KR20100039523A - Automatic plan system for gerotor oil pump - Google Patents

Abstract

PURPOSE: A rotor design automation system for gerotor oil pump is provided to implement a rotor of with performance is more superior than the performance of existing rotors used in current diesel cars. CONSTITUTION: An input module inputs design parameter values for tooth form design, flow rate, flow rate irregularity, and automation of slip rate calculation. A design module generates a trajectory from an outer rotor to inner rotor by a tooth equation. The design module revises an offset amount between the outer rotor and the inner rotor. An output module performs tooth modeling, rotation simulation, instantaneous, storage of flow rate curves and data files.

Description

Rotor Design Automation System with Tooth Shape Combined Circle, Ellipse and Involute {Automatic Plan System for Gerotor Oil Pump}

The present invention relates to a rotor pump used in an oil pump and the like, and more specifically, to an internal rotor by performing a kinematic analysis considering a design variable based on the shape of a rover of an external rotor combining an involute with a circle and an ellipse. And a rotor design automation system having a toothed shape in which a circle, an ellipse, and an involute are configured to be automatically generated.

As is well known, an oil pump is an essential functional part of an engine that is installed in an engine of an automobile, and converts the mechanical energy supplied from the engine into pressure energy and velocity energy of the engine oil, thereby converting each humidity inside the engine. It is a part that supplies lubricating oil to the eastern part to prevent abnormal wear and seizure of parts. The oil pump is less noise than other pumps and is widely used as a source of lubricating oil for lubricating an engine or a hydraulic source of an automatic transmission.

Components constituting the oil pump include an electric motor, a key, a rotary shaft seal, a bearing shell, a flange, an outer rotor, and an internal It consists of a rotor, rotor case, O-ring and screw. In addition to the other standard products in the oil pump, the rotor case is produced by die casting according to the specifications of the oil pump, and the outer rotor and the inner rotor are produced by powder forging.

The commonly used fixed-capacity hydraulic internal gear pumps and motors are used by modifying the curves of spur gears or circles created by coupling to the tooth shape of the internal gears.

Gerotor pump and motor with arbitrarily created rotors are composed of internal and external rotors, which are simple in structure and easy to process even if the shape is complicated as the precision of processing increases due to the development of manufacturing technology for sintered products. It is easy to assemble and there is little relative movement between two teeth, so there is little change in efficiency and excellent suction performance even after long-term use. In addition, it is widely used as a suction and resistance pump of a tandem pump combined with a piston pump, and especially as a source of lubricating oil for lubricating an engine or a hydraulic source of an automatic transmission due to less noise than other pumps. have. In addition, it has an advantage that the amount of discharge per revolution is larger than that of the vane or gear pump compared to the total volume. For this reason, it is widely used in hydraulic systems, and there is a situation in which the applicability gradually expands with the recent development of machining technology.

Therefore, much research has been carried out with respect to the rotor tooth design of the gerotor pump / motor. Colbourne simulated the contact between the inner and outer rotors to obtain the coordinates of the inner rotor teeth and calculated the area in the chamber that is closed by the tooth curves of the inner and outer rotors. Sae-gusa et al. Derived the trajectory for the center of the arc of the outer rotor by fixing the inner rotor and rotating the outer rotor and derived the teeth of the inner rotor from the bite characteristics of the inner rotor and the outer rotor.

In addition, Tsay recently published a method to obtain the teeth of an internal rotor by simulating the cutting process. Mimmi et al. Investigated the flow rate and flow rate pulsation values of involute gear pumps and rover pumps, and Kim Chung-yeon et al. Observed the change of contact stress according to the Gerotor design parameters.

In addition, Kim Chul et al. Proposed a new method for deriving tooth equations when the tooth shape of the external rotor related to the tooth of the troroid, which is the rotor pump, is based on the trajectory of the internal and external rotor, the trajectory of the contact point, the rotation simulation, An integrated system was established to automatically obtain flow rates and pulsations.

As described above, in the conventional research, a rotor was created in consideration of design variables in an external rotor having a robe shape consisting of only a circle or an ellipse.

Literature Information of the Prior Art

Colbourne, J. R., "Gear Shape and Theoretical Flow Rate in Internal Gear Pumps," Transactions of the CSME, Vol. 3, No. 4 pp. 215-223, 1975.

[2] Saegusa, Y., Urashima, K., Sugimoto, M., Onoda, M. and Koiso, T., "Development of Oil-Pump Rotor with a Trochoidal Tooth Shape," SAE Paper, No. 840 454. 1984.

3 Tsay, C. B. and Yu, C. Y., “Mathematical Model for the Profile of Gerotor Pumps” J. CSME, Vol. 10, No. 1, pp. 41-47, 1989.

[4] Yu, C. Y. and Tsay, C. B., "The Mathematical Model of Gerotor Pump Applicable to Its Characteristic Study" J. CSME, Vol. 11, No. 4, pp. 385-391, 1990.

[5] Lee, S. C., and Lee, S. N., "Design and Analysis of Gerotor for Hydraulic Motors" Journal of KSTLE, Vol. 11, No. 2, pp. 63-70, 1995.

[6] Mimmi, G. C. and Pennacchi, P. E., "Involute Gear Pumps Versus Lobe Pumps: A Comparison," Journal of Mechanical Design, Vol. 119, No. 4, pp. 458-465, 1997.

[7] Kim, C. H., Kim, D. I., Ahn, H. S. and Chong, T. H., "Analysis of Tooth Contact Stress of Gerotor Hydraulic Motors" Journal of KSTLE, Vol. 15, No. 2, pp. 164-170, 1999.

[Reference 8] Kim, J. H. and Kim, C., "Development of an Integrated System of Automated Design of Gerotor Oil Pump" J. of The Korean society of precision engineering, Vol. 23, No. 2, pp. 88-96, 2006.

9, Kim, J. H., Kim, Chul and Chang, Y. J., "Optimum Design on Lobe Shapes of Gerotor Oil Pumps" J. of Mechanical Science and Technology, Vol. 20, issue. 9, pp. 1390-1398, 2006.

10. Y. J. Chang, J. H. Kim, C. H. Jeon, Chul Kim and S. Y. Jung., "Development of an Integrated System for the Automated Design of a Gerotor Oil Pumps" Journal of Mechanical Design, ASME, Vol. 129, pp. 1099-1105, 2007.

The present invention proposes a configuration equation for the rotor through the geometric and kinematic analysis of the outer rotor having a combined rover shape of circle, ellipse and involute, and based on this automatically generates the teeth of the internal rotor, It has a tooth shape that combines circle, ellipse and involute to realize the integrated rotor design automation for oil and fuel pumps by computerizing the complex calculation process involved in calculating the flow rate and flow pulsation of the generated internal and external rotors. Its purpose is to provide a rotor design automation system for a rotor oil pump.

The present invention is to achieve the object as described above, the technical features of the rotor design automation system for a rotor rotor pump having a tooth shape combined circle, ellipse and involute; For the tooth design and the automation of flow rate, flow pulsation and slip rate calculation, the number of teeth of the external rotor corresponding to the value of the design variable (z ₂ ), the eccentricity (e), the ellipse shortening distance (r ₁₂ ), the center of the outer rotor and the ellipse An input module for inputting a distance (d) between centers, a length-to-axis ratio (k) of an ellipse, a tip clearance (t _p ) and a starting angle (γ) and a range angle (η) of the involute; After generating the trajectory of the internal rotor from the external rotor by the tooth equation from the value of the design variable input from the input module, correcting the offset amount between the internal rotor and the external rotor, and the flow rate and pulsation of the generated tooth A design module for calculating a sliding rate; By using the trajectory of the inner and outer rotors obtained in the design module, the teeth can be created according to the rotation angle by inputting the curvature of the end of the outer rotor, the distance between the inner and outer rotors, the amount of offset of the inner rotor, and the rotation angle of the inner rotor. It comprises a tooth modeling submodule, and an output module consisting of a rotation simulation submodule that checks the shape and size of the chamber, interference during the rotation by simulating the actual rotation of the inner and outer rotor.

The present invention has developed an integrated rotor design automation system that can automatically calculate the flow rate and flow rate pulsation for the automatic creation of the internal rotor shape and the generated rotor shape, thereby realizing a rotor with much higher performance than the rotor currently used in diesel passenger cars. Can be. In addition, there is an advantage that the flow rate and flow rate pulsation can be further improved by combining the involute shape with the external rotor shape having the rover shape of the conventional circle and ellipse.

In addition, the output module of the present invention has the advantage of generating a tooth by the input variable value and automatically calculates the instantaneous flow and pulsation according to the rotation angle of the external rotor and outputs the result as a graph. And by simulating the rotation of the rotor, it is possible to prevent design errors in advance, and it is effective to suggest a proper tooth shape determination method to the manufacturers according to the specifications of the automaker.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings. In the following detailed description, exemplary embodiments of the present invention will be described in order to accomplish the above-mentioned technical problems. And other embodiments that can be presented with the present invention are replaced by the description in the configuration of the present invention.

The present invention is to implement a rotor design automation system in which the internal rotor is automatically generated by performing kinematic analysis in consideration of design variables based on the robe shape of the external rotor combining involutes with circles and ellipses.

Specifically, the number of teeth of the outer rotor (z ₂ ), the distance between the center of the inner and outer rotor, that is, the amount of eccentricity (e), the ellipse shortening distance (r ₁₂ ), the distance (d) between the center of the outer rotor and the center of the ellipse. The starting angle (γ) and the range angle (η) of the involute for changing the length and length ratio (k) of the ellipse, the design variable value of the tip clearance (t _p ) and the shape of the ellipse into the involute shape are described in the present invention. In the rotor design automation system of the present invention, the system of the present invention automatically generates an internal rotor within a range that does not generate cusps and loops, which are geometric design limitations, and flows through the generated rotors. We propose a rotor design automation system that can automatically calculate the flow rate, pulsation rate and slip rate and output the result graphically.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

First, a rotor configuration equation according to an embodiment of the present invention will be described in detail with reference to FIGS. 1 to 5.

The number of rovers of the outer rotor, the radius of the pitch circle of the inner rotor and the outer rotor is shown in Equation 1.

z ₂ = z ₁ + 1, r ₁ = ez ₁ , r ₂ = ez ₂

The pitch point P at which the pitch circles of the inner and outer rotors intersect is fixed, and the outer rotor is rotated about the center of the pitch circle O ₂ to derive the tooth equation. The center of the pitch circle of the outer rotor (O ₂ ), the center of the pitch circle of the inner rotor (O ₁ ), the amount of eccentricity (e) between the O ₂ and O ₁ , the outer rotor is part of the curvature having the shape of the ellipse At this time, as shown in FIG. 1, the intersection point of the normal line, the center point of O ₂ , and the line segment connecting the center of the ellipse is C ^' ₀ (x ^' , 0) at the initial starting point, and the rotation angle is α by rotating around O ₂ . _{When a} is the point after the rotation of C ^' ₀ , C ^' _a is the intersection point of the straight line C ^' _a P and the outer rover shape becomes the contact point Q _a (x _a , y _a ), and to obtain the contact point Q _a Ζ, which is ∠O ₂ C _a P, is obtained, and η is obtained from Equation 2 to obtain the point Q ₀ (x ₀ , y ₀ ) on the initial outer rover shape.

In this case, the point Q ₀ on the initial outer rover shape is a point on the outer rover shape in which a circle, an ellipse and an involute are combined to obtain a case in which an ellipse section and an involute section are respectively divided. This is described in detail below.

In addition, the contact point Q _a (x _a , y _a ) rotated by the rotation angle α _a can be represented by Equation (3).

Hereinafter, the case where the point Q ₀ on the initial outer rover shape mentioned above exists in the ellipse section and in the involute section will be described in detail.

First, the case where the external rotor is part of the involute tooth shape will be described with reference to FIG. As shown in FIG. 2, the involute function should be the same as the straight line AB and the arc DB.

In the standard involute tooth, the radius of the base circle is defined as shown in Equation 5. In this case, Equation 5 is " J. R. Colbourne, "The Geometry of Involute Gears" Springer-Verlag, pp. 24-44, 1987.

Α _a is the same as Equation 6.

Involute tooth locus equations obtained from Equations 4 and 5 may be represented by Equations 7 below.

Secondly, a case in which the external rotor is part of an ellipse will be described in detail with reference to FIG. 3.

The distance from the center of the ellipse to the contact point (ρ) and the involute range angle (η) in the ellipse, which is the parent of the external rotor, are obtained from Equation 8, Equation 9 and Equation 10 from FIG. Can be.

From the above Equations 8 to 10, an elliptic tooth locus equation may be represented by Equation 11 below.

Meanwhile, in the present invention, a case in which the external rotor is a combination of an ellipse and an involute shape will be described in detail with reference to FIG. 4.

Referring to FIG 4, the slope e ₁ (hereinafter referred to as "grad e _1") and the slope i ₁ (hereinafter "grad i _1" shall mean) of G _e1 and involute tilt the same moment in that moment gradient G _i1 Find the point and find the G _e2 and G _i2 points with the same instantaneous slope at the grad e ₂ and grad i ₂ points. At this time, the instantaneous slope of the ellipse and the involute may be represented by Equation 12 and Equation 13.

So that the slope of the line G G _{e1 e2} segment slope and G G _{i1 i2} of the same on the above-described Fig. 4 going to rotate the involute find again the two points G _i1 and G _i2 on the involute. Then increase or decrease the size of the base circle radius (r _b ) of the involute so that the segment length l _e of G _e1 G _e2 and the segment length l _i of G _i1 G _i2 are equal.

On the other hand, in the present invention, it is possible to obtain a flow rate, flow rate pulsation and sliding rate calculation formula, which will be described in detail with reference to FIG.

Instantaneous flow rates and pulsations can be calculated using information on contact points and teeth of internal and external rotors. It is assumed that the working fluid is an incompressible fluid and no volume change occurs. The chamber hatched in FIG. 5 is a closed section region closed by two contact points where the inner and outer rotors meet.

In each chamber, the length of the side changes as the rotor rotates by a minute angle at regular intervals, thereby increasing and decreasing the volume. At this time, since the area indicated by the suction and discharge areas is proportional to the square of the distance from the center to the contact point, the instantaneous flow rate, which represents the degree to which the chamber contributes to the change in flow rate, is expressed by Equation 14 Can be obtained as>

5, the distances from the center points of the inner and outer rotors to the start contact point A and the end contact point B of the i-th chamber are obtained by Equation 15 and Equation 16, respectively.

Here, α _{i + 1} = α _i + 2π / z ₂ .

In addition, the flow rate per revolution is represented by <Equation 17>, and the specific flow rate can be obtained by <Equation 18>.

In addition, the flow rate irregularity affecting the noise and vibration may be represented by Equation 19, and the specific sliding rate may be obtained from Equation 20.

Here, s ₁ and s ₂ are distances at which contact points move from the shapes of the inner and outer rotors, respectively, in accordance with the amount of rotation.

Next, a rotor design automation system for a rotor rotor pump having a tooth shape combining a circle, an ellipse, and an involute according to an embodiment of the present invention may automatically generate an internal rotor from an external rotor having an ellipse tooth and an inverter shape. The Auto LISP language of Auto CAD is used to create the software.

In particular, the rotor design automation system of the present invention is composed of an input module, a design module and an output module, and a schematic diagram for this is shown in detail in FIG. 6. In addition, in the present invention, the algorithm for generating the trajectory of the internal rotor is shown in detail with reference to the flowchart of FIG.

Hereinafter, the input module, the design module, and the output module constituting the automation system of the present invention will be described in detail.

Input module

The input module is a module for inputting design variable values for tooth design and automation of flow rate, flow pulsation and slip rate calculations. The input variables are the number of teeth of the outer rotor (z ₂ ), the distance between the center of the inner and outer rotor, that is, the amount of eccentricity (e), the short distance of the ellipse (r ₁₂ ), the distance between the center of the outer rotor and the center of the ellipse (d), The length-to-short ratio k, the tip clearance t _p and the starting angle γ and range angle η of the involute. An input window of the rotor design automation system of the present invention for inputting the value of such a design variable is shown in FIG. 7.

Design module

In the design module, the trajectory of the internal rotor is generated from the external rotor by the tooth equation from the input design variable value, the offset amount between the internal and external rotor is corrected, and the flow rate, pulsation and slip rate of the generated tooth are calculated. do.

An algorithm for generating the trajectory of the inner rotor is shown in the flowchart of FIG. 8A, and the algorithm for calculating the instantaneous flow rate and pulsation is shown in detail in the flowchart of FIG. 8B.

Output module

The output module performs modeling, rotational simulations, instantaneous flow curves and storage of data files. The tooth modeling submodule of the output module receives the curvature of the end of the outer rotor, the distance between the inner and outer rotors, the amount of offset of the inner rotor, and the rotation angle of the inner rotor using the trajectories of the inner and outer rotors obtained from the design module. Create teeth according to the angle of rotation. In the rotation simulation submodule, the user may prevent the error in advance by checking the shape and size of the chamber and the interference during the rotation by simulating the actual rotation of the inner and outer rotors.

As described above, the results of applying the rotor design automation system for the rotor rotor pump having a tooth shape combining a circle, an ellipse, and an involute according to the embodiment of the present invention will be described below.

The outer diameters of the external rotors calculated by Equation 21 and Equation 22, which calculate the tooth diameter and the base diameter of the external rotor, were fixed, and the flow rate and flow rate pulsations, which are the objective functions, were investigated.

The number of internal and external rotor teeth, 9/10 external rotor width (w = 7.2mm), outer diameter (Φ29mm), eccentricity (e = 1.15mm), radius of curvature (r ₁₂ ), and radius of curvature Distance to the center of the outer rotor (d = 11.93mm), long and short ratio of the ellipse (k = 1.21), external rotor clearance (t _p = 0.02mm), involute starting angle (γ = 0 °) and range angle ( By inputting η = 30 ° respectively, the shape of the combined external rotor of the ellipse and the involute is created. This is illustrated in detail in FIG. 9.

In the above-described design module, the shape of the outer rotor of the ellipse and the involute is calculated by the configuration equation, and then automatically completes the shape of the contact point and the inner rotor, which are shown in FIGS. 10A and 10B.

In the above-described output module, when the tooth width (b = 7.2mm) is input for the created tooth, the flow rate and the flow pulsation are automatically calculated and output as shown in FIG. 11, and the actual inner and outer rotors are rotated as shown in FIG. 12. By checking the shape and size of the chamber, interference during rotation, etc., the user can prevent the error in advance.

On the other hand, the objective function considers the flow rate and the flow rate pulsation first, and then the sliding rate affecting the service life within the allowable pressure angle and within the range where no peak or loop occurs.

Among the rotors of the same size, in order to find the optimal rotor, the number of inner and outer rotor teeth of rotor (9/10), outer rotor width (w = 7.2mm), outer diameter (Φ29mm), between outer rotor and outer diameter of outer rotor The distance of (d = 2.5 mm) was kept constant. The eccentricity (e) is set to 1.11, 1.14, 1.18, and the radius of curvature of the ellipse (r ₁₂ ) is set to 2.1, 2.2, 2.3, 2.4, 2.5, and the long-to-short ratio k of the ellipse is 0.9, 1.0, 1.1, The internal rotor is generated from an external rotor having an elliptic shape while changing to 1.2 and 1.3, and the flow rate and flow rate pulsation are calculated and shown in FIGS. 13A and 13B.

As shown in FIGS. 13A and 13B, it can be seen that the flow rate and flow rate pulsation are improved as the amount of eccentricity increases. However, when the eccentricity increases above a certain threshold, since peaks and loops occur, it can be seen that the optimum amount of eccentricity is 1.15 in the region where peaks and loops do not occur. In addition, the smaller the long-term reduction ratio (k) of the ellipse was, the better the flow rate was. In the combination of ellipse and involute, the flow rate is excellent and the optimum flow rate pulsation is k = 1.21. At this time, the radius of curvature is not significantly related to the flow rate, but the flow rate pulsation is also excellent.

On the other hand, influencing the flow rate and flow rate pulsation while changing the involute start angle (γ) and the range angle (η) of the involute region in the shape of the external rover of FIG. Specifically shown. As shown in Table 1 below, when the starting angle is the center (γ = 0 °), the larger the range of the range angle (η), the lower the flow rate pulsation.

Starting angle (γ) Range angle (η) Flow rate (cc / rev) Irregularity (%)  0 ° 10 ° 0.1547 2.2365 20 ° 0.1548 2.2238 30 ° 0.1548 2.2071  10 ° 10 ° 0.1546 2.3831 20 ° 0.1546 2.3799 30 ° 0.1547 2.3417  20 ° 10 ° 0.1547 2.3417 20 ° 0.1547 2.3417 30 ° 0.1547 2.3417  30 ° 10 ° 0.1547 2.3417 20 ° 0.1547 2.3417 30 ° 0.1547 2.3418

On the other hand, the design variable values for the optimized shape of the outer rotor used in diesel vehicles in the original, the rotor used for the fuel pump in the ellipse, and the combination of the new tooth with the ellipse and involute And the results of the flow rate and flow rate pulsation calculated automatically from these, and the results of the rotor shape generated by the automation system of the present invention are shown in detail in Table 2 and FIG.

In Table 2 and FIG. 15 below, when the external rotor is a circle, it is represented by "(a) Circle", and when it is an ellipse, it is represented by "(b) Ellipse", and when it is a new tooth shape in which an ellipse and an involute are combined, "(c) Ellipse-involute ".

Product z ₂ e d r ₁₂ k γ η Flow rate (cc / rev) Irregularity (%) (a) Circle  10 1.14 11.9 2.29 1.13 . . 0.1486 2.7346 (b) Ellipse 1.0 . . 0.1486 2.5787 (c) Ellipse-involute 1.15 11.93 2.25 1.21 0 ° 20 ° 0.1548 2.2938

As shown in Table 2 and FIG. 15 above. It can be seen that "(c) Ellipse-involute" of the present invention is excellent in terms of flow rate and flow rate pulsation.

1 is a view showing the contact point equation for the shape of the ellipse and involute according to an embodiment of the present invention.

2 is a view showing a configuration equation of the involute according to the present invention.

3 is a view showing a configuration equation of an ellipse according to the present invention.

4 is a view showing a combination method of the ellipse and the involute according to the present invention.

Figure 5 shows the shape of the chamber for determining the instantaneous flow rate in accordance with the present invention.

Figure 6 is a view showing a rotor design automation system for a rotor rotor pump having a tooth-shaped combination of the circle, ellipse and involute according to the present invention.

7 is a view showing a design variable input window according to the present invention.

8A shows a flow chart of an internal tooth shape in accordance with the present invention.

8B shows a flow chart of flow rate and flow rate pulsation in accordance with the present invention.

9 is a view showing the result after inputting the variable value in the rotor design automation system according to the present invention.

Figure 10a is a view showing the shape of the automatically generated internal rotor according to the present invention.

Figure 10b is a view showing the shape of the automatically generated external rotor according to the present invention.

11 shows the automatically generated flow rate and flow rate pulsation in accordance with the present invention.

12 shows the results of a rotation simulation according to the invention.

Figure 13a is a view showing the result of the flow rate for the various design variables in accordance with the present invention.

Figure 13b is a view showing a comparison of the results of the flow rate pulsation with respect to various design variable values in accordance with the present invention.

14 shows a method of determining the extent of an involute in a design module according to the invention.

Figure 15 is a view showing a comparison of each rotor of the circle, ellipse and involute according to the present invention.

Claims (6)

An input module for inputting design variable values for tooth design and automation of flow rate, flow pulsation and slip rate calculations; After generating the trajectory of the internal rotor from the external rotor by the tooth equation from the value of the design variable input from the input module, correcting the offset amount between the internal rotor and the external rotor, and the flow rate and pulsation of the generated tooth A design module for calculating a sliding rate; In a rotor design automation system for a rotor rotor pump consisting of an output module that performs tooth modeling, rotational simulation, instantaneous flow curves and storage of data files, The design variable values input to the input module may include the number of teeth of the external rotor (z ₂ ), the amount of eccentricity (e), the short distance of the ellipse (r ₁₂ ), the distance d between the center of the outer rotor and the center of the ellipse, Gerotor oil having a tooth-shaped combination of a circle, an ellipse and an involute, characterized in that it consists of a short and short ratio (k), a tip clearance (t _p ), a starting angle (γ) and a range angle (η) of the involute. Rotor design automation system for pumps. The method of claim 1, When the outer rotor is part of an involute tooth, a point Q ₀ (x ₀ , y ₀ ) on the shape of the outer rover in which a circle, an ellipse and an involute are combined is determined from Equation 7 below. A rotor design automation system for a toothed rotor pump having a toothed shape combining a circle, an ellipse and an involute. [Equation 7]

The method of claim 1, When the outer rotor is part of an ellipse, a point Q ₀ (x ₀ , y ₀ ) on the shape of the outer rover in which the circle, the ellipse and the involute are combined is determined from Equation 11 below. Rotor design automation system having a toothed shape that combines a circle, an ellipse and an involute. [Equation 11]

The method of claim 3, The distance ρ from the center point of the ellipse to the contact point is determined from Equation 8 below, and the involute range angle η is determined from Equations 9 and 10 below. A rotor design automation system having a toothed shape in which a circle, an ellipse and an involute are combined. [Equation 8]

[Equation 9]

[Equation 10]

The method of claim 1, The outer rotor is oval and involute the case of a root-like combining one case, the inclination e ₁ and the slope i, find the _point G _e1 and the involute moment gradient G _i1 point of the gradient moment in the following, the inclination e ₂ and slope find the G _e2 and G _i2 point of the instantaneous slope in i ₂ points, the G _e1 line slope of G _e2 and G _i1 G so that the line gradient of the _i2 like involute two points on going to the root rotating involute G _i1 And G _i2 is found again, and the base circle radius r _b of the involute is increased or decreased such that the segment length l _e of G _e1 G _e2 is the same as the segment length l _i of G _i1 G _i2 . Automated rotor design for Gerotor Oil Pumps with tooth-shaped combination of circle, ellipse and involute. The method of claim 5, The instantaneous slope of the ellipse and the involute is a rotor design automation system for a rotor rotor pump having a tooth shape combined with the ellipse and the involute, characterized in that the following formula (12) and (13). [Equation 12]

[Equation 13]

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