JPS59131787A - Rotary pump - Google Patents

Abstract

PURPOSE:To reduce leakage against low viscosity and high pressure of fluid to be pumped by a method wherein a crescent is provided between an outer rotor and an inner rotor while a paratrochoidal curve is employed to form the shapes of the teeth of both rotors. CONSTITUTION:The shapes of the teeth of the outer rotor 12 and the inner rotor 11 are formed by the paratrochoidal curve and the crescent 5 is provided between the outer rotor 12 and the inner rotor 11. According to this method, the low pressure side and the high pressure side of the pump may be partitioned by surface contacts between the crescent 5 and the inner diameter of the outer rotor 12 as well as the outer diameter of the inner rotor 11, therefore, leakage may be reduced against the low viscosity and the high pressure of the fluid to the pumped.

Description

Detailed Description of the Invention The present invention relates to a rotary pump used for an oil pump for supplying engine lubricating oil or a high-pressure or low-viscosity pump.More specifically, in a rotary pump using an internal gear, the outer rotor and A crescent is provided between the rotor and the inner rotor, and both the outer rotor and the inner rotor are characterized by having baratrochoid curves as tooth shapes.

Trochoid curve T is a basic circle with diameter A in Fig. 1 with diameter B = A/n (n is usually a positive integer,
It is a curve drawn by a fixed point that is eccentric from the rolling circle by e when the rolling circle (number of inner teeth) rolls without slipping. If the envelope for this group of circles created when the center of a locus circle with diameter C moves on this trochoid curve is the baratrochoid curve TC, then this baratrochoid curve TC is the shape of the teeth of the inner rotor of a pump with a normal trochoid tooth profile. Use as a curve.

At this time, the curve of the outer rotor is usually an arc of diameter C (
It is made up of n+1) pieces.

Conventionally, a pump rotor using a trochoid curve has an outer rotor having an arcuate trajectory, and an inner rotor using a baratrochoid curve, with a difference in the number of teeth between the inner and outer rotors of one tooth.

The drawbacks of this type of rotor are that it requires a lot of rotation to generate high pressures of 100 to 9 J or more, and that the discharge efficiency is poor at low viscosity.

That is, as shown in FIG. 2, the tooth curve of the outer rotor 1 consists of one more circular arc than the number of teeth of the inner rotor 1, and the inner rotor is made of a paratrochoid curve as described above.

The inner rotor and outer rotor are eccentric by an eccentricity e.

When the inner rotor rotates in the direction of the arrow, the outer rotor follows and rotates, and the space volume S created by the inner rotor and outer rotor gradually increases on the suction port side, reaches its maximum, and then gradually decreases on the discharge port side. It's becoming.

When the rotor rotates from the suction hole side to the discharge hole side, the place that separates the high pressure side (P) from the low pressure side LP is the line contact area between the inner rotor and the outer rotor, as shown in Figure 3. Since the leakage is large, this effect becomes significant especially when the pressure becomes high or the viscosity becomes low, resulting in a disadvantage that the volumetric efficiency deteriorates.

Therefore, if it were possible to use a crescent 5 similar to that used in the internal involute gear shown in Fig. 4, which is used in the engine-directly connected type of conventional oil pump for engine lubrication, a countermeasure would be taken. However, this is not possible with conventional rotors of the above shape.

This invention was made in view of the above points, and uses a paratrochoid curve for both the outer rotor and the inner rotor, and the tips and roots of the inner rotor and outer rotor are shaped into circular arcs centered on their respective rotation centers. This feature allows the crescent to be inserted.

As a result, even a pump rotor using a paratrochoid tooth profile can be used as a pump for low viscosity fluids or high pressures.

For example, recent engines have become more efficient, such as turbos, and the temperature around the engine increases accordingly, the oil temperature also rises, and the viscosity decreases, making it impossible to ensure sufficient displacement. The rotary pump of the present invention is effective in such cases.

Because there is a crescent, the partition between the low pressure side and the high pressure side can make surface contact between the talescent and the inner diameter of the outer rotor and the outer diameter of the inner rotor, which can reduce leakage not only for low viscosity but also for high pressure. It is.

Hereinafter, the rotary pump of the present invention will be explained with reference to FIG. 5. The number of teeth of the inner rotor 11 is 01, the number of teeth of the outer rotor 12 is n, (n, > n, ), the radius of rotation is B mm, and the trajectory circle is When the diameter is Cmm, the eccentricity is e, and IIl is a positive integer, the inner rotor is a trochoid with A, -〇l, i B as the basic circle diameter, rolling circle diameter B1 locus circle diameter C1 eccentricity e The paratrochoid curve of the curve is taken as a tooth curve, and the outer rotor is AL=n! , &B as the base circle diameter, and the baratrochoid curve of the trochoid curve with the radius B1 of the locus circle diameter C1 and the eccentricity i1e is taken as a tooth curve. At this time, the distance E between the centers of the inner rotor and the outer rotor is E
= - E - Of course - B.

2. Also, set the tooth tip diameters of the inner rotor and outer rotor to d3. If d2, the thickness t of the talent is t = -+ E when the clearance is zero and 4 degrees.

If only the teeth are H and the clearance is zero, the rotary pump of the present invention can use a crescent between the outer rotor and the inner rotor as described above, so it can be used efficiently even at high pressure or low viscosity.

However, the rotary pump of the present invention can be used as an oil pump for supplying engine lubricating oil, a high pressure (over 100 kflJ) hydraulic pump, a pump for low viscosity fluid (water, gasoline), an oil pump for automatic transmissions, etc. be.

[Brief explanation of the drawings] Figure 1 is an explanatory diagram of trochoid curve specifications, Figure 2 is an example of a conventional paratrochoid gear pump, and Figure 3 is an illustration of the inner rotor and outer surface of the paratrochoid gear pump when it rotates. FIG. 4 is a front view of an involute tooth type internal gear pump, and FIG. 5 is a front view of an embodiment of the rotary pump of the present invention. 5...Crescent 11...Inner rotor 1
2... Outer rotor 13... Discharge hole 14.
...Suction hole Figure 1 Figure 2 Figure 4 Figure 5 Procedure? ■Authentic document (spontaneous) 1. Indication of the case Patent Application No. 7113 of 1982 2. Name of the invention Rotary pump 3. Person making the amendment Relationship to the case Patent applicant address Address 5-15 Kitahama, Higashi-ku, Osaka name
(213) Sumitomo Electric Industries, Ltd. 4, Agent Address: Wakasugi Building 6, 1-18-18 Nakatsu, Oyodo-ku, Osaka, Contents of Amendment As shown in the attached document, ``Contents of Amendment, Page 1, Line 19, Rotor 1'' Inner rotor 2" is corrected. 0 2, page 5, line 3, Fnj is corrected to "nl". 1. 3. Same! Correct rnJ on page 5, line 4 to "n,". 4, page 5, line 7 1 [Al= n+/ mB j k [At= B ×j
I will correct it. 5, page 5, line 10 L r Az = na/mB J 'i r Al = BX
- Correct as J. 6, page 5, line 14, change n L n 1 mB J to [E = B x −J m
2m

Claims (1)

[Claims] A rotary pump using an internal gear, characterized in that a talent is provided between an outer rotor and an inner rotor, and a baratrochoid curve is used for the tooth shape of both the outer rotor and the inner rotor.