Background technique
The liquid pump that universal machine is conventional has reciprocating pump, plunger pump, diaphragm pump, roller pump and centrifugal pump, wherein: (post) plug pump of living has higher outlet pressure, but requires the sealing between piston and cylinder barrel reliable, and pressure surge is large; Diaphragm pump can produce a liquid stream more stably when multi-cylinder, but complex structure; Roller pump delivery is uniformly when stabilization of speed, and along with the raising of pressure, leakage rate increases, and the lifting rate of pump and efficiency are corresponding to be reduced; Centrifugal pump structure is simple, easily manufacture, but its discharge capacity is large, and pressure is low, for the less demanding occasion of working pressure.There is defect separately in these pumps, can't meet well the constant flow rate of part special mechanical requirement, the demand of high pressure.
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 is born alternate load, produces gear tooth noise, and each pair clearance also can cause impact noise when 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 key parameters that affects pump performance.This angle is larger, and pump delivery is also larger, and still, 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, it is mainly eccentricity and deformation coefficient that its eccentric circle non-circular gear pitch curve is adjusted parameter, adjustment amount is limited, adjust precision not high, cause velocity ratio optimization, adjust inconvenience, design dumbly, be unfavorable for further optimal design, be difficult to optimize the problems such as pressure pulsation, tired liquid.Summary of the invention
The object of the invention is for the deficiencies in the prior art, the quaterfoil differential pump that provides a kind of oval noncircular gear to drive, this blade differential pump displacement is large, pressure is high, stability of flow, compact structure; The variable speed rule of driving mechanism is easily adjusted, convenient function optimization; By unidirectional Decompression valves is installed in blade, during pressure limit, get through contiguous enclosed cavity, effectively solve the tired liquid problem of existing differential pump.
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 is the two side at driving gearbox by two bearings; Described the first oval noncircular gear and the second oval noncircular gear are all fixedly mounted on input shaft; The two ends of output shaft respectively by bearings on the tank wall of driving gearbox and pump case, 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 the 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; The first impeller is fixed on output shaft; The first described impeller and the second impeller are all symmetrically arranged with two blades; Along the circumferential direction, the alternate setting of blade of the blade of the first impeller and the second impeller; All blade interior are all installed 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 the oval noncircular gear of given the first oval noncircular gear and 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 oval eccentricity,
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:
The oval noncircular gear of the first oval noncircular gear and the first conjugation is second order noncircular gear, therefore, and during the first oval noncircular gear rotating 360 degrees, also rotating 360 degrees of the oval noncircular gear of the first conjugation, can calculate the iterative of centre distance a:
Get centre distance initial value a
0adopt the search of advance and retreat method to calculate the exact value of centre distance a.
Described the first 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.
The first described oval noncircular gear and parameter and the structure of the second oval noncircular gear are in full accord, parameter and the structure of the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation are in full accord, 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 initial installation phase difference of the first oval noncircular gear and the second oval noncircular gear, the oval noncircular gear of the first conjugation and the oval noncircular gear of the second conjugation is 90 °.
The velocity ratio of the oval noncircular gear of the first oval noncircular gear and 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 oval noncircular gear of the second oval noncircular gear and 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 oval noncircular gear of the first oval noncircular gear and the first conjugation
21equal the velocity ratio i of the oval noncircular gear of the second oval noncircular gear and the second conjugation
43, can try to achieve four different corners
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 °.The first liquid port centre bit angle setting of pump case
the first liquid sucting port centre bit angle setting
the 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 blades
now this enclosed cavity is minimum volume:
Wherein, R is blade radius, and r is impeller shaft radius, and h is vane thickness.
The maximum subtended angle of adjacent two blades
now this enclosed cavity is maximum volume:
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:
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, the tired hydraulic coupling change calculations representation of maximum volume:
The Young's modulus that wherein K is 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 is easily adjusted, and easily realizes the optimization of the performances such as differential pump delivery, pressure, flow.By unidirectional Decompression valves is installed in blade, during pressure limit, get through contiguous enclosed cavity, effectively solve the tired liquid problem of existing differential pump.Due to differential pump liquid sucting port and liquid port symmetry that oval non-circular gear mechanism drives, radial equilibrium is good, and non-constant speed transmission is for rotatablely moving, and therefore operates steadily reliably, radially work loads balance, the controllability of pulsing are good; Blade is many, discharge capacity is large, and internal surface and the blade shape of pump case are simple, and volumetric efficiency is high.
Core institution of the present invention is two pairs of different oval noncircular gears that phase place is installed, 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 mounting point 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, 5, the second oval noncircular gear, 6, the oval noncircular gear of the 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, 13, the 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 4, the second oval noncircular gear 5, the oval noncircular gear 6 of the first conjugation, the oval noncircular gear 7 of the second conjugation 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 motor 10, by coupling 9, power is passed to the oval noncircular gear 4 of input shaft 2, the first and the second oval noncircular gear 5 is all fixedly mounted on input shaft 2; The two ends of output shaft 3 respectively by bearings on the tank wall of driving gearbox 1 and pump case 11, 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 the second conjugation and the second impeller 13 are all cemented on axle sleeve 8, and axle sleeve 8 kinks are 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, the first impeller 12, the 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, the first liquid port 11-1 and the second liquid port 11-3 are symmetrical arranged, and the first liquid sucting port 11-2 and the second liquid sucting port 11-4 are symmetrical arranged; The first impeller 12 is fixedly mounted on output shaft 3; The first impeller 12 and the second impeller 13 are all symmetrically arranged with two blades, the inwall laminating of the outer arced surface of every blade and pump case 11; Along the circumferential direction, the alternate setting of blade of the blade of the first impeller 12 and the second impeller 13, all forms an enclosed cavity between every adjacent two blades; 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 in full accord, 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 in full accord, and the first oval noncircular gear 4, the second oval noncircular gear 5, the oval noncircular gear 6 of the first conjugation 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 second oval noncircular gear 5, the oval noncircular gear 6 of the first conjugation and the oval noncircular gear 7 of the second conjugation is θ
1-θ
2its value is 90 °, and the differential of realizing the first impeller 12 and the second impeller 13 rotates, and makes the volume cyclically-varying of differential pump enclosed cavity, at the first liquid port 11-1 and the second liquid port 11-3, produce discharge opeing, at the first liquid sucting port 11-2 and the second liquid sucting port 11-4, produce imbibition.Because the non-at the uniform velocity transmission of oval noncircular gear is continuous, at enclosed cavity, in complete when airtight, blade still has differential to rotate, and this will make enclosed cavity pressure exceed limit value, and unidirectional Decompression valves 14 is got through pressure release by vicinity enclosed cavity, prevents from being stranded liquid.
The working principle of the quaterfoil differential pump that this ellipse noncircular gear drives:
Motor 10 is passed to the first oval noncircular gear 4 and the second oval noncircular gear 5 by coupling 9 and input shaft 2 by power.The first oval noncircular gear 4 engages with the oval noncircular gear 6 of the first conjugation, the second oval noncircular gear 5 engages with the oval noncircular gear 7 of the second conjugation, the oval noncircular gear 6 of the first conjugation is passed to the oval noncircular gear 7 of the first impeller 12, the second conjugation by power by output shaft 3 power is passed to the second impeller 13 by axle sleeve 8.The installation phase place difference of two pairs of oval noncircular gear pairs, the differential of realizing the first impeller 12 and the second impeller 13 rotates, thereby realizes imbibition and discharge opeing.
According to pump structure, the centre distance initial value a of the oval noncircular gear 6 of given the first oval noncircular gear 4 and 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 oval eccentricity, 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:
The oval noncircular gear 6 of the first oval noncircular gear 4 and the first conjugation is second order noncircular gear, therefore, and during the first oval noncircular gear 4 rotating 360 degrees, also rotating 360 degrees of the oval noncircular gear 6 of the first conjugation, can calculate the iterative of centre distance a:
Get centre distance initial value a
0=120mm, the exact value that adopts the search of advance and retreat method to calculate centre distance a is 120mm.
Try to achieve after the exact value of centre distance a, can solve row, the liquid sucting port central position of pump case, quaterfoil differential pump delivery, instantaneous flow and minimum volume, the tired hydraulic coupling of maximum volume change representation.Specifically be calculated as follows:
The velocity ratio of the oval noncircular gear of the first oval noncircular gear and 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 oval noncircular gear of the second oval noncircular gear and 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 oval
noncircular gear 6 of the first oval
noncircular gear 4 and the first conjugation
21equal the velocity ratio i of the oval
noncircular gear 7 of the second oval
noncircular gear 5 and the second conjugation
43, can try to achieve four different corners
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 °.The first liquid port centre bit angle setting of pump case
the first liquid sucting port centre bit angle setting
the 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 °.
The minimum subtended angle Δ of adjacent two blades ψ
min=(ψ
2+ 90 °)-(ψ
1+ θ
leaf), now this enclosed cavity is minimum volume:
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.
The maximum subtended angle Δ of adjacent two blades ψ
max=(ψ
1+ 180 °)-(ψ
2+ 90 °+θ
leaf), now this enclosed cavity is maximum volume
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:
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, the tired hydraulic coupling change calculations representation of maximum volume:
The Young's modulus that wherein K is liquid.
By the tired hydraulic coupling of minimum volume, maximum volume of calculating quaterfoil differential pump, change, can be the unidirectional Decompression valves of selecting in blade reference is provided, be generally used for the CLV ceiling limit value of determining unidirectional Decompression valves.