector 20 and also in the circumferential direction. In this case, the through holes 22, 2
3 are bored at an angle of about 45 degrees with respect to the vertical line L passing through the axis, so that they have an opening angle θ of about 90 degrees. The opening ends on the lower end side of each of the through holes 22, 23 are set to have a small hole diameter, thereby forming small diameter opening ends 24a, 24b.

Reference numerals 25 and 26 denote wires that are inserted through the respective through holes 22 and 23, and these wires 25 and 26 have an outer diameter that is approximately the same as the hole diameter of the small diameter opening ends 24a and 24b, so that the opening ends 24a, Only the portion 24b contacts the inner circumferential wall of the hole, and the other portions remain in a non-contact state. And each wire 25, 26
The lower end portions of the connectors protrude from the small diameter opening ends 24a and 24b and are welded and fixed to the outer peripheral surface of the connector 20.

On the other hand, the upper end portions of the wires 25 and 26 protrude from the large-diameter side opening ends 27a and 27b of the through holes 22 and 23, and
It is led out to the outside through holes 28 and 29 bored correspondingly, and is fixed to the outer peripheral surface of the housing 2 by welding. Therefore, the protruding end of the rotating shaft 1 is suspended from the housing 2 by two wires 25 and 26 that are orthogonal to each other.

In this case, even if the rotating shaft 1 rotates with the vertical movement of the float, the two orthogonal wires 25 and 26 are pushed against each other, so that the rotation center 0 is around the axis, in other words, the intersection of the two wires is (See Figure 4)
The housing 2 rotates without being eccentric with respect to the housing 2. At this time, if the rotating shaft 1 rotates clockwise in FIG. 4, the wires 25 and 26 are
As shown by the two-dot chain line, the wire portion from the intersection 0 to the fixed end on the connector side is elastically deformed.

The float lever 3 is fitted into a hole (not shown) formed in the outer peripheral surface of the connector 20, and is firmly fixed with a set screw or the like.

Thus, according to the support structure for the rotating shaft 1 having such a configuration, since the bending or elastic deformation of the wires 25 and 26 is utilized, there is no loss due to friction, and therefore the vertical movement of the float is enhanced. It can be detected with precision. Furthermore, since there are no friction parts, there is no need to replace parts due to wear even after long-term use.

In addition, in the above embodiment, two wires 2
5 and 26, the present invention is not limited to this, and it is also possible to support the rotating shaft 1 with three or four wires.
Further, the connector 20 is not always necessary, and the through holes 22 and 23 may be directly formed in the rotating shaft 1.

Further, in the above embodiment, the rotating shaft 1 is suspended and supported, but the rotating shaft 1 may be supported from below using a wire with strong legs. It is also possible to arrange the rotating shaft 1 in a vertical direction.

Note that the present invention is not limited to the rotating shaft of a liquid level gauge, but can be applied to various measuring instruments in which a detecting section and a transmitting section are connected by a rotating shaft.

As explained above, the support structure for the rotating shaft in the transmitter according to the present invention allows one end of the rotating shaft to be freely rotated by at least two wires shifted in the axial direction and circumferential direction of the rotating shaft. It has very practical effects, as there are no frictional parts, and therefore there is no friction loss or wear of parts, enabling highly accurate detection and eliminating the troublesome work of replacing parts. It's large.

[Brief explanation of the drawing]

Figure 1 is a partially cutaway perspective view showing the support structure of the rotating shaft in a conventional level gauge, Figure 2 is a front view of the main parts of the same structure, and Figure 3 is an application of the present invention to the rotating shaft of the level gauge. A partially cutaway perspective view showing an example of the case where
The figure is a sectional view of the main part. 1... Rotating shaft, 2... Housing, 7... Torque tube, 20... Connector, 22, 23...
Through hole, 24a, 24b...small diameter opening end, 25,
26... Wire, 27a, 27b... Large diameter opening end.

Claims (1)

[Scope of utility model registration request] At least two through holes each having a small diameter opening at one end are formed at one end of the rotating shaft which is inserted into the housing and whose middle portion is rotatably held by a torque tube. Different wires are drilled in the diameter direction, and wires having elasticity and having an outer diameter that is approximately the same as the small diameter portion of the through hole are inserted into each hole, and one end of the wire is inserted into the open end of the small diameter portion of each through hole. 1. A support structure for a rotating shaft in a transmitter, characterized in that each of the rotating shafts is fixed to the housing, and the other end is fixed to the housing with the other end protruding from the opening end on the large diameter side.