DE362686C - Device for reversing gas engines with cranks offset by 180 Ò against each other - Google Patents

Description

GERMAN EMPIRE

ISSUED OCTOBER 31st-OCTOBER 1922

. REICH PATENT OFFICE

PATENT LETTERING

- JVi 362686 CLASS 46 b GROUP 6

(P 37753 l \ 4Sh)

- Paul Praetorius in Darmstadt.

Device for reversing gas engines with. Offset by 180 °

Cranks.

Patented in the German Empire on May 6, 1919.

The invention relates to a device for reversing gas engines, in particular of those in which the cranks are offset by 180 °, and those with a Auxiliary engine (turbine or the like) are started. Purpose of the invention is that at to give these machines a single direction of rotation of the camshaft, so that the doubling the various cams for inlet and outlet, fuel inlet, fuel pump, etc. are no longer applicable.

It is already suggested to help achieve it

S62686

for this purpose to arrange a reversing gear between the crankshaft and the camshaft, which is reversed when the direction of rotation of the crankshaft is reversed, and thereby a rotation of the camshaft in the same sense both in forward and in Brings about reverse gear of the machine.

However, the known facilities show the essential shortcoming that the ίο Reverse gear reversing clutch when reversing rarely or never into the opposite one Coupling half can engage. As a result, it is necessary in these devices special drive devices for the camshaft or the coupling halves to be arranged in order to bring them into the to bring the correct position of engagement with the clutch. These facilities are special very extensive in the case of large machines and not necessarily reliable in their effect. Also requires the indentation Coupling in these embodiments pay special attention to the reversing operating staff.

It is also known in this device to have the reversing gear with an adhsially displaceable Design clutch. However, due to the arrangement of this coupling sleeve on a screw thread necessary to apply special braking means to the self-locking of the screws overcome and thereby only trigger the coupling effect.

In contrast, according to the invention, the coupling is freely axially displaceable on the shaft itself, and the inevitable displacement to the right or left is carried out by the special design of the coupling halves, namely in such a way that on the "two end faces of the displaceable coupling and the one with it Coupling halves of the reversing gear each have a self-contained coupling tooth n, p, o, q , the engagement surfaces of which lie in a plane laid through the coupling axis, and the backs of which form a whole thread of a helical surface rising from the tooth root to the tooth head, such as that when the crankshaft rotation is reversed, the clutch is automatically pushed into the other clutch position.

An embodiment of the invention is shown in the accompanying drawing.

Here, the intermediate shaft α of a marine diesel engine is driven from the crankshaft b through a screw c and helical gear d and makes the same number of revolutions as the crankshaft. The intermediate shaft is supported by bearings e and f above and below. The transmission of the movement to the camshaft g happens through three bevel gears, namely the two bevel gears h and i are loosely on the intermediate shaft, the bevel gear k is firmly attached to the camshaft.

■ The ratio from intermediate shaft to camshaft is 2: 1. A cylindrical control slide I is installed on the intermediate shaft in such a way that it rotates continuously with the shaft d and can be moved in the direction of its axis. Shifting is done by lever m. By shifting the control slide downwards (position 1 shown), when the machine is started by the starter motor, the stop surface η rests against the stop surface 0 of the bevel gear h and drives the bevel gear k . If the machine is to run backwards, the control slide is pushed upwards (position 3 shown in dashed lines) and works when the engine is started by the auxiliary machine (turbine, electric motor) nadh backwards with its stop surface p against the surface q of the upper bevel gear i, after the Slide the cranks of the motor and the pistons covered the required path, and the bevel gear i now actuates the bevel gear k. In forward gear the bevel gear i runs with it, in reverse gear the bevel gear h loosely.

The device described ensures that the camshaft in forward and reverse gear of the engine maintains the same direction of rotation.

So that the position of the camshaft and the cams are always set automatically, regardless of the crank position at which the engine is started, or, in other words, so that the cams always operate the valves correctly in forward and reverse gear, it is necessary that the stop surfaces n, 0, p, q are in the same plane through the axis of the shaft and perpendicular to each other when the cranks are at dead center. With this arrangement, when the engine is reversed, the camshaft is only moved again after the pistons have assumed the same position in the other direction of rotation as they had in the previous one when the machine was at a standstill. The position of the stop surfaces marked in Fig. 1 is that which is required when the piston passes through the dead center position. According to the invention, the contact surfaces of the control slide on the one hand and the hubs of the bevel gears on the other hand are helical surfaces with a slight incline. For explanation, a view of the control slide from above is added as Fig. 2 and a section AB through the control slide and intermediate shaft is added as Fig. 3.
The process of reversing the engine

from forwards to backwards is the following: The fuel supply to the fuel valve is turned off in a known manner and the engine stops. Then the control spool is moved into the position required for reverse gear, while at the same time the Fuel supply to the fuel valve is turned on again, and then the engine with the help of the auxiliary engine turned on. After starting

ίο the machine is the auxiliary motor whose The rotor then runs as a flywheel, turned off.

The invention achieves the following essential advantages:

The camshaft only runs in one sense. As a result, the doubling of the cams for forward and reverse gear can be saved. This advantage is only due to a special design of the coupling and setting the same to the wheels to be coupled, without it being necessary ^{to arrange special 1} devices by which the coupling halves are rotated into the correct position to each other. The reversal can be done both by hand and automatically, so that when the coupling halves are formed in the special peculiar shape according to the illustrated and illustrated embodiment, the reversal of the camshaft takes place automatically with the change in the direction of rotation of the crankshaft. No special lever is therefore necessary for reversing the camshaft and the operating personnel are consequently relieved of the need to monitor the camshaft reversal, which significantly increases the maneuverability of the machine.

The movement of the camshaft to control the suction valves of the fuel pump can be derived from the main camshaft, which always rotates in the same direction and therefore only one cam per pump is required here as well, while otherwise two are necessary, one for reverse and one for forward gear, of the machine. aside from that the devices for moving the fuel pump camshaft are not required. This results in a reduction in the manufacturing and maintenance costs of the machine system and an increase in their operational safety.

The coupling does not necessarily have to be arranged as shown in the drawing! represents, in particular, the movement of the crankshaft on the clutch can be done by intermediate shafts of any type. Likewise, driven by the common KupplungsJiälften tooth need not necessarily wheel on the camshaft to sit, but can also propel the same through the intermediary of intermediate shafts.

Claims (1)

Patent claim: Device for reversing gas engines with cranks offset by 180 °, which are started with an auxiliary motor, in which a reversing gear equipped with an axially displaceable clutch is arranged between this and the crankshaft to achieve the same direction of rotation of the camshaft, characterized in that the clutch (1) is freely displaceable on the axis, and that on the two end faces of the displaceable coupling and the halves of the reversing gear to be coupled with it, a self-contained coupling tooth (n, p, 0, q) is arranged, the engagement surfaces of which are in one through the coupling axis and the back of which form a whole thread of a helical surface rising from the tooth root to the tooth tip, in such a way that when the crankshaft rotation is reversed, the coupling is automatically pushed into the other coupling position. For this purpose ι sheet of drawings.