CA1231925A - Oil distribution system for a compressor - Google Patents

Abstract

ABSTRACT

In a refrigeration compressor having at least one piston-cylinder arrangement 36, 38 therein for compressing gaseous refrigerant, an elongated tube 58 extending upwardly from a lubricant passage 60 in the crankshaft 18 for slinging oil radially, outwardly therefrom, and a lubricant deflector 82 upstanding from the cylinder head 48 to deflect slung oil over exterior surfaces of the cylinder head for conducting heat energy therefrom.

Description

OII, DISTRIB~TION SYSTEM FOR A ~OMPRESSOR
This inventlon relates to hermetically sealed refrigeration compressors, and more particularly to an oil distribution system for such compressors adapted to conduct heat energy from the cylinder heads within the compressor housings.
In those refrigeration compressors utilizing a piston-cylinder arrangement for compression, the gaseous refrigerant becomes extremely hot upon compression and conducts heat energy to the cylinder and cylinder head, thereby increasing temperatures of the cylinder and cylinder head. These higher temper~
atures may cause lubricant to boil and lose its lubricating properties, which eventually results in carbon deposits forming on valves, valve seats, leaf plates and the like. The steady accumulation of such deposits will eventually destroy the integrity of the valve arrangement requiring shutdown of the compressor and replacemen-t of the defec-tive parts.
Generally, the cooling of the cylinder head i5 left to the suction inlet refrigerant that is delivered direct]y into the compressor housing. Although adequate to acceptably cool the cylinder head, higher compressor efficiencies are obtainable if the cylinder he~d is cooled even further.
The most relevant prior art of which applicants are aware is U.S. Patent No. 2,215,~45 issued to Money on August 2, 1938. Money has a short tube extending upwardly from the top opening of the oil passage in the crankshaft that serves to spray oil upon the top surfaces of compressor components. To insure that some o~ the oil will fall upon the outer ~ ~3~

surfaces of Lhe piston and cylincler to lubrica-te them. a baffle is connected to the tOp of the cylinder to deflect some of the sprayecl oil so that i-t may drip downward:ly onto the ou~er surfaces of the piston. rt appears that the majority of the oil which is sprayed over the baffle impacts the compressor housin~
to returrl to the oil sump in the bottom of the con~pressor. It should be noted that the baffle in the ~oney pa-tent is disposed on the most axially inwarclly~portion of the cylinder to insure deflection of oil to lubricate the pis-ton.
Other devices have been used to decrease the e~-tremely hi~h temperatures of the cylinder head~ for example. heat radlation fins disposed on -the cylinder head. which have been effective in various de~rees in lowerin~ the cylinder heaà temperature.
However. fur-ther cylincler head temperature reduction ls desirable ln order to lncrease compressor efficlency. prevent accum~llation of carbon depos:its on the va:Lve arran~emen-ts. and prolon~ -the life of parts such as bearings. insulation and the like.

One technic~ue for maintaining the àischarge valve -tempera-ture low enou~h to prevent an accumulatlon of carbon deposits ls to -transfer heat energy from -the cylinder head e~pedi-tiously.
This lnvention accomplishes such heat -transfer by batning the cylinder head with a flow of oil.

The present invention resides in a compressor which includes a hermetically sealed housing having a crankcase therein with the cylinders disposed in the crankcase and a sump in the botcom por-tion thereof. .~ crankshaft is rota-tably received in the crankcase and has a piston operably connected thereto and clisposecl in -the cylinder, The~e i3 provlded a cylinder head. and the cranksha~t has pumping means connected to its bottom portion and disposecl in the sump for .:
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pumping lubricant from the sump upwardly -through a lubricant passage in -the crankshaft. The crankshaft has means connected to its upper end for slin~incr lubrican-t radially ou-t:wardly there-from. and a lubricant deflector is provided which is in the form of means transversely upstanding from the cylinder head for directing a portion of -the slung lubricant to the cylinder head to conduc-t heat energy ~herefrom.

It can be seen that the present invention remedies the above clescribed problem of e.~-tremely high cylinder head -tempera-tures by providing an oil deflector on the cyiinder head~ wnich may be cast of aluminum, to direc-t slung oil to the cylinder head side and end e~terior surfaces to concluct heat therefrom. To ensure -tha-t a portion of -the slung oil collects and rlows downwardly over the end surfaces of the cylinder head the deflec~or may be provided wi-th at leas-t one opening therein -throu~h which some of the slung oil may pass.

The means ~hicll is provicled for slir-ging -the oil may be a generally elongated hollow body connected to the rotatable crankshaf-t and in eommunica-tiou wi-th the lubricant passage and having an opening throllgh which lubricant is radially thrown outwardly llpOII ro-tation of the c,rankshaf-t.

In a specific embodimen-t of the invention~ an opening is disposed -through the sit3e of the elonga-ted~ hollow body e~tend:ing upwardiy from the oil passage in the top o~ the erankshaft~ The hole may be disposed appro~imately level with the deflector on the cylinder head to provide a generally horizontal spray of oil -thereto upon rotation of t:he crankshclf-t~ ~~he position of the hole .ill the tube may be ~aried above the oil deflector to compensate for varyin~ centrifugal speeds antl angular adjustmellts of the elon~ateci~ hollow body.

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~ 'pon rotation of the crankshaft. a port.:ion of the oil pumpecl upwardly through the elongated bod,v is slurlg generally radially outwardl~ -through -the opening in -the sicle of the bocly. and. upon reaching the transversely disposed oil deflector on the cylinder head. deflec-ted by -the oil deflector to flow ovet the side and end exterior surfaces of the cylinder head to conducl heat therefrom.

It is an object of the present invention to provide sig-nificant additional cooling to the cyl:inder. and particularly to -the cylinder head. of a refrigera-tion connpressor. -thereby increasing the compressor's efficiency. preventing the ~remataure accumulation oE carbon deposi-ts on valve arrangements. and increasing the useful life of bearings. insulation and the like.

~ he above Inen-tionecl ancl other features ancl objects of this invention. and the manner of obtaining them will become more apparen-t and the invention i-tself will be better understood by referellce to the following description of an embodilnent of the invention taken in conjunction with -the accompany:ing drawings.
wherein:
Fig. 1 is a sec-tional view of Fig. 2 along line 1-1 and viewed in the direction of the arrows;
Fig. ~ is a broken-away, -top plan view of Fig. 1:
Fig. 3 is a broken-away. elevational view of the upper portion of a compressor viewecl from the lef-t side of Fig. 1:
Fig. 4 is an internal view of the cylinder head of the compressor;
Fig. o is a sectional view of Fig. -1 along line o-~ as viewed in the direction o~ the arrows: and ~rp~
~ ~ ' ~2;3~

Fig. 6 is a side elevational view of an oil tube disposed in the oil passage of a crankshaft.
Referrlng -to the drawings, and particularly Fig. 1, conventional compressor 8 comprises a lower housing 10 and upper housing 12, which may be welded or brazed at seam 14. Mounted wi-thin compressor 8 is crankcase 16 having crankshaft 18 rotatably received therethrough, and a motor 20 comprlsing rotor 22 secured to crankshaft 18 and sta-tor 24 with field windings 26.
The upper portion of crankshaft 18 has closed-loop end 28 of connecting rod 30 connected thereto and which has its opposite end connected by wrist pin 3~ and spring clip 3~ to piston 36 disposed in cylinder 38 of crankcase 16. C~linder 38 has connec-ted thereto gasket 40, leaf plate 42, valve plate 44, gasket 46, and cylinder head ~8 by four bolts 50 The piston- cylinder arrangement is dynamically balanced by counterweight 52 connected to crankshaft 18.
Disposed in lower housing 10, along with refriger-ant tubing 5'1, is oi.l pump 56 which is connected to the bottom end portion of crankshaft 18 in oil sump 58. Crankshaft 18 has axially disposed therein oil passage 60 and upper oil passage 62 for delivering oil to lubrica-te typical points, such as main bearing 64 and thrust bearing 66.
During operation, very high temperatures exist within compressor 8 causing the components therein, for example, motor 20, crankcase main bearing 64, crankshaft bearing 66, and mos-t particularly cylinder head 48 to become extremely hot, thereby re~uiring cooling.
Generally, the cooling of the above men-tioned parts is accomplished by oil pump 56 pumping oil from oil sump 58 upwardly through oil passage 60 to not only lubricate points, such as crankcase main bearing 64 and crankshaft bearing 66, but also to conduct heat energy from motor 20, crankcase main ~earing 6~1, crankshaft bearing 66, and other parts connected or in close proximity to crankshaft 18. Upon termination of its upward travel through oil passage 60 or upper oil passage 62, the oil is returned to oil sump 58 at very high temperatures, and, if not properly cooled, may prematurely lose its luhricating properties, thereby possibly resulting in the early fallure of wrist pin, bearings and the like.
A uni~ue means of cooling the oil is provided by oil slinger tube 68, which is fittecl in opening 63 of upper oil passage 62 in the top end of crankshaft 18.
In the present embodiment, slinger 68 is angu].arly disposed relative to the rotational axis of crankshaft 18. Slinger 68 is of a predetermined length for reasons which will be discussed below and has opening 70 disposed therein, which, as measured from the rotational axis of crankshaft 18, has an effective radius longer than the effective radius of crank-shaft 18.
The cooling of the oil takes place upon motor 20 being energized through conventional multi-pin terminal 72, which causes rotor 22 to rotate crank~
shaft 18 and oil pump 56. As the oil is pumped upwardly ~y oil pump 56 through oil passage 60 and upper oil passage 62, a portion o:E the oil will be urged upwardly through slinger 68 and opening 70 to be slung generally upwardly and radially outwardly against side surfaces 73 of upper housing 12.
Because both lower housing 10 and upper housing 12 are cooler than the oil, heat energy will be conducted from the oil to housings 10 and 12 thereby cooling the oil as it flows dow.nwardly to oil sump 58. To insure the oil being slung by slinger 68 does not impact top surfaces 75 of upper housing 12, and consequently drip downwardly upon compressor parts, such as discharge muffler cover 7~, suction muffler cover 76, and the other above mentioned parts, slinger 68 is made of a rigid material that allows it to be angularly oriented from the vertical to ~irect the spray of oil away from top surface 75 and toward side surfaces 73 of upper housing 12. Furthermore, should certain compressor parts be disposed above the top end of crankshaft 18, as illustrated in Fig. 1, slinger 68 may be manufactured having a predetermined length which will insure opening 70 being above such parts, thereby preventing the existence of any obstruction in the path of the oil being slunq by slinger 68.
To reiterate, slin~er 68, due to its angular orientation relative to the rotational axis of crankshaft 18 and the increased effective radius of opening 70, is able to sling the oil against the surfaces 73 of upper housing 12. In addition, slinger 6S is bent -to allow directional control of the spray path of the oil exiting opening 70 for various compressor models.

2~i It was earlier mentioned that cylinder head 48 experiences e~tremely high temperatures during the operation of compressor 8. This is primarily due to the temperature existing within the interior space of compressor 8 and the high temperatures produced within cylinder 38 upon compression of gaseous refrigerant. Conventional means to alleviate the extremely high temperatures experienced by cylinder head ~8 include disposing a plurality of fins 78 on cylinder head ~8 to conduct the heat energy thereErom to the interior space of compressor 8. In spite of this, cylinder head A8 may still remain at undesirable temperatures during the operation of compressor 8.
To reduce the temperature of cylinder head ~8, bleed holes 80 and 81 are disposed in the side of oil slinger tube 68, with hleed hole 80 facing radially outwardly therefrom. ~ecau~e slinger 68 rotates with crankshaft 18, hleed hole 80 will always rota-te facing towards upper housing 12. This permits a portion of the oil traveling upwardly through sllnger 68 to be sluny generally horizon-tally, radially outwardly through bleed hole 80. As slinger ~8 rotates past cylinder head '18, a spray of oil is slung from hleed h~le 80 onto cylinder head for cooling purposes. Little oil is slung from hole 81 since it faces radially inwardly towards the rotational axis of crankshaft 18. Hole 81 i5 present only because of manufacturing expediency.
To insure that a portion of the oil s~ung from bleed hole 80 flows over end portion ~9 of cylinder head ~8 and ribs 78 disposed thereon, a deflector and heat sink 82 having slots 8~1 disposed therein is transversely disposed on the top surface of cylinder head 48. Consequently, upon slinger 68 rotating past cylinder head 48 a portion of oil is caught by deflector 82 and caused to flow over the surfaces of cylinder head 48 adjacent valve plate 4~, while at the same time allowing a remaining portion of the oil to pass through slots 8~ and to flow over end portion 49 of cylinder head ~8 and ribs 78.
As illustrated in Figs. 1 and 5, deflector 82 is transversely disposed on the top surface portion of cylinder head 48 ad~acent gasket 46~ Deflector 82 could be disposed on the top surface of cylinder head 48 adjacent end portion 49, however, due to the small confines generally existing between cylinder head 48 and upper housing 12, it has been found that deflector 82 performs its desired function most effici~ntly when disposed ad~acent gasket ~6. Furthermore, deflector 8~ is of a predetermined height and de-sirably disposed away from housing 10 to allow for production tolerences.
While this invention has been described as having a specific embodiment, it will be understood that it is capable of further modification. This application is therefore intended to cover any variations, uses, or adaptations of the invention following the general principles thereof, and including such departures from the present disclosure as come within known or customary practice in the art to which this invention pertains and fall within the limits of the appended clalms.

Claims (10)

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1. In combination with a compressor including a hermetically sealed housing having a crankcase therein with a cylinder disposed in said crankcase and a sump in a bottom portion thereof, a crankshaft rotatably received in said crankcase and having a piston operably connected thereto and disposed in said cylinder, a cylinder head, said crankshaft having pump means connected to its bottom portion and disposed in said sump for pumping lubricant from said sump upwardly through a lubricant passage in said crankshaft, a lubricant distribution system comprising:
a generally elongated hollow body connected to said rotatable crankshaft and in communication with said lubricant passage and having an opening through which lubricant is radially thrown outwardly upon rotation of said crankshaft, and means transversely upstanding from said cylinder head for directing a portion of the lubricant slung by said generally elongated hollow body to said cylinder head to conduct heat energy therefrom.

2. The compressor of Claim 1 wherein said directing means is a flange member transversely upstanding from said cylinder head and having at least one opening therein to allow passage therethrough of lubricant to conduct heat energy from said cylinder head.

3. The compressor of Claim 2 wherein said flange member is in good thermal contact with said cylinder head.

4. The compressor of Claim 1 wherein an upper portion of said hollow body is angularly disposed relative to the axis of rotation of said crankshaft to dispose said opposite end upwardly and radially outwardly from said crankshaft, said body having in a side thereof facing said housing said opening for propelling lubricant radially outwardly therefrom and against said directing means.

5. The compressor of Claim 4 wherein said directing means is a flange member transversely upstanding from said cylinder head and having at least one opening therein to allow lubricant to pass therethrough to conduct heat energy from said cylin-der head.

6. The compressor of Claim 5 wherein said flange member transversely upstands from a portion of said cylinder head to direct lubricant over exterior surfaces of said cylinder head.

7. The compressor of Claim 6 wherein said crankshaft is vertically disposed.

8. In combination with a compressor including a hermetically sealed housing having a crankcase therein with a cylinder disposed in said crankcase and a sump in a bottom portion thereof, a cylinder head, a crankshaft rotatably received in said crankcase and having a piston operably connected thereto and disposed in said cylinder, said crankshaft having centrifugal pump means connected to its bottom portion and disposed in said sump for pumping lubricant from said sump upwardly through a lubricant passage in said crankshaft, said crankshaft having means connected to its upper portion for slinging lubricant radially outwardly therefrom, a lubricant deflector comprising:

means transversely upstanding from said cylinder head and in good thermal contact with said cylinder head for catching a portion of the lubricant slung by said slinging means to conduct heat energy from said cylinder head.

9. The compressor of Claim 8 wherein said directing means is a flange member transversely upstanding from said cylinder head and having at least one opening therein to allow passage there-through of lubricant to conduct heat energy from said cylinder head.

10. In a compressor including a hermetically sealed housing having a crankcase therein with a cylinder disposed in said crankcase and a sump in a bottom portion thereof, a crankshaft rotatably received in said crankcase and having a piston operably connected thereto and disposed in said cylinder, a cylinder head, said crankshaft having pump means connected to its bottom portion and disposed in said sump for pumping lubricant from said sump upwardly through a lubricant passage in said crankshaft, a lubricant distribution system comprising:
a generally hollow body connected to said crankshaft and in communication with said lubricant passage and having an upper end through which lubricant is thrown against the housing, said body including a side opening through which lubricant is thrown radially outwardly as the crankshaft rotates, and heat sink means upstanding from said cylinder head and in good thermal contact therewith for catching at least a portion of the lubricant thrown out of said side opening to thereby conduct heat away from said cylinder head to the lubricant.