Barring-tool system and method

Abstract

A barring-tool system improving safety, speed, effectiveness, and number of personnel required for maintenance, repair, and inspection of large engines, generators, and turbines, providing controlled bidirectional rotation and locking of crankshafts during maintenance, and a method for maintenance of large engines, generators, and turbines using the barring-tool system.

Claims

1. A barring-tool system for controlled rotation and locking of crankshafts of large engines, generators, and turbines, said engine, generator, or turbine each featuring a frame of said engine, generator, or turbine, comprising: a retractable pinion adapted to extend toward and to engage with and drive a ring gear surrounding the crankshaft of the engine in either a right-handed or left-handed direction and to hold the ring gear in position when no driving force is applied; a barring motor connected to said retractable pinion, where said barring motor is adapted to extend and retract said retractable pinion according to the state of a signal at a pinion-extension port, and to drive said retractable pinion in either direction at low speed and high torque, or to hold said retractable pinion in position against high torque; a force generator adapted to provide motive force to said barring motor sufficient to drive said retractable pinion in either direction at low speed and high torque, or to hold said retractable pinion in position against high torque; a manual control unit, further comprising: a middle control switch controlling the state of a signal at said pinion-extension port, in turn causing said barring motor to extend said retractable pinion into contact with the ring gear or to retract away from such contact; a right control switch causing said force generator to transmit motive force to said barring motor such that said retractable pinion is driven at low speed and high torque in a nominally left-handed direction resulting in a nominally right-handed rotation of the ring gear; and a left control switch causing said force generator to transmit motive force to said barring motor such that said retractable pinion is driven at low speed and high torque in a nominally right-handed direction resulting in a nominally left-handed rotation of the ring gear; where said barring motor with said retractable pinion is further adapted to be mounted to a mounting surface fixed in relation to the frame of the engine so that said retractable pinion, when extended, contacts the ring gear, and so that the required torque can be applied without dislodging said barring motor with said retractable pinion; and a manual secondary brake movably mounted to said mounting surface fixed in relation to the frame of the engine of said barring motor and retractable pinion, where said manual secondary brake is adapted to be placed out of contact with the ring gear to prevent further rotation of the crankshaft; where said force generator further comprises a bidirectional relay adapted to respond to signals from said right control switch and said left control switch, in turn controlling release of motive force from a bidirectional manifold such that either a right-turning force, a left-turning force, or an equal, static force is transmitted to said barring motor and said retractable pinion according to the state of said control switches.

2. The barring-tool system of claim 1, where said manual control unit further comprises pneumatic control of said pinion-extension port and said bidirectional relay.

3. A barring-tool system for controlled rotation and locking of crankshafts of large engines, generators, and turbines, said engine, generator, or turbine each featuring a frame of said engine, generator, or turbine, comprising: a retractable pinion adapted to extend toward and to engage with and drive a ring gear surrounding the crankshaft of the engine in either a right-handed or left-handed direction and to hold the ring gear in position when no driving force is applied; a barring motor connected to said retractable pinion, where said barring motor is adapted to extend and retract said retractable pinion according to the state of a signal at a pinion-extension port, and to drive said retractable pinion in either direction at low speed and high torque, or to hold said retractable pinion in position against high torque; a force generator adapted to provide motive force to said barring motor sufficient to drive said retractable pinion in either direction at low speed and high torque, or to hold said retractable pinion in position against high torque; a manual control unit, further comprising: a middle control switch controlling the state of a signal at said pinion-extension port, in turn causing said barring motor to extend said retractable pinion into contact with the ring gear or to retract away from such contact; a right control switch causing said force generator to transmit motive force to said barring motor such that said retractable pinion is driven at low speed and high torque in a nominally left-handed direction resulting in a nominally right-handed rotation of the ring gear; and a left control switch causing said force generator to transmit motive force to said barring motor such that said retractable pinion is driven at low speed and high torque in a nominally right-handed direction resulting in a nominally left-handed rotation of the ring gear; where said barring motor with said retractable pinion is further adapted to be mounted to a mounting surface fixed in relation to the frame of the engine so that said retractable pinion, when extended, contacts the ring gear, and so that the required torque can be applied without dislodging said barring motor with said retractable pinion; and a manual secondary brake movably mounted to said mounting surface fixed in relation to the frame of the engine of said barring motor and retractable pinion, where said manual secondary brake is adapted to be placed out of contact with the ring gear to prevent further rotation of the crankshaft; where said force generator further comprises a source of hydraulic force and a bidirectional manifold further comprising hydraulic valves.

4. A barring-tool system for controlled rotation and locking of crankshafts of large engines, generators, and turbines, said engine, generator, or turbine each featuring a frame of said engine, generator, or turbine, comprising: a retractable pinion adapted to extend toward and to engage with and drive a ring gear surrounding the crankshaft of the engine in either a right-handed or left-handed direction and to hold the ring gear in position when no driving force is applied; a barring motor connected to said retractable pinion, where said barring motor is adapted to extend and retract said retractable pinion according to the state of a signal at a pinion-extension port, and to drive said retractable pinion in either direction at low speed and high torque, or to hold said retractable pinion in position against high torque; a force generator adapted to provide motive force to said barring motor sufficient to drive said retractable pinion in either direction at low speed and high torque, or to hold said retractable pinion in position against high torque; a manual control unit, further comprising: a middle control switch controlling the state of a signal at said pinion-extension port, in turn causing said barring motor to extend said retractable pinion into contact with the ring gear or to retract away from such contact; a right control switch causing said force generator to transmit motive force to said barring motor such that said retractable pinion is driven at low speed and high torque in a nominally left-handed direction resulting in a nominally right-handed rotation of the ring gear; and a left control switch causing said force generator to transmit motive force to said barring motor such that said retractable pinion is driven at low speed and high torque in a nominally right-handed direction resulting in a nominally left-handed rotation of the ring gear; where said barring motor with said retractable pinion is further adapted to be mounted to a mounting surface fixed in relation to the frame of the engine so that said retractable pinion, when extended, contacts the ring gear, and so that the required torque can be applied without dislodging said barring motor with said retractable pinion; and a manual secondary brake movably mounted to said mounting surface fixed in relation to the frame of the engine of said barring motor and retractable pinion, where said manual secondary brake is adapted to be placed out of contact with the ring gear to prevent further rotation of the crankshaft; where said barring motor further comprises a bidirectional hydraulic motor adapted to drive said retractable pinion in either direction at low speed and high torque, and to hold said retractable pinion in position against high torque.

Description

BRIEF DESCRIPTION OF DRAWINGS

(1) Reference will now be made to the drawings, wherein like parts are designated by like numerals, and wherein

(2) FIG. 1 is a schematic view of the prior art of barring.

(3) FIG. 2 is a schematic view of the prior art of jacking.

(4) FIG. 3 is a schematic view of the invention in use.

(5) FIG. 4 is a schematic view of the invention's optional split ring gear before installation.

(6) FIG. 5 is a schematic view of the invention's optional split ring gear after installation.

(7) FIG. 6 is a schematic view of the invention coupled to an engine's ring gear.

(8) FIG. 7 is a schematic view of the invention uncoupled from an engine's ring gear.

(9) FIG. 8 is a schematic view of the invention's manual secondary brake disengaged from an engine's ring gear.

(10) FIG. 9 is a schematic view of the invention's manual secondary brake engaged with an engine's ring gear.

(11) FIG. 10 is a schematic view of an embodiment of the invention coupled to an engine's ring gear at two points.

DETAILED DESCRIPTION OF THE INVENTION

(12) Referring to FIG. 3 & FIG. 10, my invention provides a barring-tool system 1 having a manual control unit 10 controlling a barring motor 30 driven by a force generator 40 and in turn driving a retractable pinion 50 which drives a ring gear 90 surrounding a flywheel 95 of a large engine. A middle control switch 11 causes the barring motor to start and to extend the retractable pinion 50 into contact with the ring gear 90 or to retract away from such contact. A right control switch 12 causes the force generator 40 to deliver a force 42 to the barring motor 30 such that the pinion 50 is driven at low speed and high torque in a nominally left-handed direction resulting in a nominally right-handed rotation of the ring gear 90. A left control switch 13 causes the force generator 40 to deliver a force 43 to the barring motor 30 such that the pinion 50 is driven at low speed and high torque in a nominally right-handed direction resulting in a nominally left-handed rotation of the ring gear 90.

(13) In a preferred embodiment, the system uses a combination of electrical, pneumatic, and hydraulic forces for safety, efficiency, and reliability reasons. The control paths 21, 22, 23 emerging from the manual controller are pneumatic, providing an explosion-proof, reliable lower-pressure motivating force for extension of the pinion when pneumatic force is applied at the pinion-extension port 31 of the barring motor 30, and for activating the bidirectional relay 45 of the force generator 40, which in turn activates the appropriate directional force 42, 43 from the bidirectional manifold 46. The force provided by the force generator 40 to the barring motor 30 is hydraulic, providing an explosion-proof, reliable higher-pressure motivating force to drive the barring motor 30 to rotate the pinion in either direction at low speed and high torque. The hydraulic pressure in the preferred embodiment is in turn generated by an electric motor.

(14) In the preferred embodiment, the pneumatic pressure 80 is supplied by an outside air compressor such as an engine room's standard compressed air supply. Air pressures in the range of 70 to 100 p.s.i. are sufficient, and only a modest volume of flow is required by the system. Depending upon the size and other characteristics of the engine to be turned, hydraulic pressures between 200 and 400 p.s.i. are likely to be needed by the barring motor 30 in order to provide the required torque for turning the engine.

(15) For very large or hard-to-turn engines, an embodiment having two or more barring motors 30 driving two or more pinions 50 at different points on the ring gear can be used, as shown in FIG. 10. In such an embodiment, the shared channels of pneumatic and hydraulic forces ensure that the two or more barring motors perform in coordination with each other.

(16) When neither the right nor the left manual control switches are activated, or when they are both activated, the barring motor 30 and the pinion 50 are locked in place by the equal hydraulic pressures on both the right- and left-turning sides. If the pinion 50 remains extended and in contact with the ring gear 90 when the barring motor and pinion are locked in place, the ring gear and the engine will also be locked in place so that the engine cannot accidentally or spontaneously rotate out of the locked position. An optional check valve 15 placed somewhere in the pneumatic line 21 feeding the pinion-extension port 31 of the barring motor 30 will latch the pinion in a pressurized and therefore extended state until the check valve is cleared and the pinion is allowed to retract, thereby keeping the pinion extended for locking purposes even if the middle button 11 of the manual controller 10 is released.

(17) The barring-tool system 1 is adapted to both permanent and temporary installation on any single large engine or for use, in turn, on several large engines. In order to apply the proper rotational force, the barring motor 30 and pinion 50 must be either permanently or temporarily mounted to either the frame of the engine itself or to a mounting surface fixed in relation to the frame of the engine, so that the pinion 50, when extended, contacts the ring gear 90, and so that the required torque can be applied without dislodging the barring motor.

(18) The force generator 40 or hydraulic-pressure generator is not mounted in any fixed relation to the engine, and can be located at a variety of locations near to or farther from the engine, within any performance limitations of long runs of pneumatic and hydraulic lines. In an engine room with multiple engines, a single force generator 40 or hydraulic-pressure generator could serve, in turn, all engines. And the barring motor 30 or motors could be moved from engine to engine as needed, or could be mounted on particular engines for longer periods if a frequent need for barring is anticipated. The barring-tool system 1 is also well adapted to use as a transportable system that can be carried in a small truck or van from site to site as needed for periodic scheduled or emergency maintenance of engines.

(19) Referring to FIG. 4 & FIG. 5, in order that the barring-tool system can be used on engines that do not normally have a suitable exposed ring gear 90, or where an existing ring gear has been damaged beyond use, my invention provides split-ring-gear adapters 91 that can be mounted on an engine's flywheel 95 or crankshaft and connected together to form a temporary or semi-permanent ring gear suitable for use with the barring-tool system. The split-ring-gear adapters 91 are two or more semi-circular or partially circular sections of ring gear that together form a circle of an appropriate inner-face diameter matching the outer diameter of a particular engine's flywheel 95 or crankshaft, and a geared outer-face diameter performing as a ring gear with which to rotate the flywheel and the crankshaft of the engine. The split-ring-gear adapters 91 are provided with matching connection points 92 which can be connected by standard bolts 93 and nuts 94, where the clamping or compressive force of the split-ring-gear adapters can be regulated by the force placed on the connection points by the bolts and nuts connections. The resulting ring gear allows an engine to be barred with the barring-tool system. Although the resulting ring gear assembled from split-ring-gear adapters might be poorly balanced due to the added mass of the connection points or due to imprecise placement upon the flywheel, the ring gear is only necessary for the low-speed barring operations during maintenance or inspection, and can be removed afterwards, so that it does not affect the normal running of the engine in any way. The split-ring-gear adapters allow for the use of the barring-tool system on a temporary or emergency basis on a greater variety of engines.

(20) Referring to FIG. 6 & FIG. 7, the barring motor 30, when a control signal is present at the pinion-extension port 31, extends the pinion 50 so that it makes contact with the ring gear 90 surrounding the flywheel 95 and crankshaft of the engine. Conversely, when the control signal is absent at the pinion-extension port 31, the pinion 50 returns to its retracted position out of contact with the ring gear 90. In a preferred embodiment, compressed air in a pneumatic tube acts as both the control signal for extension of the pinion and as the motive force for extending the pinion, directly working upon a pneumatic extending actuator against the retracting force of a spring. The same function could be accomplished with electricity or hydraulic pressure, but at greater cost and complexity in the potentially explosive conditions of many engine rooms.

(21) Referring to FIG. 8 & FIG. 9, the barring-tool system of the invention also provides a manual secondary brake 60 essentially in the form of a pinion 50 to engage the ring gear 90, but mounted in a non-rotating, fixed, locked state with regard to rotation of the ring gear. The manual secondary brake 60 is movably or removably mounted to the same mounting surface as the barring motor 30 and pinion 50 in such a way that the manual secondary brake 60 can be placed out of contact with the ring gear 90 to allow rotation of the crankshaft of the engine, or be placed in contact with the ring gear 90 to prevent further rotation of the crankshaft, thus locking the engine in place to prevent any spontaneous rotation or any accidentally initiated rotation, either of which can be dangerous and damaging to personnel or to the engine. Because the barring-tool system provides a pinion 50 that also locks an engine against rotation whenever the pinion is extended into contact with the ring gear but is not being actively rotated in either direction, the manual secondary brake 60 serves as an additional means of locking the engine against rotation, under manual control independent of any accidental improper operation of the manual control unit 10, malfunction or failure of the electric, pneumatic, or hydraulic components of the barring-tool system, or other potential sources of unwanted and dangerous rotation of the crankshaft during maintenance or inspection. In a preferred embodiment, the manual secondary brake is mounted on an offset pivot point so that it can be manually rotated into or out of contact with the ring gear.

(22) Many changes and modifications can be made in the present invention without departing from the spirit thereof. We therefore pray that our rights to the present invention be limited only by the scope of the appended claims.