JPH05296810A - Bearing structure of volume flowmeter - Google Patents

Abstract

PURPOSE:To obtain the bearing structure wherein it can be applied to all volume flowmeters, it can lubricate a bearing forcibly, simply and at low costs and it can enhance the accuracy of the flowmeters. CONSTITUTION:In a shaft-fixed volume flowmeter in which a rotor shaft 12 is fixed and bonded to a measuring chamber 2, a suction means constituted in the following manner is installed: a plurality of grooves 9b which are opened toward the outer circumference from a recessed part 9c around a shaft hole 9d are formed in a rotor thrust seat 11 on one side of a rotor 9; and a measuring liquid is sucked from the rotor-shaft hole 9a by utilizing a centrifugal force caused by the rotation of the rotor 9. By using the suction means, the measuring liquid, at an inflow pressure P1, which has been housed, through an oil groove 3, in a liquid reservoir 10 in a measuring-chamber thrust seat 4 arranged and installed around the shaft of the measuring chamber 2 opposite to the suction means is sucked through a gap between the rotor shaft 12 and the shaft hole 9d.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure of a bearing portion of a positive displacement flowmeter, and more particularly, to a bearing of a positive displacement flowmeter that automatically supplies a lubricating fluid to a rotor bearing portion in accordance with the rotation of a rotor for lubrication. Regarding the structure.

[0002]

2. Description of the Related Art As is well known, in a positive displacement flowmeter, a pair of rotors are rotationally driven by a fluid pressure difference of a measurement fluid in a measuring chamber.
The flow rate is measured by utilizing the fact that the fluid in the measuring chamber is proportional to the rotation speed of the rotor. Since the flowmeter rotor thus rotates in proportion to the flow rate, the volumetric flowmeter is provided with a metering chamber, a rotor, a rotor shaft, and a bearing for bearing the rotor shaft. In many medium and small volume flowmeters, one end of the rotor shaft is fixed in the measuring chamber, and the bearing is fitted in the rotor, so-called fixed shaft type. However, in a large volumetric flowmeter, a so-called shaft-rotation type in which a rotor shaft is inserted and fixed to a rotor and a bearing is mounted on a housing of a main body is mainly used.

In a positive displacement flowmeter, the running clearance between the shaft of the rotor bearing and the bearing is required to be minimum in terms of measurement accuracy. Is insufficiently supplied to cause insufficient lubrication and insufficient cooling, and the solid friction portion of boundary lubrication increases. As a result, the bearing torque increases, the accuracy decreases, and the bearing wears faster. Especially in the case of a low viscosity liquid, the shaft may be burned. The conventional rotor shaft lubrication method uses an external pressure source that adds a certain static pressure to the pressure of the measured fluid and pumps the lubricating fluid to the bearing, and the inflow pressure and outflow of the measured fluid. It is classified as a method that uses an internal pressure source that pumps the measured liquid to the bearing part by using the pressure difference of the pressure.However, most of the conventional rotor shaft lubrication methods are large because they are large devices. It was used for a compact volumetric flowmeter and could not be used for a small volumetric flowmeter.

[0004]

[Object] The present invention has been made in view of the above-mentioned circumstances, and is a simple and inexpensive forced lubrication structure that can be applied to bearing lubrication of all large-scale to small-volume flowmeters, particularly a low-viscosity measurement fluid. An object of the present invention is to provide a suitable bearing structure.

[0005]

In order to achieve the above object, the present invention provides (1)
A main body having a measuring chamber communicating with the inflow port and the outflow port and sealed with a lid, a rotor shaft having at least one end fixed to the measuring chamber of the main body, and the rotor in the measuring chamber. A rotatably supported rotor on a shaft, and a bottom surface of the measuring chamber in a positive displacement flowmeter for measuring a flow rate from rotation of a rotor that rotates according to a volume of a measurement fluid introduced into the measuring chamber. A thrust seat on the side of the measuring chamber, the outer peripheral end surface of which serves as one thrust surface of the rotor, and the concave portion inside the thrust surface serves as a reservoir for containing the measurement fluid introduced from the inlet side; A thrust seat on the rotor side formed on the opposite end surface of the thrust seat on the side of the measuring chamber, and from the axial hole of the thrust seat on the rotor side toward the outer periphery, and in the direction opposite to the rotation of the rotor. Forming a plurality of slanted grooves, or (2 A main body having a measuring chamber communicating with the inflow port and the outflow port and sealed with a lid, a rotor shaft having at least one end fixed to the measuring chamber of the main body, and the rotor in the measuring chamber. A rotor having a rotor rotatably supported on a shaft, and a thruster of the rotor in a positive displacement flowmeter for measuring a flow rate from rotation of a rotor rotating according to a volume of a measurement fluid introduced into the measuring chamber. A plurality of grooves that have a liquid pool in a recess on the inner side of the seat, that is formed in one thrust seat of the rotor and that opens from the axial hole toward the outer periphery, and that is inclined in the direction opposite to the rotation of the rotor; Having a plurality of grooves formed in the other thrust seat of the rotor and opening from the shaft hole toward the outer periphery and inclined in the rotation direction of the rotor; and (3)
A spiral groove is formed on the rotor shaft. Hereinafter, it demonstrates based on the Example of this invention.

1 (a), (b), and (c) are views for explaining the bearing structure of the volumetric flow meter according to the present invention.
1A is a cross-sectional view taken along the line AA of FIG. 1B, and FIG.
1A is a sectional view taken along the line BB of FIG. 1A, and FIG.
It is a figure for explaining the inside of the dotted line C of (b), in the figure, 1 is a main body, 2 is a measuring chamber, 3 is an oil groove, 4 is a measuring chamber thrust seat, 5
Is a bottom surface, 6 is an inlet, 7 is an outlet, 8 is a lid, 9 is a rotor, 10 is a liquid reservoir, 11 is a rotor thrust seat, and 12 is a rotor shaft.

In FIG. 1, a body 1 of a volumetric flowmeter is provided with a measuring chamber 2 having an opening at one end and a bottom surface 5.
An inflow port 6 and an outflow port 7 are open in the. In the measuring chamber 2, rotor shafts 12 and 12 are arranged on the X-X line which divides the inflow port 6 and the outflow port 7. The rotor shaft 12, 1
Reference numerals 2 are perpendicular to the bottom surface portion 5 of the measuring chamber 2 and parallel to each other and fixed at one end. There is a minute gap between the rotor shaft 12 and the shaft hole 9a, and the rotor 9 (non-circular gear) is rotatably meshed and supported. The opening of the measuring chamber 2 is closed by the lid 8. The rotor 9 and the measuring chamber 2 rotate with a minute gap, but the end face 9a side of the rotor 9 is separated from the lid 8 by the rotor thrust seat 11 (for the sake of explanation in FIG. 1B). The end face 9b side of the rotor 9 is formed by a measuring chamber thrust seat 4 projecting in the vicinity of the rotor shaft of the main body bottom face 5 (Fig. 1 (b)).
Are exaggerated for the sake of explanation).

The thrust end 4 of the measuring chamber is a projection surface whose outer peripheral end surface is a sliding surface that slides on the rotor end surface 9b, and a liquid reservoir 10 is formed around the rotor shaft 9 inside the outer peripheral end surface to form a recess. The groove 3 communicates with the liquid reservoir 10. Groove 3 is bottom surface 5
The shallow groove formed at one end communicates with the measuring chamber 2 on the side of the inflow port 6 into which the measurement liquid having the pressure P ₁ flows. On the other hand, rotor 9
The rotor thrust seat 11 on the side of the other end surface 9a has a recess 9c formed around the shaft hole 9a as shown in FIG. 1 (c) of the detailed drawing, and the recess 9c extends from the recess 9c toward the outer peripheral surface of the rotor thrust seat 11. The groove 9c is formed so as to open. The groove 9c is inclined in the direction opposite to the direction in which the rotor 9 rotates.

Next, the operation of the bearing structure of the volumetric flow meter according to the present invention will be described. The rotor 9 meshed when the measuring fluid having the pressure P ₁ flows into the measuring chamber 2 from the inlet 6 in the direction of the arrow,
Reference numeral 9 alternately generates a rotational force based on the pressure difference between the upstream pressure P ₁ and the downstream measured pressure P _2, and rotates according to the flow rate. Rotor 9
By rotating, the volume of measurement fluid formed by the rotor 9 and the measuring chamber 2 flows out from the inflow port 7. At this time,
Since the rotor thrust seat 11 also rotates with the rotation R of the rotor 9, the measurement fluid in the recess 9c receives centrifugal force and flows out in the direction of arrow F. As a result, the pressure in the recess 9c decreases, and a pressure difference is generated between the oil groove 3 and the measurement fluid having the pressure P ₁ stored in the liquid reservoir 10. Due to this pressure difference, the liquid flows from the liquid reservoir 10 toward the recess 9c through a minute gap between the shaft hole 9d of the rotor 9 and the rotor shaft 12. Centrifugal force is the rotational angular velocity of 2
Since the amount is proportional to the power, it increases as the rotational speed increases, that is, as the flow rate increases. Therefore, the rotor shaft 12 can be stably lubricated even with a measurement fluid having a low viscosity and poor lubrication. The direction of the groove 9b is inclined in the direction opposite to the rotation direction, and due to the viscosity, a pressure difference larger than the pressure difference generated by only the centrifugal force is obtained on the outer circumference of the rotor thrust seat 11, but the groove 9b is inclined. Instead, a groove may be formed in the radial direction so that centrifugal force acts. FIG. 2 is a view showing another shape of the thrust seat shown in FIG. 1C. The recess 15a of the thrust seat 15 is the same as that in FIG.
Although formed around, the groove 15b of the thrust seat 15 is formed in the radial direction.

FIGS. 3 (a) and 3 (b) are views for explaining another embodiment of the bearing structure of the volumetric flow meter according to the present invention. FIG. 3 (a) is a sectional view and FIG. 3 (b). 2 is a detailed view of the thrust seat, in which 20 is a pressurizing thrust seat and 21 is a depressurizing thrust seat. In the drawing, the same acting parts as those in FIG. 1 are designated by the same reference numerals.

In FIG. 3, the pressure thrust seat 20 is shown in FIG.
Similarly to the above case, the thrust seat 21 projects to the rotor end surface 9b side on the opposite side, although it projects in a thin cylindrical shape on the embellishment-hammer embankment a. The groove 20b of the thrust seat 20 is shown in FIG.
As illustrated in (b), it is inclined toward the outer circumference from the recess 20a in the rotation direction R side. Although the thrust seat 21 is not shown in the drawing, the rotation direction R is the same as in the case of FIG.
And is inclined to the other side.

In the bearing structure of FIG. 3, the thrust seat 20 and the thrust seat 21 rotate together with the rotor 9, but in the thrust seat 20, the groove 20b is inclined from the recess 20a toward the outer periphery in the rotational direction R side. Therefore, the portion of the thrust seat 20 partitioned by the groove 20b serves as a pressurizing means for pressing the measurement fluid into the groove 20b at the pressure P. On the other hand, the opposite end surface 9b
The groove 21b of the thrust seat 21 on the side has a function of sucking the measurement of the recess 21a toward the outer periphery from the recess as in the rotor thrust seat 11 of FIG. 1C, and therefore the thrust seats 20 and 21 of the rotor shaft 19 are provided. And a pressure difference is generated between the two, and the measurement liquid flows through the gap between the rotor shaft 12 and the shaft hole 9d due to the pressure difference. It should be noted that the thrust seat 20 and the thrust seat 21 may be arranged opposite to each other, and the thrust seat 21 may be omitted.

FIG. 4 is a diagram for explaining one embodiment of the shaft structure of the rotor shaft of the bearing structure of the volumetric flow meter according to the present invention, in which 30 is a rotor shaft and 31 is a spiral groove. is there. By providing the spiral groove 31 on the rotor shaft 30 as shown in the figure, the fluid resistance between both ends of the rotor shaft 30 is reduced, and the flow rate of the measured fluid is increased even if the pressure difference generated between both ends of the rotor shaft 30 is constant. Lubrication effect becomes large.

[0014]

As is apparent from the above description, according to the present invention, (1) the measurement fluid having the upstream pressure is stored in the liquid reservoir of the thrust chamber thrust seat, and the stored measurement fluid is on the opposite side of the rotor. Due to the action of the rotor thrust seat with suction action arranged on the end surface, the measured fluid in the liquid reservoir flows through the bearing to the rotor thrust seat, so that the bearing is lubricated and the suction action is squared to the flow rate. Since the flow rate is proportional, the larger the flow rate, the greater the lubricating action, the smaller the bearing torque, and the more stable the rotation of the rotor. Therefore, the accuracy of the flow meter can be improved. Further, it eliminates problems such as a shaft burner of a low viscosity fluid. (2) Since the suction action is applied to one thrust seat of the rotor and the pressurization action is applied to the other thrust seat, the pressure difference between both thrust seats of the bearing is doubled, and more stable bearing lubrication is performed. (3) Since the spiral groove of the rotor shaft is formed, the fluid resistance in the axial direction of the rotor shaft is reduced and the lubrication effect is enhanced.

[Brief description of drawings]

FIG. 1 is a diagram for explaining a bearing structure of a volumetric flow meter according to the present invention.

FIG. 2 is a view showing another shape of the thrust seat shown in FIG. 1 (c).

FIG. 3 is a diagram for explaining another embodiment of the bearing structure of the volumetric flow meter according to the present invention.

FIG. 4 is a diagram for explaining an embodiment of a shaft structure of a rotor shaft of a bearing structure of a volumetric flow meter according to the present invention.

[Explanation of symbols]

1 ... Main body, 2 ... Measuring chamber, 3 ... Oil groove, 4, 11 ... Thrust seat, 6 ... Inlet, 7 ... Outlet, 8 ... Lid, 9 ... Rotor,
10 ... Liquid reservoir, 12 ... Rotor shaft.

Claims (3)

[Claims] 1. A main body having a measuring chamber communicating with an inlet and an outlet and sealed with a lid, a rotor shaft having at least one end fixed to the measuring chamber of the main body, and the measuring unit. In a volumetric flowmeter having a rotor rotatably supported on the rotor shaft in a chamber, and measuring a flow rate from rotation of a rotor rotating according to a volume of a measurement fluid introduced into the measuring chamber, A thrust seat on the side of the measuring chamber, which is formed on the bottom surface of the measuring chamber and whose outer peripheral end surface serves as one thrust surface of the rotor and the concave portion inside the thrust surface serves as a reservoir for containing the measurement fluid introduced from the inlet side. A rotor-side thrust seat formed on an end surface of the rotor opposite to the measuring chamber-side thrust seat, and a rotor-side thrust seat that opens toward the outer periphery from the axial hole of the rotor-side thrust seat. Forming a plurality of grooves that are inclined in the opposite direction to the rotation Bearing structure of the characteristic volumetric flow meter. 2. A main body having a measuring chamber communicating with the inlet and the outlet and sealed with a lid, a rotor shaft having at least one end fixed to the measuring chamber of the main body, and the measuring unit. In a volumetric flowmeter having a rotor rotatably supported on the rotor shaft in a chamber, and measuring a flow rate from rotation of a rotor rotating according to a volume of a measurement fluid introduced into the measuring chamber, A plurality of liquids having a liquid pool in a concave portion inside the thrust seat of the rotor, formed in one thrust seat of the rotor and opening toward the outer periphery from a shaft hole, and tilting in the direction opposite to the rotation of the rotor. And a plurality of grooves that are formed in the other thrust seat of the rotor and open from the shaft hole toward the outer periphery, and that are inclined in the rotation direction of the rotor. 3. The bearing structure for a volumetric flow meter according to claim 1, wherein a spiral groove is formed on the rotor shaft.