US2241077A - Regulator device for power machines - Google Patents

Description

May 6, 1941. D. THOMA 2,241,077

REGULATOR DEVICE FOR POWER MACHINES Filed March 6, 1959 mwa mo L we're RMOM P\ BY V KT-f0 KNBY- Patented May 6, 1941 REGULATOR DEVICE FOR POWER MACHINES Dieter Thoma, Munich, Germany, auignor to American Voith Contact 00., Inc., New York, N. Y., a corporation of New York Application March" 0, 1939, Serial No. 259,981

In Germany March 28, 1938 6 Claims. (Cl. 1-21-42) This invention relates to regulator devices for power machines in which servomotors are operated by oil pressure, and the principal object of the invention is to increase the sensitiveness oi the regulator device, i. e., to increase the responsiveness of the servomotor piston.

In the devices heretofore used, the response was sluggish due to the relatively large distance which the relatively large diametered control valve had to move before the valve was opened or closed. The object of the present invention is to overcome this disadvantage and to enable quantity of oil flowing from the fine control valve to the auxiliary motor.

a very quick response in the servomotor to be had, thereby augmenting the precision of action of the regulator device.

The present invention consists in providing a secondary valve cooperating with the aforesaid primary valve, the secondary valve being considerably smaller in diameter than the primary valve, and in consequence necessitating a smaller movement in its opening or closing than the primary valve. To still further increase the sensitiveness, the invention also consists in operating the secondary valve by a lever action which transposes its movement in a manner to augment its movement so that the secondary valve is given a relatively quick and large movement. This lever action is operated by mechanism dependent upon the speed of rotation of the'governor of the power machine, and any variation therein moves said lever and hence the secondary valve before the primary valve is operated. The primary valve may be called the main control valve, and the secondary valve may be called the fine control valve.

The invention consists further in a governing contrivance for engines or power machines having an auxiliary motor actuated by pressure liquid for changing the position of the inlet member oil to the auxiliary motor, while the main control valve, which is provided with large laps, sets free the inflow of oil only when the displacement of the fine control valve has become so large v that a further increase in its displacement no longer provides any substantial increase oithe This invention consists further in the mechanism for controlling the main control valve and the fine control valve by a common control rod system in such a way that the fine control valve traverses a greater distance than the main con trol valve, in which connection the lap of the fine control valve is equal to or smaller than the lap of the main control valve.

The invention consists further in the mechanism for controlling the main control valve and the fine control valve by a control rod system in such a way that in case of a displacement they both traverse the same distance, in which connection the fine control valve has a substantially smaller lap than the main control valve.

Finally, the invention consists in the mechanism for controlling the main control valve and the fine control valve in a manner that the ratio of the shift distances of the main control valve and the fine control valve is approximately equal to the inverse ratio of their diameters.

In the accompanying drawing, Fig. 1 shows diagrammatically a valve casing with its primary and secondary valves for controlling the action of the servomotor, together with the lever devices for controlling the movement of the primary and secondary valves in the valve casing, together with the appurtenant operative parts for the flow of the oil and for determining the speed of the prime mover; and Fig. 2 is a section taken on the line 2--2 of Fig.- 1.

Referring to the drawing, the servomotor 6| has a piston it with piston rods 28a and 15. At one side of the piston It, a pipe lia enables the flow of oil to and from that end Gla of the cylinder, and at the other side of the piston IS, a pipe lib enables the flow of oil to and from that end 6! b of the cylinder.

The double arrow 31 indicates the to and fro flow of oil in pipe Ito, and the double arrow 38 indicates the to and fro fiow of oil in pipe lib.

The control valve casing 2| has a main valve rod A therein, with valves a and a" thereon. These valves cooperate with circular ports d and d", which when uncovered by valves 0. and 0." allow oil to flow into or from the pipes Ito. and lGb. Oil is supplied to the casing by pipe 20a, and discharges from the casing pipe l8b, arrows 20b and lac indicating the direction of flow. The discharge of the oil is into container lit, by pipe Ila which is a continuation of pipe l8b. A gear pump l1 pumps the oil from the container I! through pipe l9, and through a check valve 22 and pressure tank 23 to pipe 29, which is a continuation of pipe 20a. Thereby, oil under pressure is supplied to the casing 2| and to the cylinder, at either end, of the servomotor 5|.

A turbine I .is supplied with steam or water or otherfluid by the nozzle II, the opening of which is controlled by the valve Ila, preferably a needle valve, which is operated by a rod l2 pivoted to one leg of an elbow lever l3 pivoted at |3a, the other leg being connected by a rod ll with the piston rod l5 of the servomotor.

The other end 28a of the piston rod is connected with a rod 23, pivotally connected at 21a with a lever 21, the free end of which engages a pulley 29, and is moved thereby in opposite dircetions, depending on the direction of movement of the pulley 29. The lever -2'! at 26c has pivotally connected therewith a lever 26 connected with the valve rod A at 24a, and intermediate of 24a and 25a, the lever 26 is pivotally connected with a lever 25, having one end pivotally connected with a bracket 24 on the exterior of the casing 2|.

The pulley 29 is moved in one or the other direction of movement by a governor 34, this being rotated by the shaft 33 of the pulley 29, which shaft 33 has a bevel gear 32 engaging a second bevel gear 32a on a shaft 3|, to which a bevel gear is secured. This meshes with a bevel gear 30a on the shaft 30b of the turbine wheel l0.

By the operation of the parts described, the servomotor BI is actuated depending on the position of the valve rod A, its position being dependent upon the speed of the turbine l0. As the speed increases, the pulley 29 ascends and raises the rod A, and vice versa.

All of the parts so far described are old and known. h

The disadvantage with the form described and heretofore used, is that the valves 0. and a" of valve rod A are required to travel the considerable distance 35 corresponding to the lap of valve a, before being opened, and thus this form of control valve and its mechanism has not shown itself sufficiently accurate and responsive.

For the purpose of giving a precision action and quick response, the casing 2| is provided with a secondary or fine control valve having a valve stem B with valves 1: and b" thereon. These valves b and b" also operate in connection with circular ports e and e", which are connected with and in communication with ports d and d" by channels 39 and 0. The distance of movement from closed to open position is only the very small distance 36 corresponding to the lap of valve b. Passages or channels ll, 42, 43, 44, and 46 operate in the known way to receive and discharge the flow of oil.

To operate the valve stem B, it is pivotally connected at 48 with a rod 39, pivotally connected at 50. with a lever 5| which is part of and forms a continuation of lever 25. Thus, as soon as lever 21 is moved in one direction, say downwardly, the lever 5|, due to its long leverage arm from the bracket 24, has its free end lowered, and the valves b' and b" are lowered accordingly, it requiring only that the lap distance 36 be uncovered to open the valves b and b". The reverse action takes place when the lever 5| is moved upwardly by the lever 26 and pulley 29.

From the foregoing, it will be seen that the control of the servomotor is brought about by providing a secondary valve having a smaller diameter than the main control valve, and which might be called a fine control or precision valve.

These two valves are arranged in such a manner in connection with the control connections that the secondary or precision valve receives a greater initial movement than the primary valve. The arrangement is so carried out and so selected that the principal valve frees the oil flow first then when the secondary valve has been moved out.

of its central or neutral position to such an extent that by any further movement the quantity of oil which is passed through the secondary valve is not considerably increased.

- be determined in respect to each other thereby that the sum of the operative areas of openings and thereby the governed oil flow passing through both valves, proportionately increases until the valves have been moved their entire distance by the governing connections. It has been seen that this is achieved by giving the secondary valve a greater movement than the primary valve by means of the control lever connections.

The invention is especially applicable to such regulator devices for power machines or engines which necessitate a large regulation, and inconsequence require valves to control the necessary diameters of the valves.

However, merely using large valves has not given that degree of sensitiveness which is imperative. While such a single control valve is simpler from a constructive standpoint, it is attendant with the disadvantageous use that it demands a large lead or lap at the control edges of the valve casing. The amount of this lead, in other words, the amount which the valve must move in respect to the valve casing in order to open or: close the valve, is dependent upon the loss of oil which is passed in the central position of the valve. The larger the diameter of' the valve, the larger also must be the lead or lap, in general. By this, however, there comes into being a very disadvantageous lack of sensitiveness of the governor action and a lag in the movement of the piston of the servomotor in respect to the valve. This disadvantage has been heretofore sought to be reduced by recesses in the valves at the controls acting as the lap. Experience has taught, however, that such devices did not cause a responsiveness in those cases where an accurate governing action is demanded. Also, the necessary preparation between the secondary oil quantity and the governor adjustment could not :be obtained.

Within the domain or sphere of smaller adjustments of the piston of the servomotor when out of its central position, there is only of value in respect to doing the work that part of the piston circumference which is provided with recesses. The increase of the cross section to enable the flow to pass therethrough which takes place with a smaller adjustment within said sphere of influence is equal to the sum of the circumferentially measured width of recesses multiplied by the adjustment. Within the domain or sphere of larger adjustments, the entire piston circumference is effective and the increase of the flow cross section at a small adjustment is equal to the entire piston circumference multiplied by the adjustment. From this rule it appears that a real proportion between the governed oil quantity and the size of the adjustment from its middle position cannot be even approximately reached, in order to govern within the total sphere of the adjustments.

. Contrary to the known devices pointed out, the present invention, by utilizing two control valves working in the manner described and moved in the manner described, gives a high degree of sensitiveness, notwithstanding the large lap of the primary or main control valve.

While I have illustrated and described the preferred form of construction for carrying my invention into effect, this is capable of variation and modification without departing from the spirit of the invention. 1, therefore, do not wish to be limited to the precise details of construction set forth, but desire to avail myself of such variations, modifications and adaptations as come within the scope of the appended claims.

What is claimed is: r

l. A regulator device for power machines, comprising an auxiliary motor actuated by a pressure fluid for changing the position of the inlet member of the machine, a plurality of valves for supplying to and dischargingfrom said auxiliary motor the pressure fluid, one of said valves'being a main control valve and one a fine control valve, a governor, responsive to the speed of the power machine, and connections between said governor and said valves, the connections including an extended lever for first opening the fine control valve before opening the main control valve, to enable the pressure fluid to first fiow from the fine control valve to the auxiliary motor or to first flow from said motor to said fine control valve, before the main control valve is operated.

2. A regulator device for power machines, comprising an auxiliary motor actuated by a pressure fluid for changing the position of the inlet member of the machine, a plurality of valves for supplying to and discharging from said auxiliary motor the pressure fluid, one of said valves being a main control valve and one a fine controlvalve, a governor, responsive to the speed of the power machine, and connections between said governor and said valves, th connections including an extended lever for first opening the fine control valve before opening the main control valve, to enable the pressure fluid to first flow from the fine control valve to the auxiliary motor or to the first flow from said motor to said fine control valve, before the main control valve is operated, the lap of the main control valve being larger than the lap of the fine control motor, connections between the servomotor and the throttle valve, and connections between the governor and the said power mechanism, the lap of the fine control valve being equal to or smaller than the lap of the main control valve, whereby the operation of the governor opens the fine control valve before the main valve, the governor being operated by the power mechanism.

4. In a regulator device for power mechanism, having a machine to be regulated, a throttle valve for the same, a servomotor for said throttle valve, and a governor responsive to the speed of the power machine, the combination of a main valve having a lap for controlling the pressure fluid operating the servomotor, a fine control valve having a lap controlling the pressure fluid operating the servomotor, the main valve having a larger diameter and larger lap than that of the fine control valve, and means connecting with the governor and with the servomotor for moving said valves for opening the fine control valve with its shorter lap before opening the main valve.

5. In a regulator device for power mechanism, having a machine to be regulated, a throttle valve for the same, a servomotor for said throttle valve, and a governor responsive to the speed of the power machine, the combination of a main valve having a lap for controlling the pressure fiuid operating the servomotor, a fine control valve having a lap controlling the pressure fiuid operating the servomotor, the main valve having a larger diameter and larger lap than that of the fine control valve, and means connecting with the governor and with the servomotor for moving said valves for opening the fine control valve with its shorter lap before opening the main valve.

' the ratio of shift distances of the main valve and fine control valve being approximately equal to the inverse ratio of their diameters.

6. In a regulator device for power machines, a main valve, a fine control valve, a lever connected with said valve, said lever being pivotally supported at one end, means connecting said lever at its free end with the fine control valve, means disposed between the pivoted connection and the free end of the lever connecting said lever with the main valve, a second lever pivoted at one end and having a free end, a governor connected with the free end of said second lever, a prime mover for actuating the governor, an auxiliary motor for receiving pressure fiuid from said main and fine control valves and discharging the same to said valves, means connecting said auxiliary motor with the pivoted end of said second lever, a throttle valve for the prim mover. and means connecting the throttle valve of the prime mover with said auxiliary motor, whereby the auxiliary motor controls the speed of the prime mover, and the governor operated by the prime mover controls through the levers the main and fine control valves.

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