US2008535A - Timing control for hydraulic power transmission - Google Patents

Description

July 1e, 1935. n. E. WINKLER 2,008,535

TIMING CONTROL 'FOR HYDRAULIC POWER TRANSMISSION Filed Aug. l1,v 193.3

4 ATTORNEYS.

Patented July 16, 1935 UNITED STTEs TIMING CONTROL FOR HYDRAULIC POWER TRANSMISSIGN Herman Winkler, Indianapolis, Ind., assigner to Schwitzer-Cummins Company, Indianapolis,

Ind., a corporation Application-August lll, 1933, Serial No. 684,679

2 (Claims.

This invention relates to a timing control for a hydraulic power transmission of the character set forth and disclosed in the co-pending application of Carl J. Winkler and Herman E. Win- 53 kler, Serial No. 648,229, filed December 2l, 1932,

entitled .Hydraulic power transmission and timing control therefor.

The power transmission above referred to is the type particularly adaptable for operating the l@ feed for furnace stokers employing a housing containing a quantity of oil or similar fluid which is pumped by a motor driven pump into a cylinder for forcing a piston through a power stroke to aetuate the stoker feed.

It is desirable in suchpower transmissions, and particularly in stokers, that the speed at which fuel is fed to a furnace be variable so that the pounds of fuel fed per hour may be controlled, depending upon heat requirements.

The object of this invention is to provide a simple manually adjustable timing control which will accomplish the same result in a hydraulic power transmission as a variable speed control in a gear transmission. The ultimate purpose gg.; thereof is to control the timing of the power stroke of the piston. Thus, when it is desired to feed a greater quantity of fuel, the timing is set whereby the speed of movement of the power stroke of the piston will be increased, thereby 3@ decreasing the time interval. When it is desired to feed a lesser quantity of fuel, the movement of the piston through its power stroke iscaused to slow up so as to take a longer period of time to travel and increase the time interval. Thus,

35 the control will vary the operation of the transmission from the slowly moving piston to a rapidly moving piston through the travel of the power stroke. This is the equivalent of the variable speed transmission of the gear type.

The above is accomplished by providing a variable capacity pump, illustrated herein as comprising an adjusable by-pass associated with the fluid pump in such manner that it will control the rate of discharge of fluid into the cylinder 45 and, therefore, the rate at which the piston is caused to move through its power stroke.

The full nature of the invention will be understood from the accompanying drawing and the following description and claims:

In the drawing, Fig. 1 is a vertical section through a hydraulic power transmission embodying the invention. Fig. 2 Yis an enlarged section through the pump and fluid control valve on the line 2--2 of Fig. 4. Fig. 3 is a horizontal section 55 through the fiuid pump and cylinder. Fig. 4

is a section taken on the line t-tl of Fig. 3. Fig. 5 is a section taken on the line @-5, of Fig. 2.

In the drawing there is illustrated a housing l@ in which the mechanism is enclosed and supported. Mounted thereon there is illustrated an 5 electric motor ll having a pulley l2 driving a pulley lt through a belt M. rlhe pulley itis keyed to the drive shaft i3 mounted in an elongated bearing it having an intermediate oil reservoirl'l. Keyed to the shaft lf there is an eccentrically-mounted hydraulic pump head or disk i3 rotated in an annular chamber l0. Associated therewith there is a cylinder in vwhich the piston 2l is adapted to reciprocate, said cylinder being open at its forward end and closed at its rear end.

As illustrated in Fig. 3, the chamber i9 is closed by a rotatable and pivotally-mounted bypass control disk 22 having an operative handle 23. Said disk'is mounted and rotatable within the head 2li which provides a supporting plate for the pump and cylinder as well as a closure therefor. As illustrated in Fig. 4, there isvan oil intake passage 25 connected with the chamber lil, said passage communicating with the intake pipe 2@ which extends to the bottom of the housing. An exhaust or discharge passage 2l having a check valve therein is likewise formed in said head leading from the chamber i9 into the recessed portion 28 formed in the head 24 and communicating with the interior of the cylinder 20. Slidably mounted in a suitable recess formed in said head there is an abutment 29 which ismaintained under pressure by a spring 30 against the peripheral surface of the pump head or disk I8 for preventing direct flow of the oil between the passages 25 and 21.

As illustrated in Fig. 1, the piston 2| is clo'sed at 4its forward end and carries thereon a roller 3l rotatably mounted on a pin 32 secured in the forwardly protruding ears 33. The upper ear is provided with a U-shaped extension 34 extending forwardly suflicient to clear the forward end of the cylinder when the piston is in retracted position and then extending rearwardly over the outer surface of the cylinder to support the camhead 35, said cam head moving back and forth with the movement of the piston and being so positioned as to engage in its reciprocating movementthe xed cam head 36 secured on top of the cylinder in its path of movement, thereby imparting an oscillatory rotary motion to the piston.

The cylinder is provided with a main exhaust port 37 while the piston is provided with an exhaust port in the form of an elongated slot 33 extending at an angle to its axis. Said slot is provided with a narrow neck portion, as illustrated in Fig. 3. which serves to retard the return movement of the piston after it has completed its power stroke by restricting the exhaust after the initial return movement throughout the distance of travel of the piston corresponding with the length of the reduced neck portion. This serves in the same capacity as the restricted auxiliary port, hereinafter described, which may or may not be eliminated in view thereof, depending on whether or not adjustment is desirable, the principal purpose of the restricted portion of the exhaust slot being to eliminate noise and wear which would otherwise result from a sudden engagement of the control elements, of the piston.

The disk-control valve 22 is provided with an exhaust port l0 which communicates with an annular peripheral groove All extending thereabout by means of the passage 42. The port fl@ is in communication with the chamber |19 adjacent the periphery thereof, whereby upon rotation of the control valve by the handle 23 the port 40 may be positioned at varying distances from the discharge passage 2l. groove 4l which communicates through the exhaust port l0 with the chamber i9 is in direct communication with the intake passage 25 through the passage 43 formed in the head 211.

At one side of the cylinder 20 there is a boss having an auxiliary exhaust port 44 extending therethrough with which a corresponding port 45 in the piston is adapted to register. Connected with the port 44 there is a valve head 4E provided with an adjustable control valve 4l. The valve head discharges oil into the'oil reservoir i'l for lubricating the pump shaft bearing. This auxiliary exhaust port and the control valve fil further acts to control the initial return movement of the piston, as will be hereinafter more specifically described.

A curved power transmitting lever 52 is pivotally mounted upon the driven shaft 53. Keyed to said shaft there is a ratchet wheel 58. The upper end of said power transmitting lever 52 is provided with a flanged roller 59 adapted to engage the rollers 3l on the piston. Pivotally mounted on the lever intermediate the ends thereof there is a pawl El) adapted to engage the ratchet 58 for rotating the same counterclockwise upon the roller end of the lever 52 being moved forwardly or to the left. Connected with said lever through the arm 6I there is a spring 63 which acts to force the piston rearwardly on the exhaust stroke under spring tenl sion upon registry of the exhaust ports.

It will be noted from the position of the rollers 3i and 59 that whereas the cams 35 and 36 will oscillate the piston so that the rollers 3| carried thereby will extend at an angle relative to the roller 59, the rollers 3l will at al1 times seek a central vertical position under tension of the spring 63, which action will cause the cam 35 carried by the piston to be thrownl to one side of the cam 36 during the power stroke and to the opposite side thereof during the exhaust stroke, as more specifically set forth and described in the above-mentioned co-pending application. This oscillatory movement of the piston caused by the actions of the cams under the influence of the rollers and the spring 63 opens and closes both the principal and auxiliary exhaust ports.

In operation, the motor will cause oil to be The peripheral pumped to the cylinder through the effective portion of the chamber i9. The eective portion of said chamber will regulate the volume of oil pumped to the cylinder upon each revolution of the pump which in turn controls the rate of flow of oil for acting uponv the piston. Thus, the speed at which the piston is moved through the power stroke, or the time required for the power stroke, is dependent upon the effective area of the chamber i3.

The disk valve 22 controls the effective area and may be adjusted to any desired position by the hand lever 23 positioned exteriorly of the housing l5. The effective area of the chamber corresponds with the position of the port 4U. 'lIt l is increased upon being moved away from the disnot be effective until the port has been closed by rotation of the pump, the oil in the remaining area of the chamber then being forced into the cylinder. variable quantities of oil will be discharged into the cylinder upon each revolution of the pump so that the speed at which the piston moves in its power stroke, and consequently the duration of time of its movement may be controlled; This, in turn, controls the pounds of fuel per hour delivered to the furnace when applied to the Stoker.

The initial exhaust stroke of the piston occurs upon registry of the auxiliary exhaust ports 44 and l5 through the medium of the spring 63. This occurs when the piston is oscillated in the proper direction by the engagement of the cam 35 with the cam 36 during the forward movement of the piston. During such forward movement, the cam 35 rides to one side of the cam 36 so as to maintain the exhaust port 38 out of registry with the exhaust port 3'1, and the exhaust port 44 out of registry with the exhaust port 45, but as soon as the forward movementof the piston causes the cam 35 to pass the cam 36, the rollers 3l and 59 will return the piston to normal position, bringing the auxiliary exhaust ports 44 and 45 into registry. This has the effect of releasing the pressure on the piston and permit it to slowly retract under pressure of the spring 63, its return movement being controlled by the valve 41 so as to gently and without noise bring the cam 35 into engagement with the cam 36. The main exhaust port 38 then registers with the exhaust 4port 31 so as to permit free discharge of the oil and the rapid return stroke of the piston.

The invention claimed is:

1. A uid pump comprising a drive shaft, an annular chamber having an annular rotating piston mounted on said shaft eccentrically of said chamber, means for rotating said shaft and piston to draw fluid into said chamber through an inlet port and force the same therefrom through a discharge port, a disk pivoted adjacent said chamber and the face of said piston having a by-pass port therein communicating with said chamber adjacent the periphery thereof, said disk having an annular groove extending about the periphery thereof communicating with said by-pass port Thus, by manipulating the handle 23 and the inlet port of said chamber, and meansv for rotating said disk to move said by-pass port to varying positions for by-passing a variable portion of the fluid from the pump chamber to the inlet port.

2. A fluid pump comprising a drive shaft, an annular chamber having an annular rotating piston mounted on said shaft eccentrically of said chamber, means for rotating said shaft and piston to draw fluid into said chamber through the inlet port and force the same therefrom through a discharge port, a disc rotatably journaled adjacent said chamber and substantially coextensive therewith incross sectional area, the face of said disc having a by-pass port therein communicating with said chamber adjacent the periphery thereof, and means for rotating said disc to move said by-pass port to varying/positions about the said chamber adjacent its periphery for by-passing a variable portion of the fluid therefrom'.

HERMAN E. WINKLER.

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