US2372180A

US2372180A - Angularly adjustable coupling

Info

Publication number: US2372180A
Application number: US397715A
Authority: US
Inventors: Herbert C Edwards
Original assignee: Timken Roller Bearing Co
Current assignee: Timken Co
Priority date: 1941-06-12
Filing date: 1941-06-12
Publication date: 1945-03-27
Anticipated expiration: 1962-03-27

Description

March 279 E945.- H C, EDWARDS 2,'3728@ A1\I ftJI..ARLYA ADJUSTABLE COUPLING Filed June l2. 1941 f 2 Sheets-Sheet 2 Patented Mar. 27, 1945 UNITED STATES Pa'risu'rl oFFicE ANGULARLY ADJUSTABLE COUPLING Herbert C. Edwards, Massillon, Ohio, assignor to The Timken Roller Bearing Company, Canton, Ohio, a corporation of Ohio Application June 12, 1941, Serial No. y397,715

(ci. i4-24)I Claims.

This invention relates to angularly adjustable couplings, particularly hydraulic timing coupiings or governors for fuel pumps for compression ignition engines. the present invention is to utilize the varying pressure developed by the fuel pump for automatically regulating the time ofinjection of the Theprincipal object of fuel lnaccordance withthe speed of the engine.

Other objects are simplicity and cheapness of construction and compactness of design. The invention consists in the hydraulic timing device and in the construction, combinations and arrangements of parts hereinafter described and claimed.

In4 the accompanying "drawings, which form part of this specification and wherein like sym-` bols refer to likel parts wherever they occur,

Fig. 1 is a side 4elevational view of a'Diesel engine fuel injection pump provided with a hyj draullcally actuated timing mechanism or governor embodying my invention,

Fig. 2 is an elevational view of the governor shown in Fig. l,

on the lines 5 5 and 8 4, respectively, in Fig. 4, 35

Figa? is a horizontal V fragmentary section on the line 1-1 in Fig. 3; and

Fig. 8 is a vertical fragmentary section on the line 8 3 in Fig. 3. K Inthe accompanying drawings, my invention is illustrated in connection'with a pump for the fuel injection system of a compression ignition engine. The pump apparatus illustrated in the accompanying drawings is of the type shown in my co-pending application, Serial No. 364,232,

filed November 4, .1940, and comprises three superposed, rigidly connected sections, namely, an upper fuel supply pump section A that communi-- cates through a fitting 4 and conduit 5 with a fuel supply tank `(not shown), an intermediate fuel injection pumpl section B having a plurality '.'of fuel discharge conduits 31, one for each engine cylinder, and a lower base section C containing the driving mechanism. for the fuel injection pump.

'I'he lower or fuel section C of thebase pump comprises a housing 45, which contains the mechanism for continuously reciprocating and rotating, the pump plunger 3,3. This mechanism comprises a cam shaft 46 extending horizontally through the lower portion of the housing 45 below and at right angles to the pump plunger 33. The cam shaft 46 is driven by or in unison with the engine and is adapted to rotate a cam 41 having identical circumferentially spaced lobes corresponding in number tothe number of dischargeA passageways 34 of the injection pump. The cam shaft is supported in suitable roller bearings 48 mounted in alined openings in opposite ends of the housing 45. Surrounding the

cam shaft

4,6 adjacent to the driven end thereof is a'suitable oil seal- 49 that is supported in an opening provided therefor in a plate 50 that is removably secured said housing 45 by cap screws 50a.

The lobes of the cam.: 41'are adapted to suc 'cessively engage a tappet roller 5I that is loury naled on a pin 53 carried by a cylindrical tappet block 54 having an outer shell 56 rigid therewith. This tappet block is reciprocable in an up right cylindrical guide sleeve 59 that is disposed in a vertical bore 60 that leads upwardly through the top of the housing from the cam shaft receiving opening therein; and said tappet guide sleeve has an outstanding peripheralA ange 6I at the top thereof that rests on an annular seat 62 provided therefor in said vertical bore. The tappet block 54 has a diametrical T-slot 65m the top thereof adapted to receive a grooved lower end portion 65 of the pump plunger 33, whereby said tappet block and plunger are connected` together for joint reciprocating vmovement but may be disconnected by relative movement crosswise of the plunger axis. The upward or pressure stroke is imparted tothe pump plunger 33. by the engagement of the lobes of the cam 41 with the tappet roller 5Iv carried by the lower end of said plunger. The downward or suction stroke is imparted to the plunger 33 by a coil compression plunger retracting spring 51,.which surrounds the tappet guide sleeve with its lower end seated' on an outstanding basenange 58a on the tappet shell 55 and with itsunder end nearing against the upper side of the cut standing base flange 6I `of said tappet guide sleeve.

In accordance with the present invention,

means are provided for circumferentially adjust- Y ingthe pump operating cam '4l relative to the cam shaft 45 during rotation to advance or re- Il tard the time of thefuel injection; and this timing means is operatively connected to the supply pump for automatic operation by the pressure' r developed by the supply pump A. This timing device comprises a sleeve having the cam 41 formed thereon or rigid therewith. This sleeve,

The driving connection between the cam-shaft 46 and the cam sleeve |00 comprises a tubular coupling member |02 that is disposed in axial alinement with said cam shaft at the inner end thereofY and has two diametrically opposed lon gitudinally disposed arms or branches |03 that extendbetween said cam shaftand sleeve mounted thereon. These splines or branches |03 of the coupling member |02 iit within and are slidable lengthwise of diametrically opposed longitudinal peripheral grooves |04 in the cam shaft 46, thereby providing an axial sliding driving connection between said cam shaft and said coupling member. The branches |03 of the coupling member |02 have series 0f external teeth or ribs |05v that are disposed at an oblique angle to the axis of said member and intermesh with a corresponding series of teeth or ribs |06 formed in the borev of the cam sleeve |00. By this arrangement, the rotary motion of the cam shaft 46 is transmitted tothe cam sleeve |00 through the coupling member |02 in all positions of axial adjustment of the latter,A while axial movement of said coupling causes relative rotary movement of said cam shaft and sleeve, thereby advancing of retarding the cam 46 with respect to the cam shaft, depending I on the direction of axial sliding movement of |01 that is reciprocable in a horizontal bore |08 provided therefor in the lower portion of a housing D that is secured latwise to the adjacent end face of the injection pump housing C. The horizontal piston supporting bore |08 is disposed in axial alinement with the horizontal cam shaft receiving bore of the injection pump housing C and' the piston |01 cooperates' with the closed inner endof the bore |08 to form a pressure space or chamber |09 inwardly'of said piston. The pisend thereof that snugly fits the cylindrical wall of the pressure space or chamber |09 and is tightly clamped to the end wall of said piston round an axial stud ||0 thereon by means of a clamping washer ||0 and a nut |20 threaded on said stud.

The piston |01 is slid endwise against the pressure of the springs ||2 and HS by means of fluid pressure developed by the supply pump A for the'fuel injection pump B. The connection between the supply pump A and the pressure space or chamber |00 of the fuel injection timing device comprises a passageway 85h which opens through the side wall of the housing 45 and is `connected by a ferrule 00a to a passageway 05e in the housing D. This passageway 85e opens at its inner end into the pressure space or chamber |00 between the inner end of the bore |08 in said housing and the piston |01 working in said bore. The passageway 05c is provided with an extension or branch 06d that opens into the lower end of a bore |2| that leads downwardly through the top of the housing D.

The lower end portion of the bore |2| is threaded to receive a needle valve |22 for controlling the size of the orifice |23 between the branch passageway 85d and said bore. The needle valve |22 has a diametrical bore |24 therein below the threaded portion thereof and an axial passage-Y way or bore |25 leading upwardly from said diametrical bore and opening through the top of said valve, thereby permitting passage of the fluid pressure through said valve when the latter is open; The upper end of the bore |2| for the valve |22 is closed by a screw plug |2|a, which is spaced above the upper end of said valve to provide a chamber |28 therebetween; and this chamber communicates through a horizontal passageway |21 with a conduit or passageway |28 that leads from the housing D to the fuel supply tank for the fuel supply pump.

By the arrangement described, the pressure developed by the supply pump A is utilized for automatically adjusting the timing coupling |02 to thereby advance or retard the cam sleeve E00 with respect to the cam shaft 46 while the latter is rotating and thus change the timing of the fuel injection. The supply lpump A, delivers a fixed quantity of fuel per stroke, and the pressure necessary to deliver this fuel to the injection pump will vary according to the square of ton |01 is an outwardly opening cup-shaped piston that is adapted to receive the closed end of the coupling member |02; and said end of. said coupling member abuts iiatwise against the end face of a hardened stud or button H0 that is press fitted in an axial recess i provided therefor in the end wall of said piston. The closed lend of the coupling member |02 is held against the button ||0 provided therefor in the piston |01 by means of a coil compression spring H2 having one end seated within an axial recess I3 provided therefor in said end of said coupling member and the other end seated in an axial seat ||4 provided therefor in the adjacent end of the cam shaft 46.

The piston |01 is shifted inwardly in the bore the speed of rotation of the cam shaft 45. Thus, this supply pump pressure will increase as the speed of the engine increases and thus cause the operating piston |01 of the timing device to move against the pressure of the springs ||2 and M5 and force the timing coupling |02 axially of the cam shaft 46 and the cam sleeve |00 driven thereby. During this movement of the coupling member |02, the helical or oblique rib-and-groove connection |06, |06 between said member and the cam sleeve |00 will produce a, phase change |08 by means of a coil compression spring H6 that surrounds the coupling member |02 and has one end seated in the cup portion of said piston and the other end supported in an annular spring seat member IIB that fits within the adjacent end of the horizontal cam shaft receiving bore in the injection pump housing C. The piston |01 has a rubber packing ring ||1 xed to the inner between the cam shaft 46 and said cam sleeve, and thus bring about a change in the timing of the fuel injection. The timing may be adjusted to suit diierent engine characteristics by providing springs 2 and ||5 of different strength of deflection. lThe timing device may be manually adjusted by means of a screw |29 that is threaded through the housing D in abutting relation to the axial stud H0 on the timing control piston |01. The housing D may be provided with an opening leading from the pressure space or chamber |00 and normally closed by a screw plug |30 so as to allow the escape of air from said space