US2580594A - Crankcase scavenger - Google Patents

Description

Jan. 1, 1952 c. c. RANDALL 2,580,594

CRANKCASE SCAVENGER Filed June 6, 1947 2 SHEETS-SHEET l 25' 8 7 2 V o I T] 5 o :IPG 2 IO FIG I 9 2/ INVENTOR. CLARK 0. NBA LL ATT'YS Jan. 1, 1952 c. c. RANDALL CRANKCASE SCAVENGER 2 SHEETS-SHEET 2 Filed June 6, 1947 FIG.4

F INVENTOR.

22 CLARK QRQNDALL @Mi w-M ATT'YS Patented Jan. 1, 1952 UNITED STATES PATENT OFFICE 3 Claims.

This invention is directed to new and useful improvements in crankcase scavengers whereby the crankcase of an internal combustion automotive engine is thoroughly and eflicient ventilated of all undesirable fumes, gases and vapors produced during the operation of such engine.

The inventions disclosed herein are modifications, refinements and improvements on the crankcase scavenger described in my United States Letters Patent No. 2,406,103 dated August 20, 1946. While utilizing the same basic idea of creating the pressure necessary to produce the vacuum to exhaust the fumes from the crankcase by use of the flywheel teeth certain important changes in construction of the parts will be noted.

The primary object of this invention is to provide an efiicient crankcase scavenger or ventilator that will produce the necessary combination of high volume of removal at low velocity.

Another object of this invention is to provide a crankcase scavenger whereby increased pressure is obtained from the flywheel teeth and directed to an improved aspirator or Venturi attachment whereby an increased volume of undesirable crankcase fumes are removed from the crankcase.

Still a further object of the invention is to provide such a device wherein there is provided adequate means for preventing the removal of desirable liquid lubricants from the crankcase during the operation of the scavenger.

A still further object is to provide in a crankcase scavenger an improved aspirator attachment.

Another object of the invention is in provide an improved, eflicient airscoop for obtaining pres sure from the flywheel teeth.

And yet another object of the invention is to provide in a scavenger of this type a baflle means for preventing liquid lubricants of the crankcase from being removed by the scavenger from the crankcase.

A further object of this invention is to provide in such a scavenger a novel separator or trap whereby any liquids that may have entered the scavenger from the crankcase will be separated from the undesirable fumes and be returned to the crankcase to continue their lubricating function.

Other objects and advantages will become apparent iromian examination of the following detailed specification:

In the drawings:

Fig. 1 is aside elevational view of an internal the improved crankcase scavenger embodying the inventions hereof.

Fig. 2 is a sectional view taken along line 2-2 of Fig. 1 showing the assembly of the airscoop with relation to the flywheel.

Fig. 3 is a perspective view of the improved airscoop attachment.

Fig. 4 is.a vertical sectional view of the new aspirator or Venturi attachment.

Fig. 5 is an enlarged side elevational view of the separator and baflie assembly.

Fig. 6 is an enlarged side elevational view of the bailie attachment.

Fig. '7 is an enlarged end view of the baflle and separator assembly.

In detail, the engine block is indicated by reference character I, the crankcase 2 and the flywheel casing 3. The usual air inlet to the crankcase is shown at 4 and an outlet from the crankcase is provided at 5.

Connected on the inside of the crankcase at outlet 5 is a baffle member 6 and connected to the outlet 5 outside of the crankcase is liquid and gas separator or trap 1. A conduit 8 leads from separator I to Venturi or aspirator attachment 9. An airscoop I0 is secured to the flywheel casing 3 below and ad acent the flywheel ll, an appropriate opening having been cut in the bottom of the flywheel casing. A conduit I2 connects the airscoop Hi to Venturi 9 to complete the general assembly of the scavenger.

In detail, the bafiie assembly 6 comprises two spaced plates 13 and I4 secured together :at their tops. The sides of the plates are spaced from each other to form vertical slots l5 and the lower edge of plate i3 is bentoutwardly to form a lip H5. The outer plate [4 is of less height than the inner plate I 3. Plate l4 has a central aperture I4 that aligns with the outlet 5 of the crankcase. Thus is formed a protected exit from the crankcase being in fact only a slot extending around the sides and bottoms of the two plates, the access to the bottom being further protected by lip it of inner plate l3. Bolts I! are secured to the upper edges of the plates l3 and I4 and extend outwardly to form means for securing the baffle assembly to the inner side of the crankcase. The baflle thus formed is in fact a casing with a slot entrance at its bottom and an outlet in one side. A fitting I8 is positioned opposite the baflle on the outside of the crankcase wall l9 and is secured thereto, with a gasket 20 in between by means of bolt-2| and nut 22 and by means of nuts 23 tightened onto bolts l'l.

A conduit 26 is clamped to fitting I8 and leads to the bottom of separator i. Separator assembly 1 comprises a tubular receiving chamber 25 horizontally disposed and provided with a removal cap 25'. The outlet from chamber 25 is a tube 25 that extends'from a point outside and below the chamber 25 through the lower wall of chamber 25 to a point substantially above the floor of the chamber. Thus the separator is provided with an inlet 21 at the bottom of receiving chamber 25 and an outlet 28 substantially above the bottom of chamber 25. The removable cap 25 is held in closed position by nut 29 threaded on bolt 30 that is secured to brace 3| that extends across the end of chamber 25.

The conduit 8 leads from the outlet tube 26 to the tube e2 of aspirator s. Aspirator 9 has.

a crankcase or fumes inlet 33 and an airscoop or air pressure inlet 34 and one outlet passage 35. Tube 32 extends well below side inlet 34 as is usual in this type of aspirator. An outer tubuar casing 38 forms the main body'of the aspirator, surrounds tube 32 and extends well below its lower end. Within'outlet passage 35 and spaced from its outer end and surrounding the outlet end of tube 32 is a restricting fitting 3? that has its inlet substantially the diameter of casing 33 and its lower outlet end 38 of less diameter than casing 36 but of greater diameter than tube 32. Thus the passageway from air inlet 3 to the outlet 35 is restricted adjacent the outlet of tube 32 but increases in area thereafter until outlet 35 is reached. 4 Airscoop ii) is provided with a. cylindrical outlet 39 that merges into a small covered rectangular collecting chamber 40. The entrance to chamber 49 is an open flat bottomed channel or trough formed by bottom 4! and parallel sides or flanges 42 with upper edges diverging from the inner end of bottom 4! to the top of collecting chamber 40. Thus is formed an open channel 43 partially enclosing the teeth of the flywheel as they pass the airscoop for receiving the air from the flywheel teeth. Attaching extensions 44 provide means for securin the airscoop to the flywheel casing. Conduit 12 connects outlet 39 with inlet 34 of the aspirator.

The device is assembled on an engine by cutting a hole in the bottom of the flywheel casing adjacent the teeth of the flywheel and securing the airscoop as shown in Fig. 2. If no ventilating air inlet is provided in this casing then one is made preferably near or at the top. An outlet. hole is cut in the crankcase above the oil level and any other breather outlet located higher is plugged up. The baiile assembly is secured to this outlet as above described. The conduits connecting the baffle with the separator, the separator with the aspirator and the airscoop with the aspirator are then positioned and the assembly is ready for operation.

In operation the rotation of the flywheel teeth creates a blower action to drive air into the airscoop. It has been found that the flanged inlet channel 13 partially enclosing the flywheel teeth and the enclosed collecting chamber 49 located adjacent the point the teeth leave channel 43 results in highly efiicient operation for the air moved by the flywheel teeth is thus collected and directed out of the airscoop with a minimum of loss. The bafile construction 5 makes it diflicult for lubricating oil to be drawn or forced into the scavenger assembly and the separator l prevents oil thathas entered the scavenger from being discharged with the undesirable fumes, gases and vapors and permits its return to the crankcase. It is clear that the lighter gases and fumes will readily be drawn through the separator outlet while .the heavier oils will be held in the separator chamber and will return by gravity to the crankcase.

The novel aspirator 9 provides an additional restriction of the pressure from the airscoop seeking the outlet of the system, at a point adjacent the lower end of the inlet tube 32. The restriction is released within the aspirator, as shown and described, and this assembly has been found highly eflicient in creating the desirable suction to withdraw the undesirable vapors from the crankcase.

It is obvious that in some cases the scavenger may be advantageously installed directly to the outlet breather of the engine without cutting a new outlet in the crankcase casing and without using the baflie assembly. Also it may be desirable to omit the separator fromv the installation in certain instances where it is desired to minimize the cost of equipment or where the crankcase. outlet is so positioned that there is little likelihood of oil entering. the scavenger. However, the inclusion of both bafiie and separator. in the installation will assure eflicient crankcase scavenging without loss. of desired lubricating oils.

I claim:

1. In a crankcase scavenger assembly for internal combustion engines wherein the teethof the flywheel are utilized as the blower means, the improvement which comprises an airscoop having flanges at each side to provide a troughli'ke'inlet wherein the teeth of the flywheel will be positioned to move air into the airscoop when in operation.

2. In a crankcase scavenger assembly for internal combustion engines wherein the teeth of the flywheel are utilized as the blower means, the improvement which comprises an airscoop having a collecting chamber and a troughlike inlet with parallel sides leading thereto and means for securing the airscoop adjacent the flywheel with a part of the teeth thereof extending. within the troughlike inlet.

3. In a crankcase scavenger assembly for in-- ternal combustion engines wherein an airscoop is positioned on the flywheel casing to. utilize the flywheel teeth as the blower means; the improve ment which comprises. an airscoop having a troughlike entrance formed by flanged sidesex- 7 tending upwardly from the bottom and means on theairscoop for securing it to the. flywheel casing with said sides extending within the casing to position the teeth. of the flywheel within the troughlike entrance.

CLARK C. RANDALL.

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

UNITED STATES PATENTS Number Name Date 1,723,412 'DeWaters 'Aug. 6', 1929 1,788,897 Taylor Jan. 13, 1931 1,795,927 Daubner Mar. 10, 1931 1,828,085 Syrovy-et al Oct. 20, 1931 7 2,305,186 Muenk Dec- 15, 1942 2,406,103 Randall "an... Aug. 20, 1946-

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