US2738046A - Hydraulic transmission - Google Patents

Description

March 13, 1956 F. KOSTENKO 2,738,046

HYDRAULIC TRANSMISSION Filed Sept. 14, 1953 2 Sheets-Sheet l 132?. Z. INVENTOR.

RFD/A AOSTf/VKO March 13, 1956 F. KOSTENKO HYDRAULIC TRANSMISSION Filed Sept. 14, 19s:

2 Sheets-Sheet 2 INVEN TOR. 550/? XOSTE/VA/O H ATTORNEX United States Patentfflice HYDRAULIC TRANSMISSION Fedir Kostenko, Philadelphia, Pa. Application September 14, 1953, Serial No. 379,914

5 Claims. (Cl. 192-60) This invention relates to a hydraulic transmission for automobiles and more particularly to a novel type ofhydraulic transmission that is automatic in its operation.

The type of hydraulic transmission with which the present invention is concerned comprises a housing that is drivably connected to the crank shaft of an engine and which housing carries a cover in which is journalled the drive shaft of a motor vehicle. The housing also carries a pair of diametrically opposed cylinders in each of which reciprocates a piston With a connecting rod extending from each piston to a cam concentrically mounted on the drive shaft. The cylinder is formed with ports which communicate with the interior of the housing and, as the latter is filled with a hydraulic medium, the housing may be rotated independently of thedrive shaft so long as the ports are open to permit of a free circulation of the hydraulic medium through the cylinders and housing. In addition, the housing carries a pair of diametrically opposed smaller cylinders in each of which is mounted a spring-biased cylindrical weight whose purpose is to induce an off-center movement of the cam in a manner and for a purpose to be described below.

The driving relation between the housing and the drive shaft is established through the joint action of the abovementioned weights, which induce the off-center movement of the cam to which the piston connecting rods are attached initiating reciprocation of the piston, and the closing of the cylinder ports so as to cut off, or restrict, communication between the interior of the cylinders and the housing, and thus limit reciprocation of the piston. After these ports are completely closed and the pistons. are at rest, the housing and drive shaft will rotate simultaneously as a single unit.

An important object of the present invention is to pro vide, in a hydraulic transmission of the chai-acterindicated, a cylinder having ports therein, together with a floating ring that encircles the cylinder and which is adapted to be yieldably maintained in a position leaving the ports open by a spring but which is adapted to be moved by centrifugal force against the influence of the spring to close the ports. Inasmuch as the amount of centrifugal force which is generated is directly proportional to the speed of rotation of the housing, it is evident that the extent to which the ports are closed depends directly upon the speed at which the housing rotates. Furthermore, the initiation of reciprocation of the pistons in said cylinders is dependent upon the centrifugal force of the weights carried by the housing, which force is directly proportional to the speed of rotation of the housing. Thus the driving relation between the crank shaft of the engine and the drive shaft of the vehicle is automatically controlled by the speed'of rotation of the crank shaft.

Still another object of the invention is to provide a hycylinder being provided with one of the floating rings aforesaid. Thus as many of the cylinders may be included Patented Mar. 1 1956 as to meet the engineering requirements of any particular transmission and the motor vehicle in which it is installed. A further object of this invention is to provide, in a hydraulic transmission of the type here involved, a pair of diametrically opposed spring-biased weights mounted in cylinders and adapted to induce the off-center movement of the cam to which the above-mentioned pistons are attached, initiating reciprocation thereof.

Various other more detailed objects and advantages of the invention such as arise in connection with carrying out the above noted ideas in a practical embodiment will, in part, become apparent, and in part be hereinafter stated as the description of the invention proceeds. The invention therefore comprises a hydraulic transmission which consists essentially of a housing that is connected to the crank shaft of an engine, with the housing being provided with a cover plate in which is journalled a drive shaft carrying a cam. The housing carries a pair of cylinders, each of which is formed with ports and in which reciprocates a piston that is operatively connected with the cam carried by a drive shaft. Each cylinder is provided with a floating ring that encompasses the cylinder and which is normally biased intoa position leaving the ports open by a spring. These rings are adapted to be moved under the influence of centrifugal force of rotation of the housing to close the ports and thus build up'resistance to reciprocation of the pistons by reason of the presence of a hydraulic medium in the housing. The housing also carries a pair of diametrically opposed Weights residing in cylinders and adapted to induce an off-center movement of the cam, and thus initiate reciprocation of the pistons causing drivable rotation of the drive shaft. When the cam is on-center, the pistons will not reciprocate with the result that the housing will rotate while the-drive shaft will remain at rest.

vFor a full and more complete understanding of the invention, reference may be had to the following description and accompanying drawings wherein similar numerals, refer to similar parts throughout the several views.

Figure l is a cross-sectional view of the hydraulic transmission of the invention showing the diametrically opposed cylinders mounted in the housing, and also showing the means employed for causing the off-center movements of the cam. p

Figure 2 is a sectional view taken along the line 2-2 of Figure 1. i

Figure3 is a sectional view of the transmission taken along the line 33 of Fig. 1 and showing the diametrically opposed spring-biased weights adaptedto induce the off-center movement of the cam in cooperation with the means shown in Fig. 1. i

Figure 4 is a sectional 'view of the transmission taken along the line 44 of Fig. 3 illustrating the mechanism employed in conjunction with the spring-biased weights in moving the cam off-center to cause reciprocation of the pistons.

Referring now to Figs. 1 and 2 of the drawings, the hydraulic transmission of this invention is shown as comprising a housing which is referred to in its entirety by the reference character H, and which housing is provided with a cover it The housing H comprises a circular flat wall 11 which has integrally formed therewith a central embossment 12 which is drivably connected to the crank shaft 13 of an internal combustion engine. Integrally joined to the fiat'wall 11 of the housing H isa pair of concentric cylindrical walls 14 and 15." The walls 14 and 15 are provided with diametrically opposed, aligned openings in which are mounted a pair of cylinders 16. Since the cylinders and their corresponding elements are identical, the description thereof will be limited to only one of them. Each cylinder v1'6ji's provided with a plurality of ports 17 for a purpose to be described below. Surrounding said cylinder in slidable engagement therewith, and lying between the Walls 14 and 15, is a cylindrical ring 18 which is biased against the wall 15 by a coil spring 19, also surrounding said cylinder between said walls. The coils of this spring increase in diameter in a direction from the axial extremities of the spring toward the center thereof, as shown in the drawings, so as to permit maximum compression thereof and thus allow the rings 18 to completely cover the ports 17 for a purpose to be discussed below. The openings in the wall 14 are provided with a cover plate 20, secured to said wall by means of screws 21.

Each cylinder 16 carries a piston 22 therein, said pistons being connected by a connecting rod 23 to a rim 24 circumscribing a cam 25 in slidable engagement therewith, as shown in Figures 1 and 2. It is to be noted that the cam 25 is common to both connecting rods. The cam 25 is provided with a rectangular opening 26 bevelled at 27 and 28 to accommodate a second cam 29 residing therein and is slidably mounted on the automobile drive shaft 39. The portion of the shaft 30 Within the confines of the housing H is of square cross-section and the cam 29 has a square opening therein for slidably accommodating said shaft. The said drive shaft has one end 31 rotatably positioned in the flat wall 11 of the housing H, while the other end passes through the cover It Outstanding from said cover is a stuffing box 32 carrying a suitable stufling material 33, such as felt or the like, and a packing gland 32 to prevent leakage of hydraulic fluid from the transmission.

Outstanding from the flat wall 11 within the confines of the wall 15 is a cylindrical member 34, attached thereto by bolts 35, or other suitable attachment means. The said cylindrical member 34 circumscribes the drive shaft 30 and houses the cam 29 which resides on said drive shaft. The cylindrical member 34 and a similar member .34 mounted on the cover 10 prevent axial movement of the cam 25 along the drive shaft 30 during reciprocation of the pistons 22. Residing on the outside of said cylindrical member 34 in slidable relationship therewith is a cylindrical band 36 having inwardly extending fingers 37 engaging the cam 29, and outwardly extending fingers 38, as shown in Fig. 1.

Referring now to Figs. 3 and 4, the outwardly extending fingers 38 carry U-shaped brackets 39, pivotally connected thereto, having L-shaped arms 40 depending therefrom which are pivotally supported by pins 41 on lugs 42 outstanding from the wall 15. The arms 40 are pivotally attached to diametrically opposed piston weights 43 by means of links 44, the said piston weights residing in cylinders 45 and adapted for reciprocation therein. The cylinders 45 are provided with apertures 46, and a coil spring 47 resides in each of said cylinders holding the weights 43 in a biased condition therewithin.

Operation When the motor vehicle is at rest and the engine is turning at idling speed, the cam 25 will be on-center relative to the drive shaft 30. At this speed, the housing H is rotated by the crankshaft 13, and inasmuch as the cam 25 is on-center the pistons 22 remain stationary with the ports 17 of the cylinders 16 in the fully open position, allowing free circulation of the hydraulic fiuid within the transmission. Under such conditions of operation, the drive shaft 30 remains at rest. As the speed of the engine is increased through the normal and customary acceleration of the motor vehicle, the housing H rotates at correspondingly higher rotational speed. As this rotational speed progresses, the piston weights 43 tend totravel outwardly in a radial direction against the resistance of the coil springs 47 by virtue of the centrifugal force of rotation, thehydraulic fluid within the cylinders 45 escaping through the apertures 46 therein. As the wegihts 43 travel outwardly, the L-shaped arms 40 on the U-shapedbrackets 39 are activated in pivotal fashion through the links 44, causing said brackets to act on the outwardly extending fingers 38 on the cylindrical band 36. This action is transmitted to the inwardly extending fingers 37 which are in engagement with the cam 29 causing the said cam to slide forward on the drive shaft 30 toward the cover 10, so that the said cam 29 extends further into the opening 26 in the cam 25. Due to the configuration of the cam 29, as shown in Fig. l, the cam 25 is gradually forced off-center relative to the drive shaft 30 as the said cam 29 moves forward on the said drive shaft 30, causing the eccentric 25 to make a pressure contact on the rim 24 to which the connecting rods 23 are attached. This condition initiates reciprocation of the pistons 22 with the cylinders 16, whereupon the cam 25, cam 29 and drive shaft 30 begin to rotate, power thus being transmitted through the drive shaft to the various driven elements of the motor vehicle.

As the speed of the engine increases further, the rings 18 will move outwardly in a radial direction by virtue of the centrifugal force developed, slowly overcoming the resistance of the coil springs and gradually closing the ports 17 in the cylinders 16. This restriction of the ports 17 builds up a resistance to circulation of the hydraulic fluid, causing rotation of the drive shaft 30, though not r at the same speed as the housing H. When the said ports are fully closed, the circulation of hydraulic fluid therethrough is terminated. Under these conditions, the reciprocation of the pistons 22 comes to an end and all the elements, including the housing H, cylinders 16, pistons 22, cam 25, cam 29 and drive shaft 30 rotate together as an integral unit, whereupon full power is transmitted to the motor vehicle driven members. Thus the driving ratio of 1 to 1 between the crank shaft of the engine and drive shaft of the vehicle is established.

When the motor vehicle encounters an upward grade or other increased load, the engine speed will decrease, thus reducing the centrifugal force which holds the rings 18 in a port closing position, thereby permitting the springs 19 to move said rings away from the ports and partially open them. Thus, circulation of the fluid in the transmission housing is again restored and a differential in the speed of rotation between the housing H and drive shaft 30 obtains.

From the foregoing, it is apparent that the operation of the hydraulic transmission herein disclosed is entirely automatic, and depends directly upon the speed at which the engine is operated.

While the present discussion of this invention has been limited to the above described preferred embodiment, it is to be understood that variations thereof are possible without departing from the spirit of the invention. It is not intended, therefore, that the invention be limited to the particular embodiment disclosed, but only to the inventive concept as defined by the appended claims.

What isclaimed is:

1. In a motor vehicle hydraulic transmission, a housing adapted to be operatively connected to the engine of a motor vehicle, a cover for said housing, a drive shaft journalled in said cover and extending into said housing, a cam drivably mounted on said drive shaft within said housing and concentric with said shaft, a pair of cylinders carried by said housing and radially disposed therein in diametrically opposed relationship, a piston reciprocal in each of said cylinders and operatively connected to said cam, said cylinders having ports in the walls thereof, a hydraulic medium in said housing, a floating ring about each of said cylinders and adapted to be moved into a position closing said ports under the influence of the centrifugal force generated by rotation of said housing, a spring normally biasing each floating ring into a position leaving said ports open, and means for moving said cam into an off-center position relative to said drive shaft so as to initiate reciprocation of said pistons through the driving force of said shaft.

2. In a motor vehicle hydraulic transmission, a housing adapted to be operatively connected to the engine of a motor vehicle, a cover for said housing, a drive shaft journalled in said cover and extending into said housing, a cam drivably mounted on said drive shaft Within said housing and concentric with said shaft, a pair of cylinders carried by said housing and radially disposed therein in diametrically opposed relationship, a piston reciprocal in each of said cylinders and operatively connected to said cam, said cylinders having ports in the walls thereof, a hydraulic medium in said housing, a floating ring about .each of said cylinders and adapted to be moved into a position closing said ports under the influence of the centrifugal force generated by rotation of said housing, a coil spring normally biasing each floating ring into a position leaving said ports open, a second cam cooperating with said first camto move it off-center relative to said drive shaft so as to initiate reciprocation of said pistons through the driving force of said shaft, and means for activating said cam to move said eccentric off-center.

3. In a motor vehicle hydraulic transmission, a housing adapted to be operatively connected to the engine of a motor vehicle, a cover for said housing, a drive shaft journalled in said cover and extending into said housing, a cam drivably mounted on said drive shaft within said housing and concentric with said shaft, a pair of cylinders carried by said housing and radially disposed therein in diametrically opposed relationship, a piston reciprocal in each of said cylinders and operatively connected to said cam, said cylinders having ports in the Walls thereof, a hydraulic medium in said housing, a floating ring about each of said cylinders and adapted to be moved into a position closing said ports under the influence of the centrifugal force generated, by rotation of said housing, a coil spring normally biasing each flpating ring into a position leaving said ports open, a second cam slidably mounted on said drive shaft in engagement with said first cam to move it off-center relative to said drive shaft so as to initiate reciprocation of said pistons through the driving force of said shaft, and means operatively responsive to the centrifugal force of rotation of said housing for activating said second cam to move said first cam off-center as the rotational speed of said housing increases. 1

4. In a motor vehicle hydraulic transmission, a housing adapted to be operatively connected to the engine of a motor vehicle, a cover for said housing, a drive shaft journalled in said cover and extending into said housing, a cam drivably mounted on said drive shaft within said housing and concentric with said shaft, a pair of cylinders carried by said housing and radially disposed therein in diametrically opposed relationship, a piston reciprocal in each of said cylinders and operatively connected to said cam, said cylinders having ports in the Walls thereof, a

hydraulic medium in said housing, a floating ring about each of said cylinders and adapted to be moved into a position closing said ports under the influence of the centrifugal force generated by rotation of said housing, a coil spring normally biasing each floating ring into a position leaving said ports open, a second cam slidably mounted on said drive shaft in engagement with said first cam to move it off-center relative to said drive shaft so as to initiate reciprocation of said pistons through the driving force of said drive shaft, and a pair of Weights in diametrically opposed relationship operatively connected to said second cam and adapted to activate movement of said cam to force the said first cam off-center under the influence of the centrifugal force of rotation of said housing.

5. In a motor vehicle hydraulic transmission, a housing adapted to be operatively connected to the engine of a motor vehicle, a cover for said housing, a drive shaft journalled in said cover and extending into said housing, a cam drivably mounted on said drive shaft Within said housing and concentric with said shaft, a pair of cylinders carried by said housing and radially disposed therein in diametrically opposed relationship, a piston reciprocal in each of said cylinders and operatively connected to said cam, said cylinders having ports in the walls thereof, a hydraulic medium in said housing, a floating ring about each of said cylinders and adapted to be moved into a position closing said ports under the influence of the centrifugal force generated by rotation of said housing, a coil spring normally biasing each floating ring into a position leaving said ports open, a second cam slidably mounted on said drive shaft in engagement with said first cam to move it off-center relative to said drive shaft so as to initiate reciprocation of said pistons through the driving force of said drive shaft, and a pair of spring-biased Weights in diametrically opposed relationship operatively connected to said second cam and adapted to activate movement of said cam to force the said first cam off-center under the influence of the centrifugal force of rotations of said housing, the said weights beingreciprocally mounted in vented cylinders carried by said housing.

References Citedin the file of this patent UNITED STATES PATENTS 1,261,287 Postell et a1 Apr. 2, 1918 1,519,957 Corneil Dec. 16, 1924 2,539,872 Sprague Jan. 30, 1951 2,592,015 Dionigi Apr. 8, 1952 FOREIGN PATENTS 352,622 Great Britain July 16, 1931

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