US2622538A - Vane pump - Google Patents

Description

Dec. 23, 1952 H. c. G. VINCENT 2,622,538

VANE PUMP Filed Oct. 4, 1949 2 SHEETSSHEET l Fig.1

1 I I l 3nnenfor fi-wz/ C6 [/m/aE/vr @JWSW (Ittornegs Patented Dec. 23, 1952 VANE PUMP Henri Charles Gustave Vincent, Renens, Switzerland Application October 4, 1949, Serial No. 119,457 In Switzerland October 19, 1948 4 Claims.

The idea of housing a revolving drum fitted with mobile vanes in an eccentric body is a very old one. From the very beginning of pressure lubrication for internal combustion motors, there is found an application of such an idea including vanes subjected to the push of one or more springs which ensure the constant bearing against the wall of the pump casing. The use of these springs is not satisfactory and it has been necessary to turn to gear pumps in spite of their being so expensive.

The present invention aims at remedying these drawbacks; it makes it possible to obtain, at a more advantageous price, pumps working in an excellent manner at any speed.

The drawing shows, by way of example, two embodiments of the object of the invention applied to the pumping of a liquid.

The Fig. 1 is a longitudinal cross-sectional View of the pump.

The Fig. 2 is a transverse cross-sectional view of the pump taken along the line IL-II of the Fig. 1.

The Fig. 3 is a view on a larger scale of a crosssection taken along the line II--II of the Fig. 1.

The Figs. 4., 5 and 6 show respectively a profile, front and top view of a vane in accordance with the invention.

The Fig. 7 is a transverse cross-sectional View of the pump in accordance with the second embodiment.

In a cylindrical drum I including a central bore for the passage of the driving axle, eight longi tudinal slots 2 distributed over the periphery have been provided. These slots have an arcuate shaped bottom as shown in Figure 1.

Inside the slots 2 can move, with slight friction, the vane 3, having in particular two adjacent grooves or hollow parts. One is a transverse groove 4, which is provided on the front face and which connects the two edges, and the other groove 5 is provided all along the lower part, which fits the bottom of the slot 2, this latter groove having also an arcuate shaped bottom.

The upper face of the vane 3 is rounded to the radius of the chamber of the pump casing and its leading edge includes a bevel 8 throughout its length.

The pump casing 1 includes a longitudinal bore 9 for the passage of the driving shaft it! and a cylindrical chamber H eccentric in relation to the axis of the drum I. Two access chambers are also provided one, [2, for the intake, the other, I3, for the pressure side or discharge,

these two chambers communicating with the outside by means of the pipes 19 and 20.

A driving gear [5 is fixed on the axle ill at its part protruding from the end of the pump casing, which is fitted at this place with a usual packing gland It. The other end of the casing ends in a lateral flange I1, fixed by screws l8, said flange including a socket in which is mounted the end of the shaft H).

The slots of the drum 1, housing the vanes, are comparatively deep and enable the vanes to have a great width, so as to obtain the greatest possible guiding of said vanes giving a long working life to the vanes. In order not to weaken the drum, the bottoms of these slots 2 have an arcuate shape as shown in Figure 1 so that the deepest point is situated at the middle of the drum, the ends of which are thus strengthened. The vane 3, driven by the revolving drum, receives, at every pressure cycle, an impulse from the liquid which enters the transverse groove 4. The liquid quickly fills the free space in pressing against the longitudinal grooved bottom 5, thus imparting to the vane an ejection movement which causes the outer edge of the vane to bear against the inside wall of the pump casing with a tightness great enough to cause the retention of the liquid charge contained in the interval between two vanes.

In Figs. 2 and 3, the point A indicates the working zone, that is to say the crescent shaped zone, where the stroke of the vanes outside their housing I is the greatest, the point B marks the dead centre, where the drum is flush with the wall of the pump casing.

It is first by inertia, then by pressure, that the liquid brought to the bottom of the slot by the transverse groove 4 pushes the vane and brings it to bear against the internal wall of the casin l, in order to ensure the required tightness as well as the repetition of the reciprocating movement, without the help of springs or extension parts likely to cause trouble. During the cycle which it performs, the Vane comes first in front of the dead centre B, entirely withdrawn; then the revolving of the drum brings it in the working zone where it meets the liquid stream drawn by the back face of the preceding vane. It strikes that liquid, engages it and receives a part of it which flows to the bottom of the slot 2 through the transverse groove 4, the vane being thus pushed outwardly against the wall of the casing i, the pressure thus developed becoming a function of the pump back pressure.

The bevel 8 provided at the leading edge of the vane is intended for allowing the impurities of the liquid to gather in this small space at the passage of the dead centre, prior to being drawn out from the pump. The jamming of the drum and harmful jerks are thus avoided.

The transverse groove 4 is also intended for decreasing friction by allowing an easy discharge of the liquid contained at the bottom of the housing of the vane whenapproaching the dead centre. The longitudinal groove reduces the sticking of the vane at the bottom of its housing.

The discharge is abundant, with a high pressure, and the priming is instantaneous, which makes this pump particularly valuable for the lubrication of internal combustion motors and for all the applications where these conditions are considered necessary.

The efficiency of the pump such as described can be increased by providing in the drum I, between the vanes 3, a longitudinal orifice 2| traversing the whole thickness of said drum. These orifices make it possible to obtain better results and, in particular, to decrease the weight of the drum, to secure a higher vacuum degree at the intake, to do away with the jerks during the back pressing, to ensure the permanence of the hydraulic seal on the faces of the drum and to effect a substantial saving in the driving power.

The orifices 2| decrease in no way the resistance of the drum, which is very good due in particular to the arched form of the bottom of the grooves 2; by drilling the said orifices, the drum is made lighter in weight, while keeping a judiciously distributed mass of material. This weight saving leads to a noticeable decrease in the inertia of the drum during the operation of the vanes.

The passage of each orifice in front of the intake port has the result of still improving the depression prevailing in the intake chamber, which makes it possible to obtain the quick priming of the pump at a low speed, for instance at 24 revolutions per minute.

The orifices 2| also make it possible to completely suppress the jerk-s due to the successive discharge from the spaces between the vanes, which takes place at low speed, as well as the vibrations which could take place when high speeds were reached. Indeed, the empty space constituted by the orifice acts as a pneumatic damper, which avoids the strangling of the oil and therefore its emulsion when this liquid or other oil derivatives are pumped.

When passing in front of the back pressure port, the hollows formed by the orifices 2| receive a liquid which they hold and send back in the confined space existing between the drum faces and the bottoms of the pump casing and of the flange, which ensure the permanence of the efficient hydraulic seal.

The decrease in weight of the drum causes a noticeable saving of the driving power, which becomes considerable when drums of large size are considered.

A cast iron drum and steel vanes will be employed preferably in the case of application to motors, while, for pneumatic pumps, plastic materials or light metals may be used.

Upon inspecting Fig. 3 of the drawings it will be noted that between the upper dead center and a position about 90 in advance of upper dead center, the transverse grooves '4 in the vanes provide a leak or by-pass 3a from one side of the vane to the other. This leak is due to the fact that in this position the vanes are not radially disposed with respect to the cylindrical inner surface f '4 the pump housing and the outer end faces of the vanes do not make contact throughout their entire thickness with said cylindrical surface.

Due to this peculiarity of construction, the leakage or by-pass effect avoids the production of a water hammerin effect as the blades approach their upper dead center position.

I wish it to be understood that I do not desire to be limited to the exact details of construction shown and described, for obvious modifications will occur to a person skilled in the art.

I claim:

1. A rotary pump of the sliding vane type comprising a housing having a pump chamber, the inner surface of which is cylindrical, an intake chamber extending axially of the housing and a discharge chamber extending axially of the housing, said intake and discharge chambers communicating with the pump chamber adjacent the periphery of the pump chamber at substantially diametrically disposed regions for the flow of fluid into and from the pump chamber in a direc tion axially thereof, a rotor mounted in said pump chamber for rotation about an axis eccentric relative to the pump chamber, said rotor having a plurality of circumferentially spaced radially extending slots disposed axially thereof, each of said slots having an arcuate bottom and the radial depth of said slots increasing from the ends of the rotor towards the intermediate portion thereof, and a vane radially slidably mounted in each slot and having its radially innermost edge of arcuate formation corresponding to that of the bottom of the slot, each of said vanes having in its leading face a groove extending radially from its inner edge to its outer edge to facilitate penetration of fiuid into the bottom of the slots in which the vanes are mounted, said radial grooves being of suiiicient depth to provide a bypass from one side of the vane to the other when the vane lies between its upper dead centre position and a position in advance of dead centre to prevent hammering.

2. A rotary pump of the sliding vane type comprising a housing having a pump chamber, the inner surface of which is cylindrical, an intake chamber extending axially of the housing and a discharge chamber extending axially of the housing, said intake and. discharge chambers communicating with the pump chamber adjacent the periphery of the pump chamber at substantially diametrically disposed regions for the flow of fluid into and from the pump chamber in a direction axially thereof, a rotor mounted in said pump chamber for rotation about an axis eccentric relative to the pump chamber, said rotor having a plurality of oircumferentially spaced radially extending slot-s disposed axially thereof, each of said slots having an arcuate bottom and the radial depth of said slots increasing from the ends of the rotor towards the intermediate portion thereof, and a vane radially slidably mounted in each slot and having its radially innermost edge of arcuate formation corresponding to that of the bottom of the slot, each of said vanes having its arcuate edge provided with a groove to avoid adherence of the vane to the bottom of the slot in which it is mounted, each of said vanes having in its leading face a groove extending radially from its inner edge to its outer edge to facilitate penetration of fluid into the bottom of the slots in which the vanes are mounted, said radial grooves being of suflicient depth to provide a bypass from one side of the vane to the other when the vane lies between its upper dead center position and a position in advance of dead center to prevent hammering.

3. A rotary pump of the sliding vane type comprising a housing having a pump chamber, the inner surface of which is cylindrical, an end wall closing one end of the cylindrical pump chamber, an intake chamber extending axially of the housing and a discharge chamber extending axially of the housing, said intake and discharge chambers communicating with the cylindrical pump chamber through the end opposite that closed by said end wall adjacent the periphery of the pumpchamber at substantially diametrically disposed regions for the flow of fluid into and from the pump chamber in a direction axially thereof, a rotor mounted in said pump chamber for rotation about an axis eccentric relative to the pump chamber and with one end in engagement with said closed end wall, said rotor having :a plurality of circumferentially spaced radially extending slots disposed axially thereof, and a vane radially slidably mounted in each slot, said rotor having a plurality of circumferentially spaced openings extending axially therethrough between the vane receiving slots and positioned between the axis and periphery of the rotor to communicate at one end with the intake and. discharge chambers as the rotor moves relatively to said chambers and to be closed at their other ends by said end Wall.

4. A rotary pump of the sliding vane type comprising a housing having a pump chamber, the inner surface of which is cylindrical, an end wall closing one end of the cylindrical pump chamber, an intake chamber and a discharge chamber each extending axially of the housing, said intake and discharge chambers communicating with the cylindrical pump chamber through the end opposite that closed by said end wall, adjacent the periphery of the pump chamber at substantially diametrically disposed regions for the flow of fluid into and from the pump chamber in a direction axially thereof, a rotor mounted in said pump chamber for rotation about an axis eccentric relative to the pump chamber and with one end in engagement with said closed end wall, said rotor having a plurality of circumferentially spaced radially extending slots disposed axially thereof, each of said slots having an arcuate bottom and the radial depth of said slots increasing from the ends of the rotor towards the intermediate portion thereof, and a vane radially slidably mounted in each slot and having its radially innermost edge of arcuate formation corresponding to that of the bottom of the slot, each of said vanes having its arcuate edge provided with a groove to avoid adherence of the vane to the bottom of the slot in which it is mounted, each of said vanes having a groove extending radially from its inner edge to its outer edge to facilitate penetration of fluid into the bottom of the slots in which the vanes are mounted, said rotor having a plurality of circumferenti-ally spaced openings extending axially therethrough between the vane receiving slots and positioned between the axis and periphery of the rotor to communicate at one end with the intake and discharge chambers as the rotor moves relatively to said chambers and to be closed at their other ends by said end wall.

HENRI CHARLES GUSTAVE VINCENT.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 1,793,007 Pearson Feb. 17, 1931 2,035,465 Erskine et a1 Mar. 31, 1936 2,178,425 Johnson Oct. 31, 1939 2,225,803 smith Dec. 24, 1940 2,287,369 Anderson June 23, 1942 2,333,323 Livermore Nov. 2, 1943 2,335,284 Kendrick Nov. 30, 1943 2,423,639 Czarnecki July 8, 1947 2,468,948 Smith May 3, 1949 FOREIGN PATENTS Number Country Date 58,400 Sweden Mar. 3, 1925

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