US2879757A - Starting device for reserve aggregates driven by a combustion engine - Google Patents

Description

March 31, 1959 M. LINDEN 2,879,757

STARTING DEVICE FOR RESERVE AGGREGATE-S DRIVEN BY A COMBUSTION ENGINE Filed March 1, 1956 3 Sheets-Sheet 1 w Y .INVEEITOR. Marim Lznc'ien March 31, 1959 M. LINDEN 2,879,757

STARTING DEVICE FOR RESERVE. AGGREGATES DRIVEN BY A COMBUSTION ENGINE Filed March 1, 1956 5 Sheets-Sheet 2 Fig.2

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March 31, 1959 LINDEN 2,879,757

M4 STARTING DEVICE FOR RESERVE AGGREGATES DRIVEN Filed March 1, 1956 BY A COMBUSTION ENGINE Z: Sheets-Sheet 3 Fig.4

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-22 4 sea 42 /7 I 20 T 49 7- /e 47 50 5/ /9 M'I I INYENTOR. Marfm Lande States Patetit H STARTING DEVICE FOR RESERVE AGGREGATES 1 DRIVEN BY A COMBUSTION ENGINE lt la'rtin Lindn, Stockholm, Sweden, assignor to Allmanna svenska Elektriska Aktiebolaget, Vasteras, Sweden, a I

; corporation of Sweden Application March 1, 1956, Serial No. 568,781 I Claims priority, application Sweden March 10, 1955 3 Claims. (21. 123-179 1 In important electrical plants aggregates comprising a combustion engine coupled with a generator are often Patented. Mar. 31, 1953.

. current approximately simultaneously with the circuit used as reserve power source. At interruption of the current supply from the network the combustion engine is started'as quickly as possible manually or automatically, and the plant is fed from the reserve aggregate.

1 In most plants the combustion engine is startred by an electric starting motor driven by an electric accumulator, which during the starting period by means of a gear wheel is coupled with the combustion engine and rotates the same. 1 Generally the starting motor is of the slide armatrue type, but also starting motors with a Bendix-drive can be used. At starting motors with a sliding arma- I ture gear wheel and a rotor are stationarily attachedto a common shaft, slidingly carried in a stator-housing and actuated by axial spring'power. When starting the engine the auxiliary magnet-ising winding of the starting motor is first engaged. The magnetic field is sliding the rotor axially and the gear attached to the starting motorshaft is brought into engagement with a toothed rim on the flywheel of the combustion engine. As the resistance in this auxiliary winding is high, the current and consequently also the moment of the rotor will be small during the displacement. Now the main magnetising winding and the rotor winding are automatically connected in series and the starting motor is enabled to drive the combustion engine. When the combustion engine starts working and the current of the' starting motor is interrupted, the rotor is axially displaced by spring power and the tooth gear is released from the toothed rim.

- The starting arrangement described, however, is combined with many disadvantages due to the fact that great reliability of service and a short starting time are required. It has proved that sometimes may starting attempts must be made before the starting motor and the combustion engine are connected. The starting is then seriously delayed. Even if the starting should be successful at the first starting attempt, the coupling of the gear takes up a great deal of the starting perioid.

The present invention relates to an arrangement for a quicker and more secure starting of electrical reserve aggregates and the like in that the starting motor and the combustion engine are coupled together imme diately afterthe combustion engine has stopped and are thereafter permanently connected until the engine is'startcd next time. Owing to this the engine can be started with more security and quicker, as the starting: motor is giving full torque immediately after that ithas'been switched in. The invention is chiefly characterized in that the starting motor is provided with a connecting controlling device, by which the tooth gear of the starting motor, the combustion engine being at a stand-still, after an operating impulse is automatically slid .Ealong to engage. with a toothed rim on the flywheelof the engine without rotating the same. The starting: device is also provided witha blocking means of the starting motor being closed at starting the combustion engine. A valve in the fuel system or a switch in the ignition system of the combustion engine can ad-' vantageously be operated by a magnet. In the operating circuit of this magnet there is suitably a breaking gap provided with a contact member, which is actuated by the blocking member and closes the breaking gap, when the blocking means is lifted from its blocking position. The starting device can also be provided with a member generating impulses, which is so arranged that the operating member steering the coupling inaction performs a coupling attempt for each impulse from the member generating impulses.

One form of a starting device in accordance with the invention will now be described with reference to the accompanying drawings, in which,

Figure l is a schematic diagram showing the positionof the coupling members when the combustion engine" of the stand-by power plant is ready for starting, the

starting motor being connected to the engine, and .all'

relays and magnet coils, except a relay connected to a transmission line, being de energized,

Figure 2 is a schematic diagram similar to Fig. 'l,

but shows the position of the coupling members when the voltage of the transmission line has disappeared and with a sliding armature, and

is provided with a circuit breaker 14 attached tothe.

Figure 4 is a schematic diagram corresponding to Figures 1 and 2 but showing the conditions when the pinion 2 is just being introduced into meshing position with the toothed rim 4.

In the drawings, 1 indicates a transmission line. the occasion of an interruption of the current from the transmission line a stand-by power plant, driven by a combustion engine, is automatically started and overtakes the current supply.

As shown in Fig. 1 the standby power plant is made ready for an extremely quick start in that the pinion 2 of a starting motor 3 having a sliding armature 8, is brought into mesh with a toothed rim on a flywheel 4 attached to the crank-shaft 5 of the internal combustion engine of the stand-by power plant 51 shortly after the engine has been stopped. The pinion is kept in mesh with the rim on the wheel 4 by a blocking catch member 6 until the next time the engine is started.

The starting motor 3 is of the type having a sliding armature 8, and is similar to those commonly used in automobiles. The motor comprises a housing 15 in which a shaft 9 carrying the pinion 2 and the armature 8, is slidingly journalled. The armature 8 is influenced towards the right by a spring 10. The starting motor is a series motor having two excitation windings 11 and 12 connected in parallel as shown in Fig. 3, the winding 11 being an auxiliary winding which has great resistance and 12 being main winding with a low resistance. The motor is connected toa battery 13 and housing 15. This circuit breaker comprises a stationary contact 16 connected to the battery 13, a stationary contact 17 connected to the main v nding 12 and a movable contact bridge 18 connected to the auxiliary winding 11. The contact bridge is influenced downwardly by a spring 19 and is, by an operating rod 20 connected to an armature 21 and a member 22 limiting the movement of the contact bridge 18 until the armature 8 has moved a certain distance to the left, so that the main winding 12 can be connected in only when the pinion 2 is in mesh with the rim on the wheel 4. The armature 21 is raised by energizing the coil 23. A ring 24 on the armature 8 limits the upward movement of the member 22. The blocking catch member 6 is connected to an armature 25 arranged in a casing 26 attached to the casing 15 of the starting motor 3. A rod 27 carrying contact bridges 28 and 29, is also connected to the armature 25. These contact bridges close the breaking gaps 30 and 31 when in their uppermost positions. The rod 27 and therefore the armature 25 and the catch member 6 are influenced downwardly by a spring 32. 33 is an operating coil for the armature 25. 34 designates an ignition coil and 35 a distributor of the kind usually used with petrol engines. 36 designates a voltage relay having a break contact 37 and make contacts 38, 39 and 40. The relay is connected to the transmission line 1. Relays 41 and 42 are provided with break contacts 43 and 44. The operating windings of these relays are connected to the terminals of the stand-by power plant generator. A relay 45 is so arranged that it is energized from the battery 13 and has a make contact 46 arranged in the operating circuit of the coil 23. Relays 47 and 48 are operated by current from the battery 13, which is provided by make contacts 49 and 50 through which the relay 45 may be supplied with operating current.

As mentioned, Fig. 1 shows the starting device of the stand-by power plant when it is ready for starting, but when the voltage on the transmission line 1 disappears, the relay 36 is de-energized and drops out. The operating circuit of the relay 47 is then closed by the contact 40 whereby the said relay picks up and closes the operating circuit of the relay 45 by the contact 49. Then the relay 45 is energized, picks up and the contact 46 closes the circuit through the operating coil 23. When this coil is energized it raises the armature 21 and the connected contact bridge 18. As the armature 8 is kept in its left-hand position by the catch 6 the armature 21 can at once move the contact bridge 18 to its uppermost position and thus immediately close the circuit through the main excitation winding 12, so that the starting motor can at once generate its highest torque and causes the flywheel 4 to rotate. At the same time as the starting motor 3 is connected to the battery 13 the circuit through the coil 33 is closed by the contact 39. The coil 33 is then energized from the battery 13, the catch 6 is raised and the breaking gaps 30 and 31 are closed by the contact bridges 28 and 29. The armature 8 is then kept in its left-hand position by magnetic forces only. The circuit through the distributor 35 and the ignition coil is closed over the contact bridge 29 and the relay contact 38 of the relay 36 so that the engine 51 may be started. When the engine 51 has been started the relays 41 and 42, connected to the stand-by generator 52, are energized and pick up. The relays remain in the on position as long as the generator 52 provides a voltage. When the relay 42 picks up, the contact 44 breaks the current through the operating winding of the relay 47 and it drops out, and the contact 49 thereby breaks the operating current through the operating circuit of the relay 45 so that this relay also drops out and the contact 46 breaks the circuit through the coil 23. The armature 21 and the connected contact bridge 18 are then drawn downwardly by the spring 19 so that the current through the starting motor is interrupted. The spring "10 is now able to move the shaft 9 with the armature 8 and pinion 2, to the right until it reaches the position shown in Fig. 2. The pinion 2 and the toothed rim on the wheel 4 are now out of mesh.

When the voltage on the transmission line 1 returns, the relay 36 is energized and picks up. The contact 38 opens and interrupts the current supply to the ignition system of the engine, as indicated by the ignition coil 34 and distributor 35. The engine then stops after a short time. The current through the coil 33 is also interrupted and the catch member 6 is, by means of the spring 32, forced downwardly against that part of the shaft 9 which extends out from the right-hand end of the housing 15. The breaking gaps 30 and 31 are still closed by the contact bridges 28 and 29. The relays 41 and 42, the operating windings of which are connected to the stand-by generator 52, are de-energized when the generator has been stopped and the voltage between the terminals of said generator has disappeared. The relays then drop out and the circuit of the operating circuit of the relay 48 is closed by the contacts 43, 37 and the contact bridge 28, and the relay 48 picks up and the contact 50 closes the operating circuit of the relay 45, whereby this relay also picks up. The contact 46 then closes the circuit through the coil 23, and the armature 21 with the contact bridge 18 and the member 22 is raised until the upward movement is stopped by the ring 24. In this position the contact bridge 18 touches the stationary contact 16. The circuit through the auxiliary winding 11 of the starting motor is closed and the armature 8 is drawn to the left by the magnetic forces in the motor and rotates slowly. When the armature has reached its left-hand end position the toothed rimof the flywheel 4 and the pinion 2 are in mesh and the catch 6 can be moved downwardly by the spring 32. The contact bridge 28 then opens the operating circuit of the relay so that both this relay and the relay 45 drop out and the coil 23 is de-energized. The armature 21'is then drawn downwardly by the spring 19 and the circuit through the starting motor is opened. The spring 10 now tends to move the armature 8 to the right but the catch 6 member keeps it in the position shown in Fig. 1 until the next time the stand-by power plant is started.

To prevent the armature 8 from being blocked in'an intermediate position if the ends of the teeth of the pinion 2 meet the ends of the teeth of the gear rim on the wheel 4, a suitable member for opening and closing the circuit between the relays 48 and 45, may be used, whereby a number of enmeshing attempts can be made. A time lag relay not shown on the drawing may be used in the device, which breaks the operating current supply to the relay 45 if the combustion engine does not start within a predetermined time or if the pinion 2 and the toothed rim are not enmeshed after a number of at tempts. Alarm devices indicating faults may also be used in the starting device according to the invention.

I claim as my invention:

1. A starting device for electric stand-by power plants driven by an internal combustion engine, comprising an electric starting motor, an axially movable pinion drivenby the starting motor, a toothed rim on the engine, means automatically engaging the said pinion with the said toothed rim a short time after the engine has been stopped but without-restarting the engine, blocking means for retaining the said pinion and toothed rim in the en meshed position until the engine is re-started, a release device for releasing the said blocking means by re-start ing the engine, and means disengaging the said pinion from the said toothed rim when the engine has been Started.

2. A starting device according to claim 1, comprising spring means actuating the said blocking means to wards its blocking position, an electromagnet iormoving 5 said blocking means from its blocking position, and means whereby the said magnet is supplied with operating current when the circuit of the starting motor is closed.

3. A starting device according to claim 1, comprising an operating magnet for controlling the supply of fuel to the engine, an opearting circuit for said magnet, 21

breaking gap and a contact member provided in said circuit and actuated by said blocking means to close the said breaking gap when the blocking means releases the movable pinion of the starting motor.

No references cited.

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