阅读说明：本技术 非圆齿轮变速驱动的齿轮泵流量脉动平抑方法及齿轮泵 (Gear pump flow pulsation stabilizing method driven by non-circular gear in variable speed and gear pump ) 是由 刘大伟 谭万鑫 张晋铭 于 2021-07-19 设计创作，主要内容包括：本发明提出一种非圆齿轮变速驱动的齿轮泵流量脉动平抑方法及齿轮泵,属于流体传动领域。目的在于解决现有齿轮泵流量脉动大的问题,提出一种能大幅度降低齿轮泵流量脉动的齿轮泵。低脉动齿轮泵包括一个电机、一个齿轮泵和一个变速器,齿轮泵主要包含一对渐开线圆齿轮,变速器主要包含一对非圆齿轮和一对减速齿轮,变速器输入轴通过联轴器与电机相连,变速器输出轴通过联轴器与齿轮泵主动轴相连。本发明提出的低脉动齿轮泵在不改变现有齿轮泵结构的前提下,通过含非圆齿轮的两级变速器变速驱动有效抑制了齿轮泵的流量脉动,具有脉动小、成本低、可靠性高、结构简单以及维护方便等优势。(The invention provides a non-circular gear variable-speed driven gear pump flow pulsation stabilizing method and a gear pump, belonging to the field of fluid transmission. Aim at solves the big problem of current gear pump flow pulsation, provides a gear pump that can reduce gear pump flow pulsation by a wide margin. The low-pulsation gear pump comprises a motor, a gear pump and a transmission, wherein the gear pump mainly comprises a pair of involute circular gears, the transmission mainly comprises a pair of non-circular gears and a pair of reduction gears, an input shaft of the transmission is connected with the motor through a coupler, and an output shaft of the transmission is connected with a driving shaft of the gear pump through the coupler. The low-pulsation gear pump provided by the invention effectively inhibits the flow pulsation of the gear pump through the variable speed driving of the two-stage speed changer containing the non-circular gear on the premise of not changing the structure of the existing gear pump, and has the advantages of small pulsation, low cost, high reliability, simple structure, convenience in maintenance and the like.)

1. A method for stabilizing flow pulsation of a gear pump driven by a non-circular gear in a variable speed manner is characterized by comprising the following steps: which comprises the following steps:

s1, determining the flow expression of the gear pump along with the rotation angle of the driving shaft as

In the formula (I), the compound is shown in the specification,the turning angle of the driving rotor of the gear pump,B₅is 5 tooth widths of the rotor, r₅Is the radius of 5-pitch curve of rotor, h₅Is the tooth crest height r of the rotor 5_d5Is the base radius, Z, of the rotor 5₅The number of teeth of the rotor 5;

s2, determining the average flow of the gear pump as follows:

in the formula, ω₁For the system input speed, n₁Is a non-circular gear of order 1, n₂2 steps for non-circular gears, Z₃Number of teeth, Z, of gear wheel 3₄The number of teeth of the gear 4;

s3, determining the instantaneous flow of the gear pump as follows:

in the formula, ω₅Is the rotational speed, omega, of the gear pump drive shaft₅＝ω₄，ω₂For non-circular gear 2 speed, omega₂＝ω₃；

S4, determining the ideal transmission ratio of the non-circular gear, and enabling the expression (2) to be equal to the expression (3) to obtain the expression of the ideal transmission ratio of the non-circular gear as follows:

s5, Fourier transform is carried out on the ideal transmission ratio of the non-circular gear obtained in the step S4, and the transmission ratio of the non-circular gear is obtained

Is the rotation angle of the driven non-circular gear 2, K is the number of terms of a trigonometric function, K is a positive integer, a_n，b_nRespectively, the coefficients of a trigonometric function.

2. The method of claim 1 for smoothing flow pulsation of a gear pump driven at variable speeds by non-circular gears, wherein: a is_n，b_nAre respectively:

in the formula I₁₂For non-circular gear ideal transmission ratio, n₂The number of the steps of the non-circular gear is 2,the driven non-circular gear 2 rotates.

3. The method of claim 1 for smoothing flow pulsation of a gear pump driven at variable speeds by non-circular gears, wherein: the value range of K is [1,8 ].

4. The utility model provides a gear pump, its includes motor, derailleur and gear pump which characterized in that: the transmission comprises a non-circular gear obtained by the method for stabilizing the flow pulsation of the gear pump driven by the non-circular gear according to the variable speed drive of the non-circular gear of claim 1;

the transmission ratio of the non-circular gear is as follows:

in the formula (I), the compound is shown in the specification,angle of rotation of driven non-circular gear, n₁，n₂Is the order of the driven non-circular gear 1, 2, K is the number of terms of a trigonometric function, K is a positive integer, a_n，b_nRespectively, the coefficients of the trigonometric function terms.

5. The gear pump of claim 4, wherein: the transmission comprises a driving non-circular gear, a driven non-circular gear, a driving reduction gear, a driven reduction gear, a transmission input shaft, a transmission intermediate shaft, a transmission output shaft and a transmission shell, wherein the transmission input shaft, the transmission intermediate shaft, the transmission output shaft, the driving non-circular gear and the driven non-circular gear are arranged in the transmission shell, the driving non-circular gear is meshed with the driven non-circular gear, the driving reduction gear is meshed with the driven reduction gear, the driving non-circular gear is arranged on the transmission input shaft, the driven non-circular gear and the driving reduction gear are arranged on the transmission intermediate shaft, the driven reduction gear is arranged on the transmission output shaft, one end of the transmission input shaft extends to the outside of the transmission shell and is connected with a motor through a first coupler.

6. The gear pump of claim 4, wherein: the gear pump includes gear pump initiative rotor, gear pump driven rotor, gear pump driving shaft, gear pump driven shaft and the gear pump body, be equipped with gear pump driving shaft, gear pump driven shaft, gear pump initiative rotor and gear pump driven rotor in the pump body, gear pump initiative rotor and gear pump driven rotor intermeshing, initiative gear pump rotor establishes on the gear pump driving shaft, and gear pump driven rotor establishes on the gear pump driven shaft, and the one end of gear pump driving shaft extends to link to each other through the derailleur output shaft of second shaft coupling and derailleur behind the outside of the pump body.

Technical Field

The invention belongs to the field of fluid transmission, and particularly relates to a method for stabilizing flow pulsation of a gear pump driven by a non-circular gear variable speed 1 and a low-pulsation gear pump.

Background

Gear pumps are one of the power plants of importance today, being able to continuously supply media of different flow rates and pressures. Compared with other types of oil pumps, the gear pump has the characteristics of simple structure, good self-absorption performance, large rotating speed range, strong pollution resistance, high reliability and the like. Therefore, the design and performance analysis of high performance gear pumps have been the focus of attention. The flow pulsation coefficient of the pump is a key index for measuring the performance of the pump, and the gear pump has periodic flow pulsation due to the structure, so that the vibration and noise are brought by the periodic flow pulsation, and the service performance of the pump is seriously influenced. Therefore, the method has important significance for designing a low-pulsation gear pump with high performance.

At present, the pulsation of the gear pump is stabilized mainly by means of optimizing tooth profiles, arranging unloading grooves, connecting a plurality of pumps in parallel, driving at variable speed and the like. And the variable speed drive has better stabilizing effect on flow pulsation. The variable speed drive is mainly divided into non-circular gear variable speed drive and stepping motor variable speed drive.

As the invention patent numbers: CN108061032A, proposes a pulse-free high-order elliptic gear pump which is reversely solved by the instantaneous flow of the high-order elliptic gear pump. The design method of the non-circular gear is only suitable for specific displacement pumps and is not suitable for the gear pump.

In the patent of patent No. CN105546046A, a integrated configuration of non-circular gear set and double-cylinder reciprocating pump is proposed, two driven non-circular gears of initiative non-circular gear simultaneous drive, two driven non-circular gears link firmly respectively with the crank of double-cylinder reciprocating pump, non-linear transmission through non-circular gear, make the synthetic even instantaneous flow of double-cylinder reciprocating pump, reduce the flow pulsation of double-cylinder reciprocating pump by a wide margin, in this scheme, every crank of reciprocating pump all will be driven by a driven non-circular gear independently, after the jar number increases, it can make the transmission end very complicated to use this method.

Research on a parameter detection and control method of a constant-current pump, (china petroleum university, 2009) provides a constant-current pump of a step motor variable-speed drive gear pump, a linear regression model is introduced into modeling design of the constant-current pump, adaptive control is introduced into adaptive control of the constant-current pump, and the rotating speed of the step motor is adjusted by adjusting the current of each winding, so that stable flow output of the constant-current pump is realized. However, the technology excessively depends on a servo sensing system and a motion control algorithm, so that the equipment cost is high, and the technology is not suitable for the working condition of severe environment.

Disclosure of Invention

Aiming at the problem of periodic flow pulsation of the gear pump, the invention provides a method for stabilizing the flow pulsation of the gear pump driven by a non-circular gear in a variable speed manner, which can greatly reduce the flow pulsation of the gear pump on the basis of not changing the structure of the gear pump, and further effectively inhibit the vibration and noise of a pump body and a pipeline.

Specifically, the invention provides a method for stabilizing flow pulsation of a gear pump driven by a non-circular gear in a variable speed manner, which comprises the following steps of:

s1, determining the flow expression of the gear pump along with the rotation angle of the driving shaft as

In the formula (I), the compound is shown in the specification,the turning angle of the driving rotor of the gear pump,B₅is 5 tooth widths of the rotor, r₅Is the radius of 5-pitch curve of rotor, h₅Is the tooth crest height r of the rotor 5_d5Is the base radius, Z, of the rotor 5₅The number of teeth of the rotor 5;

s2, determining the average flow of the gear pump as follows:

in the formula, ω₁For the system input speed, n₁Is a non-circular gear of order 1, n₂2 steps for non-circular gears, Z₃The number of teeth of the gear 3 is,Z₄the number of teeth of the gear 4;

s3, determining the instantaneous flow of the gear pump as follows:

in the formula, ω₅Is the rotational speed, omega, of the gear pump drive shaft₅＝ω₄，ω₂For non-circular gear 2 speed, omega₂＝ω₃；

S4, determining the ideal transmission ratio of the non-circular gear, and enabling the expression (2) to be equal to the expression (3) to obtain the expression of the ideal transmission ratio of the non-circular gear as follows:

s5, Fourier transform is carried out on the ideal transmission ratio of the non-circular gear obtained in the step S4, and the transmission ratio of the non-circular gear is obtained

Is the rotation angle of the driven non-circular gear 2, K is the number of terms of a trigonometric function, K is a positive integer, a_n，b_nRespectively, the coefficients of a trigonometric function.

Preferably, a_n，b_nAre respectively:

preferably, K has a value in the range of [1,8 ].

Preferably, the transmission comprises a non-circular gear obtained by the gear pump flow pulsation stabilizing method;

the transmission ratio of the non-circular gear is as follows:

in the formula (I), the compound is shown in the specification,angle of rotation of driven non-circular gear, n₁，n₂Is the order of the driven non-circular gear 1, 2, K is the number of terms of a trigonometric function, K is a positive integer, a_n，b_nRespectively, the coefficients of a trigonometric function.

Preferably, the transmission comprises a driving non-circular gear, a driven non-circular gear, a driving reduction gear, a driven reduction gear, a transmission input shaft, a transmission intermediate shaft, a transmission output shaft and a transmission housing, wherein the transmission input shaft, the transmission intermediate shaft, the transmission output shaft, the driving non-circular gear and the driven non-circular gear are arranged in the transmission housing, the driving non-circular gear and the driven non-circular gear are meshed with each other, the driving reduction gear and the driven reduction gear are meshed with each other, the driving non-circular gear is arranged on the transmission input shaft, the driven non-circular gear and the driving reduction gear are arranged on the transmission intermediate shaft, the driven reduction gear is arranged on the transmission output shaft, and one end of the transmission input shaft extends to the outside of the transmission housing and is connected with the motor through a first coupler.

Preferably, the gear pump includes gear pump initiative rotor, gear pump driven rotor, gear pump driving shaft, gear pump driven shaft and the gear pump body, be equipped with gear pump driving shaft, gear pump driven shaft, gear pump initiative rotor and gear pump driven rotor in the pump body, gear pump initiative rotor and gear pump driven rotor intermeshing, initiative gear pump rotor is established on the gear pump driving shaft, gear pump driven rotor establishes on the gear pump driven shaft, and the one end of gear pump driving shaft extends to and links to each other with the derailleur output shaft of derailleur after the outside of the pump body through the second shaft coupling

Compared with the prior art, the invention has the beneficial effects that:

the invention effectively reduces the flow pulsation of the gear pump through the variable speed drive of the gear pump by the two-stage speed changer containing the non-circular gear on the basis of not changing the structure of the existing pump body, compared with the parallel gear pump, the invention has the advantages of simple structure, convenient installation and more obvious pulsation stabilizing effect, solves the sealing problem and the pitch curve smoothing problem of the non-circular gear compared with the non-circular gear variable speed drive designed by an ideal transmission ratio, and avoids the instantaneous flow detection difficulty of a pump port and the instability of an electric control system compared with the variable speed drive of a servo motor, has high reliability and is more practical in engineering.

Drawings

FIG. 1 is a schematic view of a low pulsation gear pump configuration;

FIG. 2 is a schematic representation of a non-circular gear ideal ratio curve;

FIG. 3 is a non-circular gear ratio plot schematic;

FIG. 4 is a schematic representation of a pair of non-circular gear-pitch curves in the transmission;

FIG. 5 is a graphical illustration of the instantaneous flow rate of a gear pump before and after flow pulsation dampening;

FIG. 6 is a graphical representation of the instantaneous flow rate of the gear pump during one flow pulsation cycle before and after the trigonometric function term K ∈ {1,4,7} settling.

Some of the reference numbers are as follows:

1-transmission driving non-circular gear; 2-a variator driven non-circular gear; 3-transmission active reduction gear; 4-transmission follower reduction gear; 5-gear pump driving rotor; 6-gear pump driven rotor; 7-transmission input shaft; 8-transmission countershaft; 9-a transmission output shaft; 10-gear pump driving shaft; 11-gear pump driven shaft; 12-a first coupling; 13 a second coupling; 14-a transmission housing; 15 gear pump body; 16-motor.

Detailed Description

Exemplary embodiments, features and aspects of the present invention will be described in detail below with reference to the accompanying drawings. In the drawings, like reference numbers can indicate functionally identical or similar elements. While the various aspects of the embodiments are presented in drawings, the drawings are not necessarily drawn to scale unless specifically indicated.

The concrete structure of low pulsation gear pump is as shown in fig. 1, including motor 16, derailleur and gear pump, wherein the gear pump is by gear pump initiative rotor 5, gear pump driven rotor 6, gear pump driving shaft 10, gear pump driven shaft 11 and gear pump body 15 are constituteed, be equipped with gear pump driving shaft and gear pump driven shaft in the pump body, gear pump initiative rotor and gear pump driven rotor are arranged in the pump body, intermeshing, and initiative gear pump rotor establishes on the gear pump driving shaft, gear pump driven rotor establishes on the gear pump driven shaft, the one end extension of gear pump driving shaft is to the outside of the pump body, link to each other with the derailleur output shaft 9 of derailleur through second coupling 13. The transmission comprises a driving non-circular gear 1, a driven non-circular gear 2, a driving reduction gear 3, a driven reduction gear 4, a transmission input shaft 7, a transmission intermediate shaft 8, a transmission output shaft 9 and a transmission shell 14, wherein the transmission input shaft, the transmission intermediate shaft and the transmission output shaft are arranged in the transmission shell, the driving non-circular gear and the driven non-circular gear are arranged in the transmission shell and are meshed with each other, the driving non-circular gear is arranged on the transmission input shaft, the driven non-circular gear and the driving reduction gear are arranged on the transmission intermediate shaft, the driven reduction gear is arranged on the transmission output shaft, one end of the transmission input shaft extends to the outside of the transmission shell, and is connected with a motor 16 through a first coupler 12.

In the present embodiment, the main structural parameters in the system are shown in table 1.

TABLE 1 design parameters for the System

Parameter(s)	Numerical value
		Angular velocity omega of motor1	100rad/s
Trigonometric function term K of transmission ratio of non-circular gear	4
		Center distance A between non-circular gears 1 and 21	239.64mm
Non-circular gear 1, 2 modulus m1、m2	1
		Number n of active non-circular gear1	1
Driven non-circular gear order n2	2
		Number of active non-circular gear teeth Z1	160
Number of driven non-circular gear teeth Z2	320
		Non-circular gear reduction ratio ij1	2
Centre distance A between reduction gears 3, 42	240mm
		Reduction gear 3, 4 modulus m3、m4	3
Number of active reduction gear teeth Z3	40
		Number of driven reduction gear teeth Z4	120
Reduction gear reduction ratio ij2	3
		Gear pump rotor 5, 6 modulus m5、m6	40
Gear pump rotor 5, 6 tooth number Z5、Z6	6
		Gear pump rotor 5, 6 section curve radius r5、r6	120mm
Gear pump rotor 5, 6 base radius rd5、rd6	112.76mm
		Tooth crest height h of gear pump rotors 5 and 65、h6	40mm
Gear pump rotor 5, 6 center distance A3	240mm
		Gear pump rotor 5, 6 width B5、B6	200mm

Then a pair of higher order Fourier non-circular gear ratio functions in the transmission is

In the formula (I), the compound is shown in the specification,is the corner of the driven non-circular gear and is the corner of the driving wheel of the gear pump, a_n，b_nRespectively, the coefficients of a trigonometric function.

a_n，b_nThe determination method comprises the following steps:

s1, determining the flow expression of the gear pump along with the rotation angle of the driving shaft as

In the formula (I), the compound is shown in the specification,the turning angle of the driving rotor of the gear pump,B₅is 5 tooth widths of the rotor, r₅Is the radius of 5-pitch curve of rotor, h₅Is the tooth crest height r of the rotor 5_d5Is the base radius, Z, of the rotor 5₅The number of teeth of the rotor 5;

s2, determining the average flow of the gear pump as follows:

in the formula, ω₁For the system input speed, n₁Is a non-circular gear of order 1, n₂2 steps for non-circular gears, Z₃Number of teeth, Z, of gear wheel 3₄The number of teeth of the gear 4;

s3, determining the instantaneous flow of the gear pump as follows:

in the formula, ω₅Is the rotational speed, omega, of the gear pump drive shaft₅＝ω₄，ω₂For non-circular gear 2 speed, omega₂＝ω₃；

S4, determining the ideal transmission ratio of the non-circular gear, and enabling the expression (2) to be equal to the expression (3) to obtain the expression of the ideal transmission ratio of the non-circular gear as follows:

the ideal transmission ratio of the stabilizing noncircular gear is obtained by applying the table 1 and the formula (12), and the curve is shown in figure 2

S5, determining the coefficient as

In the formula, n₂In order to obtain the driven non-circular gear order,turning a driven non-circular gear 2;

and (3) applying the table (1) and the formula (13) to obtain the trigonometric function term coefficient of the transmission ratio function of the non-circular gear in the example, obtaining the transmission ratio of the non-circular gear in the example, wherein a curve is shown in fig. 3, continuously changing the tooth number of the gear pump, and obtaining the trigonometric function term coefficient of the non-circular gear under different tooth numbers as shown in table 2.

TABLE 2 trigonometric function term coefficients corresponding to different tooth numbers

The equation of the pitch curve of the non-circular gear is calculated by the transmission ratio of the non-circular gear

From table 1 and equation (14), it can be calculated that the pitch curve data for a pair of non-circular gears in the transmission of this example is shown in table 3, and the corresponding curve is shown in fig. 4.

TABLE 3A pair of high order Fourier non-circular gear pitch curve data in a transmission

When the non-circular gear in the transmission is installed, the longest radial alignment of the non-circular gear 1 and the shortest radial alignment of the non-circular gear 2 are ensured. The instantaneous flow equation of the low-pulsation gear pump at the moment is

In the formula of omega₁For the motor input speed, i₁₂For non-circular gear ratios, ij₂For reduction ratio of reduction gears 3, 4, B₅Is the width r of the gear pump rotor 5₅Is the radius of 5-pitch curve r of the gear pump rotor_d5Is the gear pump rotor 5 base radius, h₅The tooth top height of the gear pump rotor 5 is,is the gear pump rotor 5 angle.

When the speed changer is not used, the instantaneous flow formula of the gear pump directly driven by the motor is as follows

In the formula of omega₁For inputting rotational speed of the motor, ij₁For reduction ratio of non-circular gears 1, 2, ij₂For reduction ratio of reduction gears 3, 4, B₅Is the width r of the gear pump rotor 5₅Is a gear pump rotor 5-section curve halfDiameter r_d5Is the gear pump rotor 5 base radius, h₅The tooth top height of the gear pump rotor 5 is,is the gear pump rotor 5 angle.

The instantaneous flow rate data of the gear pumps before and after the smoothing in this example can be obtained according to table 1 and equations (15) to (16), respectively, as shown in table 4, and the instantaneous flow rate curves of the gear pumps before and after the smoothing obtained at this time are shown as curves a and b in fig. 5, respectively.

TABLE 4 instantaneous flow (L s) of gearpump of transmission or non-transmission^-1)

And continuously changing the number K of the terms of the trigonometric function of the non-circular gear to obtain the flow rates when the un-stabilized sum K takes 1,4 and 7, as shown by curves a, b, c and d in FIG. 6. And continuously changing the tooth number, and calculating to obtain the item number K belonging to [1,8] of the gear pump flow pulsation rate corresponding to different trigonometric functions by different tooth numbers as shown in the table 5.

TABLE 5 Gear Pump flow pulsation Rate for different tooth counts corresponding to different trigonometric function term counts

It can be seen from the comparison of the instantaneous flow curves before and after pulsation smoothing in fig. 5 and table 5 that, after the gear pump is driven by the two-stage transmission composed of a pair of non-circular gears and a pair of reduction gears in a variable speed manner, the flow pulsation condition is greatly improved, and the flow pulsation smoothing effect is better along with the increase of the number of terms of the trigonometric function, so that the problem of flow pulsation of the gear pump is solved from the root of the fluid machinery, the vibration and noise of the pump are reduced, and the stability of a mechanical system is facilitated.

Finally, it should be noted that: the above-mentioned embodiments are only used for illustrating the technical solution of the present invention, and not for limiting the same; although the present invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.