Patent Description:
In conventional linear motor systems, a moving element is controlled to move along a track by electromotive force. In a moving magnet linear motor, the moving element generally includes a magnet and the track includes an electromagnetic field generator. The moving element is placed on the track such that the magnet is acted on by the electromagnetic field in order to move the moving element along the track. In order to allow for smooth movement, the moving element generally has bearings which run along the track and the moving element is supported by guides or guide rails or the like on the track. The guide rails may, for example, engage with the bearings or with the moving element itself. The bearings may include plain bearings, ball bearings, needle bearings, roller bearings, wheel bearings and the like.

In linear motor systems, forces, including acceleration, on the moving element can be high in order to move or stop the moving element quickly in order to increase production speeds. In this environment, the moving elements tend to be larger in a direction of travel along the track to provide extra stability against the applied forces. However, this larger pallet size can result in a larger tooling pitch (i.e. the distance between items placed on moving elements and/or between moving elements themselves). Alternatively, the moving element may require larger or enclosing guide rails to help to counteract the forces.

In some cases, a ratio of wheel width spacing (e.g. distance between bearings/wheels along the direction of the track) to height spacing (e.g. distance between the guide rail and the centerline of the driving motor (central point of the thrust or, in some cases, center of mass of the moving element)) can have an impact on stability. A reduction of this ratio may produce moving elements that are less stable and therefore have limitations with acceleration, velocity, precision, payload, cantilever, longevity or the like.

In some conventional bearing systems, as noted above, guide rails are provided to physically engage with either the moving element or the bearings in order to provide stability. These conventional bearing systems typically require mechanical disassembly of either or all of the moving element, the bearings, or the guide rails in order to remove the moving element from the track. These types of systems may also require preloading or tight manufacturing tolerances on the guide rails and bearings in order to achieve precise movement and positioning and avoid binding. <CIT> discloses a transporting apparatus, comprising a movable conveying element for conveying a product. The apparatus also comprising a fixed-location running rail, which is arranged all the way round and defines a running track for the conveying element. The apparatus further comprises a linear-motor-drive means for driving the conveying element, wherein the conveying element has a permanent magnet which is in operative connection with coils of the linear-motor-drive means. The conveying element has at least a first sub-element and a second sub-element, which are connected to one another in an articulated manner. <CIT> discloses a linear transport system comprising at least one carriage which has at least one permanent magnet and at least one roller, an energizable stator device which has multiple coils, and a guide rail which is arranged on the stator device and which serves for guiding the carriage. The guide rail comprises a running surface for the rolling of the roller of the carriage, such that the roller can roll on the running surface during a displacement, guided by way of the guide rail, of the carriage, wherein at least one electrical contacting device is provided which is formed separately from the roller and which is designed to form an electrical connection between the carriage and the guide rail during the displacement, guided by way of the guide rail, of the carriage. <CIT> discloses a food and drink conveying device where resistance produced in a curved path in the direction opposite to the direction in which the conveyor driving body is conveyed can be minimized. The conveyor driving body is provided with an annular belt body which continuously travels along the travel path. In addition, a guide means is provided with forward-moving rollers that are supported so as to be pivotable in a horizontal plane on the inner side of the forward-going belt body in a curved path and backward-moving rollers that are supported so as to be pivotable in a horizontal plane on the inner side of the backward-going belt body in the curved path. <CIT> discloses a linear motor conveyor system and method for lubrication including: a linear motor track comprising a first guide rail and a second guide rail, wherein the first guide rail has a shaped profile and the second guide rail has a flat profile; at least one moving element provided to the linear motor track comprising a first bearing having a shaped profile with a first bearing surface of polymer configured to engage the first guide rail and a second bearing having a flat profile with a second bearing surface configured to engage the second guide rail; and a lubrication system provided to one of the track and the at least one moving element and configured to provide a lubricant between the first guide rail and the first bearing surface.

Therefore there is a need for a linear motor conveyor configured to accommodate a more compact tooling pitch between moving elements while also providing stability and ease of handling of the moving elements.

According to one aspect herein, the present disclosure provides a linear motor conveyor system including: a track comprising a shaped guide rail; a second guide rail; and a plurality of moving elements, each of the plurality of moving elements having: a body; at least two shaped bearings supported by the body and configured to match with the shaped guide rail, wherein the shaped bearings are mounted to the moving element such that the moving elements overlap along the direction of the track providing a reduced tooling pitch between the moving elements; a second set of bearings supported by the body and configured to abut against the second guide rail; and a bearing suspension system configured to provide a suspension to the second set of bearings, wherein the bearing suspension system comprises a rotation axis parallel to the axis of rotation of the second set of bearings configured to bias the second set of bearings towards the second guide rail and allow the second set of bearings to pivot in relation to the second guide rail while maintaining contact with the second guide rail.

In some cases, the shaped guide rail may have a plurality of shaped guide rails and the shaped bearings are configured such that some of the shaped bearings can run on corresponding ones of the shaped guide rails to allow the bearings and moving elements to overlap.

The track has a second guide rail and the moving element may include: a second set of bearings configured to abut against the second guide rail; and a bearing suspension system configured to provide a suspension to the second set of bearings.

In some cases, the bearing suspension system may include a thinned body of the moving element configured to bias the second set of bearings towards the second guide rail.

The bearing suspension system includes a vertical rotary axis configured to allow the second set of bearings to pivot in relation to the second guide rail.

In some cases, the bearing suspension system may include one or more of the bearings in the second set of bearings having a hollow area in the interior of the bearing.

In some cases, moving element may include: at least one magnet; a cover positioned over the at least one magnet; a body gasket positioned between the cover and the body of the moving element; and a plurality of bearing gaskets positioned between each bearing and the body of the moving element.

In some cases, each moving element may also include: a second set of bearings configured to abut against a flat guide rail of the linear motor conveyor system; and a bearing suspension system configured to provide suspension to the second set of bearings.

In some cases, the bearing suspension system may include a pair of arms, wherein each arm is configured to support a bearing of the second set of bearings and bias the bearing toward the second guide rail.

In another aspect detailed herein, there is provided a moving element for moving on a track of a linear motor conveyor system, the moving element including: at least one magnet for interacting with a linear motor of the track to move the moving element using electromagnetic forces; a first set of bearings shaped to match with a first shaped guide rail of the track; a second set of bearings configured to abut against a second guide rail of the track; a bearing suspension system configured to provide a suspension to the second set of bearings, wherein the bearing suspension system comprises a rotation axis parallel to the axis of rotation of the second set of bearings configured to bias the second set of bearings towards the second guide rail and allow the second set of bearings to pivot in relation to the second guide rail while maintaining contact with the second guide rail; and a body supporting the first bearing and the second bearing, wherein the body is shaped to allow the first bearing to at least partially overlap the body of an adjacent moving element.

The moving element includes a bearing suspension system configured to provide a suspension to the second set of bearings.

In some cases, the moving element may include: a cover positioned over the at least one magnet; a body gasket positioned between the cover and the body of the moving element; and a plurality of bearing gaskets positioned between each bearing and the body of the moving element.

In some cases, the moving element may further include a bearing suspension system configured to provide suspension to the second set of bearings.

In some cases, the bearing suspension system may further include a pair of arms, wherein each arm is configured to support a bearing of the second set of bearings and bias the bearing toward the second guide rail.

Also described is a linear motor conveyor system including: a track having: a first guide rail having a shaped profile; a second guide rail having a flat profile; and a plurality of moving elements, each moving element having: a body; a first set of bearings supported by the body and configured to match with the shaped first guide rail, wherein the bearings are mounted to the moving element such that the moving elements overlap along the direction of the track providing a reduced tooling pitch between the moving elements; a second set of bearings configured to abut against a second guide rail of the track; and a bearing suspension system configured to provide suspension to the second set of bearings.

Generally, the present disclosure provides a linear motor conveyor system and moving elements with reduced tooling pitch adapted to travel on the conveyor system without the need for enclosing guide rails or the like. Generally, it is intended that the linear motor conveyor system and corresponding moving elements can achieve a tooling pitch of <NUM> or less, <NUM> or less, <NUM> or less while continuing to have performance, reliability, ease of handling moving elements and cost similar to moving elements having larger tooling pitches. In a particular case, the conveyor system may include at least one guide rail system having dual shaped rails and the bearings of the moving elements may be correspondingly shaped. It is intended that this may allow the bearing diameter to be increased to a size that would not compromise performance and reliability. The bearings may be provided to the moving elements such that adjacent moving elements' bearings overlap with one another.

For a conveyor system without guide rails that enclose the bearings as described herein, the torque that the moving element can handle is generally impacted by i) the pitch or spacing of the supporting wheels (also referred to as "wheel pitch") and ii) the distance the linear motor (or driving element) is away from the guide rails or wheels (also referred to as "rail offset"). In particular, this may be the distance from the centerline of the guide rail/wheels (because they counter the torque) to the centerline of the linear motor (or driving force/thrust). In some cases, this may be the distance the center of mass of the moving element is from the supporting wheels (also referred to as "wheel offset"). In some situations, the friction of the lower wheels may also contribute to taking up some of the torque and could be included in the calculations if necessary. The rail offset and the wheel offset are measured along the Z-axis (described herein). As the longitudinal wheel pitch decreases and/or the rail offset increases, the torque on the bearings/wheels about the Y-Axis increases (the Y-axis is perpendicular to the direction of travel and perpendicular to the track). As this torque on the bearings increases, acceleration, deceleration and payload are constrained to achieve stable motion. A way to evaluate this is the ratio of the wheel pitch to the rail offset. The higher this ratio is the higher the chance of stable motion while maintaining acceleration, deceleration, payload and cantilever at appropriate levels for efficient operation. A ratio of <NUM>:<NUM> and higher may enable stable performance. Ratios lower than <NUM>:<NUM> may constrain performance. Similar concepts apply to the ratio between wheel pitch and wheel offset.

<FIG> illustrates a conveyor system <NUM> having a track <NUM>. The track <NUM> is configured to interact with one or more moving elements <NUM> (five of which are illustrated) which are configured to ride or travel along the track <NUM>. Some of the principles of operation of a similar track <NUM> are described in more detail in <CIT>, which is hereby incorporated herein by reference.

In some embodiments, track <NUM> may be composed of a plurality of track sections (not shown) which are mechanically self-contained and separable from one another so as to be modular in nature. In this case, the track sections may be mounted on a support (not shown) so as to align and abut one another in order to form the track <NUM>. In order to be modular, each track section may house self-contained electronic circuitry for powering and controlling the track section.

The conveyor system <NUM> includes a track surface that produces a magnetic force for moving the moving element <NUM> along the track <NUM>. The magnetic force also captures the moving element <NUM> on the track <NUM>. The magnetic force is created by the interaction of the magnetic flux created by coils (not shown) embedded under the track surface and magnetic elements of the moving element <NUM>. The magnetic force can be thought of as having a motive force component for directing movement of the moving element <NUM> along an X axis <NUM> (direction of travel) on the track <NUM>, a capturing force component to hold, on a Y axis <NUM> (laterally), the moving element <NUM> on the track <NUM> and in spaced relation to the track surface. There is also a Z axis perpendicular to both the X and Y axes. In at least some conveyor systems, the motive force and the capturing force is provided by the same magnetic flux.

The track surface includes a first guide rail <NUM> and a second guide rail <NUM> configured to support the moving element <NUM>. The first and second guide rails <NUM>, <NUM> are configured such that the moving element <NUM> may be removed from the track surface when the magnetic force is overcome. The magnetic force is overcome, for example, where a user pries the moving element <NUM> away from the track surface. In an alternative, the moving element <NUM> may be removed from the track surface where the magnetic force is reversed, reduced, or removed.

The first guide rail <NUM> supports at least some of the moving elements <NUM> horizontally while it may support other moving elements <NUM> horizontally and vertically. In particular, the first guide rail <NUM> has a "V" shaped profile <NUM> adjacent to a smooth surface <NUM> with a flat profile. It is intended that the "V" shaped profile <NUM> will support and guide some of the moving elements <NUM> horizontally and vertically while the flat profile will support other moving elements horizontally. The second guide rail <NUM> has a similar structure in that it includes a "V" shaped profile <NUM>. (in this case, on the outer side or bottom of the guide rail) and a smooth flat surface <NUM> (in this case, on the inner side or on top of the "V" shaped profile). It will be understood that rails having an alternate shape (i.e. other than "V" shaped) may be used with corresponding wheels or bearings on the moving elements.

Each moving element <NUM> has at least one shaped bearing or wheel <NUM>, wherein the profile of the wheel is configured to correspond to the shaped profile of the first and second guide rails. Each moving element <NUM> further includes at least one flat wheel <NUM>. In this embodiment, the moving element <NUM> includes a set of shaped wheels <NUM>. It is intended that the dual sets of guide rails <NUM>, <NUM> allow for the shaped wheels <NUM> to overlap as between adjacent moving elements. It is intended that, by providing the dual tracks on each guide rail, and allowing the moving elements to have some overlap, the conveyor system <NUM> may provide a reduced tooling pitch between moving elements. In particular, the tooling pitch is expected to be in a range between <NUM> and <NUM> while the wheels in the moving element include an outer dimension of at least <NUM>.

As noted above, the torque that the moving element can handle can be impacted by i) the pitch or spacing of the V-wheels and ii) the distance the linear motor (or driving element) is away from the V-rails. As the V-wheel pitch decreases and/or the distance between the V-rails and the driving element increases, the torque on the bearings about the Y-axis increases (the Y-axis is perpendicular to the direction of travel). As this torque on the bearings increases, acceleration, deceleration and payload are constrained to achieve stable motion. In the present embodiment, the goal is to obtain a ratio of <NUM>:<NUM>.

The following provides for an example of how the ratio may be obtained:.

One of the reasons to maintain a larger wheel diameter is that, at the <NUM> wheel diameter, standard rotary bearings can still be used. As an example, bearings of the size "<NUM> ID / <NUM> OD / <NUM> height" can be used. This is at the lower end of standard rotary bearing sizes that are cost effective with multiple options available for shielding, sealing and payload ratings. Bearings for smaller wheels, such as <NUM> diameter, become more delicate, are not as robust for industrial applications, have higher contact stresses and have fewer options for sealing and shielding. These are typically magneto bearings with lower payload ratings. Smaller diameter wheels also generally don't roll over rail joints as well as larger wheels. So in addition to the poor stability ratio, the resulting smaller wheels can also constrain performance and reliability.

<FIG> illustrates an embodiment with a single flat profile wheel but it would be understood that a moving element with a set of flat wheels could also overlap with adjacent moving elements.

In this embodiment, the moving elements <NUM> can be oriented in pairs, such that the wheels with the shaped profile of the first moving element are located on the first guide rail and the wheels with the shaped profile of the second moving element are located on the second guide rail. This pairing system allows for the flat profile wheel of the first moving element to be located on the second guide rail and the flat profile wheel of the second moving element would be located on the first guide rail. Generally, each moving element <NUM> has a pallet body <NUM> shaped to allow the wheels <NUM>, <NUM> of an adjacent moving element <NUM> to overlap. In this embodiment, the pallet body <NUM> has a rectangular shape with a first pallet support projection <NUM> between the wheels <NUM>, and a second pallet support projection <NUM> near the wheel <NUM>. As shown, each moving element can be inverted compared to the adjacent moving element. Accordingly, the second pallet projection <NUM> of one moving element is located between the wheels <NUM> of two adjacent moving elements in an overlapping arrangement.

The wheels, bearings, shafts and other mechanical components are intended to be robust and can operate at high performance and reliability while the conveyor system achieves a compact tooling plate pitch of approximately <NUM> or lower, approximately <NUM> or lower, approximately <NUM> or lower, including any intervening pitches.

<FIG> illustrates another embodiment of a conveyor system <NUM> and moving elements having a reduced tooling pitch. In this embodiment, a first guide rail <NUM> may include two shaped portions <NUM> and <NUM> that are adjacent to each other and in this case, at a top side of a track. A second guide rail <NUM> may be a flat rail provided opposite to the first guide rail <NUM>, in this case, at the bottom of the track <NUM>. The second guide rail is intended to be sufficiently wide to allow the guide rail to accommodate two offset wheels or bearings.

The moving element <NUM> may include two sets of wheels or bearings. The first set of bearings <NUM> rides on the first guide rail <NUM>. The first set of bearings <NUM> has an edge profile that corresponds to the profile of the first guide rail <NUM>. In this embodiment, the first set of bearings <NUM> has a "V" shaped profile that matches the opposite "V" shape profile of each of the portions <NUM> and <NUM> of the first guide rail <NUM>. The first set of bearings <NUM> may alternately have a "U" shaped profile or another appropriately shaped profile intended to support the moving element <NUM> along a Z axis. It is intended that the first set of bearings <NUM> may be offset to allow one bearing to be accommodated in the first portion <NUM> of the first guide rail <NUM> and a second bearing to be accommodated in the second portion <NUM> of the first guide rail <NUM>.

The second set of bearings <NUM> rides on the second guide rail <NUM>. The second set of bearings <NUM> is intended to have an edge profile that corresponds to the profile of the second guide rail <NUM>. In an embodiment, the second set of bearings has a flat profile (e.g., a flat wheel) that matches the flat profile of the second guide rail <NUM>. The second set of bearings <NUM> may include two offset bearings which may roll a bit higher or lower on the second guide rail <NUM> to adapt to any non-parallelism with the first guide rail. In some cases, the second set of bearings <NUM> may be a single bearing centrally located on each moving element and configured to engage the second guide rail <NUM>.

In this example embodiment, the moving pallets <NUM> may all be oriented in the same direction yet continue to overlap with neighboring moving elements on either side. For example, the moving element <NUM> has a pallet body <NUM> with a pallet support projection <NUM> and an overhang <NUM> with one wheel <NUM> supported below the overhang <NUM>. The pallet body also has a shoulder <NUM> with the other wheel <NUM> supported above the shoulder <NUM>. The wheel <NUM> on the overhang <NUM> of one moving element <NUM> overlaps the wheel <NUM> on the shoulder <NUM> of an adjacent moving element <NUM>. As the offset wheels allow for the overlap of the moving elements, the conveyor system <NUM> is able to achieve a reduced tooling pitch, which may be in a size range as noted herein.

In the embodiment shown in <FIG>, the moving element <NUM> has two offset "V" shaped bearings <NUM> and two offset flat bearings <NUM>. The two flat bearings <NUM> and the two V-shaped bearings <NUM> (four bearings in total) may provide increased stability in rotation about X, Y and Z axes. This may allow payloads mounted to the moving element <NUM> that have higher cantilever than a three bearing configuration. With four bearings <NUM>, <NUM>, the center of gravity of an added payload that is mounted to the moving element <NUM> may also be shifted farther away from the track while maintaining stability.

It will be understood that overlapping profiled bearings and/or overlapping moving elements may require a dual shaped guide rail. Manufacturing tolerances in a dual shaped rail may cause some precision variability over a single common shaped rail. In some cases, having both shaped portions on the same guide rail (as in <FIG>) may make manufacturing to acceptable tolerances easier than having a shaped profile on each of separate guide rails (as in <FIG>). Having both shaped profile portions on the same rail may also make joint alignment easier as both shapes will be aligned together. Further, there may be reduction in stack up tolerance by having both shaped profile portions close together and on the same side of the motor.

<FIG> illustrates the first guide rail of <FIG> in further detail. Allowing for the overlapping bearings or wheels is intended to provide for a smaller tooling pitch while enabling a bearing solution that can be sized to handle the forces and demands of a linear motor conveyor. Having dual portions in at least one guide rail is intended to allow for the bearings/moving elements to overlap.

As shown in <FIG>, the moving element <NUM> may include a set of offset shaped bearings <NUM> configured such that the shaped bearings overlap with a neighboring moving element and its bearings. The moving element may further include an indent <NUM> (such as a groove, or the like), intended to provide further accommodation for the bearing of the neighboring moving element. It is intended that having dual shaped rails may provide increased stability over a single shaped rail.

It will be understood that the embodiments shown in <FIG> and <FIG> provide different methods of overlapping the bearings and/or moving elements in order to bring the moving elements closer together and thus reduce tooling pitch while maintaining the stability of the moving elements on the track without adding guide rails for enclosing or otherwise holding the moving element onto the track.

<FIG> and <FIG> illustrate an alternative embodiment that is intended to support different bearing spacing on the moving elements with common rails and common linear motors. In particular, <FIG> illustrates a common curved rail while <FIG> illustrates a common straight rail. A linear motor conveyor may be used for a wide range of applications wherein some applications may benefit from a smaller tooling pitch of for example, approximately <NUM> or less, while other applications may benefit from a larger tooling pitch, for example, for wider parts or multiple parts per moving element. Accommodating various dimensions of moving elements may further provide for increased stability to support loads of varying weights and/or loads with varying cantilevers. Conventional mechanical solutions that support wheels with both narrow and wider spacing can be problematic on curves as the motor to magnet gap (that is, distance between the motor on the track and the magnet on the moving element, sometimes called the "air gap" or "magnet gap") changes with the wheel spacing of the moving element. It can be a costly solution to provide multiple curved motors and/or curved rail profiles for various wheel spacings (and the related tooling pitches).

<FIG> and <FIG> illustrate a first moving element <NUM>, which is configured to provide for a smaller tooling pitch and a second moving element <NUM> which is configured to provide for a larger tooling pitch. Each moving element includes a first set of shaped bearings <NUM> and a second set of flat bearing <NUM>. Each set of bearings <NUM> and <NUM> are offset on each moving element and are intended to overlap with neighboring moving elements. The first moving element <NUM> may be a smaller width than the second moving element <NUM>.

In <FIG>, the rail curve profiles may be determined to allow for adequate clearance for the magnet gap for the moving element with the widest wheel gap <NUM>, while the moving element <NUM> with the narrower wheel profile may have a larger magnet gap. For example, a magnet gap of between <NUM> to <NUM> is typically acceptable with a smaller gap being better for performance. The lower end of the range is determined by the precision and tolerances of the manufacturing while the higher end relates to the ability of the track to keep the moving element engaged and operating correctly when subject to higher forces. As long as the magnet gap is maintained at an appropriate distance, a range of sizes of moving elements may be used on the same rail curve.

In another case, the curve profile of the linear motor conveyor track may also be optimized to share the magnet gap variation and the guide rail profiles may be adapted to a common motor. In yet another case, the motor may be shifted relative to the guide rails to provide for a magnet gap for different bearing spacing. For example, for an "out" turn the motor may be shifted out relative to the guide rails as the spacing between the bearings decreases.

In yet another case, common motor and rail parts may be used whenever the curve radius exceeds a predetermined threshold and replacement parts may be used in curves where the radius is below the predetermined threshold. In this case where a replacement part is needed, the motor, guide rails, or both may be replaced in the curves with lower radii based on the bearing spacing of the moving elements. Replacing parts only on curves with a radius below the predetermined threshold may only be a small subset of the total parts and thus represent a cost savings over replacing the complete linear motor conveyor or having multiple conveyors each with a single size of moving elements. This type of solution is intended to be available for "in" turns, "out" turns or other curves on the track sections.

For example, in the case of two types of moving elements, a first type with <NUM> tool pitch and a second type with <NUM> tool pitch, each having V-rails and bearings and operating on the same track (similar to that shown in <FIG>), the following chart illustrates the magnet gap depending on curve radius:.

As shown, as the air gap gets larger, there is a compromise because both the magnetic thrust to move the moving element and the magnetic attraction to hold the moving element on the track are negatively impacted. It will be understood that similar considerations can be used to determine the appropriate magnet gap for other types of rails and bearings.

In another case, the profile of the magnets of the moving element may be modified based on the spacing of the set of bearings. In particular, magnets closer to the centerline could be recessed on moving elements with a wider bearing spacing to reduce magnet gap various on the outside curves. Although, this solution may provide benefit for out turns, it may not aid in in turns so may only be feasible in linear motor conveyor systems which rely solely on out turns.

It is intended that the solutions provided above allow for common linear motor parts to support various bearing spacing and sizes of moving elements. The motor curve profiles are intended to be a compromise between smallest and largest spacing to optimize the magnet gap. It is further intended that the rail curve profile may also be a compromise between the smallest and largest bearing spacing to optimize the magnet gap. Further the profile of the magnets on the moving element may be modified to optimize the magnet gap. It will be understood that all or a subset of these solutions may be employed.

<FIG> illustrate partial cross sectional views of an embodiment of a moving element <NUM>. The moving element <NUM> may include a lubrication system <NUM>. It is intended that the lubrication system <NUM> may reduce wear and tear on the shaped bearing in connection with shaped guide rails. Each bearing may be provided with a lubrication system. The lubrication system may include a lubricant inlet <NUM>, a lubricant storage area, and an absorbent material <NUM>. In some cases, the adsorbent materials may be shaped to match with and be adjacent to the bearing. In this case the lubricant, for example oil, may be added to the lubricant inlet <NUM>, stored in the storage area, and absorbed by the absorbent material <NUM>. The absorbent material <NUM> may then apply the lubricant to the bearing. In some cases, the lubricant storage may be made up of the absorbent material rather than being a container for the lubricant. In <FIG>, there are two lubricant systems (inlets, storage, absorbent material) shown but it will be understood that other embodiments may include variations such as a system that includes a single inlet, single storage, or the like.

<FIG>, <FIG> and <FIG> illustrate a front view and internal view of an embodiment of a moving element <NUM>. As in previous embodiments, this embodiment of the moving element <NUM> has two sets of bearings, a first set of bearings <NUM>, which rides on the first guide rail <NUM> and a second set of bearings <NUM>, which rides on the second guide rail. The first set of bearings <NUM> may include a shaped profile that matches the opposite shape profile of the first guide rail. The first set of bearings may be offset, with one wheel being supported by a pallet support projection <NUM>, or the overhang thereof, while the other wheel may be supported above a shoulder <NUM> of the moving element. The moving element may include a body <NUM> having a plurality of grooves or indents <NUM>, which are intended to provide an area for the bearing of a neighboring moving element.

In some cases, it was found that adding a suspension (for example, some flexibility) to the moving element provided for a smoother movement of the moving element around the track and, in particular, to allow for potential misalignment of the bearings with the rails due to magnetic forces or other factors. To achieve the flexibility, a bearing suspension system <NUM> was provided to the second set of bearings <NUM>. The bearing suspension system <NUM>, for example, a biasing wheel suspension, can allow for the second set of bearings <NUM> to maintain more consistent contact with the second guide rail during movement around the track. In some cases, the bearing suspension system <NUM> may be provided by adapting the body <NUM> of the moving element, such as by thinning the body or cutting out portions of the body. In some cases, a center area of the body <NUM> may be separated from the outer sides to provide for the movement of the bearing suspension system <NUM>. As shown in <FIG>, in some cases, a shim <NUM> may be removably attached to the body to allow the second set of bearings <NUM> to flex independently of a magnet assembly <NUM> (<FIG>). The shim <NUM> may be narrow and attach near the center of the body <NUM> of the moving element <NUM>. In some cases, the shim may have a thickness between approximately <NUM> to <NUM>. In a particular case, the shim <NUM> may be approximately <NUM> in width.

Other suspension/biasing options may be available, for example, the use of springs, elastics, or the like may be provided to the body <NUM>. In some cases, the bearing suspension may be applied to both the first and second set of bearings, although it may be preferable to bias only the second set of bearings which is intended to provide for stability and repeatability for the first set of bearings.

<FIG> illustrates another embodiment of a moving element <NUM>. The moving elements has a first set of bearings <NUM> and a second set of bearings <NUM> supported by a body of the moving element <NUM>. In this embodiment, the body of the moving element further includes an alternative bearing suspension system <NUM>. The bearing suspension system <NUM> provides for a vertical rotary axis allowing the second set of bearings to pivot or rotate in relation to the body of the moving element <NUM>. It is intended that this rotational movement may provide for improved contact with the guide rail while the moving element <NUM> is in transit. In some cases, the bearing suspension system <NUM> may be used with other bearing suspension systems described herein.

<FIG> illustrates a further alternative type of bearing suspension system. In this example, a wheel-type bearing <NUM> may include a hollow <NUM> that can provide some flexibility or compressibility to the wheel to provide a bearing suspension system. As shown, the flexibility or stiffness of the bearing may be defined by the thickness of an outer ring or lip of the bearing. The bearing <NUM> may also be used in addition to other bearing suspension systems described herein to provide further flexibility to the bearing suspension system and to generally allow the bearings a way to maintain greater contact with the guide rails. The depth and radial width of the hollow <NUM> may be dependent on one or more of the overall mechanics, geometry of the pallet and rail, amount of potential compliance difference, material properties and the like. The hollow is intended to be sized to accommodate any potential misalignment between the bearing and the guide rail, which may be caused by magnetic forces acting on the moving element. In a specific example, the potential misalignment may be expected to by <NUM>, and the radial width of the hollow may be at least <NUM>. In a specific case, the width of the hollow may be approximately <NUM> and the stiffness may be approximately <NUM>/N. <FIG> illustrates an exaggerated distortion plot of the bearing shown in <FIG>. This example allows for a force distribution of <NUM>%/<NUM>% between two bearings.

<FIG> and <FIG> illustrate an exploded view and a perspective view of an alternative moving element <NUM>. This particular embodiment includes features that may be used in a conveyor system in a clean or aseptic environment. For example, a cover <NUM> may be attached to provide an easy to clean surface and protect the environment from any contaminants, for example, dust, debris, bacteria or the like that may collect in the magnetic elements <NUM> of the moving element. The moving element <NUM> may have a solid central body 840A and a body gasket <NUM> may be provided to seal the cover <NUM> against the central body 840A to seal the magnetic element <NUM>. These features can reduce or eliminate contaminants that may otherwise accumulate in or around the moving element <NUM> and require cleaning.

Similar to other embodiments, the moving element <NUM> may include a first set of bearings <NUM>, which may include a shaped profile opposite to the shaped profile of the first guide rail. Further, a second set of bearings <NUM> are provided to contact with a second guide rail. The second set of bearings <NUM> are provided with a bearing suspension system <NUM>, which can provide some suspension/flexibility to each bearing <NUM>. The added flexibility is intended to provide for greater stability for the moving element <NUM> by having the second set of bearings maintain contact with the second guide rail during the travel of the moving element <NUM>. In this embodiment, the bearing suspension system <NUM> is provided by having the bearings <NUM> mounted on thinner arms 850A, wherein each arm is configured to support a bearing of the second set of bearings and act as a suspension for the bearing. In some cases, the arm may bias the associated bearing toward the second guide rail. A bearing gasket <NUM> may also be provided to each wheel in the first set of bearings and the second set of bearings. The bearing gasket <NUM> is placed to block contaminants and otherwise seal areas of the moving element <NUM> where contaminants could collect.

In the preceding description, for purposes of explanation, numerous details are set forth in order to provide a thorough understanding of the embodiments. However, it will be apparent to one skilled in the art that these specific details may not be required. In other instances, well-known electrical structures and circuits are shown in block diagram form in order not to obscure the understanding. For example, specific details are not provided as to whether the embodiments described herein are implemented as a software routine, hardware circuit, firmware, or a combination thereof.

Claim 1:
A linear motor conveyor system (<NUM>) comprising:
a track (<NUM>) comprising:
a shaped guide rail (<NUM>);
a second guide rail (<NUM>); and
a plurality of moving elements (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>), each of the plurality of moving elements comprising:
a body (<NUM>, <NUM>, <NUM>, <NUM>, 840A);
at least two shaped bearings (<NUM>, <NUM>, <NUM>, <NUM>) supported by the body and configured to match with the shaped guide rail, wherein the shaped bearings are mounted to the moving element such that the moving elements overlap along the direction of the track providing a reduced tooling pitch between the moving elements;
a second set of bearings (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>) supported by the body and configured to abut against the second guide rail; characterised in that, it further comprises
a bearing suspension system (<NUM>, <NUM>, <NUM>) configured to provide a suspension to the second set of bearings, wherein the bearing suspension system comprises a rotation axis parallel to an axis of rotation of the second set of bearings configured to bias the second set of bearings towards the second guide rail and allow the second set of bearings to pivot in relation to the second guide rail while maintaining contact with the second guide rail.