US908624A - Steam-engine. - Google Patents

Description

I. STUMPP. STEAM ENGELS.` APPLICATION HL'BD Am. 1815108:

Patented Jan. 5,1509.

Ina/yh A 0f/@WS J. STUMPP. STEAM ENGINE. APPLICATION PI'LBD APR. 1e, 190e.

Patented Ja11.5, 1909.

2 SHEETS-SHEET 2.

PATENT ormoni JOHANN STUMPE, or BERLIN, GERMANY.

sTEAM-ENGHTB.

Naeoaeaa.

specification of Letters resem.V

'Patensed- Jan. s, rece.

Application filed April 1s, 19os. seal No. 427,768.

To all whom t may concern:

Be it -known that I, JOHANN STUMPE, a citizen of the Empire of Germany, residing at Berlin, have invented certainnew and useful Improvements in Steam-Engines, more Particularly to the Locomotive Type, of which the following is a full, clear, :and exact description.A

This invention relates to steam engines more particularly to locomotive steam enginesA of the type wherein the exhaust steam escapes through ports .inv the wall ofthe cylinder which are vcontrolled or uncovered by the piston.

The object of the invention is to overcome the disadvantageous` effect on the steam distribution which resultsrom utilizing the same ports alternatively for admitting lsteam tothe cylinder and exhausting it therefrom.

In existing steam engines with known types of valves andvalve gearrthe passage of the exhaust steam through the same port-s through whichit Wasadmitted to thev cylinder results in great variation in the lead and compression.- This causes large losses in eiiciency namely owing to insuiiicient compression when there is a late cut-off and the cylinder is filled with steam 'and in the case of an early cut off owing to excessive compression due to early closing of the exhaust. These losses are avoidedby the exhaust .being controlled exclusively by the movement of the piston.

In a double acting-steam engine having exhaust ports situated about the center of the cylinder and controlled by the. piston'if the clearancev be' givenl normal dimensions .the compression with a late cut oil and high speed under certain circumstances may become so great as'to burst the cylinder or blow oit its cover. It is therefore necessary either to arrange suitabiy controlled auxiliary exhaust ports at the ends of the cylinder or to provide the inlet ports at the ends of the cylinder with non-returnv valves so that in the event of excessive compression occurring a portion of the compressed steam may'be able ton return to the boiler. The tirst of these arrangements would neutralize the chief advantagey as regards lead and compression which is sought to be obtained in providing: a. double acting steam engine with exhaust ports controlled by the piston. The provision of inlet ports.l

which are on occasion also used as exhaust ports is on the other hand combined with serious `drawbacks more particularly in locomotive engines. Tn consequence of a portion of the compressed .steam being returned to the boiler heavy thermodynamic lossesare brought about while moreover there is th'e possibility of smoke being drawn into the cylinder with. the resultant risk of burning the lubricating oil, d..pcsiting soot in the cylinder and racturing it. This dianger from smoke is more particularly to lbe feared when the throttle is closfl. and the pressure in the steam supply pipe reduced.

According to this invention the above mentionedy drawbacks are obviated more especially in double acting locomotive engines by the inlet ports being used exclusivelylfor the admission of steam and by their being positively controlled or operated by means of suitable'valve gear `of link 'or other type capable of reversing. Further the cylinder is'given-sutficient dimensions to provide a clearance which -Will accommodate 'the steam remaining in the 'cylinder after the exhaust ports are closed so that it is'vunnecessary to arrange for the steam admission ports to be .capable of occasionalnse as exhaust ports. 'v

Au engine with valves and gear constructed in accordance with this invention is illustrated in the accompanying drawings by way of example as appliedto a locomotive. Figure 1 is a somewhat diagrammatic view of the front portion of a locomotive showing a cylinder in longitudinal vertical 'section'. Figi 2 is a broken cross section through one side of the locomotive the section being taken midway in the length of` i the cylinder. F ig. 3 is a plan of Fig. 2 partly in section with the boiler "removed Fig. 4 is an indicator diagram illustrative of the operation of the improved engine..

Below the smoke box l on the frame 2 is mounted the cylinder provided with covers et. 'The cylinder 3 has exhaust ports 5 and 6 formed about its center these ports being intended exclusively for the steam exhausted from the cylinder and being controlled by the piston T which covers and uncovers them in its rec'iprocations. Within the cylinder covers 4 are arranged valves 8 controlling tbepassages communicating with t-he cylinder by ports 9 these ports, passages and rio admission of lne steam. The valves S are operated /by rollers on a common rod or spindle( the valve spindles being operated by cams 11 by means of sleeves lor guide blocks 12 which are disposedin cylinciprocating in the caps 13. The reciprocation of the valve spindle 17 with the guide blocks 16 necessary to effect the operation of vthe. inletapparatus S may be elfected by means of any known valve gear with eccelltrics and hnk motion or other arrangement adapted to enable reversal to be efected.-

The Walschaert reversible gear is illustrated by way of example in the present instance as asuitable link motion. The slide blocks 16 are secured 'to a' rod 1S which is pivotally connected to the upper end of a. two

rmed lever 19 the lower end ot' which is ivotally connected by a link Q0 to the cross -head l22 of the piston rod :21. At the upper end there is pivoted to the lever 19 a rod 23 whichcarries a slide block 24 adjustable in a radius link The link 25 is centrally pivoted on a. bracket 26 mounted on the frame 2 of the locomotive and is caused to oscillate in the well known manner by means of an eccentric rod 27 connected toits lower end. The end of the rod which extends beyond the radius linlc 25 isconnected by'a-link 29 with a bell crank lever 30, 31 moving on a fulcruin 28, a rod 32 from the arm 31 of this lever extending to the cab and enabling the driver to alter the gear so as to vary the cut off and reverse the engine. Live steam is supplied to the valves 8 from the boiler 33 through pipes 35 branching from a T-piece 34, the steam being delivered to the valves in such a way as to heat the cylinder covers 4.

In accordance with a further feature of` 4this invention the cylinder is constructed as hereinafter described so that hammering due to the presence of water in the cylinder is avoided, this hammering frequently occuring in locomotive engines by reason of the cylinder constituting the lowest point 1n the apparatus, since the l ive steam pipes 35 run from the boiler 33 which is situated on a level well abovey Vthe cylinder, the exhaust pipe 36 also having to be carried upwards through the smoke box 1 to the blast pipe 37. Vith this object the exhaust ports coutrolled by the piston 7 are divided into two groups disposed respectively on the upper and lower sides of the cylinder 3. The ports 5 of the upper group open intoa chamber 38 mounted on the cylinder 3 and communicating with the main exhaust pipe which leads to the blast pipe 37: The ports 6 of tlie lower group comlinumcate with a second outlet cenvleniently constituted by a chamber 39 on the underside of the cylinder l 3, the bottomot this chamber being provided with a comparatively small openingl0 communicating withl the atmosphere. The dimensions ot' the lower exhaust ports t are so calculated that it is not possible for the whole of the exhauststeamto escape through them so that the necessary blast trom the pipe 37 is always insured..

`When the exhaust ports 5 and 6 are uncove'red by the piston the greater portion of the exhaust .steam will pass through the ports and the pipe 36 toI the blast pipe 37 a smaller' portion otl the exhaust steam passing through the'ports 6 int-o the chamber 39 and carrying with it any water of condensation which is free to escape through the outlet 40. rfhe chamber 39 constitutes at the same time a water pocket and is for that reason made fairly large so as to enable it temporarily to take up large quantities of water of condensation such as are liable to be. formed when the engine is being started. ln addition to the outlet l40 there are of course provided for draining the cylinder 3 and the covers 4 the usual cylinder cocks 41 .vhich can be'opened by the driver from the cab when required by means of rods 43, 44 these rocks beingroperated simultaneously with a cock 42 which is provided for draining the steam chambers formed in the cylinder rovers Jr. Drainage Jfrom the guides tor the lower end'ot' the spindles of the valves S is provided by cocks 45 controlled 4From the cab by means of rods 46, 47.

y 'lhe operation of the improved construe-- tion is as followsr--ilyhen the lever 19 is operated b v the action of the cross head 22 and radius link 25 so as to move the valve spindle 17 in a forward direction from the position shown in Fig. 1 the valve 8 at the trout end of the cylinder will be opened by the corresponding roller 15 meeting and lifting the cam 11. the valve 8 at the other fend of the cylinder however remaining closed under the action `of its spring 14. On the return movement of thespmdle 17 the valve 8 at the forward end of the cylinderq is (dosed while the. valve at the rear end of thecyhnder 1s opened bythe4 corresponding roller 'T5 raising its cam 11. On one of the? valvesh@ being opened live steam enters the cylinder through the port 9. the piston 7 at the end of its travel in either direction leaving betweenit and the covers 4 a clearance indicated at .of in the indicator diagram shown in Fig. 4. The dimensions of this clearance are calculated so as to insure that even in the case of late cut on` that steam which fails to escape through the exhaust ports 5 and 6 can not be compressed toI an injurious egvtent on the return stroke of ithe piston. i 1

Referring to the indicator diagram shown while exhaustl is taking place.

the cut ott takes place at a followed by expansion up to the point 7) when the exhaust ports 5 and 6 are simultaneously uncovered by the piston 7 whereupon the greater portion of the exhaust steam escapes through the pipe 3U to the blast pipe 3T while a lesser portion iinds its vay into the chamber 39 and so to the atmosphere through the outlet 40 carrying with it at the saine time into the chamber 39 any water of condensation which may have been present in the cylinder. On the return stroke of the piston T the exhaust ports 5 and Gare again' covered at the point r,- so that the outlet 40 and the exhaust pipe 36 are only in communication with the interior of the cylinder is given the dimensions necessary to prevent The piston the parts 5 and 6 being uncovered except at i the desired time.

rod :23' in the link 25 by means of the rod 32 and lever 30 31 t-lie cut oit is altered or the engine reversed then owing to the exhaust ports being controlled by the pistonl T the lead and compression will still remain constant. In this way all the drawbacks in working due to the variation in the coinpressioii and lead are obviated. In the lirst place during long runs of the loconiotive down hill during which the linkage is in nudge-ar injurious drawing in of smoke f fronrthe smoke box into the cylinder and steam admission pipes 35 is avoided whichA f' inreversible engines of this type hitherto known has generally resulted from the en! gine operating as a vacuum pump. Further owing to the compression being maintained constant the forces resulting from the moving masses of -the parts of the engine arealways properly taken up so that knocking of the mechanism is effectively avoided whether in going up hill with .alate cut off or when going at high speed when the cut.

oli must also be fairly late to overcome air` resistance.

The arrangementof double exhaust herein described is particularly applicable to locomotive engines in which the main part of the exhaust is employed for assisting the chimney draft. or for feed heating purposes. Owing to the construction of locomotives. it

is impossible to lead the exhaust from the bottom of the cylinders. or such a construction is associated with considerable dithc-ulty. By arranging a separate draining exhaust. as described. only lowfpressure haust from the bottom of the cylinder are secured.

That I claim is l. In a steam engine the combination of a cylinder. a piston therein. a steam inlet port at the end of the cylinder. a valve controlling the passage of steam through said port. means for operating said valve, a group ot' exhaust ports in the upper side of the cylinder and a group of exhaust ports in the under side of the cylinder, the total area oi' the lower group of ports being less than the total area of the upper group of ports. all ot' .said ports being covered and. uncovered b v the 'piston in its travel. and each group oi ports connnunicating with a sep- :irate exhaust passage. substantiallv as dcscribed. n

il. Ina steam engine the combination of a cylinder. a piston therein whose travel and If by varying the position of the radius steam escapes through the draining passage 'l 40. and all the advantagesof leading the exthe cylinder. a valve controlling the passage i ot' 4steam throughsaid port. means for operating said valve, a group of exhaust ports in the upper side of the cylinder. a group ot' exhaust ports in the under side of the cylinder. the total area of the lower group of ports'being less than the total area ot' the uppeiygroup of ports` all of said ports being covered and uncovered by the piston in its travel. an exhaust pipe with which the upper group of lports communicates. and a separate chamber on the underside of the cylinder with which the lower group of ports cbn'iniunicates. said chamber being provided with a relatively small outlet. substantiallyv JOHAN STVII' vitnesses Hiixiii' Hxsrsii. oLDEMAR HAIPT.

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