US2775960A

US2775960A - Crankcase breather system

Info

Publication number: US2775960A
Application number: US528887A
Authority: US
Inventors: Frank C Druzynski
Original assignee: Continental Motors Corp
Current assignee: Continental Motors Corp
Priority date: 1955-08-17
Filing date: 1955-08-17
Publication date: 1957-01-01
Anticipated expiration: 1974-01-01

Description

1957 F. c. DRUZYNSKI 2,775,960

CRANKCASE BREATHER SYSTEM Filed Aug. 17, 195.2 2 Sheets-Sheet l FIGJ.

33 3| INVENTOR. 1 25 FRANK c. DRUZYN SKI BY $461 r ATTORNEY Jan. 1, 1957 F. c. DRUZYNSKI 2,775,960

'CRANKCASE BREATHER SYSTEM Filed Aug. 17, 1955 2 Sheets-Sheet 2 INVENTOR.

FRANK C- DRUZYN SKI United States Patent CRANKCASE BREATHER SYSTEM Frank C. Druzynski, Detroit, Mich., assignor to Continental Motors Corporation, Detroit and Muskegon, Mich., a corporation of Virginia Application August 17, 1955, Serial No. 528,887 Claims. (Cl. 123-119) ing stream fording operation, is a crankcase breathing system that permits satisfactory submerged engine operation and yet will not adversely affect engine performance during normal or non-submerged operation. Heretofore breathing systems developed for this type of engine have not proven satisfactory in many instances for various reasons.

in many cases, breathing systems for submersible internal combustion engines adversely affect crankcase pressures. A partial vacuum which may develop in the crankcase under certain conditions increases the opportunity for sand, water, and other foreign matter to enter the engine. On the other hand, excessive pressures developed in the crankcase are equally undesirable since oil sludge and blowby condensate are thrown out of the breather pipe, coating and clogging equipment and structure in the vicinity of the crankcase breather outlet.

Crankcase breathing systems incorporating either manually operated or pressure controlled regulating valves and the like have heretofore failed to function satisfactorily and dependably under the variable operating pressures involved and also due to their complex structure being subject to failure due to engine vibration. Moreover, such valves have previously been prone to malfunction as a result of freezing, sludging, and corrosion.

An object of my invention is to provide a dependable crankcase breathing system for submersible internal combustion engines by passing crankcase gases into the engine air intake manifold and by providing a simplified pressure sensitive control valve which balances crankcase pressure against either water or atmospheric pressures when the engine is respectively submerged or not submerged.

Another object of the present invention is to improve engine performance under operating conditions aforesaid by providing a crankcase breathing system which will maintain a pressure in the crankcase at all times slightly in excess of the engines environmental water or atmospheric pressure, as the case may be, whereby to decrease the possibility of water and foreign matter entering the engine at any time.

A further object of this invention is to improve engine performance under operating conditions aforesaid by providing a crankcase breathing system incorporating a simplified pressure sensitive control valve for preventing excessive pressure build-up in the crankcase, whereby to prevent oil sludge and blowby condensate discharge from the crankcase.

For a more detailed understanding of my invention reference may be had to the accompanying drawings illustrating one embodiment of the invention wherein like characters are referred to like parts throughout the several views and in which f'ice Fig. 1 is a side elevational view of a conventional internal combustion engine embodying the crankcase breathing system of my invention,

Fig. 2 is a section on line 2-2 of Fig. 1, showing the crankcase breathing system control valve in closed position.

Fig. 3 is a similar view as Fig. 2, but showing the control valve in open position.

Fig. 4 is a view of the valve looking outwardly from the engine, and

Fig. 5 is a fragmentary diagrammatic sectional View taken substantially on the line 55 of Fig. 1

Fig. 1 illustrates a conventional internal combustion engine 10 of the fuel injection type having a crankcase portion 11 and an air intake system provided with a throttle and manifold assembly 12. For clarity, that portion of the air intake system comprising a snorkel type air intake pipe leading upward from the throttle and manifold assembly 12 is not shown. Pipes or

conduits

13a and 13b connect into the crankcase 11 for the purpose of passing crankcase blowby gases through a breathing system control valve assembly 14, then through another pipe 15 to the air intake throttle and manifold assembly 12. Pipe 15 connects to the air intake manifold 16 downstream of the throttle valve 17, as illustrated in Fig. 5.

The control valve assembly 14 is preferably mounted high on the engine 11 adjacent the rocker boxes 18 so that oil sludge and blowby condensate from the crank case will not easily collect at the valve. Also, a conventional filler 19 is preferably installed in the pipe 15 connecting the control valve assembly 14 with the intake manifold 16 to remove any condensate or particles which manage to get through the valve, before the gases are passed into the manifold.

The preferred breathing system control assembly 14 of my invention, shown in cross-section in Figs. 2 and 3, comprises a two part housing or casing 25 consisting of a body portion 25a and a cover portion 25b clamped or secured to the body portion 25a as with screws 26 or other suitable attaching means, and supporting a diaphragm valve assembly 27 therebetween. The casing 25 thus comprises a chamber divided by the diaphragm valve assembly 27 into a crankcase pressure compartment 28 and an air pressure compartment 29. The crankcase pressure compartment of the casing 25 furthermore has a port 30 openly connecting the compartment 28 with the conduit 15 which leads to the air intake manifold 16, and another port or ports 31 openly connect the compartment 28 with the conduit or

conduits

13a and 13b leading to the crankcase 11. A port 32 in the casing cover portion 25b has a suitable air cleaner fitting 33 installed therein, and opens the air pressure compartment 29 to water or to atmosphere, depending on whether the fitting 33 is respectively submerged or not.

The diaphragm valve assembly 27 separating the

compartments

28 and 29 comprises a flexible diaphragm 35, preferably made of an oil and chemical resistant, fabric reinforced, synthetic rubber compound, a washer 36 on each side of the diaphragm 35, and all held securely together by a valve member 37, and a lock nut 38 or other suitable securing means. The valve 37 is mounted on the diaphragm 35 and the washers 36 so as to seat accurately on the valve seat 30a in the port 30 when the control;

valve assembly is in closed position, as illustrated in Fig. 2. Every possible effort has been made to provide a operating characteristics.

3 e t e 9 t nq m manitgld Pre su e a atiqns in conduit will not interfere with the valve operation; and (3) the entire construction must be of a nature that will not clog, jam, or malfunction due to engine vibration, freezing, sludgingor corrosion.

During non-submerged operation, atmospheric pressure exists in the compartment 2 9 of the cover portion b, and crankcase gas pressure; exists in the compartment 28 of the body portion 25a. Consequently, the pressure in the crankcase is substantially balanced against the atmospheric pressure. With crankcase pressure sufficicntly in excess of atmospheric pressure plus the small restraining pressure of the flexible diaphragm 35, the diaphragm valve assembly 27 will be displaced toward the air pressure compartment 29., opening the port as illustrated in Fig, 3. Blowby gases will then pass from the crankcase pressure compartment 28 into the conduit 15 and thence into the air intake manifold 16. As the crankcase pressure decreases to atmospheric, the diaphragm valve assembly 27 will return to its normal closed position as illustrated in Fig. 2, valve 37 seating with a force dependent on the differential between the pressures existing in the crankcase and air pressure compartments. Because of the opposition to displacement of the diaphragm 35, the pressure maintained in the crankcase pressure compartment, and hence the pressure in the crankcase itself will be slightly in excess of the environmental atmospheric pressure of the engine, and this positive pressure in the crankcase materially reduces the opportunity for water or foreign material to enter the engine.

During submerged operation, where water level rises above the breathing system control valve assembly 14, water will enter through the fitting 33 into the air pressure compartment 29 only until the port 32 is covered. As the water level continues to rise, the pressure of the air trapped in the compartment 2? will increase in proportion to the level of water above the port 32. Consequently, a correspondingly greater pressure will be required in the crankcase pressure compartment 28 to unseat the valve 37. This pressure will be slightly in excess of the pressure in the air pressure compartment 29, again due to the additional resistance to displacement of the diaphragm 35.

In other words, the pressure maintained in the crankcase will always be sufiiciently greater than the environmental pressure existing outside of the engine to prevent or reduce the opportunity for Water, sand, and other foreign material to enter the engine, and at the same time, excessive pressure will not be produced in the crankcase. As the water level decreases, the excess pressure in the crankcase pressure compartment 28 will displace the diaphragm valve assembly 27 toward the air pressure compartment 29, unseating valve 37 and allowing crankcase gases to pass into the conduit 15.

When the water level drops below the level of the port 32, whatever water has accumulated in the compartment 29 will drain out, due to the location of the port 32 being at the lowermost portion of the casing cover portion 251). This self-draining feature, as well as the simple valve construction, insures maximum freedom from freezing and sludging of the mechanism.

Although I have described and illustrated but one embodiment of my invention, it will be evident to those skilled in the art to which my invention pertains that various changes and modifications may be made therein without departing from the spirit of the invention or the scope of the appended claims.

What I claim is:

1'. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation While submerged underwater, a crankcase breathing tween the crankcase pressure and, atmosphere when then ne s 1 ubmer ed nd o p essur t e en i l be.- tween crankcase pressure and the pressure of water covering said control means when the engine is submerged.

2. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system operable to pass gases from said crankcase to said manifold, and comprising a pressure sensitive control means operable to relieve crankcase gas pressure which increases above atmospheric pressure when the engine is not submerged and to relieve crankcase gas pressure which increases above the pressure of water covering said control means when the engine is submerged.

3. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system comprising communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means and operable to close said communicating means to passage of crankcase gases as crankcase pressure decreases substantially to atmospheric pressure when said control means is subjected only to atmosphere, and as crankcase pressure decreases tothe pressure of water covering said control means when same is submerged.

4. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system comprising communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means, said control means having a movably supported control member actuated to check the passage of crankcase gases through said communicating means as crankcase pressure decreases substantially to atmospheric pressure when said control means is subjected only to atmosphere and as crankcase pressure decreases substantially to the pressure of water covering said control means hen same is submerged.

5. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system comprising communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means, said control means comprising a casing provided with a pressure chamber openly communicating said crankcase with said manifold, said chamber also open to atmosphere when the control means is subjected only to atmosphere and open to water covering the control means when same is submerged, a movably supported control member in said chamber and actuated to check the passage of crankcase gases from the crankcase to the manifold as crankcase pressure decreases to substantially atmospheric pressure when said control means is subjected only to atmosphere and as crankcase pressure decreases substantially to the pressure of water covering said control means when same is submerged.

6. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system comprising communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means, said communicating means comprising a crankcase conduit connecting said crankcase with the control means and a manifold conduit connecting said manifold with the control means, said control means provided with pressure chambers, and two ports connected to one of said chambers and respectively connected to said crankcase and manifold conduits and a third port connected with said other pressure chamber and with atmosphere when the control means is subjected only to atmosphere and. with water covering the control means when same is submerged, a movably supported-control disposed between said pressure chambers and actuated to check the passage of crankcase gases from leaving said first pressure chamber as crankcase pressure decreases substantially to atmospheric pressure when said third port is not submerged and as crankcase pressure decreases to the pressure of water covering said third port when same is submerged.

7. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system comprising a communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means, said communicating means comprising a crankcase conduit connecting said crankcase with the control means and a manifold conduit connecting said manifold with the control means, said control means provided with pressure chambers, and two ports connected with one of said pressure chambers and respectively connected to said crankcase and manifold conduits, a third port connected with said other pressure chamber and with atmosphere when the control means is subjected only to atmosphere and with water When said control means is submerged therein, a control member disposed between said chambers, said control member actuated by differential in pressures between the crankcase pressure and either the atmosphere when said third port is not submerged or to the water covering said third port when same is submerged, such that passage of gases through the chamber communicating with the crankcase and manifold conduits is checked as crankcase pressure decreases respectively to substantially atmospheric pres sure when said third port of said control means is not submerged and as crankcase pressure decreases to the pressure of water covering said third port when same is submerged.

8. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system comprising a communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means, said communicating means comprising a crankcase conduit connecting said crankcase with the control means and a manifold conduit connecting said manifold with the control means, said control means provided with pressure chambers, and two ports connected with one of said pressure chambers and respectively connected to said crankcase and manifold conduits, a third port connected with said other pressure chamber and with atmosphere when the control means is subjected only to atmosphere and with water when said control means is submerged therein, a control member disposed between said control member actuated by differential in pressures between the crankcase pressure and either the atmosphere when said third port is not submerged or to the water covering said third port when same is submerged, such that passage of gases through the chamber communicating with the crankcase and manifold conduits is checked as crankcase pressure decreases respectively to substantially atmospheric pressure when said third port of said control means is not submerged and as crankcase pressure decreases to the pressure of water covering said third port when same is submerged, said control member comprising a flexible diaphragm assembly supported by said control means and defining the intermediate wall of said pressure chambers.

9. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged underwater, a crankcase breathing system comprising a communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means, said communicating means comprising a crankcase conduit connecting said crankcase with the control means and a manifold conduit connecting said manifold with the control means, said control means provided with pressure chambers, and two ports connected with one of said pressure chambers and respectively connected to said crankcase and manifold conduits, a third port connected with said other pressure chamber and with atmosphere when the control means is subjected only to atmosphere and with water when said control means is submerged therein, a control member disposed between said chambers, said control member actuated by differential in pressures between the crankcase pressure and either the atmosphere when said third port is not submerged or to the Water covering said third port when same is submerged, such that passage of gases through the chamber communicating with the crankcase and manifold conduits is checked as crankcase pressure decreases respectively to substantially atmospheric pressure when said third port of said control means is not submerged and as crankcase pressure decreases to the pressure of water covering said third port when same is submerged, said control member comprising a flexible diaphragm assembly supported by said control means and defining the intermediate wall of said pressure chambers, said diaphragm valve assembly comprising a flexible diaphragm having a valve member affixed thereto and operable to coact with said port leading to the air intake system.

10. In an internal combustion engine having a crankcase and an air intake system manifold and capable of operation while submerged under water, a crankcase breathing system comprising a communicating means for passing crankcase gases from said crankcase to said manifold, and a pressure sensitive control means coacting with said communicating means, said communicating means comprising a crankcase conduit connecting said crankcase with the control means and a manifold conduit connecting said manifold with the control means, said control means provided with pressure chambers, and two ports connected with one of said pressure chambers and respectively connected to said crankcase and manifold conduits, a third port connected with said pressure chamber and with atmosphere when the control means is subjected only to atmosphere and with water when said control means is submerged therein, a control member "disposed between said chambers, said control member actuated by differential in pressures between the crankcase pressure and either the atmosphere when said third port is not submerged, such that passage of gases through the chamber communicating with the crankcase and manifold conduits is checked as crankcase pressure decreases respectively to substantially atmospheric pressure when said third port of said control means is not submerged and as crankcase pressure decreases to the pressure of water covering said third port when the third port is submerged, said control member comprising a flexible diaphragm assembly supported by said pressure control means and defining the intermediate wall of said pressure chambers, said diaphragm valve assembly comprising a flexible diaphragm having a valve member affixed thereto and operable to coact with said port leading to the air intake system, said third port located at the lowermost part of said control means such that on submersion, water will enter said chamber only until the port is covered, and the air trapped in the second mentioned compartment of said chamber will increase in pressure in accordance with the .increase in head of water above the port, the pressure increase causing actuation of said diaphragm and said valve member and the location of the third port aforesaid permitting the water to drain from the said compartment when the water level drops below the third port.

No references cited