US1496432A - Compressor valve - Google Patents

Description

v COMPRESSOR VALVE Filed DSC. 27 921 Umm@ www MM @@MM w M y Patented dune 3, 1224..

sraras WALTER W, ROBNSQN, 0F BELOET, WISCDNSIN, SSXGNGR OF @RE-HALF T0 BENJA- MXN F. LYUNS, 0F BELOIT, W'lISCONSIN.

rarer coinrnnsson venire.

Application tiled 'December 27, 1921. Serial No 524,919.

To all whom t may concern.'

Be it known that l, WALTER W. ROBINSON, a citizen of the United States, residing at Beloit, Rock County, Wisconsin, have invented certain new and useful lmprovements in Compressor Valves, of which the following is a speciication.

The present improvements relate to fluidcompressor construction involving valve means for the passage of the duid from one side of a reciprocating piston to the other, and thence away from the device. @ne object is to provide means for mechanically and positively opening and maintaining open 'throughout a desired interval in the cycle of. operations a valve in the piston lwhereby the fluid may pass freely from one specific object is to obtain such advantages according to simple means.

With respect to the outlet valve and cylinder head construction andy arrangement herein illustrated and described the chief object is to provide a simple form of construction in which the outlet valve elements may be positioned in a predetermined relative location with respect to the cylinder walls, for instance so as to lie very close to the piston end at the end of its stroke, and be maintained in the desired position regardless of the thickness of packing between the cylinder head and cylinder walls, without prejudice to the easy accessibility and removability of the exhaust valve parts as may be desired. 4

In the accompanying drawings, which form a part of this specification, Figure 1 is a medial vertical section through a compresser having these improvements embodied therein; Figs. 2, 3 and 4 are horizon- -tal sections on the lines 2-2, 3-3 and lrt respectively of Fig. 1; and Fig. 5 isa fragmentary -sectional view similar to that of Fig. l showing moving parts in various positions; j

. These improvements are of importance in compressors suitable for the circulation of a refrigerating medium in a retrigerating system, and the accompanying drawings killustrate a compressor adapted to suh use.

The compressor shown includes a crank shaft casing 10 having an inlet 11 for the refrigerating medium, cylinder walls 12, a cylinder head 13 held as bv screws 14 upon the end of the `cylinder walls, and a crank shaft 15 having a crank arm lf3-on which is mounted the pitmanv 17, the otherend ot the pitman being pivoted upon 'the pin 18 held between opposite walls ot 'the hollow piston 19, the rotation of the crank shaft 15, as by a motor or any other approved means providing the usual reciprocating motion of the pitman and piston. l

The upper end of the piston has a top wall provided with a plurality of {fluid-passageway openings 20 therethrough, these openings entering a recess or chamber 21 surrounded by an annular surface 22, the edge of which forms a seat tor the llat disclike valve 23, this valve having an integral stem member 24 loosely positioned 'for sliding movement in a hole on the axis of the piston.

A leaf spring 25 held by the nut 26 and resting at its-ends against a wall formed by opposite openings 27 in the piston maintains the valve 23 upon its seat except when it is mechanically moved away therefrom.

A lever 30'shown as a lat bar inserted through one of the openings 27 and resting against the bottom walls respectively thereof has overlying it a leaf spring 31 resting at its ends on the bar or lever 30 and is bowedv away therefrom in the middle, the middle part contacting the end of the stem 24. A cotterpin 32 holds the lever 30 and springs 31 loosely at one end upon the piston wliereby the other end of the lever 30 and spring 31 may move upward and downward.

Substantially at right angles to the effective direction of the pitman 17 and adjacent to its pivotal connection to the pin 18 is the projection 34 which constitutes a lever and forms a bearing for the rod or pushingelement 35 which is held to the projection by a pin 36 for slight rocking movement. The rod 35 has an adjustable head 37 adapted to engage the under side of the plate or lever- 30, this lever 30 and the spring 31 each having a hole whereby the end of the ro'd 35 may project through these parts loosely and be thereby held in its operative position.

'llhe pitman 17, since it is operated by a crank shaft, has not only a stroke movement which provides a reciprocating stroke movement for the piston, but it necessarily has also a sidewise or rocking movement, and since the projection 34 forms with the pitman 17 a simple substantially right-angled bell crank the sidewise rocking movement of the pitman causes an up-and-down movement of the pin 36' and push rod or pressure-transmitting element 35.

Figure 1 represents the piston in substantially its lowermost position and the pitman is almost at the end of its down stroke, being only slightly to the right of the dead center between the axes ofparts 15 and 18. ln this position the valve 23 is shown as closed, and it is to be assumed that it has just closed when the pitman is in the relative position shown in Fig. 1. The further movement of the lower end oi. the pitman to the left as viewed in Fig. 1 will simply draw the head 37 of the push rod farther away from the lever 30, and this will continue until the pitman has reached its extreme movement to the left as viewed in Fig. 1. Thence, as the lower end of the pitman moves toward the right, the head 37 will move again toward the lever 30, and the head 37 will continue to move upward so long as the lower end of the pitman moves from left to right.. The head 37 is so adjusted with respect to its associated lever 30 that in its upward movement it will not engage the lever to move it upward until after the piston has reached the extreme upward limit of its stroke, or, in other words luntil after the lower end of the pitman has passed the upper dead center, or into the relative position illustrated in full lines in Fig. 5,'in which position the head 37 is again shown as being in contact with the lever 30 and in which position it is to be assumed that contact has just been made to push the lever 30 upward. As

the lower end of the pitman continues to thel right as viewed in Figs. land 5 its sidewise or rocking movement lifts the plate 30 more and more, the piston and pitman descending the While. The upward movement of the lever 30 first attens the spring 31 and then exerts a push upon the stem 24 and thus raises the valve 23 away from its seat and allows the fluid in the crank shaft housing and lower part of the piston (being the lowpressure side of the cylinder) to flow through the openings 2() of the piston into 'the upper or high-pressure side. After the lower end of the pitman has moved as Jfar to the right as possible, its succeeding movement to the lett causes the push rod 35 to descend and the valve 23 gradually to move toward its seat until the relative positions shown in Fig. 1 are again reached, when the valve .23 closed.

According te the construction and arrangement described the valve 23 is mechanically opened on the down stroke of the piston as the device'is illustrated, and is maintained closed on the up stroke, the high pressure side receiving fluid on the ldown stroke, the piston putting it under compression and forcing it out ot' the cylinder on the upstroke.

The spring 31 between the valve stem 24 and the lever 30 not only acts to soften the impact of the parts receiving the pushing pressure of the rod 35 but, importantly, it provides take-up means for establishing and maintaining -the proper relationship ol the several parts without a fitting adjustment, both initially and from time to time, as when the valve and its seat are ground together. The screw driver slot 38 in the valve 23 is provided for such grinding purposes. With successive grindings the end of the stem 24 may come materially closer to the leve-r 30, but this di'erence is taken up by the spring 31 without any adjustment between those parts. The opening and closing of the valve 23 may be' timed by adjusting the hea-d 37 on the push rod.

Referring to the upper part of Fig. 1 and Fig 2, the cylinder walls are recessed at 40 providing an annular seat at 41 to receive the lring-like element 42 having a rightangularly-disposed ring-like seat part or flange 43 defining a passage-way opening 44, the disc-like valve 45 resting on the seat provided by the ring or flange 43. A circular flat plate 46 rests upon an annular shoulder 47, the plate 46 having openings 48 along its marginal edge for the passage of fluid, the plate 46 also having an annular downwardly-disposed rib 49 against which presses the flat leaf spring 50, a washer 51 surrounding the valve stem 52 communicating the pressure of the spring 50 to the valve 45, a coiled spring 53 pressing against the top .of the plate 46 further serving to maintain the exhaust valve normally closed.

On the upward stroke of the piston the pressure of the fluid raises the valve 45 slightly against the pressure of the leaf spring 50, the fluid passing through the openings 48 and discharge orifice 54. 1t it should happen, as is frequently the case, that a quantity ot condensed gas in liquid formis forced into the compression cham-v ber, the pressure ot' the piston upon this solid mass will put the coiled spring 53 under compression, the valve 45 moving to a greater extent than otherwise and providing more space in the unper end of the cylinder for the fluid in liquid form and atl'ording a safeguard against damage to the machine by the presence ot an incompressible liquid mass.

A feature of notable importance in the construction and arrangement shown is in the provision et annular surface at i tion of the valve seat device to the cylinder -walls and piston end. This Irelative position is determined by the seat 41, which maintains the valve-seat device in its desired position independently of any packing, and the packing at 57 may bei greater or less without changing the relative position of the valveseat device. This is important Afrom various standpoints including this that the valve seat device may be positioned so close to the Yend of the piston on its u ward stroke that the highest eiiciency of t e device may be had, vand this efiiciency may be maintained without consideration of the thickness of the packing. v

From Fig. 1 it will be noted that the valve 23 on the piston will substantially fill the opening 44 of the valve seat device when the top surface 22 of the piston substantially comes into contact with the bottom surface of the Harige 43 of the valve-seat device. It is clear that if the valve-seat device rested upon packing instead of the firm shoulder 41 there would be 'danger' ofv breakage of parts if ther packing were not maintained sufiiciently thick to space the piston from the valve-seat device, 'and in practice heretofore in such devices there has always been provided a materially large space between the end of the piston and the discharge valve mechanism so as to-provide for variations in the thickness of the packing, thus reducing the eiiiciency of the device.

l contemplate as being Within the present improvements various changes, modifications and departures from what is herein speciically illustrated and described, as indicated in the appended claims.

l claim:

1. ln combination, a piston cylinder, a piston thereinhaving a valve for the passage of fluid from one side of the piston to the other `side thereof, a pitman pivotally mounted upon the piston, means for moving the pitman with a stroke movement and with a rocking movement, spring means for holding said valve in its normally closed position, and means under the control otV the rockingmovement of the pitman for opening said valve against the pressure! of said spring means Iand for relieving the pressure thereof to permit the valve to close under the pressure of said spring means.

2. In combination, a piston cylinder, a piston therein defining a high-pressure side and a low-pressure side of the cylinder, a

valve carried by said piston, the valve hav` ing a movement toward the high-pressure side to open the valve for the passage of fluid from the low-pressure side to the highpressure side, spring means for holding said valve in its normally closed position, a pitman having a stroke movement and a rocking movement pivotally connected to said piston on its low-pressure side, connecting means including a lever and acushioning spring therefor between said valve and said pitman and operated by the rocking movement of the' pitman for forcing the valve' open against the pressure of said spring means near the beginning of a piston stroke movement in the direction or the low-pressure side.

3. In combination, a cylinder, a piston therein, a pitman pivotally connected to the piston, the piston having an opening therethrough for the passage of liuid from one side of the piston to the other side thereof, a valve normally closing said opening, spring means for holding saidvalve in its normally closed position, a lever carried by the piston and operatively connected to the valve to open the valve when the lever is moved vin one-direction, and a valve pushing element operatively connected to the pitman adjacent to its pivotal connection to the piston and adapted to move said lever in only one direction and to open said valve onsuch movement, and to relieve the pressure of said spring means on the reverse movement of the piston to permit said spring means to close the valve.

4. In combination, a piston cylinder, a piston therein having a valve for the passage of fluid from one side of the piston to the other side thereof, a pitman pivotally connected to the piston, means for moving the pitman with-stroke movements and with .,sidewise rocking movements, a lever fulcrumed at one end at one side of the piston, pushing means including a connection on the pitman for moving the other end of said lever, a spring cushion operatively between said lever and 'said valve, and spring means for closing'said valve and moving said lever in return direction when the pitman moves with a stroke movement in a direction opposite to that oir which the valve is opened.

5. Outlet valve mechanism for compressors comprising in combination means y forming an annular valve seat surrounding a -relatively large discharge opening, a plate-like valve resting thereon, said valve having a central stem, a plate-like valve guide sea-ted at a fixed distance from said valve and being loosely mounted for movement in a direction away from said valve, said guide having discharge openings therethrough, said guide being loosely mounted on said stem, the movements of said valve being guided by said stem in said guide,

a relatively strong spring pressing said guide in a direction toward said valve, and a relatively Weak spring operatively between said guide and said valve, the arrangement being such that valve opening pressure upon said valve moves the valve iirst against the pressure of said relatively weak spring and greater pressure upon the valve moves the valve and said guide against the pressure of said relatively strong spring, and whereby said valve may tilt in response to unequal valve-opening pressure upon said valve.

6. In a compressor, the combination of a piston having a plate-like disc valve head on its inner surface outstanding substantially the thickness of the valve head from the Laaaesa i end surface of the piston, mechanically operated means for opening said valve'on the Suction stroke of the piston, outlet valve mechanism including a plate-like member having a fixed relation to the end of the piston stroke and having an opening there# in slightly larger than and registering With said disc-valve head and being so positioned that at the end of the piston` stroke said disc-like `valve headI is positioned in said opening,- a Valve covering said opening on the side thereof opposite the piston, and means including a spring for hplding said secondly-mentioned valve yieldingly in closing relation to said opening.

`WALTER W. ROBINSON.

Images