Rotor for long stator line motor systems with low-wear bearings

Description

Field of the invention

[0001] The present invention relates to rotors for long stator linear motor systems which have a particularly low-wear bearing. State of the art

[0002] Runners, sleds, shuttles, or movers that are individually moved along a transport track by means of a long-stator linear motor are known in the prior art in a variety of embodiments. Frequently, the runners are mounted on guide rails by means of rollers, on which the rolling surfaces of the rollers run. The propulsion of the runners is effected by magnetic interaction between the electromagnets and / or permanent magnets of the long-stator arranged along the transport track and the secondary part of the runners, which is equipped with corresponding magnets.

[0003] Depending on the application of the sliders or the long-stator linear motor system, the transport path is generally designed as a closed system. Therefore, the transport path and thus the guide rails or running rails have both straight sections and curved sections, i.e., curved sections.

[0004] In conventional runners, the roller axes, which support the rollers on the runners, are rigidly aligned. Such a development is, for example, in Figure 1 , which shows a rotor 100 and a long stator linear motor of the prior art. The rotor 100, which is formed with a secondary part 120, is mounted with a plurality of rollers 110 on upper guide rails 150 and lower guide rails 155. For the sake of clarity, Figure 1Only the rear guide rail of the upper or lower guide rail pair 150 or 155 is shown. The runner 100 has two pairs of rollers for each pair of guide rails, by means of which the runner is movably mounted to the respective guide rail pair from below and above. The rollers 1 10 are, as in the Figure 1 indicated, with a rigid roller axis, ie fixed in space with respect to the rotor 100, attached to the rotor 100.

[0005] In addition to the secondary part 120, the rotor 100 shown here as an example also has a holding device 125, for example in the form of a neck-handling clamp for transporting bottles. The magnets of the secondary part 120 interact with the generally individually controllable coils or electromagnets of the long stator 160, which is located in the Figure 1For the sake of simplicity, only a schematic representation is shown. In addition to the long stator shown, the long stator linear motor system generally has another long stator opposite the long stator 160 shown. The rotor 100 is moved precisely along the guide rails by the magnetic interaction with the long stators. The rotor is held securely between the guide rails by the rollers 110 that engage the upper and lower guide rails 150 and 155, respectively.

[0006] As in Figure 2As shown, the transport path of a long-stator linear motor system generally has, in addition to straight sections A, curved sections B along which the guide rails 150 and 155 are curved with a specific radius. However, with the rigid configuration of the roller axles of the exemplary roller pair 1 10-1 shown, a so-called tracking error occurs when negotiating curves. While the roller axle of the running rollers 1 10 in the Figure 1 The straight section of the transport track shown is aligned perpendicular to the direction of travel or running; it deviates when cornering as shown in the diagram. Figure 3 represented by this orientation.

[0007] For example, in Figure 3The orientation of the roller, i.e., the direction of travel determined by the rigid axis of rotation, is indicated by vector R. Additionally, the direction of travel, which is determined by the course of the guide rails 150 and 155, more precisely by a tangent to the guide rails, is shown as vector K. Since the orientation R of the roller and the direction of travel K differ when cornering, the roller 1 10-1 can no longer roll correctly. Instead, a tracking error a occurs, which is represented as the angle between vectors R and K. This means that the roller 1 10-1 can no longer roll straight, but also experiences a lateral displacement. This creates a sliding friction component on the roller's running surface, leading to premature wear of the rollers. The effect is similar to incorrect wheel alignment on a car.

[0008] Runners can have both support rollers, which absorb a portion of the vertically oriented gravitational force, and guide rollers, which absorb only horizontal forces. Thus, when traveling straight ahead, the guide rollers are essentially force-free, apart from a potentially one-sided stator normal force, and are only subjected to centrifugal forces when cornering. Rollers whose axes of rotation are parallel or inclined to the plane of motion or guide plane, including support rollers, slippage, also known as rubbing, occurs when cornering because their axes of rotation are not aligned with the center of the curve radius of the guide rail. This incorrect rolling action leads to increased wear of the rollers and / or the guide rail. However, slippage or rubbing also occurs with guide rollers whose axes are parallel or inclined to the plane of motion.For better differentiation, all rollers whose roller axis has a parallel component, regardless of whether they absorb part of the gravity, are referred to as track rollers, while those rollers whose roller axis is aligned perpendicular to the plane of movement are referred to as (pure) guide rollers.

[0009] The situation is in Figure 4 shown, which demonstrates an alternative design of a runner and a transport track according to the state of the art. In the Figure 4 In the configuration shown, two guide rails 250 and 255 are arranged vertically one above the other, each having a straight section A and a curved section B. The runner 200 is mounted on the guide rails via both rollers 210 and guide rollers 212.

[0010] In the illustrated further development, the axis of rotation of the running rollers 210 is aligned parallel to the plane of motion or guide plane, while the axis of rotation of the guide rollers 212 is aligned perpendicular to the plane of motion or guide plane.

[0011] Here and in the following, the plane of motion or guidance plane always refers to the plane in which the runners are moved. It is assumed that the entire transport path or the considered section of the transport path lies in a single plane. In particular, the curves described by the guide rails, as well as their curve radii, lie in the plane of motion or guidance plane. For parallel guide rails that are curved in the plane they span, this plane thus corresponds to the plane of motion or guidance plane.

[0012] The aforementioned slippage, or deviation of the rolling direction R from the direction of travel K, generally occurs in rollers whose axis of rotation has at least one component parallel to the plane of motion or guide plane, i.e., a component that is oriented obliquely or parallel to the plane of motion or guide plane. The resulting increased wear is greater the larger this component is, or the more parallel the axis of rotation is to the plane of motion. Wear is therefore particularly high in the rollers described in the... Figure 4 The vertical support rollers 210 shown. A runner which discloses the features of the preamble of claim 1 is known from EP 0 636 561 A1.

[0013] The present invention is therefore based on the objective of providing runners and a long-stator linear motor system that enable improved rolling behavior and thus reduced wear. In particular, the aforementioned rubbing of the rollers during cornering is to be avoided. More generally, the present invention is based on the objective of providing a transport system with improved service life and reduced maintenance requirements. Description of the invention

[0014] The above-mentioned objects are achieved by a rotor for a long-stator linear motor system, wherein the rotor comprises at least one secondary part for magnetic interaction with at least one long-stator linear motor system and at least two rollers for supporting the rotor on parallel guide rails of the long-stator linear motor system, and furthermore has at least one roller of the at least two rollers with a steering axis of rotation with integrated caster, wherein the at least one roller is mounted on a roller axis by means of a bolt via an asymmetric and / or oblique bore and furthermore has a pendulum ring mounted on the bolt with an external rolling or sliding bearing, wherein the bore is provided transversely to the roller axis, wherein the bore is formed eccentrically through the roller axis and / or obliquely to the plane of movement, wherein the pendulum ring is designed such thatthat it can oscillate around the straight-ahead position within a specified angular range and wherein the pendulum ring is also mounted off-center and / or obliquely on the bolt.

[0015] According to the Ackermann principle, the extensions of all wheel axles should intersect approximately at the center of the curve when cornering. For roller axes or roller rotation axes aligned obliquely to the plane of movement, this principle applies to the component of the rotation axes aligned parallel to the plane of movement. A tracking error can thus be avoided by selecting the positions of the rotation axes depending on the curve radius of the guide rails. Ideally, the position of each roller of the runner is always such that the parallel components of the rotation axes, i.e. the projection of the rotation axes onto the plane of movement or guide plane, intersect at the center of the curve. With varying curve radii, this should always apply to the section of the curve occupied by the runner.

[0016] The present invention presents two alternative solutions, which can also be combined with each other.

[0017] On the one hand, two rollers of the runner can be rotatably mounted as a roller pair on a turntable of the runner. If one roller of the roller pair is mounted on a first guide rail and the other roller of the roller pair is mounted on a second guide rail, with the first and second guide rails defining the plane of motion, i.e., the guide plane, the rotatability of the turntable causes the parallel components of the roller pair's axes of rotation to align themselves in the direction of the curve radius, i.e., towards the center of the curve. For this purpose, the turntable can be designed to rotate about an axis perpendicular to the plane of motion or guide plane, for example, by being mounted to the runner by means of a bolt, the so-called kingpin.

[0018] According to a further development in which the runners are arranged only on one side of vertically stacked guide rails, individual rollers can also be rotatably mounted on the pivots according to the invention. Here, too, the pivots can be designed to rotate about an axis perpendicular to the movement plane or guide plane, although the movement plane or guide plane is no longer spanned by the guide rails, but rather is aligned perpendicular to the plane spanned by the guide rails. Finally, further developments with more than one pair of rollers per pivot are also conceivable.

[0019] According to the invention, at least one roller of the runner is individually steerable and equipped with a steering pivot axis with integrated caster. This is achieved according to the invention by mounting the roller on a roller axle via a bolt and an asymmetrical and / or inclined bore, and furthermore by providing a pendulum ring mounted on the bolt with an external rolling or sliding bearing. The bore is provided transversely to the roller axle, and is formed off-center through the roller axle and / or inclined to the plane of motion.

[0020] The term "caster" or "caster distance" refers to the longitudinal distance between the tracking point, i.e., the point where the axis of the aforementioned bolt intersects the road surface (i.e., the plane of motion), and the wheel contact point, i.e., the center of the roller contact surface. According to the invention, by mounting the bolt on the fixed (i.e., non-rotating) roller axle via an asymmetrical bore (i.e., a bore that does not pass centrally through the roller axle) and / or an inclined bore (i.e., a bore that does not pass perpendicularly to the plane of motion through the roller axle), a caster occurs between the tracking point and the wheel contact point of the corresponding roller.The bore is positioned in the desired direction of travel in front of the center of the roller axle and / or inclined at such an angle that the point where the bolt axle intersects the plane of motion lies in front of the wheel contact point, resulting in positive caster. This caster, as is known from shopping cart wheels, acts as a corrective force on the wheel's position when the steering wheel is turned, due to the resulting torque. Conversely, as a consequence of the tracking error described above, a torque occurs when cornering, which automatically aligns the caster-equipped roller in the direction of travel.

[0021] According to the present invention, the roller is not equipped with the external steering axis design typical of shopping carts, but rather with an integrated caster. This means, as explained below, that a pendulum ring is mounted on the bolt described above, and this pendulum ring has an external rolling or sliding bearing. The pendulum ring is designed to oscillate around the straight-ahead position within a predetermined angular range, allowing the roller to follow the alignment of the guide rail or curve within this range. For this purpose, the pendulum ring is also mounted off-center and / or at an angle on the bolt. Since the pendulum ring has an external rolling or sliding bearing according to the invention, no external bearing for the steering axis is required for the caster mechanism. Instead, the bearing can be mounted directly on the rolling or sliding bearing.In a sliding bearing, an outer ring with which the roller rests on or is supported on the guide rail or track allows it to roll or slide. Due to the pivotability of the pendulum ring relative to the rigid roller axis, the instantaneous axis of rotation about which the outer ring rolls or slides on the rolling or sliding bearing can deviate from the rigid roller axis. By providing the pendulum ring in a pivotable and off-center and / or inclined position, an integrated caster can be implemented that always aligns the roller in the direction of travel. The design according to the invention is therefore considerably more compact than steering pivot shafts with external caster bearings and is thus particularly suitable for use with rotors for long-stator linear motor systems.

[0022] The present invention provides rotors for a long-stator linear motor system, as is well known in the prior art. As described below, the rotors according to the invention can each have a secondary part for interacting with the linear motor strand(s) of the long-stator linear motor. For this purpose, the secondary part is equipped, depending on the embodiment, with at least one permanent magnet or non-switching electromagnet or at least one electromagnet.

[0023] Furthermore, the rotor has at least two rollers for mounting it on parallel guide rails of the long-stator linear motor system. The specific design of the rollers and their running surfaces is irrelevant. The rollers can have a flat or crowned running surface. A concave rolling profile is also possible. The design of the roller running surface can be selected based on the design of the guide rails. An advantageous design is achieved when the surface of the guide rails has a curved profile that logically corresponds to a concave rolling profile of the rollers. This ensures that the rollers are guided securely along the guide rail.On the other hand, due to the positive locking between the rolling profile and the rail profile, a torque acts on the rollers when cornering, which is transferred to the angular position of the turntable, so that the parallel components of the rotation axes, i.e. the projection axes, are always aligned to the center of the respective curve.

[0024] As previously mentioned, the runner can also have guide rollers in addition to the support rollers that absorb the force of gravity. The present invention provides automatic steering of the support rollers, as well as of the track rollers in general, which considerably reduces wear due to abrasion. According to a further development of the first alternative of the invention, two corresponding rollers, one of which is mounted on a first guide rail and the other on a second guide rail, with the first and second guide rails spanning the plane of movement, can be combined to form a pair of rollers, which is mounted together with its roller axles on a turntable. Turntables are well known in the field of swivel axle steering and are therefore not described in detail here. The decisive factor is simply that the above-mentioned individual rollers or the two rollers of a pair of rollers, ieTheir axes of rotation are pivoted by rotating the turntable. In particular, when the projection axes of the two rollers of a roller pair coincide, aligning the turntable in the direction of the curve radius automatically causes the projection axes of both rollers to point towards the center of the curve, thus fulfilling the Ackermann principle.

[0025] According to a further development of this alternative, the runner can further comprise at least one guide element that is displaceable perpendicular to the direction of travel or pivotable in the guide plane and is designed to maintain a constant distance from the guide rail or control cam when engaging with the long stator linear motor system, in particular with a guide rail or a control cam, wherein the at least one turntable is connected to the guide element in such a way that a displacement of the guide element perpendicular to the direction of travel or a pivoting of the guide element in the guide plane causes a change in the rotational position of the turntable.In this case, a separate guide element, in particular a separate pivotable guide element, can be provided for each turntable, or, as described in more detail below, a common guide element can be provided for two turntables spaced apart from each other along the direction of travel.

[0026] Depending on the design of the roller profile and the guide rails, it can be advantageous to actively influence the rotational position of the turntable(s). According to this further development, this is achieved by providing a movable or pivotable guide element which, through mechanical or magnetic engagement with the long-stator linear motor system, maintains a constant distance from the guide rail. For example, the guide element can be designed as a guide roller that rolls on a guide rail or a control cam. A sliding shoe that glides on a guide rail or a control cam is also conceivable. A guide pin that is guided along the guide rail or a recess formed along the transport path, such as a control cam, can also be used as a guide element.Finally, a permanent magnet can also be used as a guide element, which, due to the magnetic interaction with the guide rail, maintains a fixed distance within certain tolerances to the guide rail.

[0027] The guide element can be designed to be displaceable perpendicular to the direction of travel and can, in particular, be positioned centrally with respect to the longitudinal extent of the runner. During the transition from straight-line travel to cornering, the finite longitudinal extent of the runner causes a perpendicular displacement of the guide element, which, since the guide element is connected to the turntable, is also transmitted to the turntable's rotational position. In this way, without an active drive, solely through the engagement of the guide element with the long-stator linear motor system, the turntable's rotational position is automatically adjusted to the curve radius of the curve being traversed. It is irrelevant whether the guide element is guided on the inner guide rail, the outer guide rail, or on a guide strip, channel, or cam located inside or outside the guide rails.Only the constancy of the distance of the guide element from any guide rail is important.

[0028] Alternatively, the guide element can be designed to pivot within the guide plane. For example, the guide element can be designed as an eccentrically mounted roller that engages with a guide rail. By means of suitable preload, for example using a coil spring, the roller can always be aligned so that it is in contact with the guide rail. When transitioning to a curve or when the curve radius changes, the rotational position of the guide element changes automatically, whereby the change can be transmitted directly or via a sliding element to the turntable.

[0029] According to a further alternative, one or more guide rollers mounted directly on the turntable can serve as a pivoting guide element. For this purpose, the guide rollers are arranged offset from the rotational axis of the turntable in the direction of travel or counter to the direction of travel. When cornering or when the curve radius changes, this offset causes the rotational position of the turntable to change automatically. This development is particularly advantageous when the rollers to be steered are arranged centered relative to the rotational axis of the turntable with respect to the direction of travel.

[0030] A variety of alternative further training methods are conceivable, in which maintaining a constant distance of the guide element to a guide rail or a control cam causes a change in the rotational position of the turntable(s) of the runner when the curve radius changes.

[0031] According to a specific development, the at least one turntable can be connected to the guide element via at least one connecting element, wherein the connecting element is designed such that a displacement of the guide element towards the outside of the curve when cornering causes the turntable to be aligned in the direction of the curve radius. According to this development, the guide element thus exerts a force on the at least one connecting element when displaced perpendicular to the direction of travel or perpendicular to a longitudinal axis of the rotor, which force is transmitted to the turntable by the connecting element in such a way that a torque is generated which aligns the turntable in the direction of the curve radius. More precisely, as described above, the projection axes of the rollers mounted on the turntable are aligned in the direction of the curve center point.A variety of connecting elements of a rigid, flexible or elastic nature are conceivable.

[0032] For example, the at least one connecting element can comprise an elastic rail or rod connecting two turntables, which engages with or is connected to the guide element in such a way that a displacement of the guide element causes an elastic deformation of the rail or rod. According to the specific embodiment described above, the connection of the turntables to the guide element need not be friction-fit or rigid, but can also be positive-fit or by mechanical contact without a mechanical connection. In the present example, two turntables can be connected to each other via an elastic rail or rod that engages the turntable in such a way that the deformation force acting on the rail or rod due to the displacement of the guide element exerts a torque on the turntables, which in turn aligns the turntables in the direction of the curve radius as described above.The guide element can be permanently attached to the elastic rail or rod, or it can simply be brought into mechanical contact with it. The elastic rail or rod can, for example, be manufactured from an elastic plastic using 3D printing.

[0033] According to an alternative embodiment, the connecting element can comprise a rigid slide connecting two turntables to each other in a positive-locking manner, particularly via a groove. This rigid slide engages with or is connected to the guide element in such a way that a displacement of the guide element causes a displacement of the slide perpendicular to the direction of travel. The rigid slide can be attached to the runner, particularly centrally and slidably, with the guide element, for example, a guide roller or control roller, mounted on the slide itself. The two turntables are positively connected to the rigid slide, for example, by providing lateral arms of the slide that engage positively in a groove of the respective turntable. Thus, the turntables can rotate relative to the rigid slide; a connection via a pivot joint is also conceivable.As with the elastic rail or rod mentioned above, the rigid slider thus acts as a transmission element, which converts a translational movement of the guide element into a torque and thus a rotational movement of the turntable(s).

[0034] A transmission can also be provided between the rigid slide and the turntables. By selecting the correct transmission ratio, the rollers mounted on the turntables can roll on the guide rails without tracking errors. This is also possible in a transition zone from a straight section to a curved section, for example, in the form of a clothoid. The smaller the radius of the guide rail to which the guide element maintains a constant distance, the greater the displacement of the slide perpendicular to the runner and the greater the deflection of the turntables. With the correct transmission ratio, the rollers can thus maintain the correct orientation, i.e., towards the center of the curve, at every point on the clothoid. As mentioned above, the distance can be zero, for example, when the guide element slides or rolls on a guide rail.

[0035] The alignment of the turntable by moving the slide can be influenced, for example, by selecting a relative position of the positive connection between the turntable and a center point of the slide such that a virtual axis connecting the rollers of a pair of rollers is aligned in the direction of the curve radius of a curve with a predetermined curvature. In other words, the positive connection between the turntable and slide is arranged between the turntable and slide, for example by designing the corresponding arm of the slide with a corresponding length, in such a way that the vertical displacement of the slide caused by the curve radius with a predetermined curvature brings about the desired change in the rotational position of the turntable. Thus, the influence on the rotational position of the turntable is greater the closer the positive connection is arranged to the turntable.The virtual axis mentioned here connecting the rollers of the roller pair corresponds to the previously mentioned orientation of the projection axes of the rollers.

[0036] By equipping the rollers with steerable pivots, roller wear can be significantly reduced. By incorporating a guide element, the rollers can be guided correctly at all times, even with flat or convex rolling profiles. This requires neither an external power source nor a control device. The described improvements thus enable simple and maintenance-free steering of rollers without tracking errors.

[0037] According to the present invention, regardless of whether steering pivot axes with integrated caster are provided with or without a turntable, the rollers, i.e., the running rollers, of the runner can be designed with a concave rolling profile such that the rollers roll laterally stable on a surface of the guide rails. The concave rolling profile can, for example, be adapted to a convex surface profile of the guide rails. In this case, the laterally stable guidance of the running rollers on the guide rails causes the steered rollers to be automatically aligned in the direction of travel by adjusting the rotational position of the turntable and / or due to the caster.

[0038] As mentioned above, the technical problem is solved by providing at least one roller with a roller axis with integrated caster. The at least one roller steered in this way is in particular a track roller, i.e. the roller axis of the at least one roller is arranged parallel or obliquely to the plane of movement of the rotor. Since pure guide rollers are not subject to any component of gravity, it is generally not necessary to design the guide rollers with integrated caster. A roller whose roller axis, however, has at least one component parallel to the plane of movement bears at least part of the weight of the rotor. Due to the caster, a torque is exerted on the bearing of the roller, which automatically aligns the roller in the direction of travel.

[0039] As already mentioned, the integrated caster according to this development is achieved by supporting the roller by means of a bolt via an asymmetric and / or angled bore on a roller axle and providing a pendulum ring mounted on the bolt with an external roller or plain bearing. The off-center and / or angled bore through the roller axle, whether rigidly or mounted on a turntable as described above, together with the off-center and / or angled mounting of the pendulum ring on the bolt through the bore creates an integrated caster of the steering axis of rotation, so that the roller can be steered individually. The torque resulting from the caster when cornering automatically aligns the roller in the direction of travel, even if the roller is not designed with a laterally stable rolling profile. In this way, rubbing of the roller in curves can be avoided, thereby increasing the service life of the roller.The design with an integrated trailing arm is considerably more compact than the design with an external steering axis, making the resulting rollers better suited for use in runners for long-stator linear motor systems. Furthermore, the integrated trailing arm, via the pendulum ring, limits the maximum steering angle, thus preventing the sideways turning or flipping in a different direction that is common with shopping carts equipped with external steering axes.

[0040] As mentioned, at least one roller can still include an outer ring mounted on the rolling or sliding bearing. The outer ring thus slides or rolls on the rolling or sliding bearing, so that the axis of rotation of the roller, which is determined by the rotation of the outer ring, can deviate from the roller axis. The axis of rotation is determined by the position of the pendulum ring.

[0041] According to a further development, the bolt can be fixed to the roller axle, while the pendulum ring is rotatably mounted on the bolt. In other words, the position of the bolt relative to the roller axle is fixed, while the pendulum ring can oscillate around the bolt.

[0042] Alternatively, the pendulum ring can be fixed to the bolt, while the bolt is rotatably mounted on the roller axle. In other words, in this case the position of the pendulum ring relative to the bolt is fixed, while the bolt can rotate within the bore through the roller axle.

[0043] To allow the pendulum ring to pivot around the steering axis, its inner diameter can be larger than the diameter of the roller axle, creating an annular gap between the axle and the pendulum ring. The inner diameter of the pendulum ring is larger than the roller axle diameter by an amount dependent on the maximum angular adjustability, enabling the pendulum ring to pivot around the roller axle within the desired angular range. Alternatively or additionally, the pendulum ring can have recesses on its inner surface that allow it to pivot around the roller axle. These recesses can be located on the inside of the pendulum ring, facing either the direction of travel or the opposite direction. In this case, the pendulum ring can be positioned with minimal clearance from the roller axle, away from these recesses.Again, the recesses can be dimensioned to allow the pendulum ring to pivot through a desired angular range. As mentioned above, the pendulum ring's stop against the roller axle prevents the roller from becoming misaligned or flipping over. The angular range, i.e., the distance of the pendulum ring from the roller axle and / or the dimensions of the recesses, can be selected according to the curve radii to be negotiated.

[0044] The pendulum ring can be spaced from the roller axle, for example, by means of one or more spacer elements, by designing the bolt as a stepped bolt, and / or by press fit or bonding to the bolt. As is known, a stepped bolt has various sections, whereby the diameter of a section for receiving the bolt in the pendulum ring can be smaller or have a different cross-section.

[0045] When the runner moves along a straight section of the conveyor track or guide rail, the rollers in their initial position follow the direction of travel precisely. If the runner then moves from a straight section into a curve, the rollers, due to their restoring torque, follow the conveyor track or guide rail geometrically correctly. Similarly, the rollers realign themselves when the runner returns from a curve to a straight section.

[0046] The design of individual or all rollers of the runner with steering pivot axes featuring integrated caster can be effectively combined with the turntable steering described above. If, for example, a residual tracking error of the affected rollers occurs due to insufficient deformation of the elastic connecting element or insufficient displacement of the rigid slide, the integrated caster of these rollers can ensure correct alignment. In the combined design, it is sufficient to design the integrated caster with a small angular range of the pendulum motion. Conversely, the combined design enables the use of the runner according to the invention on curved sections with highly varying curve radii.

[0047] The present invention also provides a long-stator linear motor system with a plurality of rotors according to one of the embodiments described above, which further comprises a transport track with at least two parallel guide rails on which the rotors are movably mounted, wherein one roller of a pair of rollers of the rotors is mounted on one of the two guide rails and the other roller of the pair of rollers is mounted on the other of the two guide rails, and wherein the transport track comprises at least one straight section and at least one curved section and / or curved sections with different curve radii.

[0048] According to this further development, the transport track is thus designed as a double-rail system, whereby additional guide rails may be provided for further stabilization of the runners and / or for the guide elements described above. The parallel double rails define the plane of motion described above, since the curves described by the guide rails lie in this plane.

[0049] The runners' pivots described above thus connect two rollers, one mounted on each of the two guide rails. Changing the rotational position of the pivots thus aligns the projection axes of these rollers toward the curve center.

[0050] Long-stator linear motor systems are sufficiently known in the prior art, so a detailed description is omitted here. It should only be mentioned that the long-stator linear motor systems can be designed with one or two linear motor strands along the transport path. The linear motor strands can be designed as long stators of, in particular, synchronous, linear motors. In an alternative embodiment, the linear motor strands can also be designed as asynchronous linear motors, wherein the at least one permanent magnet and / or non-switching electromagnet of the secondary part of the rotors and / or an electrically conductive element of the rotors, for example in the form of a metallic plate to which the permanent magnet and / or non-switching electromagnet are attached, act as a conductor for the induction by the asynchronous linear motors.

[0051] Due to the magnetic interaction between the magnets of the secondary components and the linear stators, the rotors can be moved along the transport path, i.e., along the guide rails, with an individual displacement-time profile. The rotors can be controlled by selectively actuating the magnets of the rotors and / or the linear motors using a suitable control unit.

[0052] If the rotors are designed as passive rotors, i.e., with a secondary section containing one or more permanent magnets or non-switching electromagnets, the rotors are moved by interaction with the alternating electromagnetic fields generated by individual controllable electromagnets in the linear motor trains. Alternatively, the rotors can be designed as active rotors with electrical windings that can generate the alternating magnetic fields required for the drive. Accordingly, a section of the conveyor track is equipped with permanent magnets or non-switching electromagnets. In this case, both the electrical energy required for the drive and the signals required for the control system can be transmitted to the individual rotors via induction transmission.

[0053] The runners can be designed in particular as transport elements for transporting piece goods, for example containers. For this purpose, the runners can be designed as in Figure 1 The device shown is equipped with a suitable holding device, for example, in the form of a gripping element. The gripping element can be passively or actively controllable. In particular, gripping elements for positive-locking or force-locking gripping of a container's neck area, for example, in the so-called neck handling of plastic bottles, are conceivable, whereby the container being held can be rotatably mounted about its longitudinal axis within the gripping element during positive-locking gripping. Furthermore, the gripping element can be pivotable and / or height-adjustable and arranged above, below, or beside the runner.

[0054] Containers include, in particular, beverage bottles, but also other containers for food, medicines, hygiene products, cleaning products, or the like, such as cans, glass bottles or other glass containers with lids, packaging based on cardboard or composite materials, Tetra Pak, or the like. Likewise, plastic containers also include intermediate products, in particular preforms for stretch blow molding the containers. Furthermore, containers within the meaning of the present disclosure also include assembled packages comprising multiple containers. The long-stator linear motor systems with rotors according to the present invention can thus be used particularly in container processing systems.

[0055] As already mentioned, the rotors each have at least one secondary part for magnetic interaction with the at least one long stator. For this purpose, at least one sequence, i.e. a sequence in the longitudinal direction of the rotor, of generally adjacent permanent magnets and / or electromagnets, in particular non-switching electromagnets, with alternating polarity can be attached to the secondary part, which can be designed, for example, in the form of a carrier plate. Depending on the design and arrangement of these magnets, and depending on whether a one-sided or two-sided linear motor drive is used, the rotors can also have two or more secondaries. For example, a separate secondary part can be provided for each long stator. In this case, the arrangements of the sequences of magnets on the secondaries can be the same or different, in particular mirrored.For the sake of simplicity, runners with exactly one secondary part are assumed here and in the following without restriction. In a special case, the sequence may also contain only a single magnet of a specific polarity.

[0056] The at least one long stator of the long-stator linear motor systems described here can be formed in a particularly simple design by a multitude of electrical windings arranged along the linear motor strand in the form of individually or block-controlled electromagnets. More complex designs are also conceivable, for example, by means of a Halbach arrangement of the electromagnets to increase the magnetic flux on the side facing the secondary part.

[0057] The magnets of at least one sequence can be arranged transversely to the transport path on the secondary part of the rotor, such that one magnetic pole of each magnet can interact with a first long stator, while the other magnetic pole can interact with a second long stator. Alternatively, the sides of the secondary part facing the first and second long stators can also have separate sequences of magnets, which can be configured, in particular, in a Halbach arrangement to amplify the magnetic flux in the direction of the respective linear motor train. Furthermore, an embodiment with only one long stator is also conceivable, in which the magnets of the secondary part can be arranged, in particular, in a Halbach arrangement.The required electrical energy can be supplied to the at least one non-switching electromagnet in the secondary part of the rotor via an electrical cable or power supply rail arranged along the conveyor track and via the rotor's electrical contacts, for example, via power collectors. Alternatively, the required electrical energy can be transmitted via induction.

[0058] In linear motors, the magnets of the rotor and the long stator(s) are generally aligned and dimensioned such that they face each other on both sides of an air gap. The aim is to achieve the greatest possible overlap of the opposing magnetic poles in the direction perpendicular to the transport or movement direction and along the air gap, in order to achieve optimal thrust. Two basic configurations are conceivable for the orientation and relative arrangement of the guide rail(s), long stator(s), and secondary part.

[0059] In a first embodiment, the guide rail(s), long stator(s), and secondary part are arranged such that the air gap between the poles of the magnets of the secondary part and the long stator is oriented essentially perpendicular to a contact surface of the long stator linear motor system. In this "vertical" case, the generally elongated poles of the magnets of the long stator and secondary part are also oriented essentially perpendicularly. The same applies to a support plate of the secondary part. The direction of movement and the path of the at least one guide rail are assumed to be essentially horizontal, i.e., parallel to the contact surface. Thus, the plane of movement defined by the guide rails is also horizontal. In a double-ended linear motor, the two long stators also run parallel to each other in a horizontal plane.

[0060] In a second, alternative embodiment, the guide rail(s), long stator(s), and secondary parts are arranged such that the air gap between the poles of the magnets of the secondary part and the long stator is aligned substantially parallel to the contact surface of the long stator linear motor system. In this "horizontal" case, the generally elongated poles of the magnets of the long stator and secondary part are also aligned substantially horizontally. The same applies to a carrier plate of the secondary part. The direction of movement and the course of the at least one guide rail are also assumed to be substantially horizontal, i.e., parallel to the contact surface. In a double-sided linear motor, however, the two long stators now run parallel to each other in a vertical plane.

[0061] In both versions, the movement of the runners takes place in a horizontal plane, the plane of motion or guide plane. It is understood, however, that the aforementioned transport path can also include inclines, and even vertical sections. Accordingly, the relative arrangements of guide rails, longitudinal stators, and secondary components must be adapted to the orientation of the transport path. For the sake of simplicity, a horizontally oriented transport path is assumed here and in the following without restriction. It is understood, however, that the terms "perpendicular," "vertical," "parallel," and "horizontal" used below do not define an absolute reference system, but are to be understood in relation to the orientation of the transport path, unless explicitly stated otherwise.

[0062] In the prior art, the greatest possible overlap of the opposing poles perpendicular to the direction of travel, i.e. parallel to the area of ​​the air gap and perpendicular to the direction of travel, is usually provided in order to maximize the magnetic interaction.

[0063] In the horizontal configuration described above, with a horizontal air gap, the rollers bear the weight of the rotor and, in the case of a single-sided, bottom-mounted long stator, the normal force exerted by the long stator on the secondary component. In the vertical configuration with a vertical air gap, only the weight of the rotor acts on the support rollers. As mentioned several times already, this results in mechanical wear.

[0064] The present invention also provides rotors that are optimized with regard to mechanical wear. In particular, the rotors can be designed with secondary parts that have magnets arranged asymmetrically with respect to a central plane of the long stator(s), more precisely the magnets or the iron cores of the electromagnets of the long stators. In particular, the magnets of the secondary parts can be arranged such that their extent below the central plane is greater than their extent above the central plane. The central plane of the long stators is defined by half the height of the magnets or iron cores of the electromagnets of the long stators.

[0065] By equipping the secondary parts of the rotors according to the invention with magnets, the larger part of which is arranged below the central plane, an obliquely upward-directed force acts on these magnets due to the interaction with the magnets of the long stators, which counteracts the weight force of the rotors. Thus, a weight force reduced by the vertical component of the magnetic interaction force acts on the support rollers or, more generally, on the bearing elements, for example, plain bearings, of the rotors. Due to the reduced weight force, the wear of the bearing elements, in particular the support rollers, is simultaneously reduced.

[0066] According to a further development, the magnets of the secondary parts of the rotors can be designed in a vertical direction, i.e., perpendicular to the direction of travel and parallel to the air gap, with an extent, i.e., height, that is greater than or equal to the extent of the magnets or iron cores of the electromagnets of the long stator(s) in the vertical direction. The asymmetrical arrangement of the magnets of the secondary parts, with a center of gravity located below the central plane of the long stators, then leads, as described above, to a magnetic interaction force directed obliquely upwards.

[0067] While, with equally sized magnets in the secondary parts and the long stators, a downward displacement of the secondary part magnets in the vertical direction causes a reduction in the propulsive force due to the reduced overlap with the long stator magnets, the desired tilting of the magnetic interaction force and thus a reduction in the acting weight force can be achieved without reducing the propulsive force when using "oversized" secondary part magnets, i.e., magnets whose vertical extent is greater than the vertical extent of the long stator magnets or iron cores.

[0068] The magnets of the secondary components, or the secondary components themselves, can be rigidly connected to the rotors. Alternatively, the magnets or the secondary components can be connected to the rotors via a spring-elastic element, with an additional holding device, such as a gripping element for containers, attached to the rotors along with the magnets or the secondary components. A change in the load-bearing capacity of the rotor, for example, when the supported container is filled, thus automatically affects the vertical positioning of the magnets of the secondary component relative to the magnets of the long stator by increasing the extension of the spring-elastic element. In other words, an increase in the load-bearing capacity shifts the magnets of the secondary component downwards.This is counteracted by the vertical component of the magnetic interaction force described above, and the effect is stronger the further downwards the magnets of the secondary part are displaced (provided there is sufficient overlap). When using a spring-elastic element to attach the secondary part and the holding device to the runner, the reduction in weight force described above thus increases with increasing load capacity, counteracting the increased weight force resulting from the increased load capacity. To prevent vibrations, the spring-elastic element can be designed with damping.

[0069] The described further developments with asymmetrically designed and / or arranged magnets of the secondary parts reduce the forces acting on the support rollers or bearing elements due to the weight of the runners or the transported load and thus reduce the mechanical wear of the support rollers or bearing elements.

[0070] The described effect can also be used in the horizontal design with a horizontal air gap, by partially compensating for lateral forces occurring preferably on one side, for example centrifugal forces, through an asymmetrical arrangement of the magnets of the secondary parts in such a way that the larger part of the magnets is arranged on the side opposite this side.

[0071] As already indicated several times, the asymmetrical arrangement of the magnets of the secondary parts can also be used in runners that are not mounted on rollers, but on the guide rails via alternative bearing elements, in particular sliding bearings.

[0072] Transport systems based on long-stator linear motor systems are well known in the prior art. In such systems, a large number of individually movable rotors are generally mounted, at least partially, mechanically on one or more guide rails. Due to frictional processes resulting from the relative movement between the rotors and guide rails, triboelectricity can lead to a considerable electrostatic charge on the rotors, which, in the event of uncontrolled discharge, can damage people or components. Methods for dissipating electrostatic charges from a moving rotor to stationary, grounded components via an electrical contact device are known. Various designs of sliding contacts are known as electrical contact devices.However, the discharging of electrostatic charges through mechanical contact with a discharge device is subject to wear and therefore leads to wear on the rotors and the contact device through continuous operation of the long stator linear motor system.

[0073] The present invention is therefore based on the objective of enabling the most wear-free neutralization of electrostatic charges on the rotors of a long-stator linear motor system. More generally, the present invention aims to extend the service life of the long-stator linear motor system and reduce maintenance costs.

[0074] The above-mentioned problem is solved by a long-stator linear motor system with a transport track and a plurality of rotors which are movably mounted on the transport track, wherein at least one device for electrostatic charging and / or discharging of the rotors is provided on the transport track, and wherein the device is designed to charge and / or discharge the rotors without contact by means of a fluid.

[0075] As mentioned, long-stator linear motor systems are well known in the art, so a detailed description is omitted here. A long-stator linear motor system always has a transport track, which in particular can comprise one or more guide rails along which the plurality of rotors can be moved in an individually controlled manner. The individual movement of the rotors occurs through magnetic interaction of the secondary parts of the rotors with the long stator(s) of the long stator linear motor system. To avoid repetition, reference is only made here to the above-described further developments of the rotors, in particular the secondary parts with permanent magnets or non-switching electromagnets as passive rotors or with specifically controlled electromagnets as active rotors. Accordingly, as mentioned above, the long stators can be designed as synchronous or asynchronous linear motor trains.

[0076] As mentioned, electrostatic charging of the rotors occurs due to the relative movement of the rotors, which are at least partially mechanically mounted on the transport track, particularly on the guide rails, and the transport track itself. However, the present invention can also be applied to fully magnetically or fully pneumatically mounted rotors that are electrostatically charged in any other way. In particular, the embodiments described below can also be used for the targeted charging of uncharged rotors with a desired charge polarity. Specifically, the embodiments described below are particularly applicable to the rotors described above, which are mounted on guide rails by means of rollers and / or guide rollers. However, the present invention is not limited to the rotors described above, but is generally applicable to long-stator linear motor systems.

[0077] According to the present invention, at least one device for electrostatically charging and / or discharging the rotors is provided at a stationary position on the transport track, wherein the device is designed to charge and / or discharge the rotors without contact using a fluid. The device for electrostatically charging and / or discharging the rotors, hereinafter referred to as the discharge device, is arranged on the transport track such that passing rotors can be charged or discharged via charge exchange with a fluid. Accordingly, the discharge device is arranged in the area of ​​the transport track at a distance and in a position such that the fluid can be brought into contact with the surface of the rotors to be charged or discharged by the discharge device.Here and below, the term "contactless" with regard to charging and / or discharging is to be understood in such a way that no mechanical contact with a solid body, such as a sliding contact, is required for charging and / or discharging. Rather, the discharge device can be designed to deliver a flow of fluid toward the rotor to be discharged and / or charged. The discharge device can also be designed to electrically charge the fluid with a desired charge polarity before or during discharge.

[0078] To discharge an electrostatically charged rotor, the discharge device can be designed to electrically charge the discharged fluid with charges of the inverse polarity of the rotor's charge. This can be predetermined, for example, if the materials used for the rotor's bearing elements and the transport track or guide rails result in electrostatic charging with a predetermined polarity.

[0079] Alternatively, a sensor can be provided on the transport path in the upstream section of the discharge device, which is designed to determine the polarity of the electrostatic charge of the runners passing by the sensor. The sensor can be designed, for example, as an electric potential sensor (EPS), in particular as a surface potential sensor, ion equilibrium detection means, or potential detection device. The sensor can thus be used to determine the polarity of the electrostatic charge. Additionally, the sensor can be designed to determine the amount of electrical charge on the surface of the runner.

[0080] According to a further development, the sensor can be connected via a signal line or transmitter to a control unit designed to regulate the polarity and / or the magnitude of the charges generated by the discharge device per unit of time, depending on the signals transmitted by the sensor. For this purpose, the discharge device can be designed to charge the fluid either positively or negatively, for example, by adjusting electrical currents. Accordingly, positive or negative ions can be generated in the fluid, which are then released along with the fluid towards the rotor. The rotor is discharged upon contact of the positive or negative ions with its charged surface.By means of the sensor and the control unit, the flow of positive or negative ions can be regulated, for example by adjusting the current, in such a way that the charged surface of the runner is essentially neutralized.

[0081] However, further developments are also conceivable in which the surface of the rotor or part of it is specifically charged through contact with the positive or negative ions. The specifically applied charges can then be used to perform special functions of the rotor. For this purpose, the rotors can have one or more capacitors that store the applied charges. The charge energy stored in this way can then be used, for example, to operate sensors or actuators of the rotors that move along with them. Likewise, the applied charge can be used to pick up objects of opposite charge using electrostatic attraction. Furthermore, the rotors can also be individually marked by the targeted application of charges, for example for product tracking.By means of an additional potential sensor located downstream of the discharge device, the thus charged rotors can be clearly identified. The long-stator linear motor system according to the invention can thus have an additional potential sensor designed to determine the amount of electrostatic charge of the rotors passing by it. This potential sensor can also be connected to the control device, which then performs specific treatment steps on a conveyed product depending on the identified rotor.

[0082] In its basic form, the present invention can comprise a discharge device designed to neutralize the charged surfaces of the runners passing by. The discharge of the runners can take place, in particular, upstream of a cleaning station arranged on the transport path for cleaning the runners. Since dirt particles adhere less strongly to the runners' surfaces after neutralization, they can be cleaned more easily.

[0083] Numerous other embodiments are conceivable in connection with the long-stator linear motor system according to the invention. The further developments of the discharge device described here also include devices that specifically serve to charge the rotors with desired charges.

[0084] According to a further development, the fluid can be a gas that is partially ionized by the discharge device. The gas can be, in particular, air. The discharge device can be designed as an ionizer, for example, a high-voltage ionizer. The discharge device is designed to partially ionize the surrounding air. For this purpose, the ionizer can be equipped with conductive tip electrodes, for example, in the form of a comb or sawtooth, on which atoms and molecules in the air are ionized by corona discharge and field emission. For example, oxygen molecules can be positively or negatively charged by field emission, so that corresponding oxygen ions are formed. The partially ionized gas can then be brought into contact with the surface of the rotor to be discharged.

[0085] For this purpose, the discharge device can further comprise a gas supply device, by means of which the gas can be guided past the electrodes of the ionizer to the surface of the rotors. For example, this gas supply device can be a blowpipe directed in the direction of the rotors being guided past. Alternatively, the gas supply device can comprise a flow line with a valve connected to an air supply source, for example, a compressed air source. By selectively opening and closing a controllable valve, a specific quantity of gas ions per unit of time can be brought into contact with the surface to be discharged.

[0086] The gas supply device can be configured to direct the ionized gas continuously or via gas pulses towards the runners. In particular, the gas supply device, in conjunction with the control unit, can be configured to release ionized gas only when a runner is in the vicinity of the discharge device, in order to prevent unwanted charging of the transport track.

[0087] Charging or discharging the rotors using a high-voltage ionizer is contactless and wear-free. Compared to prior art discharge devices based on mechanical contact, the described discharge device according to the invention is therefore more reliable and requires less maintenance. The method – especially with air supply – is very effective for charging or discharging rapidly moving objects, such as the rotors. Furthermore, existing transport systems can be easily retrofitted by installing the high-voltage ionizer described above on the transport track. A structural modification of the transport system, particularly the rotors, is therefore not necessary.

[0088] According to an alternative embodiment, the fluid can be an electrically conductive liquid. Preferably, an electrically conductive liquid, such as an electrolyte, can be used that is neither corrosive nor caustic and does not form deposits. The discharge device can then be configured to direct a jet of the electrically conductive liquid onto the surface of the passing rotors to be discharged. Here, too, the discharge device can emit such a jet of liquid, particularly in pulses, when a rotor is passing through the discharge device. The long-stator linear motor system can also have a collection device for dripping liquid below the transport track, from which the liquid can be conveyed back to the discharge device via a line.

[0089] To direct the liquid jet onto the passing runners, the discharge device can, for example, have one or more fixed spray heads that continuously or in pulses spray the passing runners with the electrically conductive liquid. The spray heads, or more generally, a supply line for the electrically conductive liquid, can be connected to a potential equalization system, for example, by being grounded. When the surface to be discharged comes into contact with the liquid jet, the excess charge is thus carried away by electrical conduction in the liquid jet to the spray head or supply line.

[0090] As with the use of a gas, discharging the rotors using a liquid jet is contactless and wear-free. Compared to the contact-based method of the prior art, the described discharge device requires less maintenance and is therefore more cost-effective. As with gas discharging, the liquid-based discharge device also requires no structural modification of the transport system or the rotors. Existing long-stator linear motor systems can therefore be easily retrofitted with the discharge device described above.

[0091] The aforementioned problem is also solved by a method for the contactless charging and / or discharging of rotors of a long-stator linear motor system, comprising the following steps: supplying a rotor to be discharged and / or charged to a discharge station and contactless discharge and / or charging of the rotor using a fluid in the area of ​​the discharge station. Here, too, the term "discharge station" is generally used for both a station for discharging and a station for charging the rotors. As described above, the contactless discharge and / or charging using a fluid can be carried out by supplying an ionized gas, in particular ionized air, and / or by supplying an electrically conductive liquid via the discharge station. The method according to the invention can thus also include the controlled ionization of the gas, for example, by means of a controllable high-voltage ionizer.The method can also include the controlled continuous or pulsed supply of the ionized gas or the electrically conductive liquid to the surface of the rotor to be discharged or charged.

[0092] This can be achieved, as described above, using a gas supply device, such as a compressed air supply, a blowpipe, and / or a valve. Similarly, the electrically conductive liquid can be supplied via a spray head in the form of a liquid jet.

[0093] The method can further include detecting the polarity and / or magnitude of the electrostatic charge of a rotor in the inlet to the discharge station, for example, by means of an electrical potential sensor. The measured polarity and / or magnitude of the electrostatic charge can be transmitted via signal line or wirelessly to a control unit, which controls the discharge station accordingly to release the precise amount of ionized gas required for neutralization.

[0094] As described above, the runners can also be selectively electrostatically charged in the discharge station. For example, a charge applied to the runners by the discharge station can be stored in an integrated capacitor on the runners to power sensors or actuators that are moved with them at a later time. The process can thus also include the targeted electrostatic charging of the runners. Oppositely charged objects can be picked up by the runners after they have been charged, due to electrostatic attraction. Furthermore, the runners can be individually charged to mark them, for example, for product tracking. For this purpose, as described above, each passing runner can be uniquely identified using an additional potential sensor located downstream of the discharge station.

[0095] The process can also include automatic cleaning of the rotors in a cleaning station of the long-stator linear motor system after they have been discharged in the discharge station. After neutralization of the electrostatic charges, the rotors are considerably easier to clean, as dirt particles then adhere less strongly.

[0096] The same variations and further developments previously described in connection with the long stator linear motor system according to the invention can also be applied to the inventive method for contactless charging and / or discharging of the rotors.

[0097] The described devices and methods are both more reliable and require less maintenance than the contact-based discharge devices of the prior art. Furthermore, existing long-stator linear motor systems can be easily retrofitted with the described devices without any design modifications.

[0098] Further features and exemplary embodiments as well as advantages of the present invention are explained in more detail below with reference to the drawings. It is understood that the embodiments do not exhaust the scope of the present invention. It is further understood that some or all of the features described below can also be combined in other ways. Figure 1 This is a schematic diagram of a long-stator linear motor system with a state-of-the-art rotor. Figure 2 shows the runner's state-of-the-art technology when cornering. Figure 3 Explains, by way of example, the tracking error of an unsteered roller when cornering. Figure 4 shows an alternative design of a runner and a transport track according to the state of the art. Figure 5 shows an exemplary embodiment of a runner with turntable steering according to the present invention. Figure 6 shows the runner of the Figure 5 in vertical plan view of the plane of movement along a straight section of the transport path. Figure 7 shows the runner of the Figure 5 in vertical plan view of the movement plane along a curved section of the transport track. Figure 8 shows a three-dimensional elevation of an individually steerable roller with integrated caster according to the present invention. Figure 9 illustrates the integrated wake of the Figure 8 shown role. Figure 10 shows the secondary part of a state-of-the-art rotor. Figure 11 shows schematically the relative arrangement of the magnets of the secondary part and the long stator for the rotor of the Figure 10 . Figure 12 shows schematically the relative arrangement of the magnets of the secondary part of a rotor according to the present invention. Figure 13 shows schematically the relative arrangement of the magnets of the secondary part of another rotor according to the present invention. Figure 14Figure 1 schematically shows a three-dimensional representation of a long stator linear motor system with a discharge station according to the present invention. Figure 15 shows an exemplary embodiment of a runner with turntable steering and pivotable guide element according to the present invention.

[0099] In the figures described below, identical reference symbols denote identical elements. For clarity, identical elements are described only upon their first appearance. However, it is understood that the variants and embodiments of an element described with reference to one of the figures can also be applied to the corresponding elements in the other figures.

[0100] In the Figure 5Figure 1 schematically illustrates an exemplary embodiment of a runner with turntable steering according to the present invention. The runner 300 shown here is individually movably mounted on upper guide rails 350 and lower guide rails 355 by means of a plurality of rollers 310. As already described in the Figure 1 For clarity, only the rear guide rails of the upper and lower guide rail pairs are shown. In reality, however, the runner 300 moves between the upper and lower guide rail pairs, with one roller 310 of each roller pair mounted on the rear guide rail and the other roller 310 of the roller pair mounted on the front guide rail (not shown). The double-rail design allows for particularly stable guidance of the runner 300. However, further developments are also conceivable in which the runners are mounted as in Figure 4The linear motors are supported on only one side by vertically stacked guide rails. In this case, rollers are provided on the turntables only on the guide rail side. However, the further developments of the turntable and the guide element described below remain applicable even with single-sided linear motor guidance.

[0101] The long-stator linear motor system is in the Figure 5 In addition to the guide rails 350 and 355, a linear motor train 360 is shown only schematically. However, to achieve better propulsion, as indicated by the arrangement of further magnets on the front of the secondary part 320, another linear motor train (not shown) can be provided, which runs parallel to the linear motor train 360 shown, along the front guide rails (not shown). Figure 5Figure 1 shows a straight section A of the transport track, i.e., the guide rails 350 and 355 and the linear motor train 360. In the Figure 5 In the illustrated, non-limiting further training, the runner 300 is equipped with a holding device 325 in the form of a neck handling clamp, by means of which, for example, plastic bottles can be transported.

[0102] The one in the Figure 5 The runner 300 shown is also designed with the turntable steering system according to the invention. For this purpose, the runner 300 has a total of four turntables 330, which are attached to the runner 300 by means of kingpins 335 so as to be rotatable about an axis perpendicular to the plane of movement. The turntables 330 each carry a pair of rollers 310 engaging opposite guide rails and, as described above, enable the alignment of the rotation axes of the rollers 310 according to the radius of curvature of the respective path section.

[0103] In the non-limiting further development presented here, the rollers 310 are rotatably mounted on the turntable 330 via rigid roller axles 315. The rollers are mounted on the turntables 330 in such a way that the projection axes, i.e., the projections of the roller axles 315 onto the plane of motion, coincide.

[0104] The projection axes of the rollers are in the Figure 6 The plane of motion, which shows a perpendicular top view, is indicated by dashed lines. Since the path segment is a straight path segment A, the projection axes are parallel to each other, which corresponds to a curve with an infinite radius of curvature. Figure 6 The figure further shows that the rollers 310 are mounted on the turntable 330 via their rigid roller axles 315 in such a way that the projection axes coincide with a central axis of the turntable 330. However, alternative configurations in which this is not the case are also possible.

[0105] As seen through the double arrow in the Figure 6 The turntables 330 are rotatable about an axis perpendicular to the plane of motion. According to the embodiment shown here, the rotation of the turntables is effected by a guide element in the form of a guide roller 345 rolling along the guide rail 350. In the embodiment shown, the guide roller 345 is provided on both sides of a slide 340 that is displaceable perpendicular to a longitudinal axis of the runner 330 (shown with dashed lines), so that the slide 340 can be displaced perpendicular to the longitudinal axis of the runner 300 via the engagement of the guide rollers 345 with the guide rails, as indicated by the double arrow.

[0106] In the illustrated development, the translational movement of the slide 340 upon entering a curve section is converted into a rotational movement of the turntable 330 via the engagement of lateral arms of the slide in corresponding grooves 346 of the pivot 330. The ratio of the length of the arms of the slide 340 to the distance of the groove 346 from the respective central axis or the bearing pin 335 of the turntable 330, due to the lever arm, determines a transmission between the translational movement of the slide 340 and the change in the rotational position of the turntable 330. As described above, the lever arm can be selected such that the projection axes of the rollers 310 during cornering as in Figure 7 The images should be displayed oriented towards the center of the curve.

[0107] In the Figure 7The runner 300 is shown along a curved section B of the transport track. Due to the curvature of the guide rail 350, the guide roller 345 following the guide rail is displaced perpendicular to the longitudinal axis of the runner 300, as indicated in the figure by the dashed line. This causes the bearing of the slide 340 to rotate in the grooves 346 and thus changes the rotational position of the turntable 330, as indicated in the figure by the dashed lines.

[0108] Since the rollers 310 with their roller axles 315 are mounted on the turntables 330 such that the projection axes of the rollers of each pair coincide, the device shown automatically aligns all steered rollers in the direction of the curve radius. This results in a different situation than in the Figure 3The runners shown in the prior art always combine the direction of travel K and the rolling direction R of the rollers of the runner 300 according to the invention. The controlled steering of the rollers significantly reduces the wear of the rollers caused by the tracking error.

[0109] Figure 8 shows a three-dimensional elevation of an individually steerable roller with integrated caster according to the present invention. The roller 410 shown in the figure has a flat rolling surface with which it rolls on the guide rail 350 or the transport track. However, the present invention can also be applied to rollers with crowned, i.e., convex, or concave rolling profiles.

[0110] The Figures 8 and 9 The roller 410 shown is designed with an integrated follower. For this purpose, the roller 410 has a pendulum ring 414, which is rotatably mounted on the rigid roller axle 415 via a pivot pin 413. As can be seen from the Figure 9 The pivot bolt 413 is visibly guided through the roller axle 415 by an asymmetrical, i.e., off-center, bore. Depending on the design, the pivot bolt 413 can be mounted in this bore in a rotationally fixed or rotatable manner. The pendulum ring 414 is mounted accordingly, either rotatably or rotationally fixed, on the pivot bolt 413.

[0111] To allow the pendulum ring 414 to pivot relative to the central axis of the roller axle 415 (indicated by dashed lines), the pendulum ring 414 is spaced from the roller axle 415 by an annular gap 418. This can be achieved, as described above, for example, by press fit, adhesive bonding, or by providing a stepped bolt, or by using spacers. Due to the annular gap 418, the pendulum ring 414 can pivot within a desired angular range around the orientation of the roller axle 415. Since the pendulum ring is mounted asymmetrically with respect to the central axis of the roller axle 415 via the pivot bolt 413, the roller 410 has a positive, integrated caster d, as described in the Figure 9The following is shown. The trailing effect causes a restoring torque to act on roller 410 when the radius of curvature of the transport track changes, automatically aligning the pendulum ring 414 and thus the axis of rotation of the roller in the direction of travel.

[0112] According to the illustrated embodiment, the pendulum ring 414 is designed with an external rolling or sliding bearing 416 on which the outer ring 417, which forms the rolling surface of the roller 410, rolls or slides. The position of the pendulum ring 414 thus defines the instantaneous axis of rotation of the roller 410. The pivot pin 413 defines the Figure 8The steering axis, indicated by a dashed line, allows for individual steering of roller 410. Roller 410, with its integrated caster and steering axis, is extremely compact and therefore versatile enough for use in long-stator linear motor systems. In particular, the individual wheel steering of this improved design can be combined with the turntable steering described above. This individual wheel steering compensates for any remaining track errors of the running wheels, thus minimizing wear on the running wheels.

[0113] In Figure 10 is a variation of a runner according to the Figure 1 The state of the art is shown in the Figure 1 is also the one in the Figure 10 The runner shown is mounted on an upper guide rail 550 via rollers 510-1 to 510-4. In addition, the runner of the Figure 10Guide rollers 512 guide the rotor along the lower guide rail 555. For clarity, only the rear guide rails 550 and 555 and the rear longitudinal stator 560 are shown here.

[0114] As in the Figure 10 Schematically shown, the long stator 560 has a series of coils 561, whose iron cores have a height H perpendicular to the direction of movement, i.e. in the Y-direction. The coils 561 are arranged at a distance W from each other along the long stator. The alternating magnetic fields of the coils 561 interact with the permanent and / or non-switching electromagnets of the secondary part 520, which are arranged with alternating polarity N or S in a row, i.e. sequence 522, which is shown in the vertical configuration. Based on the illustration in Figure 10It can be seen that the extension of the magnets 522 of the secondary part 520 in the Y direction corresponds to the height H of the iron cores of the coils 561. Instead of the non-limiting sequence of alternating polarities shown here, a single magnet can also be used as the magnet of the secondary part 520.

[0115] In Figure 1 1 is schematically the relative arrangement of the magnet(s) 522 of the secondary part 520 of the rotor of the Figure 10and the iron core 562 of the coil 561 of the elongate stator 560. The iron core 562 and the magnets 522 of the secondary part 520 have the same height H in the prior art. In addition, the magnets 522 on the secondary part 520 are arranged symmetrically with respect to a center plane M of the elongate stator 560, which is indicated by the dashed line at half the height H / 2. Due to the symmetrical arrangement, the magnetic interaction force N acts perpendicular to the vertical, i.e., in the Z direction, and therefore has no influence on the vertically downward force of gravity FG.

[0116] In contrast to the symmetrical arrangement of the prior art, the magnet(s) 622 of the secondary part 620 of a rotor according to the present invention are, as shown in Figure 12 schematically represented, arranged asymmetrically with respect to the central plane M of the long stator 560. In the Figure 12In the illustrated further development, the magnets 622 are shifted downwards with respect to the central plane M. Since in this further development the height P of the magnets 622, i.e., their vertical extent, is equal to the height H of the iron core 562, the downward shift of the magnets 622 reduces the total overlap between the iron core 562 and the magnets 622.

[0117] As a result, the secondary part, which is paramagnetic due to the magnets 622, is no longer in its optimal energetic position. Consequently, the magnetic interaction force N is now directed obliquely upwards, pulling the secondary part 620 into a more energetically favorable position. However, this is counteracted by the downward-directed gravitational force FG, so that while the secondary part 620 remains in its shown position, the weight force FG acting on the rollers of the runner is reduced by the vertical component of the magnetic interaction force N. Since the overlap between the magnets 622 and the iron core 562 is also no longer complete, the propulsive force generated by the magnetic interaction between the long stator and the secondary part is also reduced.

[0118] This reduction can be avoided if, as in Figure 13As shown schematically, the magnets 722 of the secondary part 720 are designed with a greater height P' than the iron core 562. In the illustrated, non-limiting embodiment, the magnets 722 completely overlap the iron core 562 and additionally project a certain amount below it. As a result of this asymmetrical arrangement, a magnetic interaction force N directed obliquely upwards is again generated, which at least partially compensates for the vertically downward-directed weight force FG. This also applies if the magnets of the secondary part 720 project both upwards and downwards beyond the iron core 562, but the lower projection is greater than the upper projection. With this embodiment, a reduction in the weight force acting on the support rollers, and thus in the mechanical wear of the support rollers, can be achieved without any loss of propulsive force.

[0119] In the Figure 14Figure 1 shows a three-dimensional representation of a long-stator linear motor system with a discharge station for contactless discharge and charging of rotors. The rotors 800-1 to 800-3, the linear motor train 860, as well as the transport track and guide rails, are only schematically indicated.

[0120] Due to the frictional electricity generated by the movement of the runners along the transport track, especially the guide rails, the runners become increasingly electrostatically charged. This is in the Figure 14 This is exemplified by the negatively charged rotor 800-1. The electrostatic charge of the rotors can damage people or components if it discharges uncontrollably.

[0121] In order to discharge the rotors without contact, according to the development presented here, a discharge device 870 is arranged at at least one point on the transport path 860, which is passed through by the rotors 800-1 to be discharged. In this development, the discharge device 870 is designed as a high-voltage ionizer 872 with rod-shaped electrodes 874 and 876, which are arranged transversely to the direction of movement of the rotors 800-2 indicated by the arrows. The electrodes 874 and 876 have a series of tip electrodes 875 and 877 aligned in the direction of the rotors 800-2, at which ions are formed by means of corona discharge and field emission by ionizing the surrounding air. In this development, the high-voltage ionizer 872 is designed, in particular, to generate positive ions, which, upon contact with the surface of the rotor 800-2, neutralize the negative charges.After passing through the discharge station 870, the runner 800-3 is thus freed from its electrostatic charge.

[0122] The Figure 14 The illustrated, non-limiting further development comprises a control unit 880 and a potential sensor 882 arranged upstream of the discharge station 870, which is connected to the control unit 880 via a signal line. The potential sensor 882, arranged on the transport track 860, determines the polarity and magnitude of the electrostatic charge of the rotor 800-1 as it approaches the discharge station 870 and transmits this information to the control unit 880. In turn, the control unit controls the high-voltage generator of the high-voltage ionizer 872 such that the ions generated by the electrodes 875 and 877 are produced in sufficient quantity and polarity to completely neutralize the rotor 800-2 located in the area of ​​the discharge station.

[0123] Additionally, the information contained in the Figure 14 The further development shown includes an additional potential sensor 884, which is arranged downstream of the discharge station 870 and is connected to the control unit 880 via a signal line. The success of the discharge can be monitored by means of this additional potential sensor 884, so that the control unit 880 can control the high-voltage generator 872 depending on the signal measured by the potential sensor 884.

[0124] As mentioned above, the high-voltage ionizer 870 can also be used to selectively apply charge to uncharged rotors (not shown). In this case, the amount of charge applied can be monitored using the potential sensor 884. In particular, by selectively charging the rotors with rotor-specific charge amounts, individual rotors can be uniquely identified, for example, for product tracking purposes, using potential sensors 884 located downstream of the discharge station 870.

[0125] The discharge device 870 shown operates more reliably and requires less maintenance, as it is contactless, than prior art discharge devices based on mechanical contact. The described long-stator linear motor system thus achieves a longer service life and lower maintenance costs.

[0126] In Figure 15Finally, an alternative development of the turntable steering is shown, whereby the change in the rotational positions of the turntables is effected by means of guide rollers as guide elements.

[0127] The schematically depicted runner 900 is mounted on the guide rails 350 and 355 by means of guide rollers 912 and support rollers 910 and is moved by the interaction of the secondary part 320 with the long stator 360. Unlike the guide rollers 912, whose roller axes are aligned perpendicular to the plane of motion, in this embodiment the roller axes 915 of the support rollers 910 are aligned parallel to the guide plane. Thus, without steering, the known tracking error would occur with the support rollers 910.

[0128] According to the Figure 15In the further development shown, the automatic change of the rotational position of the turntables 930, on which the support rollers 910 are mounted, is effected by guide rollers 945, which are also mounted on the respective turntable 930 and thus form a guide element 945 that can be pivoted in the guide plane. The figure shows four guide rollers arranged on each turntable 930 as an example. However, a single such guide roller is sufficient, as long as its axis of rotation is offset in or against the direction of travel relative to the axis of rotation of the turntable.

[0129] A change in the curve radius, such as occurs during the transition to cornering, causes the guide roller(s) 945 to pivot around the bearing pin 935 of the turntable 930, which in turn leads to a change in the rotational position of the turntable 930. This causes an automatic correction of the tracking error of the support rollers 910, which are mounted on the turntable 930. The correction is optimal when the support rollers 910, as shown in the Figure 15 shown, centered in the direction of travel on the turntables 930.

Claims

1. Rotor (300) for a long-stator linear motor system, having at least one secondary part (320) for magnetic interaction with at least one long stator (360) of the long-stator linear motor system; at least two rollers (310; 410) for mounting the rotor on parallel guide rails (350, 355) of the long-stator linear motor system, characterized by at least one roller (410) of the at least two rollers (310; 410) with a steering rotational axis with integrated castor, wherein the at least one roller (410) is mounted on a roller axle (415) by means of a bolt (413), via an asymmetric and / or sloping bore, and further comprises a pendulum ring (414), which is mounted on the bolt and has an external ball or slide bearing (416); wherein the bore is provided transverse to the roller axle, whereby the bore is made eccentric through the roller axle and / or oblique to the plane of movement; wherein the pendulum ring is designed in such a way that it can oscillate around the straight position within a specified angular range, and wherein the pendulum ring is also eccentrically and / or obliquely mounted on the bolt.

2. Rotor according to claim 1, further comprising: at least one rotatable bolster (330), on which at least one roller, in particular at least one pair of rollers, of the at least two rollers (310; 410) is rotatably mounted.

3. Rotor according to claim 2, wherein the rotor (300) comprises at least one guide element (345) which can be displaced perpendicular to the direction of travel or pivoted in a guide plane and which is designed to maintain a constant distance from a guide rail or a control cam in mechanical or magnetic engagement with the long-stator linear motor system, in particular with the guide rail (350) or the control cam; and wherein the rotatable bolster (330) is connected to the guide element (345) in such a way that a displacement of the guide element perpendicular to the direction of travel or a pivoting of the guide element in the guide plane causes a change in the rotary position of the rotatable bolster.

4. Rotor according to claim 3, wherein the guide element (345) comprises a guide roller, a sliding shoe or a guide pin.

5. Rotor according to claim 3 or 4, wherein the rotatable bolster (330) is connected to the guide element (345) via at least one connecting element (340), wherein the connecting element is designed such that displacement of the guide element during cornering toward the outside of the curve causes an alignment of the rotatable bolster towards curve radius.

6. Rotor according to claim 5, wherein the connecting element comprises an elastic rail or rod connecting two rotatable bolsters (330) together, which is in engagement with or is connected to the guide element (345) such that displacement of the guide element causes an elastic deformation of the rail or rod.

7. Rotor according to claim 5, wherein the connecting element comprises a rigid slide (340) which interconnects two rotatable bolsters (330) in each case in a positive manner, in particular via a groove (346), and which is in engagement with or connected to the guide element (345) in such a way that a displacement of the guide element causes a displacement of the slide perpendicular to the direction of travel.

8. Rotor according to one of the preceding claims, wherein the rollers (310; 410) have a concave roll-off profile configured such that the rollers roll in a laterally stable manner on a surface of the guide rails (350, 355).

9. Rotor according to one of the preceding claims, wherein the roller axle of the at least one roller (310; 410) is arranged parallel or obliquely to a plane of movement of the rotor (300).

10. Rotor according to one of the preceding claims, wherein the at least one roller (410) further comprises an outer ring (417) mounted on the ball or slide bearing (416).

11. Rotor according to one of the preceding claims, wherein the bolt (413) is non-rotatably connected to the roller axle (415) and the pendulum ring (414) is rotatably mounted on the bolt (413).

12. Rotor according to one of claims 1 to 10, wherein the pendulum ring (414) is non-rotatably connected to the bolt (413) and the bolt (413) is rotatably mounted on the roller axle (415).

13. Rotor according to one of the preceding claims, wherein an inner diameter of the pendulum ring (414) is greater than a diameter of the roller axle (415) by a predetermined amount, so that an annular gap (418) is formed between the roller axle and the pendulum ring, and / or wherein the pendulum ring (414) comprises recesses on the inside which permit oscillation about the roller axle (415).

14. Rotor according to claim 13, wherein the pendulum ring (414) is spaced from the roller axle (415) by means of one or more spacer elements, by forming the bolt (413) as a stepped bolt and / or by press fitting or adhesive bonding to the bolt (413).

15. A long-stator linear motor system comprising a plurality of rotors (300) according to one of the preceding claims, and further comprising: a transport path having at least two parallel guide rails (350, 355) on which the rotors are movably mounted, wherein a respective roller (310; 410) of a pair of rollers of the rotors is mounted on one of the two guide rails and the other roller (310; 410) of the pair of rollers is mounted on the other of the two guide rails, and wherein the transport path comprises at least one straight piece and at least one curved piece and / or curved pieces with different radii of curvature.