Patent ID: 12209619

DETAILED DESCRIPTION

Referring now to the drawings, a pulley assembly10for a supercharger12is shown. The pulley assembly10is mounted to a shaft14of the supercharger12. The pulley assembly10may have three different components, namely, a shaft mount16, a body18and a plurality of bolts20. The body18is mounted to the shaft mount16with the plurality of bolts20. In particular, each of the bolts20may have a shoulder22having an outer diameter24which is smaller than and within 0.001 inches of an inner diameter26of a neck54of a countersunk hole28formed in the body18. The shaft mount16has a plurality of threaded holes30which receive the bolts20. In this manner, the neck54of the body18aligns the body18to the shaft mount16. Additionally, an outer surface32of the body18may have a plurality of friction lines34which mitigate slip between the outer surface32of the body18and a belt being driven by the pulley assembly10or driving the pulley assembly10. The increased friction mitigates noise by reducing slippage between the belt and the pulley assembly10.

More particularly, referring now toFIG.2, the pulley assembly10is made up of at least the shaft mount16, the body18and the plurality of fasteners or bolts20. To mount the pulley assembly10to the shaft14of the supercharger12, the shaft mount16is heated to a temperature above the temperature of the shaft14. The inner diameter36of the hole38of the shaft mount16is enlarged due to the heat so that the shaft mount16may be slid over the shaft14. When the shaft mount16cools down, the shaft mount16is fixedly secured to the shaft14of the supercharger12. The inner diameter36of the hole38of the shaft mount16is slightly smaller than an outer diameter40of the shaft14when the shaft14and the shaft mount16are at the same temperature. The shaft mount16compresses on the shaft14when the temperature of the shaft mount16reaches the temperature of the shaft14.

The shaft mount16may have a flange42that extends outwardly around a periphery of the shaft mount16. The flange42may have a plurality of threaded holes44symmetrically disposed about a central axis46. The flange42may have a proximal surface48which mates with a distal surface50of the body18. The body18is mounted to the shaft mount16with the plurality of fasteners20. The body18has a set of corresponding countersunk holes28that receive the bolts20. These countersunk holes28are aligned in the same pattern as the threaded holes44formed in the flange42of the shaft mount16. The body18has an inner cavity55which is large enough to receive the shaft mount16and a portion53of the supercharger12that holds the shaft14. The body18is disposed over the shaft mount16and the countersunk holes28are aligned to the threaded holes44. Each of the fasteners20are then inserted through the countersunk holes28and engage to the threaded holes44of the shaft mount16. The fasteners20fixedly secure the body18the shaft mount16. Also, the interference fit between the hole38of the shaft mount16and the shaft14of the supercharger12fixedly secure the shaft mount16to the shaft14.

To align the body18to the shaft mount16, the bolts20have a shoulder22that mates to a neck54of the countersunk hole28formed in the body18. In particular, referring now toFIG.3, a cross-sectional view of the pulley assembly10is shown. The countersunk hole28has two different diameters. A first diameter at a neck54identified as inner diameter26. A second diameter at a countersunk portion56identified as inner diameter58. The inner diameter58receives a head60of the bolt20. More particularly, the inner diameter58is significantly larger than an outer diameter62of the head60of the bolt20. In contrast, the inner diameter26of the neck54of the threaded hole28is only minimally larger than an outer diameter24of the neck portion22of the bolt20. More particularly, the inner diameter26is within 0.001 inches of the outer diameter24of the neck22of the bolt20. As the threads64of the bolt20engage the threads66of the threaded hole30of the flange42of the shaft mount16, the shoulder22of the bolt20enters the neck54of the hole28of the body18. Since the inner diameter26of the hole28is within 0.001 inches to the outer diameter24of the shoulder22, the body18begins to align to the shaft mount60as two or more bolts20engage the threaded holes44of the shaft mount16.

Optionally, to further secure the shaft mount16to the shaft14, the shaft mount16may have one or more socket set screws68that engage the shaft14. In particular, the shaft mount16may have an extended length. A threaded hole70may be formed in the extended length. Preferably, a plurality of threaded holes70are symmetrically formed about the central axis46to maintain rotational balance of the pulley assembly10during rotation. By way of example and not limitation, threaded holes70may be placed on opposed sides of the central axis46. Alternatively, three holes70may be disposed 120° apart from each other about the central axis46or four holes may be disposed 90° apart from each other about the central axis46. After the shaft mount16is mounted to the shaft14, the socket set screws68are threaded into the threaded holes70and engaged to the shaft14. Preferably, the socket set screws68have a knurled end to further engage the shaft14.

To mount the pulley assembly10to the shaft14of the supercharger12, the shaft mount16(seeFIG.2) is heated to a temperature above the temperature of the shaft14of the supercharger12. In doing this, the heat enlarges the inner diameter36of the shaft mount16so that the inner diameter36of the shaft mount16when heated is greater than the outer diameter40of the shaft14. While the shaft mount16is heated to an elevated temperature, the shaft mount16is placed over the shaft14so that the shaft14is now disposed within the hole38of the shaft mount16. As the shaft mount16cools down, the inner diameter36of the shaft mount16decreases. When the temperature of the shaft mount16is equal to the temperature of the shaft14, the inner diameter36of the shaft mount16is equal to the outer diameter40of the shaft14. Since the inner diameter36of the shaft mount16is less than the outer diameter40of the shaft14(when the shaft mount16and the shaft14are at the same temperature and the shaft mount16is not mounted to the shaft14), the inner surface defining the inner diameter36of the shaft mount16compresses upon the outer surface of the shaft14when the shaft mount16is mounted to the shaft14of the supercharger12.

To further ensure that the shaft mount16is retained on the shaft14, socket set screws68may be threaded into the threaded holes70formed in the extended length of shaft mount16. A distal tip of each of the socket set screws68may have knurls to further engage the shaft14and mitigate inadvertent movement between the shaft mount16and the shaft14.

The body18is then disposed over the shaft mount16so that the shaft mount16is disposed within the cavity55of the body18. The bolts20are inserted through the countersunk holes28of the body18and threadedly engaged to the threaded holes44formed in the flange42of the shaft mount16. As the bolts20are tightened, the neck54of the bolts20seat into the neck54of the body18. Due to the tight tolerances between the shoulders22of the bolts20and the necks54of the countersunk holes28of the body18, the body18begins to align to the shaft mount16. The user tightens the bolts20to securely attach the body18to the shaft mount16, and in turn, to the shaft14of the supercharger12.

To remove the pulley assembly10from the shaft14of the supercharger12, the user loosens the bolts20to remove the body18from the shaft mount16. The purpose of removing the body18from the shaft mount16is to provide the user with access to the socket set screws68, if used. The user loosens and removes the socket set screws68from the shaft mount16. The user may then reinstall the original body18or install a sacrificial body72(seeFIG.2). The sacrificial body72may incorporate the counter sunk holes28and an enlarged distal flange74. The enlarged distal flange74is used to pull the body18and shaft mount16off of the shaft14. The user may then pull the pulley assembly10from the shaft14with the puller.

Referring back toFIG.1, the body18of the pulley assembly10may have an outer surface32. The outer surface32may have a plurality of grooves76circumscribing the body18about the rotational axis46. In the embodiment shown in the figures, the pulley assembly10has a plurality of grooves. However, it is also contemplated that the various aspects described herein may be applied to a pulley have a single groove or a pulley or tensioner having a cylindrical surface. The outer surface32, and in this instance, the grooves76engage a belt that wraps around the body18and fits within the grooves76. The outer surface32of the body18may be smooth so that during use, the belt wrapped around the body18may inadvertently slip so that the linear speed of the outer surface32of the body18is not equal to the linear speed of the belt driving or driven by the pulley assembly10. To mitigate slippage between the belt and the outer surface32of the body18, friction patches or lines34may be formed on the outer surface32of the body18. Although the friction patches or lines34are described as being applied to the pulley assembly10, the friction patches or lines34may also be applied in the same manner, with the same materials and machines and the same methods to a bead seat212of a wheel rim200,200a(seeFIG.18), a flat drum pulley204(seeFIG.24), a flat surface and a V groove pulley206(seeFIG.25). In relation to the wheel rim200,200a, the goal is to prevent slippage between the tire202(instead of the belt) and the rim200,200a(instead of the pulley). The formation of a surface to increase a coefficient of friction on the wheel rim200,200a, the flat drum pulley204and the groove pulley206will be discussed below.

In particular, referring now toFIGS.4and5, particulate matter or substance may be fused to the outer surface32of the body18and have a coefficient of friction with the belt greater than the coefficient of friction between the smooth outer surface32of the body18and the belt. The particulate matter may be coated over the outer surface32. A laser beam78of the laser80may be directed to selective locations on the outer surface32of the body18to fuse the particulate matter to the outer surface32of the body18. Preferably, the particulate matter when fused to the outer surface32has a coefficient of friction with the belt greater than the coefficient of friction between the smooth outer surface32of the body18and the belt. Moreover, the particulate matter provides a slightly raised surface so that the edges of the friction lines38create additional friction between the friction lines34and the belt. The fusing of the particulate matter to the outer surface32of the body18is a physical bonding process wherein the particulate matter is heated and permanently bonded to the outer surface32of the body18.

To coat the particulate matter onto the outer surface32of the body18, the particulate matter is applied82(seeFIG.4) to the outer surface32of the body18. The particulate matter may be applied82to the outer surface32of the body18either by way of an aerosol100or airbrushing102. If the particulate matter is delivered or coated onto the outer surface32of the body18with an aerosol100, the aerosol can100is purchased in a prepackaged form. The user sprays the entire outer surface32of the body18, and more particularly, sprays the grooves76. In the event that the particulate matter is formed on the wheel rim200,200aor the flat drum pulley204, the particulate matter is disposed (e.g. sprayed or coated) on the bead seat212of the rim200,200aor the interface surface where the belt rides on the flat drum pulley204. If the particulate matter is delivered or coated onto the outer surface32of the body18by way of airbrushing102, the particulate matter is mixed with denatured alcohol then sprayed on the outer surface32with a sprayer. Two types of particulate matter may be utilized when air brushing. A first type is one sold under the trademark Thermark. A second type is one sold under the trademark Cernark. For low production runs, the Thermark particulate matter is preferred since un-fused particulate matter on the outer surface32is easily removed by wiping with a damp wet rag. However, for large production runs, Cernark is preferred since the particulate matter may be applied to the outer surface32of the body18and stored for an extended period of time.

If Thermark is used, then the user applies the particulate matter shortly before fusing82the particulate matter to the outer surface32of the body18. If Cermark is used, then the user may optionally store84the coated bodies18in storage for an extended period of time. When desired, the user takes the coated bodies18out of storage and fuses82the particulate matter to the outer surface32of the body18. Regardless of whether Thermark or Cermark is utilized, the particulate matter may be fused82to the outer surface32(or bead seat212of rim or interface surface of the drum pulley) of the body18with a laser beam78. The laser beam78heats up the particulate matter and the outer surface32of the body18. The heat permanently attaches the particulate matter to the outer surface32of the body18so that the particulate matter does not rub off as the belt runs over the outer surface32of the body18.

Generally, the particular matter may be provided as a powder. The powder may be delivered by aerosol or a spray gun. The material of the powder may be a metallic material. More particularly, the powder may be any form of a metallic oxide material. By way of example and not limitation, the metallic material may be tungsten, carbides (e.g., tungsten carbide, titanium carbide, silicon carbide, calcium carbide, boron carbide), cobalt, titanium, aluminum, steel or combinations thereof. The average size of the of the powdered material may be up to about 100 microns, and is preferably up to about 35 microns with a minimum size being 2 microns. The texture of the fused material may be increased or decreased by respectively using larger or smaller sized powdered oxide material. During tests, a powder metallic oxide material having a size of about 35 microns has created a 0.007 inch texture to the outer surface32.

To form the friction lines or patches34, the body18(or rim200,200aor drum pulley) may be attached to a chuck86after applying the particulate matter to the outer surface32. The chuck86may have a plurality of arms88with serrated teeth. The plurality of arms88may be inserted within the internal cavity55of the body18and expanded outward. Upon outward expansion, the arms88automatically center the body18onto the chuck86. The chuck86and the body18are placed on a rotary table or an indexer that controls the rotational movement90of the chuck86and the body18about rotational axis46. The laser80is capable of traversing longitudinally along the central or rotational axis46in the direction of arrows92,94. Preferably, the laser beam78of the laser80intersects and is perpendicular to the central or rotational axis46. Additionally, the laser80may be a direct beam laser80.

The laser beam78may be traversed longitudinally along the axis46and simultaneously, the body18may be rotated about axis46so that the laser beam78traces the pattern of lines, circles, curves, patches and other shapes (straight, curved or combinations thereof) to form a mark, word, pattern on the outer surface32of the grooves of the body18. InFIG.1, the friction lines34are shown as being linear along the longitudinal length of the central axis46. However, other types of patterns and shapes are also contemplated. It is also contemplated that the laser beam78may trace a random series of lines, circles, curves, patches, indentations and other shapes (straight, curved or combinations thereof). Nevertheless, these random series may still be considered a pattern since the circle would be a pattern.

After fusing82, the particulate matter to the outer surface32of the body18, the excess particulate matter which is not fused to the outer surface32of the body18may be removed96and reclaimed98for subsequent use. More particularly, the body18may be placed in a wash tank such as an ultrasonic tank. Fluid within the ultrasonic tank is heated up to 200° F. and the tank is vibrated. The fluid is run through a filter and the particulate matter that was not fused to the body18is reclaimed98and reused at a later time.

The direct beam laser80produces a laser beam78having a focal depth104. Preferably, the focal depth104is greater than a distance106between a peek108and valley110of the grooves76formed in the body18. The laser80and laser beam78are positioned so that the focal depth104covers the entire distance106. By way of example and not limitation, the focal depth104of the laser beam78may be about 0.200 inches. In this manner, the laser beam78heats up the particulate matter and the surface32along the entire height of the grooves76to provide optimal friction lines34.

It is also contemplated that the process of forming the friction lines34as discussed above and in relation toFIGS.4and5may be repeated over existing friction lines34as shown by process line112(seeFIG.4). In particular, after fusing82, the particulate matter to the surface32of the body18, additional particulate matter may be applied82to the outer surface32of the body18. The additional particulate matter may be fused82to the layer of fused particulate matter and to the bare metal of the body18. The process may be repeated to increase the thickness of the layers of particulate matter on the outer surface32of the body18.

Other types of lasers80may also be utilized to fuse82the particulate matter to the outer surface32of the body18. By way of example and not limitation, a Galvo laser which utilizes one or more lenses to position the laser beam78on the outer surface32of the body18may be utilized. In this manner, the throughput is higher than a direct laser beam78or a CO2 laser beam in that the lenses can create multiple friction lines34in one pass.

The process of forming the friction lines34is discussed in relation toFIGS.4and5with the process of producing an emboss on the outer surface32of the body18(or rim or drum pulley). However, it is also contemplated that a deboss may be formed on the outer surface32of the body18(or rim or drum pulley) by removing material. In particular, the Galvo laser may be utilized to remove material from the outer surface32of the body18. The Galvo laser utilizes one or more lenses to redirect the laser beam78instead of moving the laser head80to position the laser beam78on the outer surface32of the body18.

In addition to forming the deboss on the outer surface32with the laser80, it is also contemplated that the deboss may be formed with a micro end mill. The same is true if the deboss was formed on the rim or drum pulley. Regardless of whether the deboss is formed with a laser80or a micro end mill, the body18(or rim or drum pulley) is mounted to the chuck86. The chuck86and the body18are mounted to an indexer or a rotary table which controls the rotational angle of the body18as the micro end mill or the laser80removes material from the outer surface32of the body18. In another aspect, it is also contemplated that the body18may remain stationary while the micro end mill or the laser80both rotate about the body18and also traverse longitudinally along the axis46.

The friction lines or patches34were described as being formed on a rotary table or indexer that is coordinated with the laser. However, it is also contemplated that the friction lines or patches34may be formed manually. By way of example and not limitation, the part could be mounted to a chuck or a holding mechanism that the user may move by hand.

In another aspect, referring now toFIG.6, the friction lines or patches may be formed on other types of pulleys (e.g. adjustable pulleys, drum pulleys), and also on tensioning rollers having a cylindrical flat surface (e.g. drum pulleys). By way of example and not limitation, the friction lines or patches34may be formed on inner surfaces118of first and second parts120,122of a variable diameter pulley124of a continuously variable transmission. When the belt126is closer to the rotational axis128, the revolutions per minute of the pulley124is higher than when the belt126is further away from the rotational axis128.

Referring now toFIG.7, to form the friction lines or patches34on the inner surface118, the first and second parts may each be individually mounted to the chuck86. The part120or122is positioned with the inner surface118perpendicular to the laser beam78. The form the patch or lines34, the laser80is traversed laterally in the direction of arrows92and94and the chuck86is rotated in direction of arrow90about rotating axis46.

Referring now toFIG.8, a different set up between the part120,122and the laser beam78is shown. Instead of the part120,122being oriented so that the laser beam78is perpendicular to the inner surface118, the inner surface118may be oriented at a skewed angle with respect to the laser beam78. InFIG.8, the rotational axis of the part120,122is set up so as to be perpendicular to the laser beam78. Since the laser beam78has a particular focal depth104which is the location of the laser beam effective for heating up the particular matter and the inner surface118to fuse the two together, the laser80cannot simply be laterally traversed in a linear as shown inFIG.7if the angle of the inner surface118is too large so that the entire surface118is within the focal depth104of the laser beam. If the laser is moved to the left94or right92, the laser beam78is effective at fusing the particulate matter to the inner surface118as long as the inner surface118is within the focal depth of the laser beam. Right before the inner surface118comes out of the focal depth of the laser beam78, the laser may be traversed up 128 or down130to reposition the focal depth of the laser beam on the inner surface118. To form the friction lines or patches34, the laser80is traversed sideways92,94and vertically128,130in a staggered fashion. This technique can also be used for pulleys that have a deep groove wherein the distance106between the peak108and the valley110of the deep groove is greater than the focal depth104of the laser beam78.

Referring now theFIGS.9-13, a method and apparatus for forming the deboss on the outer surface32of the body18in order to increase a coefficient of friction of the outer surface13of the body18is shown. The same method and apparatus may be used to form the deboss on a bead seat212of a rim200,200aor an interface surface of a drum pulley. Referring back to formation of the deboss on the body18, in particular, the laser beam78of the laser80may create a plurality of kerfs150(seeFIG.12). These kerfs150form the deboss on the outer surface32of the body18. This is accomplished with a roughing pass of the laser beam78on the outer surface32of the body18. Additional passes of the laser beam78on the outer surface32of the body18may be made for different purposes. These additional passes may be a smoothing pass wherein excessively sharp protrusions formed during the roughing pass are rounded out or knocked down and an annealing pass which raises the temperature of the surface32of the body18in order to harden the outer surface32of the body18and/or recast material166formed during the roughing pass. More particularly, the laser80may perform 1) the roughing pass, 2) smoothing pass, 3) the roughing and smoothing passes, 4) the roughing, smoothing and annealing passes or 5) the annealing pass on the outer surface32of the body18.

As shown inFIG.9, the laser80is disposed above the body18having the surface32on which the deboss which increases the coefficient of friction is to be formed. A direction of the laser beam78can be controlled by lenses and mirrors in order to cover an area152of the outer surface32of the body18. Due to the curvature of the outer surface32, the laser beam cannot cover the entire outer surface32of the body18. The body18may be rotated about central axis46or the laser80may be rotated about the body18with respect to the central axis46in order to deboss the entire circumference of the body18. The same applies if the deboss was formed on a bead seat of a rim200,200aor drum pulley204. Preferably, the body18and the laser80are stationary while the laser beam78is performing one or more of the roughing pass, smoothing pass and annealing pass on the area152being worked on by the laser beam78of the laser80. After the laser beam78works the area152with one or more of the roughing pass, smoothing pass and annealing pass, either the laser80and/or the body18rotates so that the laser beam78can work one or more of the passes on a different area152on the circumference of the outer surface32of the body18.

Referring now toFIG.10, a cross-sectional view of the body18shown inFIG.9with respect to the laser80is shown. Preferably, the laser beam78is centrally aligned to the central rotational axis46of the body18(or rim200,200aor drum pulley204) in that the laser beam78is not skewed. The laser beam78may be skewed to the left or right as shown in dashed lines154,156as well as along a length of the central axis46. Theoretically, the laser beam78may be skewed to the left154or right156so that the laser beam78is tangent to the left and right sides of the body18. However, at such an excessive skewed angle, the power of the laser beam78is less or non-effective. As such, the laser beam78is skewed to the left and right154,156to a smaller angle158so that the focal depth or depth of field164of the laser beam78coincides with or encompasses the outer surface32of the body18at a valley160and peak162of a groove formed on the body18. The body18shown inFIGS.9-11is that of a pulley10,204having a plurality of grooves that define the valley and peaks160,162. However, the method and apparatus for forming the deboss may be used on a variety of other surfaces including but not limited to a pulley having a single groove such as one that is incorporated into a continuously variable transmission (CVT) or a flat pulley200(seeFIG.24). More broadly speaking, the method and apparatus for forming the deboss may be used on any surface that contacts a belt or requires an increased coefficient of friction (e.g., rim200,200a). Likewise, the laser beam78is skewed to the left and right164,156to a smaller angle158so that the focal depth or depth of field164of the laser beam78coincides with and encompasses the outer surface32of the body18. For the flat pulley (idler or drive pulley; e.g., seeFIG.24), there are no valleys and peaks. As such, the curvature of the pulley is accounted for in determining the acceptable angle158. For a CVT, the laser beam78may be applied to the surface118by forming the deboss on the first and second parts120,122separately as discussed above during the emboss process. In particular, the laser debosses the first part and the second part separately which are then assembled together at a later time.

Referring now theFIG.11A, a top view of the area152which is worked by the laser beam78of the laser80is shown.FIG.11Aillustrates the pulley10but other pulleys and rotating objects may replace the pulley10such as a wheel rim200,200a, drum pulley204and groove pulley (seeFIG.25). In this regard, the laser beam creates a series of straight line dashes at an angle172with respect to the central axis46of the body18. InFIG.11A, the grooves of the pulley are not shown for clarity. Also,FIG.11Ais a top view of only the area152worked by the laser beam78of the laser80. The laser beam78can be adjusted to pass over the area152at different angles. By way of example and not limitation, the preferred angles are 0° 30°, 45°, 60°, 90°, 120°, 125°, 150°. These angles are known as the crosshatching angles172. The laser beam78of the laser machine80creates a series of parallel short line dashes. A distance between the short line dashes is referred to as a crosshatching size 174 (seeFIG.12). The laser beam78may be adjusted to run at a particular speed measured in inches per second.

Referring now toFIG.12, the laser80is shown emitting a laser beam78onto the outer surface32the body18(or wheel rim200,200aor pulley204,206). The laser beam78vaporizes the outer surface32in order to create an indentation or a kerf150. In other words, kerf may be an elongated groove but kerf may also encompass an indentation. This is the deboss formed by the laser beam78. When the laser beam78vaporizes a portion of the outer surface32of the body18, as shown inFIG.12, recast material166lines an interior of the kerf150and/or extends outward above the outer surface32of the body18outside of the kerf150. The recast material may be described as being at the kerf150. The outward extensions are shown by peaks168of the recast material166. The kerf150is defined by a width170at the peaks168. It is also contemplated that the kerf width170may be measured at the outer surface32including the recast material166as shown by dimension line170a. The kerfs150are shown inFIG.12as being formed vertically straight up-and-down. However, the laser80from the position shown inFIG.12emits the laser beam78at a skewed angle. The first kerf150would not be formed straight up-and-down. The drawing is shown in this fashion inFIG.12because the drawing is not to scale since the distance between the laser80and the outer surface32and the distance174between kerfs150are not to scale. In actuality, the distance174is measured in thousandths of an inch whereas the distance between the laser80and the surface32is measured in inches if not feet.

Referring now toFIG.11B, a length of the kerf150and a gap between kerfs150may be defined by a pulse width178and a speed of the laser beam78which are adjusted on the laser80. The pulse width178is defined by a length of time that the laser80is generating the laser beam78over a period180of fixed time. Laser beams78pulse at regular intervals. The pulses are defined by the period180of fixed time. The pulse width178of the laser beam78and the linear speed of the laser beam78on the surface32defines a length of the kerf150. After the laser80is turned off so that no laser beam78is emitted from the laser80, the laser80is turned back on after the period180of fixed time from the beginning182of the prior pulse width178. This defines the gap between kerfs150. The kerf may be an elongate groove. In this instance, the length of the kerf is longer than the width of the kerf. However, it is also contemplated that the kerf may have its length and width be equal to each other. Other shapes are also contemplated for the kerf. For example, the kerf may form a polygonal shape (e.g, multiple straight grooves joined end to end), curved shape (e.g., non straight grooves). The polygonal shape and the curved shape may be closed to form an shape such as a square, pentagon, circle, elipse. The kerf may be formed as a combination of straight and curved lines as well.

The kerfs may be formed into a pattern. For example, the kerfs may be formed as a series of equally spaced apart straight or curved grooves, dots, indentations or combinations thereof. The pattern may also be formed based on an image or shape. For example, an image or shape may be dithered and the kerfs instead of being elongate grooves may be a plurality of dots or indentations which are spaced apart from each other so that when all of the dots or indentations are viewed by a person represents the image or shape.

The kerfs may alternatively be formed as one or more indentations, dots, straight lines, curved lines which are spaced apart from each other randomly. In other words, the spacing between the indentations, dots, straight lines, curved lines may be random so that they do not form a pattern when all of the indentations, dots, straight lines, curved lines are viewed. Nevertheless, this series of kerfs may be considered to be a pattern since the individual kerf has a pattern (e.g., straight line, dot, curved line, etc.). It is also contemplated that the each kerf may be different than every other kerf in shape, size, and relative position so as to be random.

Regardless of whether the kerf is formed into a pattern or randomly, it is preferred that the surface roughness between a surface of a first part (e.g., pulley, flat surface, table top surface) which contacts a surface of a second part (e.g., belt, container) is about the same (e.g., plus or minus 10% to 30%) regardless of where the surface of the second part is contacting the surface of the first part. By way of example and not limitation, when a belt contacts a pulley, the belt contacts a portion of the pulley. This may be referred to as the contact patch between the belt and the pulley. As the pulley rotates, the surface of the belt and the surface of the pulley comes into contact with each other then spreads apart. Nevertheless, the area of the contact path remains about the same as the pulley rotates. The surface roughness, or in other words, the coefficient of friction between the belt and the pulley remains constant through out the rotation of the pulley.

The laser80may be rated at a particular wattage. By way of example and not limitation, the laser80may be a 70 watt laser80.

Referring now to the chart below, the laser80may be adjusted differently for each of the roughing pass, smoothing pass and annealing pass. When the laser80makes the roughing pass, the laser80is set to the roughing setting shown below. In this regard, the roughing setting may create a plurality of kerfs150having a kerf width170between about 0.004 inches and about 0.0021 inches. The laser beam80may pass over the area152two times. During the first pass, the laser beam78may have a crosshatching angle172of about 45°. During the second pass, the laser beam78may have a crosshatching angle172of about 180°. The laser beam78runs parallel with respect to the central axis46of the body18. The laser80may be set at 90% power for a 70 watt laser80. The pulse width178of the laser beam78may be set to 420 ns. The laser beam78travels on the surface32of the body18at around 80 inches per second during the roughing pass. The roughing pass creates a plurality of kerfs150and projects the recast material166upward to form peaks168. The setting for the roughing pass may be set so as to create an aggressive texture in that the peaks168may tear a belt running on the pulley during use of the pulley. As such, the roughing pass may be followed up with a smoothing pass.

TABLE 1Settings of laser machine for 17-4 stainless steelStainless steelRoughingSmoothingAnnealingsettingsettingSettingKerf width0.004 inches0.0038 inches0.0026 inchesincludingrecast materialKerf width notAbout .0021About .0022About .0019including recastinchesinchesinchesCross hatching45/180 degrees45 degrees45 degreesangles (parallel linesto fill an area, 180degrees, 90 degrees,45 degrees and 120degrees. (Option ofoutlining area))Size of crossMin. distanceSmallerGreaterhatchingbetween parallelthan kerfthan kerflines is greater thanwidth ofwidth ofthe kerf width of thethe roughingannealingroughing setting plussettingsetting0.0005 inches to0.004 inches(preferably, 0.004inches or double thekerf width for a kerfwidth of 0.002inches)Power of machine90% of 70 watt90% of55% ofand % wattage70 watt70 wattPulse width420 nanoseconds20030(34 waveform)nanosecondsnanoseconds(2 waveform)(22 waveform)Speed80 inches60 inches35 inchesper secondper secondper second

The smoothing pass rounds out the peaks168of the recast material166. In order to do so, the kerf width170is set to be smaller than the kerf width170during the roughing pass. In our example, the kerf width170for the smoothing pass is set to be about equal to the kerf width170during the roughing pass. The crosshatching angle172is set to the crosshatching angle172of the roughing pass. In our example, the roughing pass had two different crosshatching angles172. The crosshatching angle172during the smoothing pass may be set to either one of the crosshatching angles172used during the roughing pass. The distance174of the crosshatching may be smaller than the kerf width170of the roughing pass. The reason is that the laser beam78during the smoothing pass needs to hit a significant amount of peaks168to round out or knock down the peaks168. In order to account for any misalignment between the laser beam78and the kerfs150made during the roughing pass, reducing the crosshatching size 174 to be smaller than the kerf width170of the roughing pass enables the laser80to round out a significant portion (i.e., more than 25%, 50% or 75%) of the peaks168of the recast material166. The smoothing pass is not meant to generate new indentations in the surface32of the body18. Rather, the smoothing pass is designed to round off the peaks168of the recast material166. In this regard, the pulse width is significantly reduced so that less energy is introduced into the surface32of the body18. Also, the speed of the laser is reduced in order to ensure that a significant portion of the peaks168generated during the roughing pass are rounded out or knocked down.

After the roughing and smoothing passes, it is also contemplated that the surface32may be annealed by adjusting the laser80with the annealing setting shown above. The annealing pass may also be used to add color to the exterior surface. In annealing the surface32of the body18, the annealing takes place on the surface32of the body18to a depth of about a few thousandths of an inch below its exterior. Referring now toFIG.13, as the laser beam78passes over the outer surface32of the body18, the laser beam78introduces heat into the outer surface32of the body18. The center of the laser78introduces the most amount of energy into the outer surface32of the body18. As such, this position increases the temperature of the outer surface32the greatest amount. As one measures the temperature going away from that position on the surface32, the temperature of the surface32decreases as shown inFIG.13. When the laser beam78creates a hatching pattern, the laser beam78forms a series of parallel lines separated by distance174. In particular, the laser beam78introduces heat into the outer surface adjacent to a first line and raises the temperature of the outer surface32in the same manner as before. However, there may be a slight overlap184so that the heat introduced into the outer surface32by the first line may be additive to the heat introduced into the outer surface32by the second line. The dashed line186shows the temperature fluctuation on the outer surface. The annealing settings on the laser80are set so that the temperature of the outer surface remains within a narrow band188sufficient to raise the temperature of the outer surface32to anneal or harden the outer surface32on the area152thereof or create a consistent discoloration thereof. The temperature range to anneal the outer surface for 17-4 stainless steel may be about 800 degrees fahrenheit to about 1500 degrees fahrenheit, and more preferably between about 900 degrees fahrenheit to about 1150 degrees fahrenheit.

The settings for the roughing pass and the smoothing passes illustrate a power saturation of the laser beam which is applied to the surface being treated. As discussed above, the roughing pass cuts a groove into the surface being treated. Moreover, recast material is ejected which is attached to the surface of the groove and the area immediately adjacent to the groove. In contrast, the smoothing pass may form (e.g., vaporize) a groove in the surface to be treated. However, the smoothing pass predominantly smooths out the sharp edges and points in the recast. The setting of the laser shown in Tables 2-19 below forms a groove in the surface to be treated in a single pass for aluminum and stainless steel. However, the settings may be varied to form a groove in other materials in a single pass. These other materials may include but are not limited to composites, plastics, polymers, diamonds and other nonorganic materials. Recast may be disposed in the groove and the surface outside of the groove immediately adjacent to the groove. This recast may have sharp or rough enough to increase a coefficient of friction of the surface being treated but also not to tear into a rubber belt (e.g., Gates belt for an automobile).

The settings specified in Tables 2-10 (shown below) are for a laser machine Model Number 200 Watt Air Cooled EP-Z manufactured by SPI for aluminum 7075-T6. Although aluminum 7075-T6 has been specified the settings disclosed herein may be utilized for a wide variety of aluminums. The specific settings shown in Table 2 provide a certain level of power saturation as a function of wave form, power density, beam spot size and speed to allow for comparable coefficients of friction with a single pass of the laser beam compared to the combination of roughing and smoothing passes described herein. Table 2 shows a laser machine with the power watt set to 200 watts, wave form set to 54, power density set to 1.24 mJ, beam spot size set to 10 μm, and the speed of the laser set to 140 inches per second. With these settings, the surface of the material (e.g., aluminum 7075-T6) is modified to have kerfs. Each kerf has a kerf width170a(seeFIG.12) of about 0.002362 inches, kerf depth171(seeFIG.12) of about 0.0045 inches, recast wall width173(seeFIG.12) of about 0.001102 inches, recast edge to edge wall175(seeFIG.12) of about 0.003937 inches, recast wall height177(seeFIG.12) of about 0.004 inches which produces a created surface roughness or RA of 22 to 35 μm from a surface initially having a surface roughness of about 2.5 μm. Table 3 and Table 4 shows the kerf data when varying the laser speed setting of the laser machine. In Table 3, the laser speed is set to 100 inches per second, and the created surface roughness RA is about 22 to 35 μm. In Table 4, the laser speed is set to 70 inches per second, and the created surface roughness RA is about 22 to 35 μm.

Tables 5-7 show the kerf data and created surface roughness when the laser machine is set to the same settings as in Tables 2-4 but the power watt is set to 150 watts. Tables 8-10 show the kerf data and created surface roughness when the laser machine is set to the same settings as in Tables 2-4 but the power watt is set to 100 watts. For settings shown inFIGS.2-10, the laser of the laser machine may be passed over the surface once and produce the created surface roughness RA identified in Tables 2-10.

TABLE 2DataRecastCreatedKerfKerfRecast WallEdge toRecast wallSurfaceWidthDepthWidthEdge WallheightRAPower200 W0.00236220.00450.001102360.003937010.00422-35 umWattWave54PWR1.24 mJDensityBeam Spot10 umSizeSpeed140IPS

TABLE 3DataRecastCreatedKerfRecast WallEdge toRecast wallSurfaceKerf WidthDepthWidthEdge WallheightRAPower200 W0.002519690.0050.001141730.004251970.00522-35 umWattWave54PWR1.24 mJDensityBeam Spot10 umSizeSpeed100IPS

TABLE 4DataRecastCreatedKerfRecast WallEdge toRecast wallSurfaceKerf WidthDepthWidthEdge WallheightRAPower200 W0.00236220.0060.001889760.005433070.00622-35 umWattWave54PWR1.24 mJDensityBeam Spot10 umSizeSpeed70IPS

TABLE 5Power Watt 150 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.002440950.0040.000590550.003385830.003522-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed140IPS

TABLE 6Power Watt 150 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.002322840.00450.000708660.003740160.00422-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed100IPS

TABLE 7Power Watt 150 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.002125980.0050.001141730.004527560.00522-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed70IPS

TABLE 8Power Watt 100 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.001889760.00250.00039370.002952760.00222-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed140IPS

TABLE 9Power Watt 100 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.001850390.00350.00078740.003228350.00322-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed100IPS

TABLE 10Power Watt 100 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.001732280.0040.001062990.00381890.00422-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed70IPS

The settings specified in Tables 11-19 (shown below) are for a laser machine Model Number 200 Watt Air Cooled EP-Z manufactured by SPI for stainless steel 17-4PH H900. Although stainless steel 17-4PH H900 is specified similar settings may be utilized on a wide range of stainless steels. The specific settings shown in Table 11 provide a certain level of power saturation as a function of wave form, power density, beam spot size and speed to allow for comparable coefficients of friction with a single pass of the laser beam compared to the combination of roughing and smoothing passes described herein. Table 11 shows a laser machine with the power watt set to 200 watts, wave form set to 54, power density set to 1.24 mJ, beam spot size set to 10 μm, and the speed of the laser set to 140 inches per second. With these settings, the surface of the material (e.g., stainless steel 17-4PH H900) is modified to have kerfs. Each kerf has a kerf width170a(seeFIG.12) of about 0.0016 inches, kerf depth171(seeFIG.12) of about 0.004 inches, recast wall width173(seeFIG.12) of about 0.0016 inches, recast edge to edge wall175(seeFIG.12) of about 0.0049 inches, recast wall height177(seeFIG.12) of about 0.005 inches which produces a created surface roughness or RA of 22 to 35 μm from a surface initially having a surface roughness of about 2.5 um. Table 12 and Table 13 shows the kerf data when varying the laser speed setting of the laser machine. In Table 12, the laser speed is set to 100 inches per second, and the created surface roughness RA of 22 to 35 μm. In Table 13, the laser speed is set to 70 inches per second, and the created surface roughness RA of about 22 to 35 um.

Tables 14-16 show the kerf data and created surface roughness when the laser machine is set to the same settings as in Tables 11-13 but the power watt is set to 150 watts. Tables 17-19 show the kerf data and created surface roughness when the laser machine is set to the same settings as in Tables 11-13 but the power watt is set to 100 watts. For settings shown inFIGS.11-19, the laser of the laser machine may be passed over the surface once and produce the created surface roughness RA identified in Tables 11-19.

TABLE 11Power Watt 200 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.001653540.0040.00157480.004921260.00522-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed140IPS

TABLE 12Power Watt 200 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.00196850.0050.001259840.004724410.003522-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed100IPS

TABLE 13Power Watt 200 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.003937010.00650.000669290.004960630.00222-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed70IPS

TABLE 14Power Watt 150 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.00157480.00350.001377950.004685040.00422-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed140IPS

TABLE 15Power Watt 150 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.00196850.0040.00118110.003622050.00322-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed100IPS

TABLE 16Power Watt 150 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.003700790.0050.000708660.004763780.001522-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed70IPS

TABLE 17Power Watt 100 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.000984250.0150.001496060.003385830.00122-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed140IPS

TABLE 18Power Watt 100 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.00118110.0030.001377950.003188980.00222-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed100IPS

TABLE 19Power Watt 100 WDataRecastRecastRecastCreatedKerfKerfWallEdge towallSurfaceWidthDepthWidthEdge WallheightRAWave540.001732280.0040.00157480.003543310.001522-35 umPWR1.24 mJDensityBeam10 umSpotSizeSpeed70IPS

The various settings described herein were for stainless steel and aluminum. However, the general principles of forming the roughing setting, smoothing setting and the annealing settings may be applied to other types of metallic materials such as alloys of iron and carbon, steel, magnesium alloy, sheet metal, aluminum, carbon steel, etc. with different settings per their own material characteristics. The settings are for a model 70W_EP_Z from SPI Lasers, LLC.FIG.14is a table of settings for 17-4 stainless steel and aluminum. The table illustrates a slightly different setting for 17-4 stainless steel compared to the chart above in that the smoothing pass may be accomplished with two passes instead of one pass as discussed above. The table inFIG.14illustrates two different settings for aluminum. The first setting sets the laser so that the aluminum material is in a sense micro machined with a slight recast material protruding upward, whereas the second setting sets the laser to have more recast material protrude upward compared to the first setting. The first and second settings may illustrate a range of settings for aluminum.

The various aspects described herein are in relation to the formation of an emboss and deboss of a textured surface on a surface of a pulley having a plurality of grooves wherein the pulley grooves engage a belt in order to transmit power from a first shaft upon which the pulley is mounted to a second shaft generally parallel to the first shaft. Moreover, the various aspects described herein for the emboss and deboss of a textured surface have also been described in relation to forming the embossed/debossed textured surface on pulleys of a continuously variable transmission or CVT. The embossed/debossed textured surface is formed on first and second parts of a pulley of the CVT, and more particularly on a gripping surface which is where the belt engages for transmitting power between the first and second shafts. More broadly, it is also contemplated that the method and apparatus for forming the emboss or debossed textured surface may be applied to other applications including but not limited to the following applicational uses. The embossed or debossed textured surface may be formed on a pulley having a helical groove or a straight or helical gear, flat cylindrical pulley, etc. By way of example and not limitation, a drum such as the drum shown inFIG.24may have a plurality of belts mounted thereto for transmitting power to or from the drum to a second shaft. The embossed or debossed textured surface may be formed on the drum where the drum engages the belt. The embossed or debossed textured surface may also be formed on a spindle of a lathe. Broadly speaking the embossed or debossed textured surface may be formed utilizing the method and apparatus as described herein on a surface that is used to engage a belt or other power transmission means to increase the coefficient of friction of the surface in order to prevent slippage between the power transmission means and the surface.

Referring now toFIGS.15-25, a friction patch or lines may be applied to a wheel rim200so that a tire202does not slip and cause the tire to be unbalanced because of tire slippage on the rim200(seeFIGS.15-23), a flat pulley204(seeFIG.24) or a pulley206with grooves (seeFIG.25). The friction patch may be formed by the emboss or deboss methods described above including but not limited to laser infusing particulates on the surface or milling or laser removing material from the surface.

More particularly, referring now toFIGS.15-23, formation of the friction patch on the wheel rim200will be described in relation to the deboss method and apparatus discussed in relation toFIGS.9-13above.FIG.15illustrates a racecar208. The racecar starts from 0 miles per hour and accelerates and reaches a high speed as fast as possible in a few seconds. In order to do this, the drive wheels create a high amount of torque in order to propel the racecar208forward. The highest level of torque is achieved when the racecar208first accelerates from standstill. The goal is to achieve the highest level of torque with minimal slippage between the tire202and the road210. Unfortunately, in generating the highest level of torque, a small amount of slippage may occur between the tire202and the rim200. As shown inFIG.16, when the racecar208accelerates forward, the wheels rotate counterclockwise. Unfortunately, even if there is a small amount of slippage between the rim200and the tire202, the wheel (i.e., tire and rim) eventually becomes unbalanced. On a typical race day, the car may be involved in multiple races. Each race generates slip between the rim200and the tire202so that by the end of the day, the slip may be about 4 linear inches. At the start of the race day, the tire202is balanced on the wheel rim200. In this way, when the racecar208reaches a high-speed, the wheel does not wobble due to any imbalance. Unfortunately, when the rim200and the tire202slips with respect to each other when the racecar208starts out of the gate, the tire rotates and the wheel is now unbalanced. As the racecar208reaches its top speed, the wheel may begin to wobble because of the unbalance. Throughout the day, the tire202slips on the rim200and becomes more and more unbalanced.

Referring now toFIG.17, a cross-sectional view of the wheel including the tire202and the rim200is shown.FIG.18illustrates a motorcycle rim200aand a passenger car rim200. The rims200,200ahas a bead seat212and a flange214. The bead seat212is between the bead hump215and the flange214. The friction patch may be formed on the bead seat212and/or the flanged surface214. The friction patch may be formed with laser by performing a roughing pass over the bead seat212and/or the flange surface214. Optionally, a smoothing pass may also be performed on the bead seat212and the flange214. Moreover, as an additional optional step, an annealing pass may also be performed on the bead seat212and the flanged214. The roughing pass, smoothing pass, and annealing pass may be formed 360° around the rim200,200a. To conduct the passes on the rim200, the rim200may be mounted to a laser as discussed above. Although a friction patch may be applied to the bead seat and flange, it is also contemplated that friction lines may be applied thereto in that they are intermittent patches or lines about a circumference of the wheel rim200,200a. Although the friction patch has been described as being formed as a laser-induced deboss, it is also contemplated that the friction patch may be formed with a laser-induced emboss method described above as well as mechanically forming the friction patch within end mill.

Referring now toFIG.19, a top view of the bead seat212and flange214is shown. The friction patch or lines216are shown. Only two (2) of the friction lines216are shown for the purposes of clarity. The friction lines216may be formed about the entire circumference of the wheel rim200,200a. They may be spread apart evenly throughout the circumference of the rim. The friction lines216may be formed so that they216are skewed with respect to a rotating axis of the wheel rim200,200a. For example, the friction lines216may be skewed in a backward direction with respect to a rotational axis218of the wheel rim200,200a, as shown inFIG.19. Alternatively, the friction lines216may be skewed in a forward direction with respect to a rotational rotation218of the wheel rim200,200a, as shown inFIG.20. The friction lines216mitigate slippage between the tire and the rim200,200a. If there is slippage between the tire and the rim, then such slippage is minimal (e.g. less than ½ inch, more preferably less than ⅛ inch for automotive drag racing situation). Moreover, if there is slippage between the tire and the rim, the friction lines216may tear into the tire. Any portion of the tire that is removed by the friction lines216may be urged out to the side220of the wheel rim because of the backwards slant of the friction lines216. For the forward skewed friction lines216shown inFIG.20, the torn up tire may be urged into the tire because of the forward slant of the friction lines216. The bits of torn up tire may works its way to the outside or the inside of the rim by way of the smooth portion of the rim between the friction lines216without the friction lines216. The skew angle between the friction lines216and the rotational axis218may be between 20 degrees to 80 degrees. At zero degrees skew angle, the friction lines216would be parallel to the rotational axis218. Preferably, the skew angle between the friction lines216and the rotational axis218may be 45 degrees. The friction lines216may have a width222of about 1/32″ to ½″ and may have a gap224away from an adjacent friction line216between about 1/32″ to ½″. Preferably, the width222of the friction lines216is 1/32″ and the gap224is about 1/32″. Instead of friction lines216, a friction patch may be formed continuously about the wheel rim200,200a. The friction lines shown inFIGS.21-23are not spaced apart but are close together so as not to form a significant space so that torn up tire can work its way to the outside or the inside of the rim. InFIG.21, the friction lines have a backwards slant. Alternatively, the friction lines may have a forward slant. InFIG.22, the friction lines have a combination backwards and forward slant formed into a V shape. InFIG.23, the friction lines have a cross hatch.

Referring now toFIGS.21and22, the friction patch formed via laser infusing particulates into the surface or laser debossing material from the surface may be formed on an exterior surface of a flat round drum pulley204or a V-shaped groove pulley206.

Referring now toFIGS.26-31, the various aspects are described in relation to an electromagnetic clutch310,410as shown inFIGS.26and29. Although two different types of electromagnetic clutches310,410have been used to describe the various aspects described herein, the various aspects may be implemented in other types of electromagnetic clutches as well as other types of rotating discs that transmit torque to rotate a shaft upon engagement of mating discs. The clutches310,410may have a driving disc (rotor318shown inFIG.1, armature412shown inFIG.29) that define flat engaging surfaces316(seeFIG.26),414(seeFIG.29). These flat engaging surfaces316,414engage flat engaging surfaces314(seeFIG.26),416(seeFIG.29) of a driven disc (armature312and pulley324shown inFIG.26, pulley424shown inFIG.29). The flat engaging surfaces316,414may have laser induced friction treatment formed thereon to increase a coefficient of friction and to reduce, eliminate or mitigate slippage between the flat engaging surfaces316,414and314,416when they contact each other. They contact and engage with each other when an electromagnet320,420are energized, as shown inFIGS.28,30. When the electromagnets320,420are energized, the driving discs (rotor318shown inFIG.26, armature412shown inFIG.29) are drawn closer to and engage with the driven discs (armature312and pulley324shown inFIG.26, pulley424shown inFIG.29) at the flat engaging surfaces316,314and414,416.

InFIG.26, the armature312and the pulley324do not rotate when the electromagnet320is not energized. The rotor318is continuously rotated by power of a separate motor322(e.g., car engine). InFIG.29, the armature412continuously rotates under the power of the422powered by electricity from a motor such as from a motor of an automobile. Laser induced friction treatment is formed on the flat engaging surfaces314,316and414,416with a laser beam. When the flat engaging surfaces614,316and414,416contact each other the driving discs engage with a pulley324,424to rotate the pulley324,424under the power of the driving disc.

Referring now specifically to the embodiment shown inFIG.26, the electromagnetic clutch310is shown. The electromagnetic clutch310has a shaft326connected to the motor322. The motor322may be a motor of an automobile. The motor322rotates the shaft326about a central rotating axis328in the direction of arrow330. It is also contemplated that the shaft326may be rotated in the opposite direction. The direction shown in the drawings is merely for convenience and to explain the aspects of the electromagnetic clutches310,410. The electromagnetic clutch310has a rotor318which is fixedly attached to the shaft326. By way of example, a key may fit into a keyway of the shaft326and the rotor318. The key may hold the rotor318to the shaft326so that upon rotation of the shaft326, the rotor318would also rotate in the same direction synchronously and at the same speed.

The armature312may be fixedly attached to the pulley324by way of a flat spring330(seeFIG.27). When the electromagnet320is de-energized, the spring330biases the armature312away from the rotor318so that the flat engaging surfaces314,316of the armature312and the rotor318do not contact each other. See the position of the armature in312inFIG.27. An airgap340is present between the flat engaging surfaces314,316. In this state, when the motor322rotates the shaft326, and the shaft326rotates the rotor318, the pulley324and the armature312do not rotate and remain stationary.

When the electromagnet is energized as shown inFIG.28, the electromagnetic field passes through the armature as indicated by the arrows376. The electromagnet320attracts the armature312toward the rotor318. At this time, the flat engaging surfaces314,316of the armature312and the rotor318are placed into contact with each other. The flat engaging surfaces314,316have laser induced friction treatment formed on them in order to increase their coefficient of friction. The rotation of the shaft326is transmitted to the armature312as torque through the rotor318and the flat engaging surfaces314,316of the armature312and the rotor318. The armature312rotates the pulley324by transmitting power through the spring330. When the electromagnet320is energized, a sufficient amount of normal force is created to draw the armature312onto the rotor to rotate the belt334on the pulley324via rotational frictional forces between the flat engaging surfaces314,316.

As long as the electromagnet320is energized, flat engaging surface314of the armature312and the flat engaging surface316of the rotor318are placed into contact with each other and are frictionally engaged to each other.

At the instance when the flat engaging surface314of the armature312contacts and engages the flat engaging surface316of the rotor318, slippage may occur. The laser induced friction treatment on one or both of the flat engaging surfaces314,316reduces, eliminates or mitigates the slippage. The laser induced friction treatment may be formed on the flat engaging surfaces314,316of the armature312and the rotor318. The laser induced friction treatment increases the coefficient of friction of the surfaces314,316to reduce, prevent or mitigate slippage and thus wear of the flat engaging surfaces314,316of the armature312and the rotor318.

Referring now toFIGS.27Aand B, the flat engaging surfaces314,316are shown. The widths342,344of the flat engaging surfaces314,316are also shown. The flat engaging surfaces314,316of the armature312and the rotor318have laser induced friction treatment formed thereon. The laser induced friction treatment may be formed by directing the laser as a straight line across the surfaces314,316. The straight line382of the laser induced friction treatment maybe aligned to a rotating axis336of the armature312and a rotating axis338of the rotor318then extend outward. The straight line of the laser induced friction treatment may intersect the rotating axis of the rotor318and the armature312. A plurality of the straight line laser induced friction treatment may be formed on each of the flat engaging surfaces314,316of the armature312and the rotor318. The plurality of straight line laser induced friction treatment maybe angularly spaced apart from each other at an angle346. The angle346may be the same between adjacent straight line laser induced friction treatments. In other words, the straight line laser induced friction treatment is angularly equidistant from each other on the respective flat engaging surfaces314,316of the armature312and the rotor318. By way of example and not limitation, each of the flat engaging surfaces314,316may have between twenty20to1440straight line laser induced friction treatments form thereon which are equidistantly spaced apart from each other as a radial array. Additionally, the straight line laser induced friction treatment may be formed on only an outer portion of the flat engaging surfaces314,316indicated by the widths342,344, as shown inFIGS.27Aand B. As such, each straight line laser induced friction treatment may not contact an adjacent straight line laser induced friction treatment. Alternatively, a sufficient number of straight line laser induced friction treatment may be formed on the flat engaging surfaces314,316so that adjacent straight line laser induced friction treatments may overlap with each other. For example, the overlap may be at least at a lower section of the widths342,344closer to the rotating axes336,338, and also contemplates the entire length of the straight line laser induced friction treatment.

Other configurations of the laser induced friction treatment are also contemplated instead of a straight line. By way of example and not limitation, the laser induced friction treatment may have a skewed configuration as shown inFIGS.27Cand D. A straight line may be drawn from the rotating axes338,336. The straight line laser induced friction treatment may be formed at an angle352to the straight lines348,350. The straight line laser induced friction treatment may be formed on both the flat engaging surfaces314,316. The straight line laser induced friction treatment may be formed on the flat engaging surface314as a mirror image compared to the straight line laser induced friction treatment formed on the flat engaging surface316. In this manner, the laser induced friction treatment formed on flat engaging surface316matches and engages with one of the laser induced friction treatment formed on the flat engaging surface314. Referring now toFIGS.27Eand F, the laser induced friction treatment may be formed as an arrow configuration. The trailing edges of the arrows may be aligned to a straight line radiating outward from the straight lines354,356. A peak of the arrows may have a height358defined by its angle358from the rotating axes338,336and be midway of a width342,344of the surfaces316,314. The angle358may be between 1 and 15 degrees from a peak of the arrow to a base of the arrow. The configuration of the laser induced friction treatment may be mirror images of each other on the flat engaging surfaces314,316. Referring now toFIGS.27Gand H, the laser induced friction treatment may be formed into a semi circular or curved configuration. The trailing edges of the curve may be aligned to a straight line radiating outward from the straight lines360,362. A peak of the curve or the straight line360,362may contact a tangent of the semi-circle defined by its angle364from the rotating axes338,336. The peak or the contact of the tangent point may be midway of a width342,344of the surfaces316,314. The angle364may be between 1 and 15 degrees. The configuration of the laser induced friction treatment may be mirror images of each other on the flat engaging surfaces314,316.

In the laser induced friction treatment discussed in relation toFIGS.27A-H, each laser induced friction treatment is identical to an adjacent laser induced friction treatment as a circular or radial array about the rotating axes336,338. However, it is also contemplated that the laser induced friction treatment may be formed as a linear array. By way of example and not limitation, a plurality of first straight line laser induced friction treatment366may be formed on the flat engaging surface316. The first straight line laser induced friction treatment366may be parallel with each other. A plurality of second straight line laser induced friction treatment370may also be formed on the flat engaging surface314. The second straight line laser induced friction treatment370may be parallel with each other. The first and second straight line laser induced friction treatment370may define an angle372. The angle372may be between or equal to 1 degrees and 90 degrees. More preferably, the angle372may be between or equal to 35 degrees and 45 degrees. The angle372creates a diamond or square shaped laser induced friction treatment on the surface314. The laser induced friction treatment formed on the surface316may be formed as a mirror image on the surface314. A distance368between the lines366,370may be between 0.001 inch and 0.125 inch. More preferably, the distance between the lines366,370may be between 0.004 inches and 0.012 inches.

Other configurations are also contemplated which include and are not limited to sinusoidal configuration with a constant or varying amplitude and constant or varying period.

The laser induced friction treatment on the flat engaging surface314may have a mirror image compared to the laser induced friction treatment formed on the flat engaging surface316. In this way, when the flat engaging surfaces314,316of the armature312and the rotor318engage each other, each laser induced friction treatment on the flat engaging surface314of the armature312engages and matches with a corresponding laser induced friction treatment on the flat engaging surface316of the rotor318.

Alternatively, one of the flat engaging surfaces314,316may have less laser induced friction treatment compared to the other one of the flat engaging surfaces314,316. In other words, the entire surface of the flat engaging surfaces314,316does not need to be covered with laser induce friction treatment. Rather, only a portion (e.g., 10%, 25%, 33%, 50% 75%) thereof need be covered with the laser induced friction treatment but yet still have enough friction to impart sufficient torque and mitigate slip between the armature112and the pulley124. For example, the flat engaging surface314may have about 33% of its surface covered with laser induced friction treatment whereas the flat engaging surface316may have 100% of its surface covered with laser induced friction treatment. As these surfaces314,316engage and disengage one another, the laser induced friction treatment formed on the flat engaging surface314would engage with only ⅓ of the laser induced friction treatment formed on the flat engaging surface316. As such, the flat engaging surface316would last three times as long as the flat engaging surface314. Preferably, one of the flat engaging surfaces314,316is a sacrificial part. The flat engaging surface which is of the sacrificial part may have less laser induced friction treatment formed thereon so that the laser induced friction treatment on the non sacrificial part randomly engages with some but not all of the laser induced friction treatment formed on the sacrificial part each time that the parts engage and disengage. In the example above, the flat engaging surface314may be the sacrificial part. However it is also contemplated that the flat engaging surface which is of the sacrificial part may have more laser induced friction treatment formed thereon.

When the respective laser induced friction treatments on the flat engaging surfaces314,316are engaged to each other, the rotor318rotates the pulley324. The pulley has a belt34which drives another component such as a condenser unit of an air conditioner of an automobile.

When the respective laser induced friction treatments on the flat engaging surfaces314,316are disengaged from each other, there is a gap between the rotor318and the armature312so that the rotor318does not rotate the armature314and the pulley324. The rotor318continues to rotate under the rotational power of the shaft326. However, because of the disengagement between the flat engaging surfaces314,316of the armature312and the rotor318, the pulley324remains stationary.

The air gap340between the rotor318and the armature312may be between the peaks of the laser induced friction treatment formed on the flat engaging surfaces314,316of the armature312and the rotor318. The air gap340may be between 0.001 inch and 0.050 inches between the peaks of the laser induced friction treatment formed on the flat engaging surface314of the armature312and the peaks of the laser induced friction treatment formed on the flat engaging service316of the rotor318.

Referring now toFIGS.29-31, a second type of electromagnetic clutch410is shown. The armature412is the driving disc which drives the pulley424(i.e., driven disc) when a flat engaging surface414of the armature412engages a flat engaging surface416of the pulley424. An electric motor422may be disposed within a housing472of the electromagnetic clutch410. The electric motor422rotates the shaft426from an external power supply such as a motor of an automobile. The armature412is fixedly attached to the shaft426. As such, when the shaft426is rotating under the power of the motor422, the armature412also rotates at the same speed and in the same direction. A spring430may be disposed within the housing472of the electromagnetic clutch410and may bias the armature412to a disengaged position which is shown inFIG.29. The pulley424may have an electrical coil420disposed within the pulley. When the electrical coil420is energized, a magnetic field is generated which passes through an air gap440and passes through the armature412. This generates a force which overcomes a force of the spring430so as to traverse the armature412to an engaged position, as shown inFIG.30. In the engaged position, the flat engaging surface414of the armature412is in contact with the flat engaging surface416of the pulley424. Torque is transferred from the armature412to the pulley424via the engaged flat engaging surfaces414,416to rotate the pulley424in the same direction and at the same speed as the armature412.

The laser induced friction treatment formed on the flat engaging surfaces414,416mitigate slip between the two surfaces414,416. The laser induced friction treatment formed on the surfaces414,416may have a mirror configurations in the same manner discussed in relation to the flat engaging surfaces314,316above. Also, the laser induced friction treatment formed on the flat engaging surfaces414,416is formed as a radial array around the rotating axes474,476of the armature412and the pulley424. Because of this, the laser induced friction treatment formed on the flat engaging surfaces414,416engages and matches with a corresponding laser induced friction treatment formed on the flat engaging surfaces414,416. Each laser induced friction treatment formed on the flat engaging surfaces414,414is frictionally engaged to a corresponding laser induced friction treatment formed on the flat engaging surfaces414,416. In certain circumstances, the entire surface of the flat engaging surfaces414,416does not need to be covered with laser induce friction treatment. Rather, only a portion (e.g., 10%, 25%, 33%, 50% 75%) thereof need be covered with the laser induced friction treatment but yet still have enough friction to impart sufficient torque and mitigate slip between the armature412and the pulley424. The other flat engaging services414,416may be fully covered with the laser induced friction treatment. When the flat engaging surfaces414,416engage each other, only a fraction of the laser induced friction treatment formed on the entire flat engaging surfaces414,416are used. Over a period of time, the flat engaging surfaces414,416that is fully covered with the laser induced friction treatment would wear down slower compared to the laser induced friction treatment formed on other one of the flat engaging surfaces414,416.

The laser induced friction treatment has been described as being formed on both the flat engaging surfaces314,316and414,416. However, it is also contemplated that the laser induced friction treatment may be formed on either the flat engaging surface314or the flat engaging surface316. As such, one of the surfaces314or316would have no laser induced friction treatment. Also, it is contemplated that the laser induced friction treatment may be formed on either the flattened surface414or the flat engaging surface460. As such, one of the surfaces414or414would have no laser induced friction treatment. Even with laser induced friction treatment formed on only one of the surfaces314or316,414or416, the friction treatment formed on the surface314or316,414or416still increases the coefficient of friction between the engagement of the surfaces314and316and the engagement of the surfaces414and416. Moreover, the laser induced friction treatment which has been formed on the surface314or316,414or416begins to form pits or depressions within the other surface314or316,414or416which does not have the laser induced friction treatment. In this regard, the laser induced friction treatments formed on the surface314or316,414or416begins to be seated on the surface314or316,414or416which does not have the laser induced friction treatment and is formed as a smooth flat surface.

It is also contemplated that one or both of the flat engaging surfaces314,316and414,416maybe annealed. By annealing the flat engaging surfaces314,316,414,416, the flat surface and if friction treatment has been formed thereon is hardened. By hardening the flat surface and/or the laser induced friction treatment, the flat surface and the laser induced friction treatment would wear down slower compared to a flat surface or laser induced friction treatment which has not been annealed. In an aspect, one of the flat engaging surface314or316,414or416maybe anneal or may to have a greater hardness compared to the other one of the flat engaging surface314or316,414or416. Preferably, the part which is not a replaceable part is annealed or made to have a greater hardness compared to the part which is replace to rebuild the electromagnetic clutch. By way of example and not limitation, the flat engaging surface314of the armature312inFIG.26may have a lower hardness compared to the flat engaging surface314of the rotor318which may be annealed to achieve this relative hardness. As the armature312wears down, it can be replaced while allowing the rotor318to have a greater lifespan. Likewise, the flat engaging surface414of the armature for 12 may have a lower hardness compared to the flat engaging surface416of the pulley424period to achieve this relative hardness, the flat engaging surface416of the pulley424may be annealed.

As discussed above, the flat engaging surfaces314,316,414,416may be formed with as a laser induced friction treatment thereon. The laser induced friction treatment may be formed utilizing the laser embossing and debossing embodiments described herein. For example, the laser induced friction treatment may be recast as induced by laser as discussed herein. Moreover, the engaging surfaces314,316,414,416have been described as being flat. However, it is also contemplated that other configurations for the engaging surfaces314,316,414,416may be used including but not limited to mating concave and convex configurations.

It is also contemplated that the various aspects described in relation to the embodiment shown inFIGS.26-28may be applied and combined with the embodiment shown inFIGS.29-31. Also, the various aspects described in relation to the embodiment shown inFIGS.29-31may be applied and combined with the embodiment shown inFIGS.26-28. By way of example and not limitation, the various configurations of the laser induced friction treatment discussed in relation toFIGS.27A-27J, as shown inFIGS.29A-29J.

The electromagnetic clutch310,410was described in relation to an electromagnetic clutch as used in an automobile. However, the electromagnetic clutch may be used in other types of machinery including but not limited to office equipment, pumps compressors, servo motors, robotics, outdoor power equipment, processing machinery, factory automation, medical equipment, and off road equipment. The shaft326,426would be rotated with a motor associated with one of these other types of equipment and used to selectively rotate a pulley324,424.

As discussed above, the pulley is described as the driven disc. Also, the rotor and the armature is described as the driving disc. However, it is contemplated that a separate disc may be attached to the pulley, rotor and armature as an intermediate part. This separate disc may rotate with the part to which it is attached. Nevertheless, the separate disc and the pulley, rotor and the armature are considered to be the same.

The above description is given by way of example, and not limitation. Given the above disclosure, one skilled in the art could devise variations that are within the scope and spirit of the invention disclosed herein, including usage of other types of lasers. Further, the various features of the embodiments disclosed herein can be used alone, or in varying combinations with each other and are not intended to be limited to the specific combination described herein. Thus, the scope of the claims is not to be limited by the illustrated embodiments.