Belt drive for feeding welding wire

A welding wire feed drive system is provided including belts mounted on wire drive rollers. One or both belts may be poly-V belts mounted on the rollers and positioned such that grooves of the belts are outward facing. Opposing grooves and projections of the belts may form an interfacing or interlocking arrangement suitable for the securement of a welding wire therein. The grooves and projections of the belts may be utilized to facilitate the movement of the welding wire towards a welding application.

BACKGROUND

The invention relates generally to wire feeding systems, and, more particularly, to wire feed drive systems.

Welding is a process that has become increasingly ubiquitous in various industries and applications. While such processes may be automated in certain contexts, a large number of applications continue to exist for manual welding operations. Such welding operations rely on a variety of control schemes to ensure the supply of welding consumables (e.g., wire feed, shielding gas, etc.) is provided to the weld in an appropriate amount at the desired time. For example, metal inert gas (MIG) welding relies on a proper welding wire feed rate to prevent weld splatter and arc outage. In many instances, a proper wire feed may be defined by parameters such as wire feed speed, consistency of the wire feed, and so forth.

To ensure that a proper wire feed is maintained throughout a welding operation, a wire drive system is typically utilized to unspool wire from a wire spool and to feed the wire to a welding torch. Such wire drive systems may include drive rollers that grip the wire, pull the wire off the wire spool, and push the wire toward the welding torch. Unfortunately, since there is typically a small contact area between the drive rolls and the wire, a substantial force is applied to the wire during feeding. Such a force may lead to deformation of the wire, and can even cause the wire to break, or result in small wire shavings being separated from the moving wire strand. These shavings may become lodged inside components of the welding system, such as the welding torch, compromising the quality of the weld. Accordingly, there exists a need for improved wire feeding systems that overcome such limitations.

BRIEF DESCRIPTION

In an exemplary embodiment, a welding wire drive system includes a drive roll system including a first roller and a second roller, at least one of which serves as a drive roller. The system also includes a first belt including a first series of generally v-shaped grooves and a first series of generally v-shaped projection, the belt being adapted to be mounted on the first roller in a back-driven configuration with the grooves and projections facing outward from a surface of the first drive roller. The wire feed drive system also includes a second belt including a second series of generally v-shaped groove and a second series of generally v-shaped projection and being adapted to be mounted on the second roller in a back-driven configuration with the second grooves and the second projections facing outward from a surface of the second roller. The first belt and the second belt form an interfacing arrangement adapted to receive a welding wire and feed the welding wire to a welding torch.

In another embodiment, a welding wire drive system includes a drive roll system including a first roller and a second roller, as well as a first belt including a groove and a projection, and a second belt with a groove and a projection. The first belt is adapted to be mounted on the first roller in a back-driven configuration with the groove and the projection facing outward from a surface of the drive roller. The second belt is adapted to be mounted on the second roller and to form an interfacing arrangement with the groove and the projection of the first belt, wherein the interlocking arrangement is adapted to receive a welding wire and feed the welding wire to a welding torch.

In another embodiment, a welding wire drive system includes a drive roll system including a first drive roller and a second drive roller. The wire drive system also includes a first belt including a first groove and a first projection and being adapted to be mounted on the first roller in a back-driven configuration with the first groove and the first projection facing outward from a surface of the first roller. The wire drive system also includes a second belt adapted to be mounted on the second roller, wherein the first belt and the second belt form an interlocking arrangement adapted to receive a welding wire.

DETAILED DESCRIPTION

As described in detail below, embodiments are provided of a welding wire drive system including one or more back-driven belts mounted on wire drive rollers or pulleys, as referred to generally in the following discussion as “rollers”. That is, in embodiments of the present invention, one or more belts may include grooves and projections, which may be generally v-shaped, may be coupled to wire rollers of a welding wire system, one or more of which may serve as a drive roller for driving the belt(s) in continuous circulation to drive welding wire. Where the belt(s) are grooved, the wire may be positioned in opposing grooves or between a groove and a projection, the arrangement forming one of a variety of possible interfacing arrangements suitable for driving the welding wire. As such, the grooves and projections of the belts may be utilized to facilitate both drawing the welding wire from the wire spool and driving the wire through a weld cable to a welding torch. In some embodiments, the belts may be offset with respect to one another such that the welding wire is positioned between a projection of one belt and a groove of another belt. The sizes of the grooves and projections of the belts may be varied along the length of the belts such that a single belt combination may support the feeding of welding wires of different diameters.

Turning now to the drawings,FIG. 1illustrates an exemplary welding system10which powers, controls, and provides supplies to a welding operation. The welding system10includes a welder12having a control panel14through which a welding operator may control the supply of welding materials, such as shielding gas, welding wire, and so forth, to a welding gun16. To that end, the control panel14includes input or interface devices, such as knobs18that the operator may use to adjust welding parameters (e.g., voltage, current, etc.). The welder12may also include a tray20mounted on a back of the welder12and configured to support a gas cylinder22held in place with a chain24. The gas cylinder22is the source of the gas that supplies the welding torch16. Furthermore, the welder12may be portable via a set of smaller front wheels26and a set of larger back wheels28, which enable the operator to move the welder12to the location of the weld.

The welding system10also includes a wire feeder30that provides welding wire to the welding torch16for use in the welding operation. The wire feeder30may include a control panel32that allows the user to set one or more wire feed parameters, such as wire feed speed. Additionally, the wire feeder30may house a variety of internal components, such as a wire spool, a wire feed drive system, a motor, and so forth. In presently contemplated embodiments, the wire feeder30may house a wire feed drive system including rollers that support drive belts. That is, the wire feed mechanism internal to the wire feeder30may feature one or more belts positioned about the rollers, and the belts may include grooves and projections that interface to hold and drive the wire, spreading the contact area between the belts and the wire far beyond that obtainable with conventional arrangements in which drive rolls contact the wire directly. Such an arrangement may facilitate the feeding of welding wire to the welding torch16as the belts contact the welding wire and feed the wire to the torch. The grooves of opposing belts may be positioned relative to one another in a variety of ways suitable for the feeding of welding wire, as discussed in more detail below.

A variety of cables couple the components of the welding system10together and facilitate the supply of welding materials to the welding torch16. A first cable34couples the welding gun16to the wire feeder30. A second cable36couples the welder12to a work clamp38that connects to a workpiece40to complete the circuit between the welder12and the welding torch16during a welding operation. A bundle42of cables couples the welder12to the wire feeder30and provides weld materials for use in the welding operation. The bundle42includes a feeder power lead44, a weld cable46, a gas hose48, and a control cable50. Depending on the polarity of the welding process, the feeder power lead44connects to the same weld terminal as the cable36. It should be noted that the bundle42of cables may not be bundled together in some embodiments.

Modifications to the exemplary welding system10ofFIG. 1may be made in accordance with aspects of the present invention. For example, the tray20may be eliminated from the welder12and the gas cylinder22may be located on an auxiliary support cart or in a location remote from the welding operation. Furthermore, although the illustrated embodiments are described in the context of a constant voltage MIG welding process, the features of the invention may be utilized with a variety of other suitable welding systems and processes. For instance, the wire feeder may be used with any wire feeding process, such as gas operations (gas metal arc welding (GMAW)) or gasless operations (shielded metal arc welding (SMAW)). For further example, the wire feeder may be used in metal inert gas (MIG) welding or stick welding.

It should also be noted that the wire feeder may be separate from the power supply, or may be integrated into the same enclosure or housing. Both arrangements may incorporate the unique wire drive techniques described herein. Similarly, the components described may be reduced in size for incorporation into other welding wire feeding components, such as so-called spool guns, in which a small spool of welding wire is held as part of a welding torch. Still further, the belt drive approach described may be incorporated, in miniaturized fashion, into welding torches that pull wire from a remote spool, such as those typically designed for aluminum wire that can support less column loading than steel wire.

FIG. 2is a perspective view of an exemplary wire drive system54that may be internal to the wire feeder ofFIG. 1. The wire drive system54includes a motor56, a support58, a first roller60, a second roller62, a third roller64, a fourth roller66, and a wire guide assembly68. In this exemplary arrangement, a first back-driven poly-V belt70is disposed about the first roller60and the second roller62. A second back-driven poly-V belt72is disposed about the drive roller64and the fourth roller66. That is, in the illustrated embodiment, the poly-V belts70and72are positioned with their respective generally v-shaped grooves facing outward from the surfaces of the drive rollers60,62,64, and66. A wire74is positioned between the first poly-V belt70and the second poly-V belt72.

The belts illustrated may be of a type used in other applications, such as on grooved pulleys of internal combustion engines, electric motor/load belt drives, and so forth. However, the belts here are “back-driven”, meaning that rather than having the grooves and intermediate protrusions facing the interior of the continuous loop, they face outwardly so that the welding wire can be positioned in one of the grooves. Additionally, the belts could be conventional-driven by using a drive roller against the outside, or v-groove side, of the belt. Moreover, as described below, the belts may include multiple grooves and protrusions, and hence the term “poly-V” belt may be used. However, embodiments of the invention may be based upon belts with a single groove. Similarly as described below, it is possible to employ a belt with only a single groove, or belts that are specially made for this application, such as belts with grooves of different size, shape, and so forth. Thus, where reference is made in this discussion to “v-shaped” grooves or projections, it should be understood that these may be actually in the shape of the letter V, or may have a flat bottom or top, various angles, and so forth.

During operation of the wire feeder, the wire drive system54is adapted to pull welding wire74through the poly-V belts70and72in the direction of arrow76. In some embodiments, the wire may be routed through an inlet guide that receives the wire and feeds it to the poly-V belts70and72. The poly-V belts70and72are configured to rotate about the drive rollers60,62,64, and66and compress the wire74in a channel formed between opposing v-grooves (or between a groove of one belt and a projection of the other) in order to advance the wire towards the welding torch. The motor56facilitates wire advancing by driving one or more of the rollers. As will be appreciated by those skilled in the art, it will typically be preferred that a downstream roller serve as a drive roller so as to pull the associated belt, although other or multiple rollers may be driven. The non-driven rollers may serve as idlers only, holding the associated belt firmly in place and guiding the belt along its continuous circulating path. All such rollers will typically be mounted on anti-friction bearings in a manner well known in the art.

The embodiment ofFIG. 2illustrates a four roller drive system54including the four rollers60,62,64, and66that provide opposing pressure on the wire to advance the wire towards the welding torch. However, it should be noted that the back-driven poly-V belts may be utilized with a variety of other wire drive systems. For example, the back-driven poly-V belts may be incorporated into a two roll drive system. Such an embodiment may be advantageous in welding applications with space or cost constraints. Still further, the poly-V belts could be incorporated into wire drive systems with any number of drive rollers (e.g., 6 rollers, 8 rollers, etc.). Furthermore, although not shown inFIG. 2, any of a variety of intermediate structures may be positioned between the rollers to maintain contact between the rollers, the belts, and the welding wire.

FIG. 3is a side view of the second roller62and the fourth roller66with the mounted poly-V belts70and72. As shown, the v-grooves of the poly-V belts70and72are positioned so as to form an interfacing arrangement78, in this case an interlocking arrangement. The interfacing arrangement78may feature the opposing v-grooves positioned in a variety of ways (e.g., opposite v-grooves offset from one another, or opposite v-grooves aligned). However, the welding wire is adapted to securely fit within the interfacing arrangement78. Furthermore, in some embodiments, the poly-V belts may be electrically isolating so as to isolate the rollers from the current in the welding wire. Additionally, the interfacing arrangement78may be advantageous since a single poly-V belt may be amenable to welding with a variety of types of wire, such as aluminum, titanium, steel, stainless steel, and so forth.

FIG. 4illustrates the interfacing arrangement78of the v-grooves of the poly-V belts70and72in more detail. As shown, the poly-V belt70includes v-grooves80that alternate with v-projections82along the length of the poly-V belt70. Similarly, the poly-V belt72includes v-grooves84that alternate with v-projections86along the length of poly-V belt72. In the illustrated embodiment, the v-projections82of the first belt70are offset by an offset distance88from the v-projections86of the second belt72. In some embodiments, the offset distance88may be equal to approximately one half of the pitch90of the v-grooves84. In other embodiments, the offset distance88between the first belt70and the second belt72may be any other suitable distance such that welding wire may be secured between the first belt70and the second belt72during operation.

In the illustrated embodiment, the offset distance88is a suitable distance to facilitate the alignment of the v-grooves84of the second belt72with the v-projections82of the first belt70. Likewise, the illustrated offset distance88facilitates the alignment of the v-grooves80of the first belt70with the v-projections86of the second belt72. Furthermore, in the embodiment illustrated, a height92of the v-projections86of the second belt72is approximately equal to a height94of the v-projections82of the first belt70. The foregoing feature may facilitate a proper wire feed since the wire may be adapted to contact portions of both the first belt70and the second belt72during use.

Again, in the illustrated embodiment, the grooves and projections are generally v-shaped. However, it should be noted that in presently contemplated embodiments, the grooves and projections may be any of a variety of other suitable shapes. For instance, the grooves and the projections may be generally rectangular, square, triangular, u-shaped and so forth. Indeed, although the illustrated embodiments show poly-V belts, any other suitable belt with grooves and projections that may be adapted to form an interfacing or interlocking arrangement may be utilized as well.

FIG. 5is a schematic illustrating an exemplary embodiment of the interfacing arrangement78. This embodiment features an offset interfacing arrangement78in which the projection82of the first belt70is substantially aligned with the groove84of the second belt72. The welding wire84in this arrangement is securely positioned between the projection82of the first belt70and the groove84of the second belt72. That is, a first point of contact96is established between the welding wire74and the projection82, a second point of contact98is established between the welding wire74and the groove84, and a third point of contact100is established between the welding wire74and the groove84. In total, in this embodiment, the welding wire74contacts the belts70and72at three locations96,98, and100. Such a positioning of the welding wire74may increase the number of contact points established between the wire and the drive mechanism as compared to traditional designs. Such a feature may be advantageous because multiple contact points may increase the grip on the wire, thereby facilitating the pulling of the wire off a wire spool and the feeding of the wire to the welding torch.

FIG. 6is a schematic illustrating another exemplary embodiment of the interfacing arrangement78. This embodiment features an offset interfacing arrangement78in which the projection86of the second belt72is substantially aligned with the groove80of the first belt70. The welding wire84in this arrangement is securely positioned between the projection86of the second belt72and the groove80of the first belt70. Although the welding wire74ofFIGS. 5 and 6is positioned adjacent to the first projections82and86of the belts70and72, respectively, in other embodiments, the welding wire may be positioned in a similar way between any of the grooves and projections of the belts. Furthermore, the welding wire may be positioned between the first projection and groove of the belts until the first projection and the first groove become worn through repeated use. Subsequently, the welding wire may be positioned between the next groove and projection and so on until all the grooves and projections along the length of the belts become worn from use. In this way, the utility of the belt may be maximized by utilizing all the grooves and projections along the length of the belts.

FIG. 7is a schematic illustrating another embodiment of the interfacing arrangement78featuring alignment between the first belt70and the second belt72. That is, in this embodiment, the groove80of the first belt70and the groove84of the second belt72are aligned. Likewise, the projection82of the first belt70and the projection86of the second belt72are aligned. The welding wire74is positioned between the groove80and the groove84. However, in further embodiments, the welding wire74may be positioned between the projection82and the projection86.

FIG. 8is a schematic illustrating a further embodiment of the interfacing arrangement78in which the projections and the grooves of the belts are unequally sized and spaced along the length of the belts. That is, the first projection82of the first belt70has an inner width102, which is smaller than an inner width104of a last projection106of the first belt70. Likewise, the first groove84of the second belt72has an inner width108, which is smaller than an inner width110of a last groove112of the second belt72. Such features may enable the belts70and72to be utilized with welding wire of varying diameters. For example, in the illustrated embodiment, the first welding wire74is positioned between the projection82of the first belt70and the groove84of the second belt72. The projection82and the groove84are sized for use with the welding wire74. However, a second welding wire114, which has a diameter greater than a diameter of the first welding wire74, is positioned between the larger projection106and the larger groove112. It should be noted that although the illustrated embodiment shows two welding wires positioned between the belts70and72, during typical use, only a single wire may be positioned between the belts. However, in other embodiments, such as in twin-wire applications, it may be desirable to deliver two wires to the weld joint simultaneously. Whereas traditional systems may utilize two separate wire feeders to achieve a dual wire feed, embodiments of the present invention may enable two or more wires to be simultaneously delivered with a single system by utilizing the plurality of provided grooves. However, the same belts70and72may be used when the smaller diameter wire74is desired as well as when the larger diameter wire114is desired. Indeed, a belt may be designed such that it accommodates more than two welding wire types and/or wire sizes as desired.

FIG. 9is a schematic illustrating a further embodiment of the first belt70and the second belt72. In this embodiment, the first belt70is a back-driven poly-V belt, as before. However, the second belt72is flat along a surface116facing the v-projections82of the first belt70. Accordingly, in this embodiment, the welding wire74is positioned for use between the flat surface116of the second belt72and the groove80of the first belt70. As shown, the wire74contacts the flat surface116of the second belt72at a first point of contact118. The wire74also contacts the first belt70at a second point of contact120and a third point of contact122. It should be noted that in another embodiment, the first belt70may feature a flat surface, and the second belt72may include the v-grooves and v-projections. Still further, the welding wire74may be located between projection82of the first belt70and the flat surface116of the second belt72.

It should be noted that the belts70and72and the drive rollers60,62,64, and66may be adapted further to facilitate proper alignment of the wire path through the grooves of the opposing belts. For example, in one embodiment, the belts70and72may feature grooves on both sides of the belts, and the rollers60,62,64, and66may also feature grooves. In such an embodiment, the grooves on the backside of the belts may be adapted to mate with the grooves on the rollers. The foregoing feature may have the effect of increasing the traction between the belts and the rollers as the belts are driven around the rollers. Additionally, such a feature may enable precise alignment between the v-grooves of the first belt and the v-grooves of the second belt, thus ensuring that the wire being fed to the welding torch remains substantially in line throughout the wire feeding process.

FIG. 10is a schematic illustrating how the belts may be secured on the drive rollers of the wire feed drive system in one embodiment. Specifically,FIG. 10illustrates the drive rollers60,62,64, and66with the belts70and72mounted thereon. In this embodiment, a first guide124applies pressure, as indicated by arrow126, on the first belt70to ensure the belt70remains taut during operation. Likewise, a second guide128applies pressure, as indicated by arrow130, on the second belt72to ensure the belt72remains tight during use. It should be noted that as the belts70and72stretch or wear, one or more adjustment mechanisms may be provided to compensate for deformities. For example, the guides124and128may be adapted to move closer to the wire, as indicated by arrows132and134as the belts stretch or wear. Indeed, any of a variety of suitable adjustment features, which may be manual or automatic, may be employed to compensate for stretch and/or wear in the belts over time.

FIGS. 11 and 12are schematic illustrations of further embodiments of the wire feed drive system. Specifically,FIG. 11is a schematic including the drive rollers60,62,64, and66with belts70and72mounted thereon, as before. In this embodiment, a belt guide136rotates in a direction indicated by arrow138. As the belt guide136rotates, the second belt72rotates in the direction indicated by arrow140. Such rotation forces the wire through the drive rollers toward the welding torch. Similarly, the embodiment ofFIG. 12includes a belt guide142that rotates in the direction of arrow144. As the belt guide142rotates, the belt72rotates about the drive rollers in the direction indicated by arrow146. Again, such rotation facilitates the movement of the welding wire74toward the welding torch.