US2515933A - Reciprocating engine with start-run conditioning means - Google Patents

Description

Jilly 1950 I w. J. VAN HEECKEREN 2,515,933

RECIPROCATING ENGINE WITH START-RUN CONDI NING MEAN Filed Sept 7, 1945 MWWTOR WILLEM JAN VAN HEECKEREN ATTORA/f Y Patented July 18, 1950 UNITED STATES PAT NT oFFiCE intorelu'it iniri'Nor ENGINE WITH START-RUN CONDITIONING MEANS Willem J an van Heeckeren, Eindhoven, Netherlands, assignor tp liartford National Bank & Trust 06., Hartford, Conn., as trustee Application September 7, 1945, Serial No. 615,048 In the Netherlands November 9, 1943 Section 1, Public Law 690, August 8, 1946 Patent-expires November 9, 1963 air. These means are used very often for explosive and combustion type motors. It has already been proposed to start a hot gas engine by the gaseous pressure in one or more cylinders after the supply of heat has been turned on, and this pressure according to the thermodynamic cycle process to be traversed must exist in the cylinder in question at a momentary position of the working piston conducive to the transmit ting of torsional moments upon a crank shaft.

Inthe latter case as well as with starting by means of compressed air, for instance, the possi bility'of starting the engine depends, however, on at least one of the pistons occupying a position advantageous for starting. In the case of engines having three or more cylinders whose cranks are at an angle with one another which in the case of two-cylinder motors have their cranks about an angle of 90 to each other,- one of the working pistons practically always oc-- cupies' an advantageous position. one of the mentioned pistons is not in an advantageous position it must be brought into such a position before starting of the engine can'be initiated.

Therefore a principal object of the invention is to provide means to overcome the above problem.

However, if

' Another object of the invention is to provide start-run conditioning apparatus for hot gas ongines.

A further object of the invention is to pro-' V'lciev an ofi-deadmenter engine positioning device.

Other objects and advantages of this inven tion will be apparent from the description of the invention set forth hereinafter.

Fig. 1 shows a diagrammatic View in elevation o'f-one embodiment of this invention.

Fig. 2 shows a similar view of another embodiment of the invention omitting the engine mechanisfn; and

Fig. 3 shows a variation of the Fig. 2 embodiment.

Generally speaking this invention proposes to add to and. combine with the pistonand allied 2 parts of an engine such as a hot gas engine, aneccentric mass so oriented with the energy trans; fer elements therein such as piston means that the energy stored in this mass during engine operation will always carry the piston means .to the proper position for engine starting from an inactive state of the same and to further combine a movable weight with this mass in such an arrangement that the eccentric mass is balanced at a predetermined minimum speed of engine rotation associated with the lower limit of normal engine speeds. Stated more succinctly the invention contemplates a combined engine start conditioning mechanism and engine run-condi= tioning mechanism including a combined eccens tric mass and movable mass in one position with allied parts forming an embodiment for the first phase, the engine start-conditioning part of the inventive concept, and the eccentric mass with the movable weight in a second centrifugally generated position with allied parts forming the second phase, the engine run-conditioning part? of the inventive concept.

According to the invention, the new hot gas engine combination includes a crank shaft which at one side is made heavy in such. a manner that when the motor comes to rest, a position is reached where at least one of the movable sur faces in the motor cylinders coupled tothe crank shaft is subjected to the action of the variation in pressure resulting from a cyclic thermal proc ess thereby producing the desired direction of rotation of the engine and enlarging the space in which the thermodynamic cycle is performed; The above constitutes the first phase of the in: ventive concept. v l 7 When such an engine is at rest the increase of the gaseous pressure in the space in which the cyclic process is performed, as a rule the cylinder of the motor, will result in such a move= ment of the movable surfaces that the volume of this space is increased. Thus, the crank shaftis set into motion and the engine is started. This increase in pressure may be effected either by introducing a gas under pressure at regular inter:-

vals or by a single introduction of a quantity of gas, whereafter the thermodynamic cycle begins.

The heavy side of the crank shaft displaces the center of gravity of the crank shaft, together with the crank, the driving rod and the counter;- weights to outside the axis of revolution. With a slow-running motor this need not necessarily be objectionable. For fast riunning motors, how:- ever; it is advisable not to continue this. position dining operation in order to prevent the occurs rence of troublesome vibrations. According to the invention in this case the center of gravity above a definite speed of the crank shaft is brought into or as well as possible into the axis of revolution preferably by the arrangement of a separate mass capable of being displaced under the action of centrifugal force. This constitutes a second phase of the inventive concept.

In Order that the invention may be clearly understood and readily carried into effect, it will be described more fully by reference to the accompanying drawing.

In Fig. 1, showing an ofi-dead-center engine conditioning mechanism, reference numeral I6 denotes the cylinder of a hot-gas motor in which the piston I2 and the displacer I I move up and down. This cylinder I6 is surrounded by a heater I3, a regenerator M and a cooler I5. The drive for the displacer II is not shown further since the drive is not essential to an understanding of the present invention. The piston I2 is coupled in the usual manner to the crank I8 on the crank shaft I9 with the aid of a piston rod I6 and a driving rod II. For starting such a motor without utilizing hand drive or a separate auxiliary motor it is necessary that the piston I2 in the desired direction of rotation has just passed the upper dead position, or in other words that it is in the beginning of the expansion stroke. This advantageous position may be attained by stopping the motor in this position at the end of a working period with the aid of a weight secured to one side of the crank shaft I9. This separate weight 24 is secured to the crank shaft with respect to the crank or the cranks in such a manner that, when this Weight occupies the lowest position under the action of gravity, at least one of the pistons is in the beginning of the expansion stroke. However, since in normal operation all the rotary parts of the machine must be balanced this separate weight must be removed again or made up for as soon as the motor is started. The separate weight 24 is secured to the heavy wheel or flywheel 20 of the motor. Diametrically opposite thereto is arranged a second weight 2| which is pivoted in 22 on the said flywheel 29. These two weights or masses 2| and 24 are so arranged and of such masses that in the position of the weight 2| which is radially directed to the circumference of the flywheel the common center of gravity of the two weights lies exactly in the center of the crank shaft I9 after the engine attains a predetermined speed. Since with a rotating flywheel the weight 2| will occupy the above-mentioned position of its own accord under the action of centrifugal force, the balancing of the crank shaft together with *the associated parts is not disturbed by this weight when the motor is rotating. The movable weight 2| has, however, fastened to it a spring 23 which tends to move this weight toward the center line of the crank shaft I9 against the action of the centrifugal force. Below a definite rotational speed of the crank shaft I9 the force of this spring or confining means 23 will exceed the centrifugal force so that the weight 2| moves to or toward the center line of the crank shaft. The distance between the point of attachment of the spring 23 on the weight 2| and the journal 22 is made as small as is possible for reasons of constructional nature, in order practically to eliminate the weight action of the resilient means 23 upon the position of the weight 2| when the definite speed is exceeded. The common point of gravity of the two weights when unaffected by rotation thereof is displaced in the direction of the weight 24 so that the motor will at last be at rest with the weight 24 approximately in its lowest position. This corresponds to such a position of the crank that at least the piston I2 is in a position advantageous for starting.

The weight 2| which can turn about the journal or pivot means 22 serves not only for the above-described object but also as a damping member for the torsional vibrations which occur in the crank shaft due to the variable tangential force on the crank I8.

Fig. 2 shows another form of construction of a start run engine conditioning device in which for stopping in a definite position when the motor is rotating above a definite speed, a weight 25 is balanced by a slidable counterweightor mass 26. The heavy wheel 26 itself has provided on it two guides or confining means 21 between which the weight 26 can move radially. In the position of rest and at low speeds a spring-or confining means 28 which fits a cylindrical cavity 29 of the weight 26 forces this weight towards the hub of the heavy wheel 20. Above a definite engine speed the centrifugal force surpasses the resilient pressure of the spring 28 and in this case the weight 29 is pressed or confined against the outer edge of the fly wheel, thus exactly balancing the weight 25. 2

Fig. 3 shows a fly wheel 29 which, as is usual with comparatively heavy flywheels, is constituted of two parts. Two cavities or reservoirs 39 and 3| are recessed diametrically opposite each other in the casting. Furthermore, in side the rim of this fly wheel lies a closed tube or concentric channel 32 which by means of a short connecting piece 33 is in open communi-' cation with one of the recessed cavities 3|. The tube or connective channel 32 and the cavity 3| are jointly filled with an amount of liquidapproximately suflicient to fill the cavity 3|. A

cavity 30 opposite cavity 3| is filled up'with ablock of solid material whose weight is equal to that of the amount of liquid filling the cavity 3|. When the heavy wheel 20 is rotating'th'e cavity 3| is filled with liquid due to centrifugal force, so that the Weight of the filling material of the cavity 30 is balanced. When the speed of the fiy wheel decreases the liquid is distributed over the tube 32 so that the filled-up cavity 36- constitutes the heaviest point of the fiy wheel. a What I claim is: 1. In a reciprocating engine a positioning 'd'e vice comprising a piston, connecting rod means therefor, crank shaft means coupled'to the free end of said means, a heavy wheel attached' -to' said shaft means, an eccentrically located first fixed mass on said wheel, said first fixed mass being located on said wheel so that whensai'd' wheel is permitted to stop rotating, said wheel finally attains a position of rest due to said first fixed mass which causes said piston, through the mechanical linkage of said crankshaft and said connecting rod means, to assume a position favorable for re-starting said engine, a second separate movable mass normally unbalanced with said first mass and confining means on said wheel for said movable mass, said mass moving into a position of equilibrium with respect tosaid' first mass under a predetermined centrifugal force and moving out of said position of equilibrium when said predetermined centrifugal forceis not attained. 1

2. In a reciprocating engine a positioning de vice comprising a piston, connecting rod means therefor, crank shaft means coupled to the free end of said means, a heavy wheel attached to said shaft means, a weight means disposed from the center of said wheel, said weight means being located on said wheel so that when said wheel is permitted to stop rotating, said wheel finally attains a position of rest due to said weight means which causes said piston, through the mechanical linkage of said crankshaft and said connecting rod means, to assume a position favorable for re-starting said engine, a movable mass forming a part of said wheel, said mass taking up a position directly opposite said weight means and in balance therewith upon said wheel attaining a predetermined minimum rotational speed and means for returning said mass to an off-balanced location relative to said weight means at a wheel speed below said minimum speed.

3. In a reciprocating engine as claimed in claim 2 wherein said movable mass is pivotally coupled to said wheel.

4. In a reciprocating engine as claimed in claim 2 wherein said movable mass is slidably coupled to said wheel.

5. A two state mechanical energy storage device comprising a heavy wheel, a fixed weight eccentrically disposed on said wheel, pivot means positioned diametrically opposite the center of said weight, a second like weight on said pivot means, and resilient means attached to said second weight and said wheel yieldable under a predetermined centrifugal action applied to said second weight at a predetermined wheel speed I,

whereby said weights are balanced.

6. A start-run engine conditioning device comprising a heavy wheel, an eccentrically located weight attached thereto, a separate movable mass normally unbalanced with said weight and confining means for said mass on said wheel, said mass taking up a position with respect to said weight to counterbalance said weight at a predetermined centrifugal force imparted to said mass by the speed of rotation of said wheel caused by the running engine, said confining means including a resorvoir joined by a connective channel.

7. In combination an engine and a conditioning device therefor comprising piston means,

crank means connected to said piston and including a shaft, 2. heavy symmetrical mass surrounding said shaft, a first eccentric weight means on said symmetrical mass oriented with said piston means, so that upon rotational stoppage of said shaft and said symmetrical mass surrounding said shaft, said eccentric weight means causes said symmetrical mass and said shaft to assume a position which in turn through said crank means assures that said piston stops in a position favorable for r -starting said engine, a reservoir located diametrically opposite said eccentric weight means, a concentric channel joined to said reservoir, a movable mass substantially equal to said eccentric means normally confined within said channel, said movable mass assuming a position within said reservoir at the time a predetermined engine speed is attained, whereby a balanced engine condition is produced metrically opposite and assuming a position within said concentric channel at the time a predetermined engine speed is not attained whereby an unbalanced engine condition is produced.

8. In a reciprocating engine a positioning device comprising a piston, connecting rod means therefor, crank shaft means coupled to the free end of said means, a heavy wheel attached to said shaft means, an eccentrically located first mass on said wheel oriented with said piston, so that upon rotational stoppage of said shaft and said heavy wheel, said eccentrically located first mass causes said wheel and said draft to assume a position which in turn through said crankshaft means assures that said piston stops in a position favorabl for re-starting said engine, guide means having a longitudinal axis on a wheel diameter containing the center of gravity of said first mass, a movable second mass confined in said guide means, and resilient means within said guide means for forcing said second mass toward said first mass under all engine speeds below a predetermined normal, said guide means including a outer stop for said second mass, whereby a centrifugal force corresponding to a normal engine speed forces said second mass into balance with said first mass.

9. A reciprocating engine comprising a piston, a crankshaft, means connecting said piston to said crankshaft, a weight attached to said shaft in eccentric relationship thereto, the position of said weight being such that upon stoppage of said engine, said weight causes said crankshaft to turn to a position which in turn through said connecting means causes said piston to stop in a position of rest favorable for restarting, and a mass movably connected to said shaft and arranged to move to a location to counterbalance said eccentrically attached weight as soon as a predetermined speed of rotation of said crankshaft is reached.

10. A reciprocating engine according to claim 9 wherein said mass is hingedly mounted on a pivot connected to said crankshaft, and a spring attached to said mass and to attachment means connected to said crankshaft and arranged to bias said mass to an unbalancing location with respect to said weight when the speed of rotation of said crankshaft falls below said predetermined speed.

11. A reciprocating engine according to claim 9 wherein said mass is slidably coupled to said shaft.

12. A reciprocating engine according to claim 9, wherein there is afiywheel on said shaft, said flywheel having a concentric annular channel adapted to have a liquid mass therein and communicating with a widened cavity situated diasaid eccentrically located weight, said widened cavity being at a greater distance from the axis of said flywheel than said annular channel, whereby the liquid mass may flow to said cavity due to centrifugal force when said flywheel attains'a predetermined speed of rotation.

WIZLEM JAN VAN I-IEECKEREN.

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

UNITED STATES PATENTS Number Name Date 79,403 Smith June 30, 1868 203,623 Jay May 14, 1878 235,876 Fay Dec. 28, 1880 579,654 Roediger Mar. 30, 1897 2,002,561 Wike May 28, 1935 FOREIGN PATENTS Number Country Date 70,953 Austria Jan. 25, 1916

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