Description
Juny - 2 1946. c . c . OF SPEED 2402951 IA @ Ew exchange mechanism August 20, 1942 Filed February Shelets lc leaves . c . OF Pew 2402951V SPEED CHANGE MECHANISM Filed August 20, 1942 2 Sheets sheets 2 July 2, 1946 . , Fi Patentediluly 2 CHAN 1946 GE MECHANISM SPEED- Chester C. De Pew , Farmingdale , N. Y1 , Fairchild mapper lEngine and Airplane Corporation , Farmingdale , NY , a corporation of Maryland Application August 20, 1942 , Serial No. 455,459 claims. ( Cl ' i4 - 277 ) ' I'his invention relates to the speed change mechanism , and has particular reference to the type transmissions variable speed planetary gear "to change the speed of a pump or drivingmexnbers for superchargerimpeller , propeller driven aircraft , or other media element .In variable speed transmissions , particularly adapted for use in aircraft such as interposed between the engine and the propeller , the motor and a compressor impeller , and the like, lightness , compactness, minimum number of parts , accessibility, and, particularly, reliability and speed of operation is essential. The mechanism described in my copending application Serial No. 337,429 , illed May 27, 1940 , now Patent No. ' 2,293,050 , dated August 18, 1943 has the features mentioned above , and the present invention is an improvement in that mechanism by which a third -speed driving is possible with a simple change materials no increase in the number of inserts , or drastic reconstruction of the mechanism of that patent , so that the size and weight of the mechanism does not increase appreciably .The mechanism of this patent comprises a rotatable driving member operatively connected to the power source, such as an aircraft engine or the like and carrying a circular array of planetary gear bearings on stub shafts secured thereto . Planet'gear each comprising a pair of pinions integral or connected , each ci dierent diameter , and each meshing with a corresponding toothed crown LTO selectively connectable via a fixed part of a stationary fluid-actuated brake . One of the planet gears meshing with each one. on the driven gear , so that , by engaging the respective brake selectively . iixed speed planet pinion rotation is imparted to the driven element , two speeds being possible with the arrangement described .The mechanism described above is modified in accordance with the present invention to provide a third speed by a drive or other driven member , andthe modification consists mainly of journalling in each double planet gear or a third auxiliary pinion , which is independent of the other two sprockets of the planetary gear which iournalled and gear4 engages a stationary ring and a ' separate sun gear connected to a separate shaft for driving a . as primary supercharger drive member regardless of the booster stage driven in either of two speeds by a double planet gear , as described ' .Simple disk brakes around the driven element coaxially with the planet searsyactu - 2 ` ated fluid actuated cylinder BYV allow control of two speeds and neutral in the auxiliary stage impeller , while the prime mover is driven at a constant predetermined speed by the auxiliary pinions arranged as described .VIT will cylindricallyshaped a very compact transmission for acquisition at will any of these speeds , neutral , which is instantly operable through control valve conveniently placed in the cockpit for controlling the pressure uid of a readily available source , as is otherwise used for adjusting the pitch of the propeller , the operating and undercarriage . the
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ING way of example , application of the invention to an engine compressor stage two bills I0 , which has the usual intakescroll , not shown, leading to the primary stage or the housing comprising main II I2 for driving introduced into the primary tubular drive shaft I3 . I3 shaft extends through the compressor housing I0 , and serves as an element actuated by the gear shift mechanism of this invention is contained in the cylindrical housing Il . adequately secured to the compressor housing I0 I3 coaxially with the driven member connected to primary drive I2.4 Interposed between the primary driver . II housing and change speed mechanism is the impeller housing I4 I5 axis stage auxiliary key totubular I8 telescopically over I3 Il axis on suitable bearings and likewise housing leading to I4 .The actuating element or shaft I8 oriented or otherwise connected to the motor or other power source, not shown , extends throughv tubular shaft or driven element 3 protruding beyond both ends thereof , as sample.Keyed on one end of the actuator I8 sun to rotate therewith is a disc or spider positloned lwithin housing I9 I 4 and having a circular array . bead should: J 20 projecting therefrom parallel to the axis of member ldriving I8 . In the construction illustrated , particularly in Fig . 2A live asuch short shafts 20 are provided , although iluid under pressure from a suitable source ' , notdiameters larger sprocket which is designated 23 and the smallest sprocket 24. These pinions 23 and 24 Kare separated to form a cube that is articulated through cap 25 , a third pinion 23 ,that are free of planetary gear 22 , rctatesin '- dependent matter.Referring RST integral pinions each planetary gear 22 , the small gear 24 meshes with a gear 21 secured on the end of the drivenmember I3 for driving the same and connected auxiliary stage impeller I5 when the transmission is running , and spinning around the idling gear 21 when the transmission . Each small gear 24 also meshes with internal ring gear 28 on the drum 23 which carries at its other end three brake parallel plates 30 which are splined non-rotatably thereto to permit limited axial movement thereof.Brake plates 33 ' are interposed between jos stop plate 3l and non-rotating brake plate 32 in the iiange spllned tubular interior 33 of the base plate '34 clamped between the compressor housing and the flange I3 35 I4 housing , more than one combination spacer and seal 33 . 23 with the brake drum plates'33 rotatable relative to the brake plates ija 3 | and 32. Be understood that the motor latch plates 33, 3 | and 32 may be coated with friction material.Formed between the tubular flange innerl a flange 31 projecting from the inner wall of housing I4 and the base plate 34 is 4AN annular chamber 38 , which serves as a pressure cylinder is supplied with pressurized fluid , such as oil, through line 33 . Linner flange surfaces = 33 and 31 are machined to form accuratelyl twoparallelcylindrical surfaces between which the annular piston 43 is mounted for axial movement slidabiy . 4I sealing ring on the piston 43 of the piston 43 seals the fluid -tight manner in its cylinder 33 . Note that the piston 40 acts as a pressure plate to the corresponding brake , designated A.A similar brake , designated B, is placed on the opposite end of the box I4 , being carried by a stationary sleeve 42 integral with the end plate 43 of the housing I4, which is fixed to a ange 44 thereof over one spacer 45 . The non-rotating brake discs 43 and 41 are mounted on the sleeve 42, plates'43 being ribbed for cleaning them . ited axial movement . Interposed between these " fixed brake plates 43 and 41 are cooperating brake plates 43 toothed non-rotatably on the inner surface of the drum 43 in alignment with the brake drum 23 A. ' Ihe inner surface of drum 43 is provided with - yan internal ring gear 53, with the larger sprockets 23 integral planetary gears 22 mesh. drum 43 with its clutch plates 43 is rotatable relative to ilxed brake plates 43 and 41.5I an annular pressure cylinder , supplied with pressurized fluid line 52 is formed between the sleeve end plate 42 of the housing 43 and spacer 45, and includes an annular piston 53, which acts as a presser plate ` the brake B and is constructed and functions as the brake piston 43 A.
, Respective drive cylinders 33 and - brake 5I A and B are connected by respective tubes 33 and 52 to a three way valve 54 located in the cockpit, or the like and properly operated , as a ` mango, to connect either tube 33 or 52 to the pressure supply line 55 is shown , and the connection at the same time fulfill the other line 53 release. the corresponding brake pressure'on , A or B. When valve 54 is in the neutral position'shown , both cylinders 3i and download 5I and describe the mechanism and the auxiliary drive shaft and I5 I6 inactive.Third or free sprockets 26 each of the planetary gears 22 mesh conA stationary internal gear 51 formed on or xed to the inner surface of the cylindrical casing I4 . Accordingly, as the spider rotates I3 freewheels thereby'rotate 23 carries around the corresponding planetary gears 22, but regardless of the rotation thereof , due to the engagement KOF these freewheels ` 26 with the ring gear steady 51 . Freewheel gears 23 also mesh with key 53 I3 tubular shaft connected to the main drive I2.Inoperation transmission of this invention, and assuming that the low-speed operation of is'desired i5 booster , the control valve 54 is rotated at low speed position , which connects the high pressure source 55 through passage of the valve 33 ' to pipe 33 which leads to - brake cylinder 33 A. Uid pressure supplied to the cylinder 33 causes piston 43 to urge the brake discs 30, 3 | and 32 in braking engagement , thus keeping the drum 23 and stationary ring 23 . Consequently, as the driving disk or spider tour I3 ,small wings 24 of the planet gears 22 drive the driven member I3 and I5 auxiliary ihipeller directly, since these small sprockets 24 are interposed between the gear 28 on the drum 23 and the gear shaft 21 in I3 . Meanwhile, the brake B is disengaged, large integral wings 23 planetary gear 22 is driving play no role .
For high speed operation of auxiliary turbine l I5 , the valve 54 is rotated at high speed position . winch results in disconnection 'pf line 33 pressure tube 55 and connecting them to the disk or spider disthough I3 rotates at the same speed as before , driven shaft I3 and I5 are connected booster driven at a higher speed, for the reason that the peripheral speed of each large integral pinion planetary gear 22 , 23 as rolls around large diameter ring gear ilxed 5I ) , is larger than the small integral pinion 24. due to the compound epicyclic gear train , as will be readily understood .When the control valve 54 is rotated to the neutral position as shown . two pipes 33 and 52 are connected to the discharge duct 56 through valves 56 , which are connected to conduits 33 ' or4 52' , so that both brakes A and B are in disengaged position , and pinions 23 and 24 whole planetary gears simply rotate disc or spider idly as I3 tour, without transmitting motion shaft and Maturity I3 I5 booster . However, ' although the brakes VFO A or B is engaged , or both are disengaged , im - I2 primary propeller is driven constantly predetermined mesh ...Consequently, two speeds , neutral for booster - I5 stage , and a third speed drive for primary stage I2 can be obtained with this invention from a unitary usually two speed transmission, whereby a multi-stage compressor or the like can be operated to get the corresponding motor thermodynamic advantages , with the same equipment , all without substantial increase in the size and weight of the transmission.While a preferred embodiment of the invention has been illustrated and described herein , it is understood that the invention is not limited thereto but is susceptible of changes in form and detail within the scope of the appended claims.
Claim: v
August . In the speed change mechanism , the combination of azdriving member , a pair of driven members axially aligned with the same , a plurality of planetary gears carried by said actuating member for rotating the body with it , each of said gears comprising a plurality of gears relatively rotatable pinion different diameters and relatively rotatable driving connection between one of said non-rotating pinions and one of said driven elements , the driving connections between said rotating pinion "and the other of said members RBI, a ring gear engaging the said ` fixedv relatively ro - tatable and sprockets which rotate around body - a ring gear meshing with each of the same diameter nonrotating sprocket , a brake member disposed and can rotate each ring gear a non-rotatable brake member cooperating with each brake ring gear , and pressure means ' actuation of any of said sets of brake elements to selectively prevent rotation of one of said gear eachof rotating ring and to release both of said sets of brake members for allowing rotation of both said rotatable ring gear .9. A speed change mechanism , the combination of a stationaryhousing , driving and two driven members rotatably mounted on and extending axially of said housing , a plurality of planetary gears supported by said drive element for rotation of the body therewith, each of said gears comprising a pair of relatively non-rotatable pinions diierent diameter , and relatively rotatable pinion journalled thereon , a pair of drums dis - posed coaxially with said one member within said housing , a gear inner ring in each of these .drums, each ring gear which meshes with all the gears rotating relatively the same diameter having a driving connection between one of the sets of relatively rotating gears of the same diameter and one of said drive elements , oneConnectionbetween driving sprocket and relatively rotating said driving element a brake elementn each of said drums and rotation therewith , iixed brake elements in said housing for cooperation with the brake elements ONV said drums , a cylinder adjacent each of said drums , said cylinders pistons'in movable to engage the brake elements on said drums and said housing maintain tothereby corresponding ring gears against rotation Iiiuid a pressure source , and means for selectively connecting the source of fluid pressure to each said icylinders for performing the corresponding sprocket while for disconnecting the source of fluid pressure from both said cylinders ' to release the two ring gears .10 . A speed change mechanism , the combination of a fixed casing , a pipe and two driven members rotatably mounted on and extending axially of said housing , a plurality of planetary gears supported by said drive member for rotation body therewith, each of said gears comprising a pair of relatively non-rotatable pinions of different diameter , and a pinion journalled relatively rotatable about a pair oi drums arranged coaxially with said member within said housing , a gear ring internal in each of said drums, each ring gear which meshes with all the gears rotating relatively the same diameter having a drive connection between one of the sets of relatively rotating gears of the same diameter and one of driven vsaid a driving connection between the relatively rotatable sprockets and said drive member an jo gears in said coupling housing gears relatively rotatable brake element each of said tumblers and with it the brake elements fixed housing onisaid for cooperation with the brake elements of said drums , a cylinder adjacent to each of said drums , said cylindersmovable piston to engage the brake elements on said drums and said housing to thereby maintain the corresponding ring gears against rotation iiuid pressure source , and means for selectively connecting
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