US1153478A

US1153478A - Pump for variable-speed hydraulic transmission-gears.

Info

Publication number: US1153478A
Application number: US73289412A
Authority: US
Inventors: Charles Bellens
Original assignee: Individual
Current assignee: Individual
Priority date: 1912-11-22
Filing date: 1912-11-22
Publication date: 1915-09-14
Anticipated expiration: 1932-09-14

Description

C. BELLENS.

PUMP FOR VARIABLE SPEED HYDRAULIC TRANSMISSION GEARS. APPLICATION FILED NOV. 22. 191 2.

1,153,478. PatentedSept. 1 .1, 1915.

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2 SHEETS- WITNESSES 5s B LEN (7% M sYf-II INVENTOR ATTORNEYS C. BELLENS. PUMP FOR VARIABLE SPEED HYDRAULIC TRANSMISSION GEARS.

APPLICATION FILED NOV. 22. I912.

Patented Sept. 14, 1915.

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CHARLES BELLENS, OF BRUSSELS-IXELLES, BELGIUM.

PUMP FOR VARIABLE-SPEED HYDRAULIC TRANSMISSION-GEARS.

Specification of Letters Patent.

Patented Sept. 14, 1915.

Application filed November 22, 1912. Serial No. 732,894.

To all whom it may concern; 7

Be it known that I, CHARLES BELLENS, of N 0. 74 Rue Faider, 'Brussels-Ixelles, Belgium, have invented certain new and useful Improvements in and Relating to Pumps for Variable Speed Hydraulic" Transmission- Gears, of which the following is a specification.

This invention has for its object a pump.

system for variable speed hydraulic transmission gears with reverse and serves particularly to increase the volumetric efiiciency and the mechanical eflicien cy of this apparatus.

In the accompanying drawing, Figure 1 is a longitudinal section through a pump system comprising a system ofv primary pump, and a secondary pump, forminga variable speed gear for a motor car. Figs. 1f to 4 are cross sections in the elements of the primary pump corresponding respectively to lines l 2, 3, and 4 of Fig. 1, showing the arrangement of said elements. Figs. 5 to 8 are similar views of a pump running on the first speed, according to this invention.

In these change speed gears, the engine generally drives a group of coupled primary pumps. The various speed stages are obtained by varying the volume of the liquid delivered by successively placing in circuit and cutting out of circuit pump elements constituting the primary group. Similarly the direction of running is reversedby reversing the direction ofthe flow. In order to obtain these effects the delivery and suction orifices of each of the elements of the primary pump system as heretofore employed, are controlled by by-pass obturators, as shown for example in Fig. 1. The obturators arranged upon the delivery direct the liquid under'pressure' toward the secondary pump or pumps or else short circuit the pump elements upon itself; these are the obturators for the speeds. The obturators 6 arranged upon the suction establish the working pressure in one or other of the conduits connecting with the secondary pump or pumps; these are the reversing obturators. p

In Fig. 1 which illustrates a rotary pallet pump by way of example the obturator a for the speeds and the reversing obturator b are in position for furnishing forward running, the liquid under pressure actuating the secondary pump or pumps through the conduit c or delivery chamber. It will be noted that this pressure the chamber 0 tends to apply the obturator a for the speeds to its seat thereby contributing to insuring a good joint but it tends to detach the reversing obturator b from its seat and causes the liquid to leak over the entire perimeter of its seat. Notwithstanding the utmost care in manufacture these leakages are inevitable; the contact surfaces are necessarily small, the parts are'light and cannot be locked because it is essential to operatethem with the greatest ease by a simple hand lever and the pressures to which they are subjected attain 30 to 40 kg. per square cm.

If in order to obtain the four speeds for example the primary group comprises four pump elements similar to that illustrated in Fig. 1, all the reversing obturators will necessarily find themselves in conditions which are eminently defective as regards the leakage at their perimeter whatever their form may be, whether slide valve, clack valve, cook or the like. In the case of the highest speed where all the pump elements are operative the four-speed obturators will be favorably situated as regards the formation of good joints but in passing fromthe fourth to the third to the second to the first speed the obturators of one, two or three pump elements will reach the position d indicated in Fig. 1 in broken lines so that they will constitute so many additional leakage perimeters. Thus 011 the first speed seven leakage perimeters will exist among the four delivery orifices and the four suction orifices.

The foregoing explanation will render it clear why automobile vehicles in which this type of hydraulic change speed gear is fitted run under favorable conditions on the level the liquid pressure are relatively low and (referring to the case described above) there are four leakage perimeters. These vehicles run under conditions of very marked inferiority on hills the pressure of the liquid increase and the leakage perimeters increase also with the efi' ort to be overcome. There will-be I'ive leakage perimeters on the third speed, six on the second speed and seven on the first speed.

In order that vehicles fitted with hydraulic change speed gear may be able to negotiate hills in conditions equal to or better than those obtaining with gear wheel change speed devices it is essential that the volumetric and mechanical efiicienoy of the pumps should be the maximum. In accordance with the present invention this maximum efliciency is obtained by dispensing with the obturator liable to leak and it resides in particular in the fact that in each pump of the system with the exception of a single pump reserved for reversing, the suction orifice (or the delivery orifice) is free that is to say presents no by-pass ob turator and is furthermore isolated from the delivery chamber (or suction chamber) by a solid wall.

Figs. 1 to 4 are diagrammatic sections of rotary pumps (primary pumps by way of example) showlng the elements of the system forming the object of the invention! These pump elements shown in Figs. 1 to 4, are coupled together to form a pump system as illustrated in Fig. 1.

In Fig. 1, P, P P and 1 indicate the rotors of the several primary pump elements.

arranged within a casing and suitably mounted upon a shaft P adapted to be driven by an engine, not shown.

6 indicates the reversing obturator of the pump element, shown in Fig. 1, 0 is the delivery chamber or conduit, 71, the suction chamber or conduit, and P is the secondary pump. Figs. 5 to 8 are also diagrammatic sections showing another applicationof the system with a special distribution as specified and claimed in this application. It is understood that the pump elements shown in Figs. 5 to 8 areto be arranged in a systemsimilar to that shown in Fig.1.

In the primary group represented in Figs. 1'to'4 and embodied in Fig. 1, the element reserved for reverse running, Fig. 1, is

provided with a speed obturator 64 upon the delivery and with a reversing obturator 7) upon the suction. The three other elements (Figs. 2, 3 and 4) also comprise a speed obturator e f g and the suction which is sepa- First speed 4 to 7. Second speed 3 to 6. Third speed"--- 2to 5. Fourth speed 1 to 4.

This arrangement while largely improving the running on inclines is also particularly adapted for racing vehicles because on the top speed the leakages are m'Z.

Reversed running is obtained-by the re h versing obturator I) Fig. 1. When the 0bturator bis reversed theliquid passes into the other side of the'pump, the obturators ofthe various pump'elements assuming then the reversed positions. A single element is sufficient for all cases. In reversed running also the leakage perimeters are reduced in the ratio of 4 instead of 7 It is to be understood that when the reversing obturator b, Fig. 1 is shifted for reversed running, the speed obturator it assumes the reversed position shown in dotted lines, the liquid then passing to the opposite sidezof the pump.

In order to obtain with a touring vehicle the best possible conditions of volumetric and mechanical efiiciency the system -of pumps is combined with a novel distributing gear, the whole being represented diagram matically in Figsi 5 to 8 for running on the first speed and in this case alsowith a four speed gear which is now required on all vehicles. The distributing gear is diiferem tiated' from such gears as hitherto constructed by the following points: a i

(1.) As the'elements of the group of 'pri mary pumps operate idly instead of being" short'circuited upon themselves through the suction chamber or pipe 71. they areshort circuited through the delivery chamber 0 (Fig. 5). V a

(2.) Ihe speed obturators a e f g are dispensed with on the delivery and shifted to the suction side of the pumps'(Figs.-5, 6, 7 and 8).

(3.) Therreversing obturator b is dispensed with on the suction and shifted to the delivery ofthe single element that it controls (Fig. 8)

When the reversing obturator is shifted from the position shown in Fig; 8,-to the reversed positlon, the obturator 9 also, assumes the reversed position, and the direction of.

the flow of the liquid is reversed from that indicated by the arrows. Owing to this combination the leakage perimeters are inverted and the ratios as above at the different speeds will be as follows: 7

First speed l i 1 to 7. Second speed- 2 to 6. Third speed 3 to 5. Fourth speed 14 to 4.

7 That is to say on inclines the joint formed by-the distributing gear will be increasingly good in'proportion as the incline is steeper andthe pressure of the liquid greater like the effort required of the engines.

' The invention is applicable to 7 all by draulic transmissionswhatever the principle or the application may be. I

It has been described by way of example as applied to a system of primary pumps but it is obvious that it is equally applicable to secondary systems or groups of pumps. I In draulic the delivery chamber 0 a safety valve may be provided for avoiding bursting in case of excess pressures and this valve (not shown in the drawing) may even be located on the solid wall i without thereby affecting the hermeticity of the said wall and without interfering with the pump obturators.

What I claim is:

1. A system of primary or secondary pumps for variable speed hydraulic transmission gears with reverse, comprising a series of pumps each having a suction and a delivery orifice, and a suction chamber and a delivery chamber for the series ofpumps, one of said pumps having a by-pass obturator at the suction and at the delivery orifice, the other pumps of the series each having a by-pass obturator at only one of said orifices, the other orifice being free, and a solid wall isolating said free orifice from the chamber connected with the other orifice, thereby increasing the volumetric and me chanical efliciency of the pumps in preventing leakages.

2. A pump system for variable hydraulic transmission comprising a series of pump units, each having a casing and a rotor therein, a suction orifice leading from the inlet to the rotor, a discharge orifice from the rotor, and a delivery chamber to which the discharge orifice leads, one of said units having a speed obturator at the discharge orifice to connect said orifice with the delivery chamber, or to short circuit with the inlet, and a reversing obturator between the suction orifice and the delivery chamber, and others of the units having a speed obturator at the discharge orifice, and a wall permanently separating the suction orifice and the delivery chamber.

8. A pump system for variable speed hytransmission, comprising pump units each having an inlet chamber, a suction orifice, a discharge orifice, and a delivery chamber to which the discharge orifice leads, and provided with'a speed obturator adjacent to one of said orifices and commanding communication with the delivery chamber, the other orifices being free and there being a closed wall separating the delivery chamber from the inlet chamber and located at one side of the said free orifice.

l. A pump system for variable speed hydraulic transmission, comprising a casing, having an inlet chamber and a delivery chamber, a series of pump units each comprising a rotor within the casing, a suction orifice from the inlet chamber to the rotor, a discharge orifice from the rotor to the delivery chamber, one side of the delivery chamber being adjacent to the suction orifice and the other side adjacent to the discharge orifice, certain of said units being each provided with a speed obturator commanding communication between the delivery chamber and one of said orifices the other orifice being free, and a solid wall permanently separating the delivery chamber from the inlet chamber and arranged adjacent the said free orifice.

5. A pump system for variable speed hydraulic transmission, comprising pump units, an inlet chamber for the pump units, each pump unit having a suction orifice, and a discharge orifice, a delivery chamber to which the discharge orifice leads, each pump unit being provided with a speed obturator adjacent to one of said orifices and commanding communication between said orifice and the delivery chamber and said orifice and the inlet chamber, the other orifice being free, and a closed wall adjacent said free orifice and permanently separating the inlet chamber from the delivery chamber.

6. A pump system for variable hydraulic transmission, comprising a series of pump units, each having a casing and a rotor therein, a suction orifice leading from the inlet chamber to the rotor, a discharge orifice from the rotor, and a delivery chamber to which the discharge orifice leads, one of said units having a speed obturator at one of said orifices to connect said orifice with the delivery chamber or to short circuit with the inlet chamber, and a reversing obturator between the other orifice and the delivery chamber, the other pump units each having a speed obturator at one of said orifices, and a wall adjacent the other orifice and permanently separating the inlet chamber fromthe delivery chamber.

7. A pump system for variable speed hydraulic transmission, comprising a series of pump units each having a suction and a discharge orifice, and an inlet chamber and a delivery chamber for the pump units, one of said pump units having an obturator at one of said orifices to connect said orifice either with the delivery chamber or with the inlet chamber or to short circuit through one of said chambers, and a reversing obturator at the other orifice, the other pump units each having an obturator at only one of said orifices, to connect the said orifice either with the delivery or with the inlet chamber or to short circuit through one of said chambers, the other orifice being free and isolated from the other of said chambers.

In testimony whereof I have hereunto placed my hand at Brussels, Belgium, this 18th day of October, 1912.

CHARLES BELLENS.

In the presence of two witnesses:

F. J. LABARRY, CHAS. ROY NASMITH.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Patents, Washington, D. G.