US 2263092 A
Description (OCR text may contain errors)
' Nov. 18, 1941. J. P. JOHNSON GEAR LUBRICATING DEVI CE Filed Feb. 20, 1939 2 Sheets-Sheet 2 IN VENTOR. Jami-:5 xQ/omvsoxv Patented Nov. 13, 1941 GEAR LUBRICATING DEVICE James P. Johnson, Shaker Heights, Ohio, assignor, by mesne assignments, to Pump Engineering Service Corporation, Cleveland, Ohio, at corporation of Ohio Application February 20, 1939, Serial- No. 257,548
This invention relates to improvements in air pumps and more particularly to that type of pump capable of discharging clean dry air under pressure and in desired volurne, especially adapted for use on aircraft for operating deicing equipment and supercharged cabins for altitude flights.
An object of the present invention is to provide a pump of the type referred to having cooperating pumping gears which, are not in contact but in. which the running clearance is at a minimum so as to maintain a high degree of efficiency.
Another object of the present invention is to provide a construction wherein the running clearances are effectively maintained irrespective of temperature changes.
Another object of the present invention is to provide adequate lubrication for the operating elements of the pump but to so direct the lubricant that it does not, detrimentally, combine with the air handled'by the pump.
A further object of the present invention is to predetermine the running clearances between the cooperating'pumping gears and thereafter effect positive relative rotation of the latter to insure maintenance of the running clearance irrespective of the speed of rotation thereof.
Another object of the present invention is to provide a pump structure which is simple in production and assembly, efficient in operation, and relatively inexpensive to manufacture.
With the objects above indicated and other objects hereinafter explained in view, a preferred embodiment of my invention consists in the construction and combination of elements hereinafter described and claimed.
Referring. to the drawings,
Figure 1 is a vertical longitudinal sectional view of a pump embodying the present invention and taken approximately along line |l in Figure 2 to illustrate different portions of the structure.
Figure 2 is a transverse elevational view partly in section to more clearly illustrate details of the structure and taken approximately along line 2--2 of Figure 1.
Figure 3 is a transverse vertical sectional view showing the pumping gears and other details of the pump structure, and taken along line 3-4 in Figure 1.
Figure 4 is a transverse vertical sectional view showing the driving and driven gears operatively associated with the pumping gears to maintain the runningcl'earances between the latter and taken approximately on line 4-4 in Figure 1.
In the drawings I have illustrated an air pump embodying the present invention and while particularly adapted for use on aircraft, the novel features may be otherwise incorporated as will be readily apparent to those skilled in the art.
The pump comprises a housing proper |0, preferably an aluminum casting for lightness, which has a bore ll extending inwardly from one end thereof and terminating in a transversely disposed wall l2 at the other end providing a pump chamber. The pumping means is in the form of cooperating rotatable impellers l3 and [4 although, it will be obvious, that other types may be employed if desired, but the type illustrated has the desirable features of simplicity in production and the maintenance of close running clearances for high efliciency. The impellers are of identical construction comprising body portions l5 and I6 of aluminum material generally circular in cross section, the respective axes being disposedin spaced parallel relation, the adjacent peripheral surfaces having a close running clearance for a purpose to be later described. Each impeller is further provided with a pair of extensions or teeth I! and I8 projecting outwardly on diametrically 'opposite sides which have their outer ends slightly flattened or rounded for close running relation with the inner peripheral surface of the bore II but likewise slightly spaced therefrom. The impellers are further provided with a pair of recesses l9 and 20 on diametrically opposite sides disposed in a plane substantially at rightv angles to said teeth, the recesses being formed and relatively disposed to receive the teeth of the opposite impeller there being pro- .vided a close running clearance therebetween.
relative rotation thereof. The impellers are further provided with a plurality of longitudinally extending openings 2|, to reduce the weight thereof which are equally disposed with respect to the axis so as to maintain proper balance during rotation. v
The housing proper H) has a pair extensions 22 projecting outwardly on diametrically opposite sides thereof the end walls of which are provided with centrally disposed openings 23 preferably in alignment with and in communication with the opposite sides-of the pump chamber. The pump isadapted for operation in either direction and the openings 23 function respectively as inlet and outlet openings depending upon the direction of rotation. Elbows 24 have attaching flanges 25-at their inner ends detachably connected to the end walls of the extensions 22 by flat inner surface 29 disposed in close relation to the adjacent ends of the impellers It and it. A gasket 36 is disposed between the cover momher and housing proper adjacent their outer edges to provide a sealed joint and bolts 3i project through openings in the cover member and screwthreadedly cooperate with aligned screwthreaded openings in the housing proper it. Provision is made for properly positioning the cover member on the housing proper by means of a pin 32 having one end embedded in the housing proper and its other end projecting outwardly for insertion into an opening 33 provided in the cover member as more clearly shown in Figure 1.
Rotation is imparted to the impellers i3 and M by means of shafts 3d and $5, the latter being the drive shaft. The construction and mounting of the shafts is identical and a detailed description of the drive shaft mounting will suffice for a clear understanding. The impeller M has an axial bore 36 extending from its inner end outwardly and terminating in an end wall 3?, the latter being provided with an axial opening 33 of smaller diameter than said bore. The inner end of the bore communicates with a circular recess 39 of slightly larger diameter to provide a shoulder ail. The inner end of the bore at has inwardly projecting radially disposed spaced teeth ti extending longitudinally outwardly from the shoulder W to substantially midway of the bore for a purpose to be later described. The drive shaft 35, preferably of steel, is disposed coaxially of the impeller and has 'a portion 62 extending longitudinally within the bore 36. The shaft has a circumferential flange d3 outwardly from the portion Q2 and abutting the adjacent end wall Sl'to maintain the shaft against axial movement. The shaft has an outer end portion M of reduced diameter which projects through the opening 38 and is rotatably mounted in any desirable manner in the cover member 28. In the present instance the cover member 28 has a tubular coaxial extension 55 projecting outwardly within which the outer races of a pair of antifriction bearings 66 are securely fitted. The inner races of the bearings are tightly fitted upon the projecting end portion 34 of the shaft and balls are mounted between the races in the usual manner. axial opening 41 through which the end portion 44 of the shaft projects, of a size to accommodate a sleeve 48 tightly fitted but axially movable upon the latter and in abutting engagement with the adjacent end of the impeller. A disc 69 has a central opening through which the shaft projects and is securely clamped between the outer end of the sleeve 48 and the adjacent inner race, the outer portion of the disc being formed with an inwardly angularly extending marginal flange 50 for a purpose to be later described. The cover member has an annular recess within which the flange 50 freely projects and a passageway 52 communicates with the recess at one end and a. screwthreaded opening 53 at its opposite end normally closed by means of a removable screwthreaded plug 54. The outer end of the shaft 35 is screwthreaded to receive a nut 55 which when tightened secures the shaft and its cooperating elements in rigid assembled relation for unitary rotation. A cap 56 extends across theopen end of the tubular extension 45 and has an annular flange 51 abutting the adjacent outer race of the bearings. Bolts 58 project through openings provided in the marginal portion of the cap and screwthreadedly cooperate with aligned The cover member is provided with an aaeegoea openings provided in the adjacent end of the tubular extension and a gasket 59 is disposed between the cap and extension to provide a sealed joint.
The shaft 35 is further provided with radially disposed spaced teeth 60 which extend longitudinally thereof and are arranged for cooperative engagement with the teeth H at the end of the bore 36 to produce a splined connection whereby rotation of the shaft is imparted to the impeller. The inner ends of the teeth 6d are formed with lateral extensions 61 disposed in circumferential alignment to provide a flange positioned Within the circular opening 39 but in spaced relation to the adjacent surfaces thereof. The shaft is formed with a circumferential groove 62, inwardly of the extensions iii, to receive a resilient ring 63 of neoprene ruber composition or other suitable sealing material. Inwardly of the ring 63 the shaft is provided with radially disposed spaced teeth El -l extending in longitudinal alignment with the teeth till. The end wall l2 of the housing proper has a circular opening 65 extending therethrough and through which the shaft projects. A bore 66 is provided on the outside of the wall i2 which extends in" wardly and communicates with the opening 65. A steel sleeve 6? is tightly fitted but axially movable over the outer end of the teeth 65 and the ring 63 and has its outer end in abutment with the adjacent portion of the lateral extensions iii. A disc 58 has a central ppening through which the teeth 5 of the shaft project, the outer portion being formed with an outwardly angularly extending marginal flange 69 for a purpose to be later described. The end wall i2 has an annular recess iii adjacent the bose of the bore 68 within which the flange 59 freely projects and a passageway it communicates at one end with the recess and at its opposite end with a screwthreaded opening '12 normally closed by a screwthreacled plug 53.
An external gear 'l i preferably of steel is disposed outwardly of the end wall and has a cylindrical hub portion l5 projecting rearwardly, the inside of the hub portion being provided with radially disposed spaced teeth 76 extending longitudinally and mounted upon the teeth 6 of the shaft. The free end of the hub portion abuts the adjacent portion of the disc 68 and the inner race of an antifriction bearing ill is tightly fitted upon the outer peripheral surface of the hub portion. The outer race of the bearing is tightly fitted within the bore 86 and balls are mounted between the races in the usual manner. A retaining ring 18 is positioned upon the outer side of the wall [2 in overlapping relation with respect to the outer race of the bearing TI and detachably secured to the end wall by means of bolts 19.
The inner end of the shaft35 has a portion of reduced diameter adjacent the teeth 64 which has a tapering screwthread 80 and a splined free end portion 8|. A disc 82 has a circular opening through which the reduced portion of the shaft projects, the outer portion being formed with an inwardly angularly extending marginal flange 83. A steel sleeve 84 fits tightly but axially movable over the reduced portion of the shaft and abuts the adjacent face of the disc 82 to maintain it in engagement with the gear II. A nut 85 screwthreadedly cooperates with the threaded portion 80 of the shaft and when secured tightly in place maintains the cooperating elements in rigid relation and in abutment with the lateral extension 6i whereby all will rotate in unison. A washer 86 is disposed between the nut and sleeve and has a tongue bent over into engagement with the former to prevent accidental removal.
For a clearer understanding of the construction, where the structural features and mounting of the driven shaft 34 are identical with that of the drive shaft 35 heretofore described and it is desirable to refer to such elements, they will be indicated by the of the corresponding reference numeral on the drawings.
The hub 15'. which is mounted upon the inner end of the driven shaft 34 preferably of steel, has a lateral .circumferentially extending flange 81 disposed slightly inwardly from its inner end to provide a circular extension 88. An external gear 89 of steel and of the same pitch diameter as the external gear 14 is disposed in meshing engagement with the latter whereby positive rotation of the drive gear 14 is imparted to the driven gear 69 and inasmuch as these gears are directly connected to their respective shafts and the'latter' directly connected with their respective impeller, the latter are positively rotatable at the same speeds. To effect the desired running clearances between the impellers during relative rotation the web 90 of the gear 89 is provided with an axial opening to permit mounting of the latterupon'the circular extension 08 and initially being adjustable angularly relative thereto. The inner free end of the shaft 34 is exteriorly screwthreaded at 9| and a washer 92 freely encircles the latter and abuts the adjacent face of the web 90. A nut 93 is screwed onto the end of the shaft and when tightened forces the web 90 and flange 81 into unitary engagement. By this construction the gear 89 can be independently adjusted angularly upon the circular,
extension 68 until the desired running clearance between the impellers has been effected whereupon aligned openings are provided in the flange .cover member 95 is substantially elliptical in shape, conforming to the outer contour of the housing proper, and is detachably connected to the latter by a plurality of bolts 96 which project through marginally spaced openings in the cover member and screwthreadedly engage aligned openings in the adjacent portions of the housing proper as more clearly shown in Figures 1 and 2., A gasket 91 is disposed between the adjacent portion of the cover member and housing proper to provide a sealed joint. The end wall of the cover member 95 projects outwardly at 98 in the region of the gear 89 and is provided with a bore 99 on its inner side in axial alignment with the axis of the shaft 34. A bronze bushing I00 is tightly fitted within the bore 99 and has a lateral flange IOI at its outer end. A disc I02 is disposed between the flange IM and the adjacent face of the cover member and has a central opening to accommodate the bushing, T
tending axially inwardly and of a diameter slightly greater than the inner diameter of the bushing I00. An oil metering pin I05 has a por-- tion I06 which rotatably fits in the bushing I00 and a portion I01 which projects into the bore I04 being secured to the adjacent end of the shaft by means of a cross pin I08 more clearly shown in Figure 4. The opposite ends of the pin I05 are spaced from the ends of the respective bores and said pin has a central passageway I09 extending inwardly from the end portion I06 communicating with a laterally extending discharge port III) inthe portion I01 inwardly from the end of the shaft. The clearance between the portion I01 and the bore I04 determines the quantity of oil discharged and this may be varied as desired by substituting metering pins having the required running clearother than the engine pad, a manner that will be later described.
The lower portion of the end wall of the cover member projects inwardly at H6 in close proximity to the gear 14 and-has an axial opening encircling the sleeve 84 in spaced relation. On the inner face of the portion H6 is a circular recess 1 into which the flange 83 of the disc 82 freely projects. The end wall of the cover member 95 is further provided with an annular extension II8 concentric with the axis of the shaft 35, which terminates in a lateral circumferentially extending flange II9 forming an attaching plate whereby the pump can be attachedto and supported by the engine in a well known manner. The splined end 8| of the shaft 35 is flexibly connected to the engine drive in any desirable manner but preferably as illustrated in the drawings. circular end plate I20 having an outwardly projecting axially disposed pinion I2I connected to the former by a portion I22 of reduced section to provide a weakened joint for breaking in case of excessive strains. The plate I20 has a lateral rearwardly extending marginalflange I23, the
inner peripheral surface l: ling slightly enlarged at I24 to provide an abutment I25. A driven member indicated generally at I26 (Fig. 1) has a circular flange I26a disposed in spaced relation to the inner peripheral surface of said flange I23, the inner adjacent faces of the flange H261: and the plate I20 likewise being in spaced relation, and an axially disposed hub portion I21 having splined teeth I28 which are adapted for mounting upon the splined end 8| of the drive shaft 35.
The flange I26 is provided with radially disposed slots I29 extending longitudinally therethrough, the adjacent faces being flared outwardly relatively as indicated at- I30. The flange I23 is also provided with radially disposed slots I3I upon its inner periphery in alignment with the slots I29. A plurality of short flat lengths of spring steel I32 arranged in superposed relation are disposed in each adjacent pair The connection comprises a,
of slots I29 and I3I in such a manner as topermit relative angular flexible movement between the flanges I 23 and I 25. Such a flexible connection is a decided advantage in that it relieves the pump elements of excessive strains and stresses imparted from the engine. The spring elements are maintained in operative position by means of a closure disc I33 which fits tightly within the peripheral surface Md in abutment with the shoulder I25, the disc having a central opening through which the hub portion I27 freely projects. A snap ring ltd is disposed within a groove I335 formed on the inner peripheral surface outwardly of the disc. The hub portion 827i is likewise provided with a groove I36 on its inner peripheral surface to receive a snap ring i3? which contracts into a groove 938 formed upon the outer surface of the splined end BI.
In order to supply oil to lubricate the rotatable pump elements, the attaching flange H9 is provided with an oil inlet opening I39 adapted to be positioned in alignment with a similar opening on the engine pad mounting for supplying oil thereto. A passageway Ifill extends through the annular extension IIB communicating at one end with the inlet opening 839 and at the opposite end with an upwardly extending passageway NH provided in the projecting portion 98. The upper end of the passageway MI communicates with the lower end of the bore I62 which in turn communicates with the upper end of the passageway H3 as more clearly shown in Figure 2. A tubular member M3 has lateral flanges I44 at its opposite ends removably disposed within the bore I52, the walls of the tubular member being provided with a plurality of transverse openings 55 spaced longitudinally to permit the flow of oil therethrough. It will be apparent therefore that the incoming oil will from this point flow 'through the passageway II3,-into the groove III, through the opening I I2, into the interior of the bushing I00, through the central passageway I09, and be discharged through the port H into engagement with the inside of the bore I04. As previously stated the quantity of oil discharged may be predeterminately effected by selecting the proper clearance between the portion I01 of pin I and the bore I0d. The discharged oil is thrown against the disc I02 where it is directed by the tapered flange I03 toward and into engagement with the web of the external gear 89 where it flows through openings I46 between the adjacent teeth and thereby lubricates the external meshing gears.
The ball bearing races are also supplied with lubricant in any desirable manner through the lubricant passageways provided andthe lubricant is .prevented from entering the pump chamber and commingling with the pumped air by the several discs as here provided.
In the operation of the pump, the pinion "I of the drive shaft 35 is operatively connected to the engine or other source of power for imparting rotation thereto. Assuming that the drive shaft 35 is driven in a clockwise direction as indicated by the arrows in Figure 3, the elbow 2| on the left hand side of Figure 3 becomes the inlet and is connected with the air source while the elbow on the right becomes the outlet and is connected with the instrumentalities to which clean dry air is to be supplied. As the drive shaft 35 is rotated it in turn imparts rotation to the impeller i l to which it is directly connected. The other impeller It which is rotatably mounted in cooperative relation without actual contact as previously described, is rotated by the driven shaft 36 on which it is mounted. Rotation of the driven shaft 36 is effected by the use of the external meshing gears 89 and M secured respectively upon the driven shai and the drive shaft 35. These gears 89 and ill are of such relative pitch diameters that both shafts are rotated so that the impellers i and I5 will be driven in a manner to draw the air into the inlet side of the pump and discharge the same under pressure from the outlet side of the pump.
The materials used and the construction provided are such that the running clearances neces-- sary in the operation of the pump, particularly at high speeds, can be maintained. This is ef- .fected particularly by definitely maintaining predetermined clearances at one end and permitting expansion and contraction at the other end, that is the spline end of the shafts, brought about by temperature changes.
While I have described the preferred embodiment of the invention it is to be understood that I am not to be limited thereto inasmuch as changes and modifications may be resorted to without departing from the spirit of the invention as defined in'the appended claim.
In a gear. lubricating construction including a driven shaft rotatably mounted in a housing and having a gear thereon adapted to mesh with another gear, the end of said driven shaft adjacent said gear mounted thereon having a bore extending axially inwardly, a metering pin having one end disposed within said bore in spaced relation with respect to the wall thereof and connected for rotation with said driven shaft, the opposite end of said metering pin being rotatably mounted in a bearing supported in an adjacent portion of said housing, said metering pin having a central passageway extending inwardly from the outer end thereof and branching outwardly adjacent said bore for discharging lubricant into said bore, passageways formed in said housing and communicating with said central bore for supplying lubricant to said metering pin, said driven gear on said shaft being formed with a circular lubricant collecting channel located in the underside of the toothed portion thereof and facing radially inwardly, said toothed portion being formed with passages leading from said channel to said teeth, and means for directing lubricant thrown centrifugally outwardly from said bore in the end of said shaft to said lubricant collecting channel, said means comprising a disc-like lubricant baiiie guide formed with a radially outwardly extending central base portion mounted on said housing adjacent the outer end of said bore in spaced relation thereto and an inwardly turned radially outwardly located wall portion projecting into said lubricant collecting channel for directing lubricant thereto.
JAMES P. JOHN-SON.