CN103758751B - Four-blade differential pump driven by elliptic non-circular gears - Google Patents

Abstract

The invention discloses a four-blade differential pump driven by elliptic non-circular gears. The problems of pressure pulsation, trapped fluid and the like are very difficultly solved in an existing differential pump. According to the four-blade differential pump, both a first elliptic non-circular gear and a second elliptic non-circular gear are fixed to an input shaft; both a first conjugated elliptic non-circular gear and a first impeller are fixedly mounted on an output shaft; the first conjugated elliptic non-circular gear is meshed with the first elliptic non-circular gear; a second conjugated elliptic non-circular gear and a second impeller are fixedly connected to a shaft sleeve; the shaft sleeve is used for movably sleeving the output shaft; a pump housing is circumferentially provided with a first liquid discharging hole, a first liquid absorbing hole, a second liquid discharging hole and a second liquid absorbing hole in sequence; each of the first impeller and the second impeller is provided with two blades; a one-way pressure relief valve is mounted in each blade. The four-blade differential pump has the advantages that the discharge capacity is large, the flow quantity is stable, the non-uniform-speed rule can be easily adjusted, and the problem of the trapped fluid can be effectively solved.

Description

The quaterfoil differential pump that a kind of oval noncircular gear drives

Technical field

The invention belongs to displacement pump technical field, relate to blade differential pump, be specifically related to the quaterfoil differential pump that a kind of oval noncircular gear drives.

Background technique

The liquid pump that universal machine is conventional has reciprocating pump, plunger pump, diaphragm pump, roller pump and centrifugal pump, wherein: live (post) fills in pump higher outlet pressure, but require that the sealing between piston and cylinder barrel is reliable, and pressure surge is large; Diaphragm pump can produce a more stable liquid stream when multi-cylinder, but complex structure; Roller pump delivery is uniform when stabilization of speed, and along with the raising of pressure, leakage rate increases, the lifting rate of pump and the corresponding reduction of efficiency; Centrifugal pump structure is simple, easily manufactures, but its discharge capacity is large, and pressure is low, for the less demanding occasion of working pressure.There is respective defect in these pumps, can't meet the constant flow rate of part special mechanical requirement, the demand of high pressure well.

Existing differential pump mainly contains following several according to the difference of driving mechanism:

Rotating guide-bar-gear type blade differential pump, its drive system bears alternate load, produces gear tooth noise, and also can cause impact noise when each pair clearance is larger.

Universal-joint gear wheel mechanism drive vane differential pump, the input shaft of its universal joint mechanism and the angle of output shaft are the key parameters affecting pump performance.This angle is larger, and pump delivery is also larger, but along with the increase at this angle, the flow pulsation aggravation of pump and the transmission efficiency of universal joint reduce.

Distortion eccentric circle noncircular gear drive vane differential pump, its eccentric circle non-circular gear pitch curve adjustment parameter mainly eccentricity and deformation coefficient, adjustment amount is limited, Adjustment precision is not high, cause velocity ratio optimization, adjustment inconvenience, design dumb, be unfavorable for further optimal design, be difficult to optimize the problem such as pressure pulsation, tired liquid.Summary of the invention

The object of the invention is for the deficiencies in the prior art, provide the quaterfoil differential pump that a kind of oval noncircular gear drives, this blade differential pump displacement is large, pressure is high, stability of flow, compact structure; The variable speed rule of driving mechanism easily adjusts, convenient function optimization; By installing unidirectional Decompression valves in blade, during pressure limit, getting through contiguous enclosed cavity, effectively solving existing differential pump and being stranded liquid problem.

The present invention includes driver part and differential pump parts.

Described driver part comprises driving gearbox, input shaft, output shaft, the first oval noncircular gear, the second oval noncircular gear, the oval noncircular gear of the first conjugation, the oval noncircular gear of the second conjugation and axle sleeve.Motor is connected with input shaft by coupling, and input shaft passes through two bearings in the two side of driving gearbox; Described first oval noncircular gear and the second oval noncircular gear are all fixedly mounted on input shaft; The two ends of output shaft are respectively by bearings on the tank wall of driving gearbox and pump case, and the oval noncircular gear of the first conjugation is arranged on output shaft, and engages with the first oval noncircular gear; The oval noncircular gear of second conjugation and the second impeller are all cemented on axle sleeve, and axle sleeve kink is on output shaft, and the oval noncircular gear of the second conjugation engages with the second oval noncircular gear.

Described differential pump parts comprise pump case, the first impeller, the second impeller and unidirectional Decompression valves; Described pump case along the circumferential direction offers the first liquid port, the first liquid sucting port, the second liquid port and the second liquid sucting port successively; First impeller is fixed on output shaft; The first described impeller and the second impeller are all symmetrically arranged with two panels blade; Along the circumferential direction, the blade of the first impeller and the alternate setting of blade of the second impeller; All blade interior all install a unidirectional Decompression valves, and unidirectional Decompression valves direction is consistent with wheel rotation direction.

According to pump structure, the centre distance initial value a of given first oval noncircular gear and the oval noncircular gear of the first conjugation ₀, then according to pitch curve sealing condition and meshing condition, adopt the search of advance and retreat method to obtain the exact value of centre distance a.Specifically be calculated as follows:

The pitch curve representation of the first oval noncircular gear is:

Wherein, n ₁be the exponent number of the first oval noncircular gear, value is 2; A is oval major axis radius, k ₁for the eccentricity of ellipse, be the corner of the first oval noncircular gear, r ₁( ) be the corresponding corner of the first oval noncircular gear radius vector.

According to the noncircular gear theory of engagement, during the first oval noncircular gear rotating 360 degrees, the angular displacement of the oval noncircular gear of the first conjugation:

First oval noncircular gear and the oval noncircular gear of the first conjugation are second order noncircular gear, and therefore, during the first oval noncircular gear rotating 360 degrees, the oval noncircular gear of the first conjugation also rotating 360 degrees, can calculate the iterative of centre distance a:

Get centre distance initial value a ₀the search of advance and retreat method is adopted to calculate the exact value of centre distance a.

The first described liquid port and the second liquid port are symmetrical arranged, and the first liquid sucting port and the second liquid sucting port are symmetrical arranged.

Parameter and the structure of the described first oval noncircular gear and the second oval noncircular gear are completely the same, parameter and the structure of the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation are completely the same, and the first oval noncircular gear, the second oval noncircular gear, the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation are second order noncircular gear; The initial installation phase difference of the oval noncircular gear of the initial installation phase difference of the first oval noncircular gear and the second oval noncircular gear, the first conjugation and the oval noncircular gear of the second conjugation is 90 °.

The velocity ratio of the first oval noncircular gear and the oval noncircular gear of the first conjugation is:

Wherein, n ₂be the exponent number of the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation, value is 2;

The velocity ratio of the second oval noncircular gear and the oval noncircular gear of the second conjugation is:

Wherein, θ is the initial installation phase difference of the first oval noncircular gear and the second oval noncircular gear, and value is 90 °.

Make the velocity ratio i of the first oval noncircular gear and the oval noncircular gear of the first conjugation ₂₁equal the velocity ratio i of the second oval noncircular gear and the oval noncircular gear of the second conjugation ₄₃, four different corners can be tried to achieve corner get minimum value time, the angular displacement of the first oval noncircular gear is the angular displacement of the second oval noncircular gear is the corner of the first impeller and the second impeller is respectively:

The blade angle θ of the first impeller and the second impeller _leafvalue be 40 ° ~ 45 °; The central angle equal and opposite in direction of the first liquid port, the first liquid sucting port, the second liquid port and the second liquid sucting port, and than the blade angle θ of blade _leaflittle 2 ~ 5 °.First liquid port centre bit angle setting of pump case first liquid sucting port centre bit angle setting second liquid port centre bit angle setting ψ _{row 2}=ψ _{row 1}+ π, the second liquid sucting port centre bit angle setting ψ _{inhale 2}=ψ _{inhale 1}+ π.

The minimum subtended angle of adjacent two blade now this enclosed cavity is minimum volume:

$V_{\min }=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{\min }}{2}(R^2-r^2)\×h\×{10}^{-6}$

Wherein, R is blade radius, and r is impeller shaft radius, and h is vane thickness.

The maximum subtended angle of adjacent two blade now this enclosed cavity is maximum volume:

$V_{\max }=\frac{\mathrm{\Δ}{\mathrm{\Ψ}}_{\max }}{2}(R^2-r^2)\×h\×{10}^{-6}$

The discharge capacity account representation of quaterfoil differential pump:

Q＝4×(V _max-V _min)＝2(Δψ _max-Δψ _min)(R ²-r ²)×h×10 ^-6

The instantaneous flow calculation expression formula of quaterfoil differential pump:

$q=\frac{\mathrm{dV}}{\mathrm{dt}}=2h(R^2-r^2)|\frac{{\mathrm{d\ψ}}_1}{\mathrm{dt}}-\frac{{\mathrm{d\ψ}}_2}{\mathrm{dt}}|=2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

Wherein, V is exhaust chamber volume; ω is the angular velocity of the first oval noncircular gear and the second oval noncircular gear, and its calculating formula is

The minimum volume of quaterfoil differential pump, maximum volume are stranded hydraulic coupling change calculations representation:

$\frac{{\mathrm{dp}}_1}{\mathrm{dt}}=\frac{K}{V_{\min }}\×q=\frac{K}{{\mathrm{\Δ\ψ}}_{\min }(R^2-r^2)}\×2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

$\frac{{\mathrm{dp}}_2}{\mathrm{dt}}=\frac{K}{V_{\min }}\×q=\frac{K}{{\mathrm{\Δ\ψ}}_{\min }(R^2-r^2)}\×2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

Wherein K is the Young's modulus of liquid.

The beneficial effect that the present invention has is:

The present invention adopts oval non-circular gear mechanism, oval non-circular gear pitch curve has six to adjust parameter, compare existing distortion eccentric circle noncircular gear adjustable parameter many, therefore oval noncircular gear variable speed transmission rule easily adjusts, and easily realizes the optimization of the performances such as differential pump delivery, pressure, flow.By installing unidirectional Decompression valves in blade, during pressure limit, getting through contiguous enclosed cavity, effectively solving existing differential pump and being stranded liquid problem.The differential pump liquid sucting port driven due to oval non-circular gear mechanism and liquid port symmetry, radial equilibrium is good, and non-constant speed drive is rotary motion, and reliable, the radial work loads that therefore operates steadily balance, pulsation controllability are good; Blade is many, discharge capacity is large, and simply, volumetric efficiency is high for the internal surface of pump case and blade shape.

Core institution of the present invention is two install the oval noncircular gear of phase place to difference, and parts are few, compact structure.

Accompanying drawing explanation

Fig. 1 is kinematic sketch of mechanism of the present invention;

Fig. 2 is the overall structure sectional view of differential pump parts in the present invention;

Fig. 3 is the meshing relation schematic diagram of oval non-circular gear pitch curve when initial makeup location in the present invention;

Fig. 4 is blade limit position schematic diagram of the present invention;

Fig. 5 is instantaneous flow figure of the present invention.

In figure: 1, driving gearbox, 2, input shaft, 3, output shaft, 4, the first oval noncircular gear, the 5, second oval noncircular gear, the oval noncircular gear of the 6, first conjugation, 7, the oval noncircular gear of the second conjugation, 8, axle sleeve, 9, coupling, 10, motor, 11, pump case, 11-1, the first liquid port, 11-2, the first liquid sucting port, 11-3, the second liquid port, 11-4, the second liquid sucting port, 12, the first impeller, the 13, second impeller, 14, unidirectional Decompression valves.

Embodiment

Below in conjunction with drawings and Examples, the invention will be further described.

As illustrated in fig. 1 and 2, the quaterfoil differential pump that a kind of oval noncircular gear drives comprises driver part and differential pump parts.

Driver part comprises driving gearbox 1, input shaft 2, output shaft 3, the first oval noncircular gear 7 of oval noncircular gear 6, second conjugation of oval noncircular gear 5, first conjugation of oval noncircular gear 4, second and axle sleeve 8.Input shaft 2 and output shaft 3 are separately positioned on the two ends of gear-box 1; Input shaft 2 is by two bearings in the two side of driving gearbox 1, and power is passed to input shaft 2 by coupling 9 by motor 10, and the first oval noncircular gear 4 and the second oval noncircular gear 5 are all fixedly mounted on input shaft 2; The two ends of output shaft 3 are respectively by bearings on the tank wall of driving gearbox 1 and pump case 11, and the oval noncircular gear 6 of the first conjugation is fixedly mounted on output shaft 3, and engages with the first oval noncircular gear 4; The oval noncircular gear 7 of second conjugation and the second impeller 13 are all cemented on axle sleeve 8, and axle sleeve 8 kink is on output shaft 3, and the oval noncircular gear 7 of the second conjugation engages with the second oval noncircular gear 5.

Differential pump parts comprise pump case 11, first impeller 12, second impeller 13 and unidirectional Decompression valves 14.Pump case 11 along the circumferential direction offers the first liquid port 11-1, the first liquid sucting port 11-2, the second liquid port 11-3 and the second liquid sucting port 11-4 successively, first liquid port 11-1 and the second liquid port 11-3 is symmetrical arranged, and the first liquid sucting port 11-2 and the second liquid sucting port 11-4 is symmetrical arranged; First impeller 12 is fixedly mounted on output shaft 3; First impeller 12 and the second impeller 13 are all symmetrically arranged with two panels blade, and the outer arced surface of every sheet blade and the inwall of pump case 11 are fitted; Along the circumferential direction, the blade of the first impeller 12 and the alternate setting of blade of the second impeller 13, all form an enclosed cavity between every adjacent two panels blade; All blade interior are all provided with a unidirectional Decompression valves 14, and two of unidirectional Decompression valves 14 is communicated with the enclosed cavity of these blade both sides respectively; All unidirectional Decompression valves 14 directions are consistent with sense of rotation.

As shown in Figure 3, parameter and the structure of the first oval noncircular gear 4 and the second oval noncircular gear 5 are completely the same, parameter and the structure of the oval noncircular gear 6 of the first conjugation and the oval noncircular gear 7 of the second conjugation are completely the same, and the first oval noncircular gear 6 of oval noncircular gear 5, first conjugation of oval noncircular gear 4, second and the oval noncircular gear 7 of the second conjugation are second order noncircular gear; The initial installation phase angle of the first oval noncircular gear 4 is θ ₁, the initial installation phase angle of the second oval noncircular gear 5 is θ ₂; The initial installation phase difference of the first oval noncircular gear 4 and the oval noncircular gear 6 of the second oval noncircular gear 5, first conjugation and the oval noncircular gear 7 of the second conjugation is θ ₁-θ ₂its value is 90 °, and the differential realizing the first impeller 12 and the second impeller 13 rotates, and makes the volume cyclically-varying of differential pump enclosed cavity, produce discharge opeing at the first liquid port 11-1 and the second liquid port 11-3, produce imbibition at the first liquid sucting port 11-2 and the second liquid sucting port 11-4.Because the non-at the uniform velocity transmission of oval noncircular gear is continuous print, enclosed cavity be in complete airtight time, blade still has differential to rotate, and this will make enclosed cavity pressure exceed limit value, and vicinity enclosed cavity is got through pressure release by unidirectional Decompression valves 14, prevents tired liquid.

The working principle of the quaterfoil differential pump that this oval noncircular gear drives:

Power is passed to the first oval noncircular gear 4 and the second oval noncircular gear 5 by coupling 9 and input shaft 2 by motor 10.First oval noncircular gear 4 engages with the oval noncircular gear 6 of the first conjugation, second oval noncircular gear 5 engages with the oval noncircular gear 7 of the second conjugation, power is passed to the oval noncircular gear 7 of the first impeller 12, second conjugation by output shaft 3 and power is passed to the second impeller 13 by axle sleeve 8 by the oval noncircular gear 6 of the first conjugation.The installation phase place of two pairs of oval noncircular gear pairs is different, and the differential realizing the first impeller 12 and the second impeller 13 rotates, thus realizes imbibition and discharge opeing.

According to pump structure, the centre distance initial value a of given first oval noncircular gear 4 and the oval noncircular gear 6 of the first conjugation ₀, then according to pitch curve sealing condition and meshing condition, adopt the search of advance and retreat method to obtain the exact value of centre distance a.Specifically be calculated as follows:

The pitch curve representation of the first oval noncircular gear 4 is:

Wherein, n ₁be the exponent number of the first oval noncircular gear, value is 2; A is oval major axis radius, and value is 100mm; k ₁for the eccentricity of ellipse, value is 0.4; be the corner of the first oval noncircular gear, r ₁( ) be the corresponding corner of the first oval noncircular gear radius vector.

According to the noncircular gear theory of engagement, during the first oval noncircular gear 4 rotating 360 degrees, the angular displacement of the oval noncircular gear 6 of the first conjugation:

First oval noncircular gear 4 and the oval noncircular gear 6 of the first conjugation are second order noncircular gear, and therefore, during the first oval noncircular gear 4 rotating 360 degrees, the oval noncircular gear 6 of the first conjugation also rotating 360 degrees, can calculate the iterative of centre distance a:

Get centre distance initial value a ₀=120mm, the exact value adopting the search of advance and retreat method to calculate centre distance a is 120mm.

After trying to achieve the exact value of centre distance a, can solve the row of pump case, liquid sucting port central position, quaterfoil differential pump delivery, instantaneous flow and minimum volume, maximum volume are stranded hydraulic coupling change representation.Specifically be calculated as follows:

The velocity ratio of the first oval noncircular gear and the oval noncircular gear of the first conjugation is:

Wherein, n ₂be the exponent number of the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation, value is 2.

The velocity ratio of the second oval noncircular gear and the oval noncircular gear of the second conjugation is:

Wherein, θ is the initial installation phase difference of the first oval noncircular gear and the second oval noncircular gear, and value is 90 °.

Make the velocity ratio i of the first oval noncircular gear 4 and the oval noncircular gear 6 of the first conjugation ₂₁equal the velocity ratio i of the second oval noncircular gear 5 and the oval noncircular gear 7 of the second conjugation ₄₃, four different corners can be tried to achieve corner get minimum value time, the angular displacement of the first oval noncircular gear 4 is the angular displacement of the second oval noncircular gear 5 is the corner of the first impeller 12 and the second impeller 13 is respectively:

As shown in Figure 4, the blade angle θ of the first impeller 12 and the second impeller 13 _leafvalue be 45 °; The size of the first liquid port, the first liquid sucting port, the second liquid port and the second liquid sucting port is all than the blade angle θ of blade _leaflittle 2 °.First liquid port centre bit angle setting of pump case first liquid sucting port centre bit angle setting second liquid port centre bit angle setting ψ _{row 2}=ψ _{row 1}+ 180 °=269.5 °, the second liquid sucting port centre bit angle setting ψ _{inhale 2}=ψ _{inhale 1}+ 180 °=315.5 °.

Adjacent two blade minimum subtended angle Δ ψ _min=(ψ ₂+ 90 °)-(ψ ₁+ θ _leaf), now this enclosed cavity is minimum volume:

$V_{\min }=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{\min }}{2}(R^2-r^2)\×h\×{10}^{-6}$

Wherein, R is blade radius, and value is 90mm; R is impeller shaft radius, and value is 20mm; H is vane thickness, and value is 50mm.

Adjacent two blade maximum subtended angle Δ ψ _max=(ψ ₁+ 180 °)-(ψ ₂+ 90 ° of+θ _leaf), now this enclosed cavity is maximum volume $V_{\max }=\frac{\mathrm{\Δ}{\mathrm{\Ψ}}_{\max }}{2}(R^2-r^2)\×h\×{10}^{-6}.$

The discharge capacity account representation of quaterfoil differential pump:

Q＝4×(V _max-V _min)＝2(Δψ _max-Δψ _min)(R ²-r ²)×h×10 ^-6=11869.8ml

The instantaneous flow calculation expression formula of quaterfoil differential pump:

$q=\frac{\mathrm{dV}}{\mathrm{dt}}=2h(R^2-r^2)|\frac{{\mathrm{d\ψ}}_1}{\mathrm{dt}}-\frac{{\mathrm{d\ψ}}_2}{\mathrm{dt}}|=2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

Wherein, V is exhaust chamber volume; ω is the angular velocity of the first oval noncircular gear 4 and the second oval noncircular gear 5, and its calculating formula is the plotted curve of instantaneous flow as shown in Figure 5.

The minimum volume of quaterfoil differential pump, maximum volume are stranded hydraulic coupling change calculations representation:

$\frac{{\mathrm{dp}}_1}{\mathrm{dt}}=\frac{K}{V_{\min }}\×q=\frac{K}{{\mathrm{\Δ\ψ}}_{\min }(R^2-r^2)}\×2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

$\frac{{\mathrm{dp}}_2}{\mathrm{dt}}=\frac{K}{V_{\min }}\×q=\frac{K}{{\mathrm{\Δ\ψ}}_{\min }(R^2-r^2)}\×2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

Wherein K is the Young's modulus of liquid.

Be stranded hydraulic coupling change by the minimum volume, the maximum volume that calculate quaterfoil differential pump, can be and select the unidirectional Decompression valves in blade to provide reference, be generally used for the CLV ceiling limit value determining unidirectional Decompression valves.

Claims (4)

1. a quaterfoil differential pump for oval noncircular gear driving, comprises driver part and differential pump parts, it is characterized in that:

Described driver part comprises driving gearbox, input shaft, output shaft, the first oval noncircular gear, the second oval noncircular gear, the oval noncircular gear of the first conjugation, the oval noncircular gear of the second conjugation and axle sleeve; Motor is connected with input shaft by coupling, and input shaft passes through two bearings in the two side of driving gearbox; Described first oval noncircular gear and the second oval noncircular gear are all fixedly mounted on input shaft; The two ends of output shaft are respectively by bearings on the tank wall of driving gearbox and pump case, and the oval noncircular gear of the first conjugation is arranged on output shaft, and engages with the first oval noncircular gear; Second impeller of the oval noncircular gear of the second conjugation and differential pump parts is all cemented on axle sleeve, and axle sleeve kink is on output shaft, and the oval noncircular gear of the second conjugation engages with the second oval noncircular gear;

Described differential pump parts comprise pump case, the first impeller, the second impeller and unidirectional Decompression valves; Described pump case along the circumferential direction offers the first liquid port, the first liquid sucting port, the second liquid port and the second liquid sucting port successively; First impeller is fixed on output shaft; The first described impeller and the second impeller are all symmetrically arranged with two panels blade; Along the circumferential direction, the blade of the first impeller and the alternate setting of blade of the second impeller; All blade interior all install a unidirectional Decompression valves, and unidirectional Decompression valves direction is consistent with wheel rotation direction;

According to pump structure, the centre distance initial value a of given first oval noncircular gear and the oval noncircular gear of the first conjugation ₀, then according to pitch curve sealing condition and meshing condition, adopt the search of advance and retreat method to obtain the exact value of centre distance a; Specifically be calculated as follows:

The pitch curve representation of the first oval noncircular gear is:

Wherein, n ₁be the exponent number of the first oval noncircular gear, value is 2; A is oval major axis radius, k ₁for the eccentricity of ellipse, be the corner of the first oval noncircular gear, it is the corresponding corner of the first oval noncircular gear radius vector;

According to the noncircular gear theory of engagement, during the first oval noncircular gear rotating 360 degrees, the angular displacement of the oval noncircular gear of the first conjugation:

First oval noncircular gear and the oval noncircular gear of the first conjugation are second order noncircular gear, and therefore, during the first oval noncircular gear rotating 360 degrees, the oval noncircular gear of the first conjugation also rotating 360 degrees, can calculate the iterative of centre distance a:

Get centre distance initial value a ₀the search of advance and retreat method is adopted to calculate the exact value of centre distance a.

2. the quaterfoil differential pump of a kind of oval noncircular gear driving according to claim 1, it is characterized in that: the first described liquid port and the second liquid port are symmetrical arranged, the first liquid sucting port and the second liquid sucting port are symmetrical arranged.

3. the quaterfoil differential pump of a kind of oval noncircular gear driving according to claim 1, it is characterized in that: parameter and the structure of the described first oval noncircular gear and the second oval noncircular gear are completely the same, parameter and the structure of the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation are completely the same, and the first oval noncircular gear, the second oval noncircular gear, the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation are second order noncircular gear; The initial installation phase difference of the oval noncircular gear of the initial installation phase difference of the first oval noncircular gear and the second oval noncircular gear, the first conjugation and the oval noncircular gear of the second conjugation is 90 °.

4. the quaterfoil differential pump of a kind of oval noncircular gear driving according to claim 1, is characterized in that: the velocity ratio of the first oval noncircular gear and the oval noncircular gear of the first conjugation is:

Wherein, n ₂be the exponent number of the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation, value is 2;

The velocity ratio of the second oval noncircular gear and the oval noncircular gear of the second conjugation is:

Wherein, θ is the initial installation phase difference of the first oval noncircular gear and the second oval noncircular gear, and value is 90 °;

Make the velocity ratio i of the first oval noncircular gear and the oval noncircular gear of the first conjugation ₂₁equal the velocity ratio i of the second oval noncircular gear and the oval noncircular gear of the second conjugation ₄₃, four different corners can be tried to achieve corner get minimum value time, the angular displacement of the first oval noncircular gear is the angular displacement of the second oval noncircular gear is the corner of the first impeller and the second impeller is respectively:

The blade angle θ of the first impeller and the second impeller _leafvalue be 40 ° ~ 45 °; The central angle equal and opposite in direction of the first liquid port, the first liquid sucting port, the second liquid port and the second liquid sucting port, and than the blade angle θ of blade _leaflittle 2 ~ 5 °; First liquid port centre bit angle setting of pump case first liquid sucting port centre bit angle setting second liquid port centre bit angle setting ψ _{row 2}=ψ _{row 1}+ π, the second liquid sucting port centre bit angle setting ψ _{inhale 2}=ψ _{inhale 1}+ π;

The minimum subtended angle of adjacent two blade now this enclosed cavity is minimum volume:

$V_{\min }=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{\min }}{2}(R^2-r^2)\×h\×{10}^{-6}$

Wherein, R is blade radius, and r is impeller shaft radius, and h is vane thickness;

The maximum subtended angle of adjacent two blade now this enclosed cavity is maximum volume:

$V_{\max }=\frac{\mathrm{\Δ}{\mathrm{\ψ}}_{\max }}{2}(R^2-r^2)\×h\×{10}^{-6}$

The discharge capacity account representation of quaterfoil differential pump:

Q＝4×(V _max-V _min)＝2(Δψ _max-Δψ _min)(R ²-r ²)×h×10 ^-6

The instantaneous flow calculation expression formula of quaterfoil differential pump:

$q=\frac{\mathrm{dV}}{\mathrm{dt}}=2h(R^2-r^2)|\frac{d{\mathrm{\ψ}}_1}{\mathrm{dt}}-\frac{d{\mathrm{\ψ}}_2}{\mathrm{dt}}|=2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

Wherein, V is exhaust chamber volume; ω is the angular velocity of the first oval noncircular gear and the second oval noncircular gear, and its calculating formula is

The minimum volume of quaterfoil differential pump, maximum volume are stranded hydraulic coupling change calculations representation:

$\frac{d{p}_1}{\mathrm{dt}}=\frac{K}{V_{\min }}\×q=\frac{K}{\mathrm{\Δ}{\mathrm{\ψ}}_{\min }(R^2-r^2)}\×2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

$\frac{d{p}_2}{\mathrm{dt}}=\frac{K}{V_{\max }}\×q=\frac{K}{\mathrm{\Δ}{\mathrm{\ψ}}_{\max }(R^2-r^2)}\×2\mathrm{h\ω}(R^2-r^2)|i_{21}-i_{43}|$

Wherein K is the Young's modulus of liquid.