US2335048A - Mechanism for the interconversion of reciprocation and rotation - Google Patents

Description

Nov. 23, 1943. A. FEROY MECHANISM FOR THE 'INTERCONVERSION OF RECIPROCATION AND ROTATION Filed April 1, 1942 Arr/vs Ii -Roy Patented Nov. 23, 1943 MECHANISM FOR THE INTERCONVERSION OF RECIPROCATION AND ROTATION Arne Feroy, Hamilton, Ohio, assignor to General Machinery Corporation, Hamilton, Ohio, a corporation of Delaware Application April 1, 1942, Serial No. 437,160

" 7 Claims; (01. 74-60) This invention relates to mechanism for the interconversion of reciprocation and rotation for engines, pumps, and compressors of the class having cylinders parallel to the shaft, the class commonly called barrel type, axial, round, or circle mechanisms. The object of the invention is to provide an improved circle engine mechanism.

The reciprocating members in circle mechanisms, ordinarily more comprehensive than simple pistons, each comprising a crosshead portion and one or two piston portions, are conveniently called recipers. Of the several mechanisms for operably connecting the recipers to the shaft in circle mechanismathisinvention is concerned with that type having a plate structure, commonly called a Wabbler or preferably a rocker, mounted on bearings on and inclined to the shaft. An object of this invention is to provide improved rocker bearing construction.

In the preferred rocker mechanism, the operable connection between each reciper and the rocker comprises a Wristpin with its axis always substantially tangent to a circle coaxial With and in the mid-plane of the rocker, and a pinhead engaging the wristpin and operable in a cylindrical bore thru the crosshead portion of the reciper, the axis of the bore being substantially radial to the shaft. As usually built, the central portion of the wristpin is received in a bore thru the rocker arm while the ends of the pin are received in similar bores in the bosses of the pinhead, the construction of the arm, wristpin, and pinhead resembling that of a connetcing rod, Wristpin, and trunk piston respectively in a crank mechanism. The wristpin is thus subjected to beam loading, and the pinhead cannot be of especially rigid construction, tending to distort under load. An object of this invention is to provide a solidconstruction for the rocker arm joint, a construction which avoids beam loading on the wristpin or distortion of the pinhead byproviding solid backing for the bearing areas of both wristpin and pinhead. Other objects areto provide larger wristpin bearingarea, and to efiectively fill the mid-plane of the pinhead with the wristpin so that by capping the outer end of the pinhead, a chamber may be formed for use in circulating oil to the pistons from within the rocker. Other objects are to provide a construction with which the wristpin and pinhead are more easily removable, permitting improved accessibility tothe various parts of the. mechanism; and to provide improved means for locking the wristpin to the rocker arm. V 1

These and other objects of the invention will be more clearly understood fromlthe following description in connection with the drawing in which: Fig. 1 is a longitudinal section of a portion of a rocker mechanism; Fig. 2 is a top or radial view partly in section taken on the line 2-2 of Fig. 1; Fig. 3 is a transverse View, partly in section, taken substantially on the line 33 of Fig. 1; and Fig.4 is a transverse section of the crosshead only, taken on the line 4-4 of Fig-2.

Referring to the drawing, shaft 20 is understood to be mounted in bearings in the fixed parts of the machine as usual, altho the fixed parts, not being involved in the invention, are not shown. Swashplate or slant 2| is fastened to shaft 2|! by bolts 22. Rocker 30 is mounted on journal bearing 32 operable uponjournal 23, the axial thrust on rocker 30 being taken by slipper bearings 33 inserted between the rocker 30 and the plane face of'slant 2|. Slippers 33 are prevented from sliding relative to rocker 30 by stop 43. Keeper ring 34, attached to rocker 30, can coact with the back face of slant 2| to prevent axial movement of rocker 30 away from slant 2|. Ring 34 also holds block 35 in place; block 35 plugs hole 36 which is provided for access to slippers 33.

Arm 38 of rocker 30 is faced off with two parallel plane faces and is essentially rectangular in section. Wristpin i!) is hollowed out to fit on arm 38 with a little freedom for axial adjustment relative thereto. Wristpin 40 may be clamped securely to rocker arm 38 by hollow screw 31. The ends of wristpin 40 are capped by spherical caps 4| held in place by screws 42.

Wristpin 40 is operable in a cylindrical bore thru pinhead 50 which is similarly operable in another cylindrical bore in crosshead the two boreshaving axes normal to each other. Pinhead 50 is essentially cylindrical in form, with a cylindrical hole transversely thru it. Pinhead 59 together with wristpin 40 form a zone of solid metal substantially filling the bore thru crosshead 60, as shown in Fig. 2, supporting the bearing surfaces of both parts and maintaining them free from distortion under load. This zone of metalalso forms one wall of chamber 5! the other wall being closed by pinhead cover 5|. Chamber 59 serves as a passage for oil flowing fromwithin rocker 30 into the reciper.

Caps 4| of wristpin 40 are formed as portions of a sphere centered at the center of wristpin 40. As is well-known, the correct motion of rocker 30 is that in which the center of wristpin 40 travels about a small circle in end view (Figs.

. .3 and 4), and caps 4| can coact with the sphere oidal surfaces M of crosshead 651 to assist in maintaining correct movement of the rocker 3ll.

Crosshead 60 is bolted to piston head with piston skirt ll clamped between them. Bolts 16 pass thru holes in the bore in which pinhead 50 operates, and are drawn up by nuts 61, as shown in Figs. 2 and 4. operate in'a crosshead guide, and piston 10, in a cylinder coaxial with the crosshead guide, these and the other fixed parts being omitted from the drawing for the sake of clearness.

During assembly, the effectivelength of wristpin 48 may be adjusted by shimming caps, and the position of wristpin 40 relative to rocker arm 38 may be shifted axially of the wristpin to accommodat any errors in indexing of the several cylinders or crosshead guides and the corresponding rocker arms 38. When wristpins 40 are properly set, they may be locked by screws 31. For accessibility to the rocker bearings and other parts, removal of screw 3'! permits the removal of wristpin, til and pinhead 50, after which ring 34 may be backer off, blockv removed, and slippers 33 removed. thru hole 36. Nuts 61 may also be removed and crosshead 60 separated from piston 16 and skirt II. If rocker journal bearing 32 weremade in three parts bolted or clamped in place as indicated in Fig. 1, these parts could also be readily replaced.

In operation, from the bottom. center position in which the mechanism is illustrated in Fig. 1, it is evident that, with rotation of shaft 20 and slant 2|,rocker 3!] would swing to the left, the center of wristpin 49] following a spherical lemniscate or figure-8" which, ,in end View, appears circular so that caps 4| wipe across surfaces EI in crosshead 60. (The center of wristpin in Fig. 3 is shown at the high point of the little circle about which it rotates, with the ends of the wristpin equidistant from the two surfaces 6!.) Piston thrust is transmitted thru solid metal of pinhead. directly to the large and well-supported wristpin bearing area, from which the load passes on, again thru solid metal, to rocker arm 38. There is no beam loading or. bending of the wristpin and all bearing. areas are well-supported to avoid distortion.

With single-ended recipers of the type illustrated, the piston thrust is largely uni-directional, so that the thrust of rocker 30 can be carried on a single set of slipper bearings 33,'pivoted on rocker 3i], and operable with film lubrication on the face of slant 2|. Keeper ring 34 serves to prevent movement of rocker 30 away from slant 2| when starting the mechanism or in case the pressure in the cylinders should b released. Since the piston thrust is uni-directional, rocker arm 33' and screw 31 may be offset somewhat from the axis of wristpin M], to'permit the wristpin bearing area on the loaded side of the pin to be increased.

If the reciper were double-ended'with piston portions at both ends, the construction of. the

wristpin joint would be symmetrical, and two sets of slipper bearings might be used to carry thrust equally well in either direction- During operation, oil is fed under pressure thru interior 26 of shaft 20, and annular chamber 28, into clearance 25) inthe corner of slant 2!, from which it can lubricate journal bearing 32 and slippers 33 with flooded lubrication. Oil flows also into theinterior of rocker 30, and outwardly thru holes 39in screw 37 into each chamber 59,

thence into. chamberBi} in. crossheadfit'. During Crosshead is adapted to- I said pinhead.

the bottom center part of reciper travel, inertia forces tend to prevent oil flow toward piston Ill, so it can gather in chamber 69, until inertia forces reverse during the top center part of reciper travel, when the oil in chamber 69 may be driven thru passage 18 into chamber 12 in piston 10, where it'may serve to cool piston 10. This flow of oil thru passage 18 from chamber 69 is facilitated by vent 13 from annular chamber M, which is vented to the outside thru passage 11. When inertia forces reverse again, oil in piston chamber 12, except that standing behind the annular wall and next to the ring zone, may be thrown out thru passage 19, facilitated'by vent 15 opening from chamber 14. In this way, positive circulation of cooling oil may be insured to piston,'l0, without building up excessive pressures from inertia forces on a column of oil of considerable length and without difficulty from water hammer. From passage 19, the oil is thrown out into the rocker casing and returned to the reservoir and pump. The structure which enables positive circulation of cooling oil by the utilization of the natural forces involved has been made the subject of my divisional application, Serial No. 463,848.

From the foregoing description, it is clear that the objects of the invention as stated have been attained, and a sturdy construction provided for a rocker mechanism. While a specific construction has been described and illustrated, it is understood that changes may be made in the construction and in the arrangement of the various parts without departing from the spirit or scope of the invention as expressed in the following claims.

1. In a rocker mechanism, a shaft capable of rotation, reciprocating members comprising crosshead and: piston portions, and means operably connecting said crosshead portions with said shaft and'comprising a rocker operably mounted on said shaft andinclined thereto, arms on said rocker substantially radial thereto, a wristpin hollowed out to fit over the end of said arm with the axis of said pin held substantially tangent to a circle concentric with and in the mid-plane of said rocker, means for fastening said wristpin to said arm, a pinhead operable upon said wristpin, and a cylindrical bore in each of said crosshead portions and operably receiving said pinhead.

2. In a rocker mechanism, a shaft capable of rotation reciprocating members comprising crosshead and piston portions, and means operably connecting said crosshead portions with said shaft and comprising a rocker operably mounted on said shaft and inclined thereto, arms on said rocker substantially radial thereto, a pair of plane faces on each of said arms and substantially parallel to the mid-plane of said rocker, a wristpin hollowed out and having internal plane faces engaging said plane faces of said rocker arm, means for holding said-wristpin in position upon saidrocker arm, a pinheadoperable. upon said wristpin, and a cylindrical bore in each, of operably receiving said crosshead portions and 3. Inmechanism of the class described; in combination, a shaft, reciprocating members operable parallel to said shaft,imechanism' operably connecting said reciprocating members to said shaft and including a rocker, and means for operably. mounting said rocker on said shaft with the axis of said rocker inclined'to. the axis of said shaft, said means comprising a slant member fastened on said shaft, a journal formed on said slant member, thrust faces on said slant member, a journal bearing on said rocker and engaging said journal, slippers supported on said rocker and operably engaging one of said thrust faces of said slant member, and means on said rocker operably engaging the other of said thrust faces to prevent the movement of said rocker away from said slant member.

4. Structure as claimed in claim 3, in which said last-named means comprises a ring fastened to said rocker.

5. In mechanism of the class described, in combination, a shaft, reciprocating members operable parallel to said shaft, mechanism operably connecting said reciprocating members to said shaft and including a rocker, and means for operably mounting said rocker on said shaft with the axis of said rocker inclined to the axis of said shaft, said means comprising a slant member fastened on said shaft, a journal formed on said slant member and a journal bearing on said rocker engaging said journal and substantially symmetrical relative to the midlane of said rocker, thrust faces on said slant member at one end of said journal, slippers supported on said rocker and operably engaging one of said thrust faces, and means fastened to said rocker operably engaging the other of said thrust faces to prevent movement of said rocker away from said slant member,

6. In mechanism of the class described, in combination, a shaft, reciprocating members operable parallel to said shaft, mechanism operably connecting said reciprocating members to said shaft and including a rocker, and means for operably mounting said rocker on said shaft with the axis of said rocker inclined to the axis of said shaft, said means comprising a slant member fastened on said shaft, a journal formed on said slant member and journal bearing means engaging said journal and secured to said rocker and removable from one end of said journal, thrust faces on said slant member at the other end of said journal, slippers supported on said rocker and operably engaging one of said thrust faces, means fastened o said rocker and operably engaging the other of said thrust faces preventing the movement of said rocker away from said slant member, and means removable from said rocker to permit easy removal and replacement of said slippers.

7. In mechanism of the class described, a shaft, reciprocating members operable parallel to said shaft, mechanism operably connecting said reciprocating members to said shaft and including a rocker, arms on said rocker, a Wristpin on each of said arms, a pinhead operably connecting said reciprocating member and said Wristpin, and means for removably securing said Wristpin and pinhead in position upon said arm; in combination with means for operably mounting said rocker on said shaft with the axis of said rocker inclined to the axis of said shaft, said means comprising a slant member fastened to said shaft, a journal formed on said slant member and a journal bearing on said rocker and operably engaging said journal, thrust faces on said slant member, slippers supported on said rocker and operably engaging one of said thrust faces, means on said rocker operably engaging the other of said thrust faces, a hole in the rim of said rocker, and means removable after the removal of said wristpin and pinhead from said rocker arm and per-- mitting removal and replacement of said slippers thru said hole.

ARNE FEROY.

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