US2845916A - Hydraulic starting system for internal combustion engines - Google Patents

Description

United States Patent M HYDRAULIC STARTING SYSTEM FOR :INTERNAL COMBUSTION ENGINES Lucien I. Pihiel, YValley Stream, N. Y., lassigner, by mesne assignments, to American Bosch Arma Corporation, Hempstead N. Y., -a corporation of New 'York Application March 29, 1956, Serial No. 574,778

6 Claims. (Cl. 12S-179) The present invention relates to an automatic'hydraulic starting system for an internal combustion engine. lIt is illustrated and described in connection with a system of this type which drives an electric generator used for auxiliaryr or emergency power. The invention is particularly useful in a system of this character which includes a hand pump for restoring hydraulic pressure in the event that the engine should fail to start before the hydraulic pressure is spent.

kIt is common practice to provide an automatic starting system for an engine driven emergency generator in-which the energy for operation of the starter which cranks the internal combustion engine is derived from storage batteries. With systems of this type, in the -event of failure ofthe main generator, the only available vsource of electrical energy for cranking the auxiliary generator consists of the storage batteries. lf diiculty is experienced in starting the auxiliary generator, and assuming nthe batteries are fully charged, they may vnevertheless become discharged in the course of repeated ineffective crankings of the engine which fail to start the generator. Under such conditions with the batteries discharged, no electrical energy whatever is available. When lthe emergency generator engine is of such large size that it cannot be cranked by hand, an extremely -serious situationprevails in isolated installations, such as in shipboard power systems.

The present invention provides -an automatic 'electrohydraulic actuating system for a starter'of the above type and which is operated by pressure fluid 'stored in an-ac cumulator which is a conventional velement of the starter per se. When power failure occurs at the main bus,the electro-hydraulic system automatically causes cranking of the emergency generator engine. If the engine `fails to start and the pressure uid in the accumulator is spent withoutstarting the engine, manually Voperable Valves are provided which permit the 'accumulator pressure to be restored 'by means of the usual hand pump.

Various other features and advantages of theinvention vwill become apparent upon reading the -following specilication together with the accompanying drawing --forming a part hereof. k

Referring tothe drawing:

'Figure l is a combined electricaland hydraulic diagram of a system embodying the invention; and

lFigure 2 is a fragmentary View showing a modified form of the system of Figure 1.

In Figure l a-main engine 10 drives a main alternator or direct current generator 111 `through a mechanical fcoupling indicated by the dotted line 13. The Amain .gen-

erator 11 normally supplies power continuously Ito-conductors 14 which constitute the -main bus. VBranchcircuit conductors 1-6 extend from main bus conductors t1-4'to1a load (not shown) which is not yrequired to `=beenergized in the event of failure of the ymain generator `121,;'failure of its driving engine 10 or other circumstances lproducing power failure at conductors 14 of the Amainbus.

A `main -bus contactor designated generally -as 17 v4is `'ventional design which is not illustrated in detail.

, 2,845,916 Patented Aug. 5, 1958 lCC provided with an operating winding 19 which is shown -a load (not shown) which is of'major importance and which is required to be energized during power failure at -the main bus conductors l14.

An emergency power contactor 24 is provided with two poles comprising normally ,open contacts 25 which may be closed by energization of its operating winding 26.

The operating winding 26 is connected to the outputterminals of an emergency generator 28. The emergency generator 28 is driven by a normally inoperative internal combustion engine 29 connected thereto by a mechanical -coupling indicated by the dotted line 31.

Afhydraulic starter 32 is arranged to start'the engine 29 through the usual self-engaging and self-disengaging coupling indicated by the dotted line 34. The 'hydraulic starter 32 comprises a suitable hydraulic ymotor of con- The starter32 may be placed in operation by leftward move- Vment of a control lever 35. Normally, the control lever `35 is positioned toward the lright as shown inthe drawing. An accumulator 37, which is preferably ofthe springpiston type, is connected to maintain a constantly available supply of hydraulic fluid underpressure'at-thestarter '32-via hydraulic lines 38 and 40. Spent pressure fluid is returned to a reservoir 41 via return lines 43and 44.

-Pressure is maintained in accumulator 37 while engine 29 is running by means of asuitable engine driven pump 46 connected to the output shaft of engine 29 througha power take-olf indicated bythe dotted vline 47. The Vinlet to engine driven pump 46 is connected to the bottom of reservoir 41 through afilter 49 included in'a fluid 'supply line 50. If required, to Aprevent back-flow through engine `driven pump 46, a check'valve 52 may be-provided mediately adjacent to the pump outlet.

A-hand pump-53 is provided and is'conncted in multiple with the engine driven pump 46 by inlet and outletliues 5S and 56, respectively. The hand pump 53 -will `'inherently Aprevent backow so that no check valve is required.

A'barrel S4 is provided having a front end cap 54a and a'rear end cap 54h. A tubular insert 54e forms acylinder which is designated as 58. Cylinder A58 is formed as the 4front end of barrel 54 and is `provided with a rod-'like piston 59 which is slidable in the insert 54e .and Which extends throughout the length of the barrel. Barrel 54 is formed with a peripheral slot 60 at the rear -end thereof. A rigid, laterally extending arm 61 travels in said slot 60 and is connected to a central portion of pislton 59. Arm 61 is connected, at its outward ylateral extending end, to a horizontally extending -control -rod v62. A compression spring 65 is disposed within the rear end of 'barrel 54 and has as its terminals the rear end -cap `54b 4and lthearm 61. Accordingly, the arm 61 is lnormally maintained in a leftward position, the spring 65 thereby -functioning as a restoring means for the control rod .62 and the piston 59 and will be shown hereinafter.

Control rod 62 is linked to the starter control lever '35 so that leftwardmovernent of control rod 62 will operate -thefhydraulic starter 32. A manually operable hand knob `64 is fixed to the right hand end of control rod 62 for initiating operation of the starter 32 manually Whenever desired. The control rod 62 and piston 59 are "both `yieldingly urged toward the right by the restoring means lexemplified by the helical compression spring v65.

The piston 59'isforced to the left for starting .engine 29 vthy-pressure uid supplied to the .righthand end of cylinder S8 through a hydraulic line 67. The cylinder line 67 extends to a junction between inlet and outlet control solenoid valves 63 and 7l) respectively. The solenoid valves 68 and 70 are provided with operating windings 71 and 73 which are connected in parallel and are both normally continuously energized from the conductors 72 of the emergency bus through the normally closed contacts 74 of a manually operable starting switch 76. control valve 68 is closed when its winding 71 is energized and thus normally prevents the flow of pressure fluid to cylinder 5S. Outlet control valve 70 is open when its operating winding 73 is energized and therefore normally connects the cylinder 58 with the reservoir 4l. through a return line 77 which merges with return line 44 permitting compression spring 65 to hold control lever 35 in its normal inoperative position.

Pressure fluid is supplied via a hydraulic line 78 to inlet control valve 68 through a manually operable inlet valve 79 which is ordinarily kept open. Ctutlet valve 70 is bypassed by a manually operable outlet valve 80 which is ordinarily kept closed. These manual valves 79 and 80 are used only while restoring accumulator pressure by means of hand pump 53 in the absence of electric power for operation of the solenoid valves 68 and 7 il. With no power available at emergency bus conductors 22, solenoid valve windings 71 and 73 are permanently de-energized, Under these circumstances, valve 79 is closed manually so that no pressure uid will be drawn from accumulator 37 until a sutlicient pressure has been built up by hand pumping to operate the starter 22 electively and crank the engine 29. Valve 8G is opened manually to permit piston 59 to move to the right. A pressure gauge 32 is connected to line 78 to permit observation of the accumulator pressure so that unnecessary hand pumping may be avoided.

In operation, when there is a power failure at main bus conductors 14, the solenoid valve operating windings 71 and 73 become de-energized. Inlet valve 68 then opens admitting pressure iluid from line 78 to the line 67 extending to cylinder 58. Simultaneously, outlet valve 70 closes preventing the direct flow of pressure uid to reservoir 41. Pressure uid is thus fed to the right hand end of cylinder 58 forcing piston 59 to the left. At the same time, the main bus contacter 19 releases thereby disconnecting and isolating the emergency bus conductors 22 from the main bus conductors 14.

As piston 59 moves to the left, control rod 62 also moves to the left causing the control lever 35 of hydraulic starter 32 to move to its operative position whereupon the starter 32 cranks the emergency engine 29. If the engine 29 starts in response to cranking, emergency generator 28 immediately builds up voltage and operates the emergency bus contactor 24, connecting the emergency generator 28 to the emergency bus conductors 22. All loads connected to the emergency bus conductors 22 are then re-energized along with the solenoid valve windings 71 and 73. Upon energization of solenoid valve windings 71 and 73, the inlet and outlet valves 68 and 70 resume their respective closed and lopen positions so that cylinder 68 is disconnected from pressure line 78 and connected to return line 77. Piston 59 and control lever 35 then resume their normal inoperative positions under the influence of compression spring 65. Failure of emergency generator Voltage at emergency bus conductors 22 will similarly cause recranking of emergency engine 29.

If the emergency engine 29 repeatedly fails to respond to cranking for any reason, the pressure in accumulator 37 will drop to a point where cranking is no longer possible. Manual inlet valve 79 is then closed to conserve pressure fluid. Manual outlet valve 80 is temporarily opened long enough to permit spring 65 to bring control lever 35 to its inoperative position, thereby shutting olf any drain on accumulator 37 through starter 32. Hand pump 33 is then operated manually until pressure gauge Inlet 82 indicates adequate pressure has been built up for eiective cranking operation of the hydraulic starter 32. Manual inlet valve 79 is then opened and the cranking operation repeated. This cranking operation can be repeated from time to time indefinitely because hand pump 53 is always available to build up the necessary hydraulic pressure in accumulator 37.

During normal operation, the emergency engine may always be started manually for test purposes by operation of manual starting switch 76 which de-energizes the solenoid valve windings 71 and 73 in the same manner as a power failure. When testing under these conditions, contactor 24 may advantageously be temporarily blocked open or otherwise rendered inoperative until after cornpletion of the test.

Figure 2 shows a modified form of the invention in which a manual starting switch 82 is provided for remote operation of starter 32 whenever desired without regard to power failure. Inlet and outlet valves 83 and S5 are connected to lines 78, 67 and 77 as in Figure l and the operation is the same, except that engine 29 may drive some load other than a generator, such as a propeller shaft or pump, for example.

The manual starting switch 82 is provided with normally open contacts 86. The inlet valve S3 is provided with a normally de-energized operating winding 88 and the valve 83 is normally closed. When winding 88 is energized, inlet valve S3 opens admitting pressure iluid from line 78 to the line 67 which extends to cylinder 58. The outlet valve 85 is provided with a normally de-energized operating winding 89. When winding 89 is energized, outlet valve 85 closes shutting off cylinder line 67 from return line 77.

The operating windings 8S and S9 of inlet and outlet valves 83 and 85 are shown connected in series for simultaneous energization by a source of current indicated as a battery 91. Thus, whenever the starting switch 82 is manually closed, engine 29 will be cranked. Because electric power is not required to maintain the valves 33 and S5 in their normal positions, the manual valves 79 and may be omitted. The hand pump 53 may be used at any time so long as the valve windings S8 and 89 are de-energized. i

While I have shown what I believe to be the best embodiments of my invention it will be apparent to those skilled in the art that various changes and modiications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

What is claimed is:

l. In combination with an internal combustion engine having a hydraulic starter for cranking said engine, an accumulator connected to said starter for supplying said starter with hydraulic pressure fluid for cranking operation thereof, and movable control means associated with said starter for controlling cranking operation thereof, the provision of hydraulic cylinder means connected to said accumulator, said cylinder means comprising piston means connected to said control means for moving said control means to control operation of said starter, valve means included in said connection between said accumulator and said cylinder means for controlling cranking operation lof said starter, means comprising an electromagnet and including an operating winding for controlling said valve means, said combination further comprising an energizing circuit for said operating winding, and switch means included in said energizng circuit for controlling said cranking operation of said starter.

2. In combination with an internal combustion engine having a hydraulic starter for cranking said engine, a hydraulic accumulator connected to said starter for supplying pressure fluid to said starter for cranking operation thereof, a reservoir connected to said starter for receiving spent pressure uid therefrom, movable con- ,trol means associated with Ysaid starter for controlling said cranking operation thereof, and pump means for returning spent pressure fluid from said reservoir to said accumulator, the provision of hydraulically operated means connected to said control means for movement thereof, said hydraulically operated means including resilient means yieldingly urging movement of said control means to maintain said starter inoperative, and valve means actuable for selectively connecting said hydraulically operated means either to said accumulator or to said reservoir, said hydraulically operated means, when connected to said accumulator by said valve means, moving said control means against said yielding action of said resilient means to cause cranking operation of said starter.

3. The combination according to claim 2, in which said hydraulically operated means comprises a cylinder having a movable piston therein, said piston being connected to said control means, and said resilient means comprising spring means yieldingly acting on said piston and on said control means.

4. The combination according to claim 2, wherein said valve means comprises at least one valve including an electromagnet having an operating winding for said selective actuation thereof, said combination further comprising an energizing circuit for said operating winding and switch means included in said energizing circuit for controlling said cranking operation of said starter.

5. The combination according to claim 2, in which said valve means comprises at leastone valve including an electromagnet having an operating winding for said selective actuation thereof, said combination further comprising a normally energized power supply circuit to which said winding is connected, said valve means maintaining said hydraulically operated means connected with said reservoir during continued energization of said power supply circuit.

6. The combination according to claim 5, wherein said pump means comprises a hand pump, said combination comprising the further provision of manually operable valvemeans for maintaining said hydraulically operated means disconnected from said accumulator during deenergization of said power supply circuit and operation of said hand pump, said manually operable valve means permitting connection of said hydraulically operated means to said reservoir. v

References Cited in the file of this patent UNITED STATES PATENTS 1,028,364 Knight et al June 4, 1912 1,795,053 Strong Mar. 5, 1931 1,965,371 Drabelle July 3, 1934 2,467,067 Wilson Apr. 12, 1949 2,498,697 Molyneux et al Feb. 28, 1950 2,802,452 Hogeman Aug. 13, 1957 FOREIGN PATENTS 942,178 Germany Apr. 26, 1956

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