CN1132002C - Positive displacement flowmeter - Google Patents

Abstract

The present invention relates to a volume flowmeter which makes the torque acting on a pair of gear rotation bodies the same and makes the sum of the torque a constant, and the volume flowmeter can not generate pulsation and can meter slurry. The shapes and the sizes of the gear rotation bodies are respectively the same, and the torsion of gear length is inclined-gear gears of pitches of an integral number. A tooth-shaped curve at the tooth top side is that a tooth tip has a tooth tip circle arc (A1B1=A2B2), a circular arc tooth-shaped (B1C1=B2C2) trochoidal curve (C1D2=C2D2) tooth shape and an involute curve (D1E1=D2E2) tooth shape; the tooth bottom side is provided with a circular arc (E1F1=E2F2) tooth shape, an involute curve (F1G1=F2G2) tooth shape and a tooth root circle (G1H1=G2H2), and thus, twisted wires 10, 11, 12, 13, P, 14, 15, 16, 17, 18, 19, P, 20, 21 and 10 are formed. When the circular arc tooth shape and the involute curve which are at the opposite sides are contacted, slurry fluid in a gap formed by trochoidal curves which are taken between the circular arc tooth shape and the involute curve can be removed by means of the slide of the involute curve.

Description

Positive displacement flowmeter

The invention technical field

The present invention relates to positive displacement flowmeter, specifically, relate to a pair of rotor that is meshing with each other and rotates in a kind of its measuring room, for torque equates and the positive displacement flowmeter of the angular gear that the torque sum is constant.

Background technology

In the prior art, for example Japanese Patent Publication 62-29730, special public clear 58-15047, special public clear 58-6131, special public clear 57-12444 disclose positive displacement flowmeter.

At present, great majority with gears as the volume-displacements of rotor, for the noncircular gear flowmeter (trade name: oval flowmeter), Roots-type flow meter, and duplex rotor meter or the like.The noncircular gear flowmeter is known a kind of typical positive displacement flowmeter, the same with its name, it with the non-round gear of a pair of homotype as rotor, utilize the differential pressure of fluid to be meshing with each other, make driving force by initiatively rotating, thereby no longer need the hydrostatic control gear to driven reciprocal variation, simple structure, and can carry out the high precision mill teeth to noncircular gear, make the instrument error characteristic good, and have reproducibility.

The structure of Roots-type flow meter is that the round envelope rotor of double leaf has predetermined phasic difference, is smoothly rotated by a contact, in order to keep this phasic difference, has clamped the hydrostatic control gear between rotor.Duplex rotor meter is with the three leaves angular gear different with the four-blade gear number body that rotates, and must use the profile of tooth sliding ratio is infinitely-great hydrostatic control gear, it is along the tooth curve of this rotor shaft right angle orientation section, in the master end is the cycloidal curve that the point on the slave end pitch circle draws, and is that the oblique cycloid that draws of the point on the external diameter of master end gear is by line at slave end.

The ideal form of positive displacement flowmeter with rotor of a pair of profile of tooth, if from the gear shape aspect, it is big to should be the little and theoretical discharge rate of gear shape, can carry out the large capacity meter amount, the shape of a pair of gear is identical, equal and opposite in direction, and make its work easy, do not need the hydrostatic control gear and simple structure can be rotated rotor voluntarily.And driven energy aspect is seen, should utilize fluid differential pressure, makes rotor produce the torque that equates, does not produce flank of tooth power, and discharges the fluid of rotational pulses such as not producing.

If from the aspect that utilizes of flowmeter, should be able to stably measure and comprise the flow of slurry at the interior multiple fluid that is measured.

Compare as can be known with above-mentioned desirable positive displacement flowmeter if will have a pair of original positive displacement flowmeter as the rotor gear, the noncircular gear flowmeter is at the constant flow of detected fluid, rotate under the constant condition of the area velocity of rotor, can produce not constant speed and rotate.This rotation is the inducement of effect of Fluid Pulsation, can produce vibration.This pulsation and vibration are also big more when theoretical discharge rate is big more.And, owing to meshing in detected fluid, noncircular gear rotates, so be not suitable for measuring slurry class fluid.

Roots-type flow meter must be equipped with the hydrostatic control gear, thus the rotor complex structure, and be attended by pulsation.When the hydrostatic control gear is installed, correctly determine position between rotor adjusting, because of being provided with backlash,, need masterful technique so what correctly adjust the hydrostatic control gear is quite difficult mutually at the rotor place.And, rub for producing between the rotor that prevents sliding contact, and be provided with the gap, yet when the gap is big, can be because of there being the fluid leakage loss that instrument characteristic is degenerated, and the gap is when too small, energy measurement slurry etc. does not contain the fluid of particulate again, and is not suitable for being used for measuring slurry class fluid.

The rotor of duplex rotor meter is the angular gear that a pair of size differs from one another, because it has angular gear, so compare with above-mentioned capacity type flowmeter, its shape is the most complicated, manufacturing cost is the highest, but also the load torque that has a slave end is for negative, and makes the hydrostatic control gear over-burden or the like problem.

As mentioned above, original capacity type flowmeter can not produce stable gear rotation kinetic moment when stable fluid flows through, and the moment sum is variable, thereby does not possess the fundamental characteristics of desired volume type flowmeter, can not stably measure slurry class fluid.

Summary of the invention

The purpose of this invention is to provide a kind of positive displacement flowmeter, it has not clamped the hydrostatic control gear, and when regime flow measured, rotor moment equated, the effect of no flank of tooth power, and the moment sum is constant, and can stably measure slurry class fluid.

According to the present invention, provide a kind of with the positive displacement flowmeter of a pair of angular gear that measures the indoor rotation that is meshing with each other as rotor, it is characterized in that aforementioned angular gear with the rectangular section of axle on the tooth top tooth curve, near the radius the crown of tooth top is crown radius of circle R ₀Crown arc toothed, link to each other with the crown circular arc be centered close near arc toothed, the pitch circle that radius on the pitch circle is a by Dynamic Radius R _C3The pressure angle that constitutes is the involute profile of α, and the Dynamic Radius of being drawn by the tooth root starting point between the arc toothed and involute profile is R at this _C1The continuous curve that constitutes of trochoidal curve profile of tooth, and the tooth root tooth curve is near the aforementioned pitch circle of the tooth bottom that is connected continuously with aforementioned involute profile arc toothed, the trochoidal curve profile of tooth of tooth root side, and radius is the continuous curve of the arc toothed formation of the radius of flute of tooth;

In above-mentioned tooth curve, the Dynamic Radius R of trochoidal curve curve in the tooth top _C1Dynamic Radius R with surplus pendulum curve in the tooth root _C2, the Dynamic Radius R of involute curve _C3Satisfy following relational expression: $R_{C1}=R[{\left(\frac{R_b}{R}\right)}^2+4\{1-\frac{R_b}{R}\cos (\mathrm{\θ}-\mathrm{\δ})\}{]}^{\frac{1}{2}}---\left(1\right)$ And, θ b '≤θ≤θ a $R_{C2}=R[{\left(\frac{R_0}{R}\right)}^2+4(1-\frac{R_0}{R}\cos \mathrm{\θ}){]}^{\frac{1}{2}}---\left(2\right)$ And, 0≤θ≤θ b $R_{C3}=R[1+{\mathrm{\θ}\cos }^2\mathrm{\α}(\mathrm{\θ}+2\left(\tan \mathrm{\α}\right){]}^{\frac{1}{2}}---\left(3\right)$ And ,-θ b '≤θ≤θ b ' here ${\mathrm{\θ}}_a={\cos }^{-1}\left[\right\{1+{\left(\frac{R_b}{R}\right)}^2-{\left(\frac{a}{R}\right)}^2\}/2\frac{R_b}{R}]+\mathrm{\δ}---\left(4\right)$ ${\mathrm{\θ}}_b={\cos }^{-1}\left[\right\{1+{\left(\frac{R_0}{R}\right)}^2-{\left(\frac{a}{R}\right)}^2\}/2\frac{R_0}{R}]---\left(5\right)$ $\mathrm{\δ}=\mathrm{inv\α}-\mathrm{inv}\left\{\mathrm{co}{s}^{-1}(\cos \mathrm{\α}/\frac{R_b}{R})\right\}---\left(6\right)$ ${{\mathrm{\θ}}_b}^{\′}=\tan \mathrm{\α}-\tan \left\{{\cos }^{-1}(\cos \mathrm{\α}/\frac{R_b}{R})\right\}---\left(7\right)$

In above-mentioned formula:

R _bIt is initial radius of a circle

A is the radius of arc toothed (Nobikovtooth ' s) circular arc

θ is an anglec of rotation parameter

Positive displacement flowmeter of the present invention, because of basic profile of tooth is a trochoidal curve, so theoretical discharge rate is bigger, because the theoretical sliding ratio of trochoidal curve profile of tooth is infinitely great, can be zero circular arc (arc toothed) as the slip that is arranged on the trochoidal curve gear parts with necessary hydrostatic control gear, and utilizes and slide less involute profile and rotate operation, no longer need the hydrostatic control gear, utilize aforementioned trochoidal curve profile of tooth, can remove slurry, so also can be used for measuring slurry class fluid by the profile of tooth engaging piece.

In foregoing invention, because the tooth of aforementioned a pair of angular gear is long, the number of teeth and all be equal to each other along the tooth curve of axle right angle orientation section, the torque between tooth is long is an integer circular pitch, thus there is not NE BY ENERGY TRANSFER between two rotors, and then can form the pulse free rotation.

Brief Description Of Drawings

Fig. 1 is the part sectioned view of a kind of embodiment of the rotor profile of tooth of explanation positive displacement flowmeter of the present invention.

Fig. 2 is the engages and seals line synoptic diagram of expression along the axial expansion of angular gear shown in Figure 1.

Fig. 3 is the axle right angle orientation sectional view that the engagement of the rotor with profile of tooth shown in Figure 1 is described.

Fig. 4 is the synoptic diagram of the embodiment of explanation positive displacement flowmeter of the present invention.

In the drawings

1... the first rotor (O ₁Gear), the 2... second rotor (O ₂Gear), 3...O ₁The crown circle of gear, 4...O ₁The pitch circle of gear, 5...O ₂The crown circle of gear, 6...O ₂The pitch circle of gear, 10～21... twisted-pair cable curve, 30... positive displacement flowmeter, 31... shell, 32... mounting flange, 33, the 34... end plates, 35... bolt, 36... count section, P... pitch point, R ₀... the crown radius of circle, the R... pitch radius, the Z... number of teeth, the L... tooth is long, β ... torsion angle.

Embodiment

The following describes example of the present invention.

Fig. 1 is the fragmentary cross-sectional view of rotor profile of tooth example in the explanation positive displacement flowmeter of the present invention, and in the drawings, 1 is that first rotor is (hereinafter referred to as O ₁Gear), 2 is that second rotor is (hereinafter referred to as O ₂Gear), 3 is O ₁The crown circle of gear, 4 is O ₁The pitch circle of gear, 5 is O ₂The crown circle of gear, 6 is O ₂The pitch circle of gear, P are node, R ₀Be the crown radius of circle, R is a pitch radius, and Z is the number of teeth.

Tooth curve shown in Figure 1 is by with axle O ₁For axle, crown radius of circle are R ₀The O that constitutes of angular gear ₁Gear 1 and and O ₁The identical equal-sized O of gear 1 shape ₂When gear 2 is in engagement, with respect to axle O ₁, O ₂The fragmentary cross-sectional view of rectangular direction.O ₁Gear 1 and O ₂Gear 2 is formed with the some P on the pitch circle 4,6 ₁, P ₂Tooth top and tooth root for boundary.O is described below ₁, O ₂The constituted mode of the tooth curve of gear 1,2.At first, because O ₁Gear 1 and O ₂Identical, the equal and opposite in direction of gear 2 shapes, O ₁Tooth curve A on the gear 1 ₁B ₁C ₁D ₁E ₁F ₁G ₁And O ₂The tooth curve A of gear 2 ₂B ₂C ₂D ₂E ₂F ₂G ₂Identical, so only use an O ₁The tooth curve of gear 1 describes.

At expression tooth top tooth curve A ₁B ₁C ₁D ₁E ₁P ₁Curve in, curve A ₁B ₁Be that radius is crown radius of circle R ₀The crown circular arc, curve B ₁C ₁Be to be centered close to that radius is the arc toothed of a on the pitch circle, curve C ₁D ₁Be by an E ₁The Dynamic Radius of drawing is R _C1The trochoidal curve of (seeing for details following), curve D ₁P ₁Be by Dynamic Radius R _C3The pressure angle that (seeing for details following) constitutes is the involute urve of α.

The tooth root tooth curve is E ₁F ₁G ₁H ₁The curve that constitutes, wherein curve P ₁E ₁Be and aforementioned D ₁P ₁Continuous pressure angle is the involute urve of α, curve E ₁F ₁For with the curved B of aforementioned circular arc ₁C ₁Corresponding arc toothed, curve F ₁G ₁Be that Dynamic Radius is R _C2(seeing for details following) by a B ₁The trochoidal curve that draws, curve G ₁H ₁Be that radius is radius of circle (2R-R at the bottom of the tooth ₀) circular arc.

In above-mentioned tooth curve, trochoidal curve curve (C in the tooth top ₁D ₁=C ₂D ₂) Dynamic Radius R _C1With surplus pendulum curve (F in the tooth root ₁G ₁=F ₂G ₂) Dynamic Radius R _C2, involute curve (D ₁E ₁=D ₂E ₂) Dynamic Radius R _C3Satisfy following relational expression.(mathematical expression 1) $R_{C1}=R[{\left(\frac{R_b}{R}\right)}^2+4\{1-\frac{R_b}{R}\cos (\mathrm{\θ}-\mathrm{\δ})\}{]}^{\frac{1}{2}}---\left(1\right)$ And, θ b '≤θ≤θ a $R_{C2}=R[{\left(\frac{R_0}{R}\right)}^2+4(1-\frac{R_0}{R}\cos \mathrm{\θ}){]}^{\frac{1}{2}}---\left(2\right)$ And, 0≤θ≤θ b $R_{C3}=R[1+{\mathrm{\θ}\cos }^2\mathrm{\α}(\mathrm{\θ}+2\left(\tan \mathrm{\α}\right){]}^{\frac{1}{2}}---\left(3\right)$ And ,-θ b '≤θ≤θ b ' here ${\mathrm{\θ}}_a={\cos }^{-1}\left[\right\{1+{\left(\frac{R_b}{R}\right)}^2-{\left(\frac{a}{R}\right)}^2\}/2\frac{R_b}{R}]+\mathrm{\δ}---\left(4\right)$ ${\mathrm{\θ}}_b={\cos }^{-1}\left[\right\{1+{\left(\frac{R_0}{R}\right)}^2-{\left(\frac{a}{R}\right)}^2\}/2\frac{R_0}{R}]---\left(5\right)$ $\mathrm{\δ}=\mathrm{inv\α}-\mathrm{inv}\left\{\mathrm{co}{s}^{-1}(\cos \mathrm{\α}/\frac{R_b}{R})\right\}---\left(6\right)$ ${{\mathrm{\θ}}_b}^{\′}=\tan \mathrm{\α}-\tan \left\{{\cos }^{-1}(\cos \mathrm{\α}/\frac{R_b}{R})\right\}---\left(7\right)$

Thus obtained O ₁Gear 1 and O ₂The contact point track of the contact point of gear 2 in static coordinate system is that node is the dotted line 10,11,12,13 of P, P, 14,15,16,17,18,19, P, 20,21,10 twisted-pair cables that constitute.

Fig. 2 is the exhibition property the opened synoptic diagram of the engages and seals line of expression angular gear axial direction shown in Figure 1, and wherein Fig. 2 (A) is O ₁Gear, Fig. 2 (B) is O ₂The stretch-out view of gear meshing potted line, O ₁Gear and O ₂Long L is identical for the tooth of gear, and torsion angle β reverses between the long L of tooth and satisfies relational expression (mathematical expression 2) when being a circular pitch $\tan \mathrm{\β}=R\frac{2\mathrm{\π}}{Z}/L$ In the drawings, X ₁-X ₁, X ₂-X ₂Be both ends of the surface.Except that the part that illustrates with mark (), its letter is followed successively by the assumed position of corresponding letters among Fig. 1.

At this moment, inflow side pressure P ₁With the outflow side pressure P ₂The potted line of effect is the thick line among the figure, promptly acts on O ₁The torque T of gear 1 ₁With act on O ₂The torque T of gear 2 ₂Equate.And, even the parallel fixedly end face X that moves ₁-X ₁, X ₂-X ₂The time, this active line also can keep this relation, so act on O ₁Gear 1 and O ₂Moment on the gear 2 can not change, and T is promptly arranged ₁=T ₂=constant.Find out that by knowing among the figure when reversing to integer circular pitch, this relation can be set up between tooth is long.Promptly when i is integer, (mathematical expression 3) also arranged $\tan \mathrm{\β}=\mathrm{iR}\frac{2\mathrm{\π}}{Z}/L$ Figure T ₁=T ₂So=constant is T ₁+ T ₂=constant does not have flow pulsation during i.e. constant speed rotation or the like.And by T ₁=T ₂=0 as can be known, and the power of appearing between gear is zero, so be no-load running.

The sectional view of axle right angle orientation that Fig. 3 has the rotor engagement of profile of tooth shown in Figure 1 for explanation, with act among Fig. 1 identical part used with Fig. 1 in identical label illustrate.

O among the figure ₁Gear 1 and O ₂Gear 2 is the gears that clearly show the gear global shape, and for have with Fig. 1 middle gear the angular gear of the identical tooth curve of tooth curve, the track of putting on contact point at stationary holder is identical with the contact point track shown in Fig. 1 dotted line.Wherein, crown is a circular arc 11～12,16～17, and arc toothed is 11～12,15～16,17～18,21～22, and surplus pendulum shape profile of tooth is straight line 13～P～14,19～P～20.As this O ₁Gear 1, O ₂When gear 2 is used as the rotor of positive displacement flowmeter, it can be contained in the housing with fluid inflow entrance, flow export.

Fig. 4 is the synoptic diagram of an example of the example of explanation positive displacement flowmeter of the present invention.In the drawings, 30 is positive displacement flowmeter, and 31 is shell body, and 32 is mounting flange, and 33,34 is end plates, and 35 is bolt, and 36 is count section.

Fig. 4 is the main body of positive displacement flowmeter, a pair of angular gear that is engaged with each other as shown in Figure 3, O ₁Gear 1 and O ₂Gear 2 is as rotor, be contained in and have inflow, in the measuring room 31a of the housing 31 of outflow side (not shown) ring flange 32, be bearing in end plates 33 with rotary way, on 34, the crown circle of this rotor has minim gap, and the inflow side has opening 32a with the rotor shaft direction that meets at right angles, and as shown in the figure, first, second rotor 1, a side of 2, by magnetic coupler (not shown) or the like, the axle rotation of rotor 1 is delivered to fluid-tight outside, drive count section 36 and carry out the flow computing, flow shows, and flow signal transmits or the like running.

The applicant is in experiment, and the fuel blend that head gets coal dust and heavy oil is that COM carried out metering experiment, and when using original gear, such as elliptic gear can be nibbled at coal dust and embed shutting down in a flash between the rotor when being the positive displacement flowmeter of rotor.What compare therewith is, when adopting profile of tooth is as shown in Figure 4 angular gear of the present invention, its along with the axle section tooth curve that direction cuts open that meets at right angles, when a part that is the trochoidal curve curve is the positive displacement flowmeter of the rotor that is made of arc toothed and involute profile, just can carry out normal continuous measurement for a long time, and can not take place unusual.So can infer, here, the coal dust particulate of the COM that is had in the space between the trochoidal curve profile of tooth that is formed between circular profile of tooth and the involute profile can be discharged by the mate of crown and trochoidal curve curve, and be formed a kind of cleaning action.

In sum, be in the positive displacement flowmeter of rotor with the indoor a pair of angular gear that rotates that is meshing with each other of metering, its aforementioned angular gear with the rectangular section of axle on tooth curve, serve as reasons and near the crown of tooth top, be arc toothed, it near pitch circle involute profile, the continuous curve that constitutes for the trochoidal curve profile of tooth between arc toothed and involute profile at this, be circular curve near the aforementioned pitch circle at the tooth root place that is connected continuously with aforementioned trochoidal curve profile of tooth, the continuous curve that the tooth root side constitutes for the trochoidal curve profile of tooth is so can be used for the metering of slurry class fluid.

In addition, the tooth of aforementioned a pair of angular gear is long, the number of teeth and with the rectangular section of axle on tooth curve all be equal to each other because the moment of torsion of tooth between long is an integer pitch,, can form flow rotation such as pulseless so the flank of tooth power between gear is zero.

Claims (2)

1. One kind with the indoor a pair of angular gear that rotates of being meshing with each other of metering as the positive displacement flowmeter of rotor, it is characterized in that aforementioned angular gear with the rectangular section of axle on the tooth top tooth curve, near the radius the crown of tooth top is crown radius of circle R ₀Crown arc toothed, near the pressure angle that is made of Dynamic Radius Rc3 that is centered close to arc toothed, the pitch circle that radius on the pitch circle is a that links to each other with the crown circular arc is the involute profile of α, and at this Dynamic Radius of being drawn by the tooth root starting point between the arc toothed and involute profile is the continuous curve that the trochoidal curve profile of tooth of Rcl constitutes, and the tooth root tooth curve is near the aforementioned pitch circle of the tooth bottom that is connected continuously with aforementioned involute profile arc toothed, the trochoidal curve profile of tooth of tooth root side, and radius is the continuous curve of the arc toothed formation of the radius of flute of tooth;

   In above-mentioned tooth curve, the Dynamic Radius R of trochoidal curve curve in the tooth top _C1Dynamic Radius R with surplus pendulum curve in the tooth root _C2, the Dynamic Radius R of involute curve _C3Satisfy following relational expression: $R_{C1}=R[{\left(\frac{R_b}{R}\right)}^2+4\{1-\frac{R_b}{R}\cos (\mathrm{\θ}-\mathrm{\δ})\}{]}^{\frac{1}{2}}---\left(1\right)$ And, θ b '≤θ≤θ a $R_{C2}=R[{\left(\frac{R_0}{R}\right)}^2+4(1-\frac{R_0}{R}\cos \mathrm{\θ}){]}^{\frac{1}{2}}---\left(2\right)$ And, 0≤θ≤θ b $R_{C3}=R[1+{\mathrm{\θ}\cos }^2\mathrm{\α}(\mathrm{\θ}+2\left(\tan \mathrm{\α}\right){]}^{\frac{1}{2}}---\left(3\right)$ And ,-θ b '≤θ≤θ b ' here ${\mathrm{\θ}}_a={\cos }^{-1}\left[\right\{1+{\left(\frac{R_b}{R}\right)}^2-{\left(\frac{a}{R}\right)}^2\}/2\frac{R_b}{R}]+\mathrm{\δ}---\left(4\right)$ ${\mathrm{\θ}}_b={\cos }^{-1}\left[\right\{1+{\left(\frac{R_0}{R}\right)}^2-{\left(\frac{a}{R}\right)}^2\}/2\frac{R_0}{R}]---\left(5\right)$ $\mathrm{\δ}=\mathrm{inv\α}-\mathrm{inv}\left\{\mathrm{co}{s}^{-1}(\cos \mathrm{\α}/\frac{R_b}{R})\right\}---\left(6\right)$ ${{\mathrm{\θ}}_b}^{\′}=\tan \mathrm{\α}-\tan \left\{{\cos }^{-1}(\cos \mathrm{\α}/\frac{R_b}{R})\right\}---\left(7\right)$

   In above-mentioned formula:

   R _bIt is initial radius of a circle

   A is the radius of arc toothed circular arc

   θ is an anglec of rotation parameter
2. 2. positive displacement flowmeter as claimed in claim 1 is characterized in that the tooth of aforementioned a pair of angular gear is long, the number of teeth and all be equal to each other at the tooth curve with the rectangular section of axle place, and the moment of torsion of tooth between long is an integer pitch.