Engine driven welding power supplies with two piece shaft

An engine driven welding system includes two power generators, each having a rotor and a stator. Each rotor is mounted on a respective drive shaft, with one of the drive shafts being driven by the engine and the other drive shaft being releasably coupled to the engine driven drive shaft. This provides a modular type construction of the welding system, in that the outboard power generator can be selected or changed as needed for a particular application. The coupled drive shafts are supported by two bearing assemblies. Also disclosed as additional features for any welding system power supply is a removable plate having one or more connectors releasably attached thereto for facilitating installation of an electrical component for a welding system power supply; and also a power switch having a member that restricts rotational movement of the switch.

TECHNICAL FIELD OF THE INVENTIONS

The present disclosure relates to engine driven welding systems. More particularly, the disclosure relates to engine driven welding systems having at least two power generators associated with the engine. Some aspects of the disclosure relate to welding systems in general, not just engine driven welding systems.

BACKGROUND OF THE DISCLOSURE

Engine driven welding systems may include two power generators, for example, a weld power generator and an auxiliary power generator. In prior systems, these power generators have been mounted on a common single-piece shaft driven by the engine. This makes build, modification and repair costly and time consuming.

In some welding systems, it may be desired to install optional equipment on the power supply. In prior systems, it is difficult and time consuming to identify and access the one or more wires needed to connect to the equipment.

Still further, prior welding systems that provide for multiple power outputs use a switch for selecting an output from the power supply. But since power supplies can vary as to the number of selectable outputs, it is necessary to maintain inventory of different switches and reactors.

SUMMARY OF THE DISCLOSURE

In accordance with an embodiment of one of the inventions presented in this disclosure, an engine driven welding system includes two power generators, each having a rotor and a stator. Each rotor is mounted on a respective drive shaft, with one of the drive shafts being driven by the engine and the other drive shaft being releasably coupled to the engine driven drive shaft. This provides a modular type construction of the welding system, in that the outboard power generator can be selected or changed as needed for a particular application. In another embodiment, the coupled drive shafts are supported by two bearing assemblies, with one bearing assembly near an end portion of the one drive shaft and the other bearing assembly near the outboard end of the second drive shaft.

In accordance with an embodiment of another one of the inventions presented in this disclosure, an exterior panel that supports electrical components and/or hardware for a power supply of a welding system includes a removable plate or cover. The plate may be removed, for example, to allow an electrical component, for example a meter, to be installed in the mounting location in place of the removed plate. The plate includes one or more conductors or connectors that are attached to the plate, so that when the plate is removed an operator may easily grasp the attached one or more conductors, remove the one or more conductors from the plate and connect them to the electrical component being installed.

In accordance with an embodiment of another one of the inventions presented in this disclosure, a power switch mechanism for a welding system power supply includes a rotary power switch having N selectable positions that correspond to different outputs from the power supply where N is an integer with N≧2, and a member associated with the rotary power switch to restrict rotation of the switch to a lesser number of selectable positions. For example, the member may be used to restrict rotation of the rotary power switch to N−1 selectable positions. In a more specific embodiment, the member comprises a plate that is mounted to the rotary power switch and interferes with rotational of at least one of the switch contacts. In another embodiment, the switch contact may be and unused contact, or a non-energized contact when the contact interferes with the member.

These and other aspects, embodiments and advantages of the inventions disclosed herein will be understood by those skilled in the art from the following detailed description of the exemplary embodiments in view of the accompanying drawings.

DESCRIPTION OF THE EXEMPLARY EMBODIMENTS

While the various inventions and inventive concepts are described herein with reference to specific embodiments, such illustrations and descriptions are intended to be exemplary in nature and not as the only embodiments. For example, an embodiment of an engine driven welding system is illustrated with specific examples of power generators, however, the particular design of the welding system and the power generators is largely a matter of design choice except as to various inventive concepts presented herein. Also, as to the inventive concepts concerning a removable plate and a rotatable power switch, such inventions will find application in many different welding systems whether engine driven or otherwise.

With reference toFIGS. 1 and 2, an exemplary engine driven welding system10is illustrated, and such a welding system10may incorporate any one or more or all of the inventions described herein. The specifics of the overall welding system10, including the engine12and power generators14,16(the latter not fully visible in the view ofFIG. 1) are not restrictive as to the nature and use of the inventions presented herein. Rather, many different types of engines, including diesel and gas powered of various sizes and designs, and many different power generators, may be used as a welding system suitable for use with the inventions herein. Moreover, some of the inventions herein will find application outside of the art of engine driven welding systems to welding system power supplies in general.

A covers assembly17may include a roof18and various side casings20(FIG. 2), typically made of sheet metal, and is omitted fromFIG. 1to illustrate the overall assembly of the engine driven welding system10. The major subassemblies may include a support base22, the engine12, a generator assembly15that includes in this example two power generators14,16, a case front and upper control panel assembly24, a lower control panel26, an inner control panel28, a case back assembly30and a reactor, rectifier and fuel tank assembly32. The support base22may include a lift frame34.

The engine12may be mounted in a rearward portion36of the support base22, and the generator assembly15may be mounted in a forward portion38of the support base22. The reactor, rectifier and fuel tank assembly32may be mounted generally above the generator assembly15, and supported by the lift frame34and the case front24. This positions the fuel tank40in a convenient location for the user. The generator assembly15is generally aligned with the drive mechanism of the engine12as will be more apparent from the below discussion.

The lower control panel assembly26may include various components that facilitate the use and control of the welding system10, for example, a fuel/hour gage42, oil temperature and pressure gages44,46and various electrical receptacles48, and output terminals50. An upper control panel52may include various control handles for manual actuation, for example, a first control handle54that may be used to select the output from the welder power supply (the welder power supply produces one or more current/voltage power outputs based on the power generated by the welder power generator). The first control handle54in this example is used to manually rotate a rotary power switch56that is mounted on the reactor, rectifier and fuel tank assembly32(the reactor and rectifier assembly are major components of the welding power supply). A second control handle58may be used, for example, to operate a rotary rheostat (not shown) mounted on the interior side of the case front24opposite the second control handle58. The case back30may support, for example, an air cleaner60for the engine12.

Various electrical cables62(illustrated in a non-connected condition) are used to connect the three phase weld stator windings to the reactor (not shown in detail inFIG. 2) via the rotary power switch56. In this exemplary embodiment, the weld power generator produces a three phase output with various taps so that different outputs can be selected using the rotary power switch56(for example, different voltage and current outputs). Many different weld power generators may be used beyond three phase, and also may provide different numbers of taps for different output options.

In the exemplary embodiments herein, two power generators14,16are used. The first power generator14may be, for example, a weld generator, and the second power generator16may be an auxiliary power generator such as may be used for auxiliary power tools and so on. However, the inventions herein may be used with welding systems that provide two weld power generators, two auxiliary generators and so on.

FIGS. 3 and 4illustrate in more detail the exemplary power generator assembly15and an embodiment of one of the inventions herein. The overall operation of the first and second power generators14,16are well known and need not be described herein, beyond stating that any suitable generator designs may be used, whether known or later developed. The first power generator14may include a stator64that is supported on a welded tie bar assembly66. The first power generator14also includes a rotor68having a first drive shaft70extending centrally there through. A first or back end of the first drive shaft70may include a coupling flange72that is mounted to the flywheel74(seeFIG. 2) of the engine12using a coupling disc76and two backing plates78. The engine12is only partly shown inFIG. 4. In this manner, the engine12rotates the first drive shaft70and with it, the rotor68of the first power generator14. A blower paddle assembly80may be mounted on the coupling disc76to provide cooling air for the power generators.

The rotor68of the first power generator14further includes two brush rings82for electrical contact to the rotor windings, and a first bearing84, all mounted on a second end88or outboard portion of the first drive shaft70. The first bearing84journals into a first bearing support86that may be provided with the tie bar assembly66. The first drive shaft70is thus fully supported at each first and second end by the engine flywheel mounting and the first bearing84respectively. The first bearing84may be any suitable shaft bearing as are well known in the art.

The outboard end portion88of the first drive shaft70extends axially beyond the tie bar assembly66and is releasably connected with a second drive shaft, as will be described herein shortly. A first brush holder assembly89is also provided for contact with the brush rings82.

The second power generator16may include a stator90that is supported on a second welded tie bar assembly92. The second power generator16also includes a rotor94having a second drive shaft96extending centrally there through. The back end98of the second drive shaft96includes an axially tapered bore100(seeFIG. 4). This axially tapered bore100slideably receives the outboard end portion88of the first drive shaft70. FromFIGS. 3 and 4it will be noted that the outboard end88of the first drive shaft70is also axially tapered in a complementary fashion with the tapered bore100of the second drive shaft96. The first and second drive shafts70,96are thus mechanically coupled together with this tapered coupling.

The first drive shaft70also includes an internally threaded bore102(FIG. 4). The second drive shaft96includes an internal through bore104. The rotor94of the second power generator16further includes two brush rings106for electrical contact to the rotor windings, and a second bearing108, all mounted on the second drive shaft96. The second bearing108journals into a second bearing support110that may be provided with the second tie bar assembly92. The second drive shaft96is thus fully supported at one end (98) by the first drive shaft second end88and the first bearing84, and at an opposite end by the second bearing108. The second bearing84may be any suitable shaft bearing as are well known in the art.

A second brush holder assembly112is also provided for contact with the second power generator brush rings106.

A threaded bolt114extends through the second drive shaft interior bore104and into the internally threaded bore102of the first drive shaft70. The bolt114mechanically joins the first and second drive shafts70,96together, and has a hex cap116that bears against the distal end118of the second drive shaft96. Note that the distal end118axially extends slightly beyond the outer facing surface of the second bearing108. A centering and lock washer assembly120may be used to secure the threaded bolt114. The second power generator16may include a cowling122having for example a first and second section122a,122b. Similarly, the first power generator14may include a cowling124having first and second sections124a,124b.

Accordingly, the welding system10provides for two power generators14,16driven by an engine, with the second power generator16supported on its own drive shaft96that is releasably coupled to the first drive shaft70of the first power generator14. This provides a modular construction in which the second power generator can be built, maintained or replaced without having to tear down the entire first power generator mounting. The use of the two bearings84,108provides excellent support for the drive shafts70,96.

Although a tapered coupling is used between the two drive shafts, such is not required. Any suitable coupling may be used, it being preferred that the coupling be releasable so that the second power generator may be easily removed without having to disassemble the first generator mounting arrangement. For example, other couplings may include but are not limited to a rubber coupling, bolted plates, a spline coupling, or a lovejoy-type coupling to name a few examples.

With reference again toFIG. 1and alsoFIG. 5, oftentimes it is desirable to provide users with the option of adding on various components which were not part of the original build. For example, a customer may wish to add various meters, gauges, timers or other instruments to the welding system10or any other welding system for that matter. To accommodate such possible modifications, the covers assembly17or other convenient support structure or exterior panel may be provided with one or more removable covers or plates126. Although in the exemplary embodiments herein the plate126is shown in the upper control panel52, such is not required and the plate or plates126may be located at any convenient location, although typically will be part of the covers assembly17. The plate126may be easily removable by using one or more attachment members128such as screws.

When an electrical component or instrument is to be installed in place of the plate126, it is necessary to locate and connect the appropriate wires to the device. In the past this has required the installer to identify and locate the appropriate wires within the welding system10interior. The wires then have to be manually routed to the opening provided for the instrument or electrical component after the plate126has been removed. In accordance with one embodiment of another inventive concept disclosed herein, the connecting wires130may be attached to the backside or interior surface132of the plate126, for example during build of the welding system10. The ends of the wires may be optionally covered by a protective material134such as tape. Any suitable means may be used to attach the wires130to the plate interior surface132, for example, a cable tie136, VELCRO™, simple tape and so on to name just a few example. The attachment technique should be secure enough that the wires will not fall off the plate132, but can be removed from the plate after the plate126has been removed from the supporting panel it is installed on, such as the upper control panel52. In this manner, when the plate126is removed, the wires130are carried with the plate132so that the wires130are immediately accessible to the person installing the electrical component. The person installing the equipment can easily remove the wires130from the plate126and connect them to the electrical component being installed, without having to identify and fish around inside the welding system10interior for the correct wires. The wires may be connected to the electrical component either before or after the component is installed in the opening or mounting location from which the plate126was removed.

With reference toFIGS. 7 and 8, we illustrate an embodiment of another one of our inventive concepts. Power generators used for welding systems often produce a number of different selectable outputs, for example, with different voltage and current ranges. This is often done with using a plurality of taps off of the stator windings, as is known.FIG. 6illustrates a typical wiring diagram for a stator output. The stator150in this embodiment produces a three phase output152at teiininals154,156and158. A selector switch function160may be used to connect the stator output152to a reactor or multi-tap transformer device162. The reactor162produces selectable three phase outputs at A1, B1and C1depending on which taps164the operator connects the stator output152to using the selector switch function160. The reactor162output (A1, B1, C1) is input to a conventional rectifier circuit166to produce the desired or selected output. NoteFIG. 6also illustrates optional meters, such as an ammeter168or voltmeter170, such as are typical electrical components that may be installed at the plate126location, for example, and a by-pass filter assembly171.

FIG. 7illustrates an embodiment of a selector switch172for carrying out the selector switch function160ofFIG. 6. In this example, the selector switch172may be realized in the form of a commercially available rotary power switch56. Other suitable rotary power switches may alternatively be used. The rotary power switch56includes a support bracket174that may be used to mount the switch172at an appropriate location in the welding system10. In this embodiment, the rotary power switch56is mounted on the reactor, rectifier and fuel tank assembly32just behind the upper control panel52(seeFIGS. 1 and 2). In this manner, the rotary power switch56is nearby the reactor164and stator150outputs to which it is connected via the electrical cables62.

The rotary power switch56includes an actuator shaft176that is axially aligned with and connected to the first control handle54on the upper control panel52(seeFIGS. 1 and 2). In this manner, an operator may turn the actuator shaft176via the handle54to one of a plurality of discreet selectable positions to select an appropriate output for a desired welding operation. The rotary power switch56includes a plurality of N rotary contacts178—wherein N is an integer with N≧2—and a corresponding plurality of stationary contact sets181. Each pair of stationary contact sets181are “hot” in that one contact of each set181is electrically connected to a stator output, and the other contact of each set181is electrically connected to one of the taps of the reactor164. The selected tap is electrically connected to the stator when the corresponding rotary contact178makes a connection between the two. Thus a rotary contact is only conducting current when it makes an electrical connection between the corresponding two stationary contacts when the handle54is turned to the selected position for the desired corresponding output. In a typical rotary power switch56, the control handle54can usually be turned fully through 360° between the various discreet positions of the switch56.

It may be desirable in some cases to prevent one or more of the switch56positions from being used, for example if a particular output from the generator is not to be made available. In the exemplary embodiment, we provide a mechanism by which one less selectable positions is made available, however, based on the teachings herein one will readily appreciate that more than one position may be rendered unavailable.

To provide this capability, we provide an optional additional member177which functions as a switch stop. The switch stop177may be realized in the form of a plate that can be mounted to the switch support bracket174using screws180or other suitable means. In this embodiment, the switch stop177includes two radially offset flanges182,184. When installed as illustrated inFIG. 8, the flanges182,184axially extend toward the rotational contacts178, and in this embodiment, toward the closest rotational contact186. With reference toFIGS. 9 and 10, the flanges182,184will interfere and block rotational movement of the rotatable contact186so as to prevent the operator from selecting one of the otherwise selectable positions of the switch56. This limits the rotary power switch56to N−1 selectable positions, in this embodiment. Which position is restricted may be selected by appropriate alignment and orientation of the flanges182,184. In the example ofFIG. 9, the upper flange182blocks clockwise rotation of the contact186at a particular rotational position of the switch56. InFIG. 10it will be noted that the lower flange184blocks the counter-clockwise rotation of the contact186at the same rotational position of the switch56.

In the embodiment ofFIGS. 7-10, we have chosen an unused rotational contact186for interfering with the flanges182,184, meaning that the contact186is never “hot” or conducting current in any of the selectable positions. Alternatively, a contact that does become “hot” in one or more of the selectable positions may still be used for interfering with the switch stop177, provided that the contact is not “hot” anytime that it contacts the switch stop flanges182or184.

In this manner of the exemplary embodiment, an operator will not be able to turn the control handle54to one of the otherwise selectable switch56positions. The switch stop177thus may be used as an optional feature and easily removed and installed as needed. This allows, for example, a single reactor164design and switch56to be used for a particular generator, when it may be desired to make less than all the generator outputs available to an operator. This reduces the need for multiple reactor and switch inventories to accommodate such changes.