Method for coating spherical bodies, and spherical body

The method addresses scalability and efficiency issues in coating spherical bodies by employing controlled multi-axis motion and coating techniques, resulting in uniform and cost-effective coatings for rolling elements.

WO2026022220A1PCT designated stage Publication Date: 2026-01-29IWIS MOBILITY SYST GMBH & CO KG
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Patent Information

Application Number
PCT/EP2025/071170
Authority / Receiving Office
WO · WO
Patent Type
Applications
Current Assignee / Owner
Priority Date
2024-07-25
Filing Date
2025-07-23
Publication Date
2026-01-29

AI Technical Summary

Technical Problem

Existing methods for coating spherical bodies, such as rolling elements in bearings, face challenges in scalability and efficiency, particularly for large production runs and small components, leading to non-uniform coating and increased costs.

Method used

A method involving controlled relative movement of spherical bodies during coating, using multiple axes of rotation and translation, combined with various coating techniques like PVD and sputtering, ensures uniform application and adhesion, suitable for continuous high-volume production.

Benefits of technology

Achieves uniform coating with high adhesion and reduced costs by optimizing the controlled motion of spherical bodies, enhancing their performance and durability in rolling bearings.

✦ Generated by Eureka AI based on patent content.

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Abstract

The invention relates to a method for coating spherical bodies, comprising the method steps of: placing a plurality of spherical bodies on a workpiece carrier; inserting the workpiece carrier equipped with spherical bodies into a coating chamber; and depositing a layer on the spherical bodies, wherein the spherical bodies perform a controlled relative movement with respect to the workpiece carrier during the deposition. The invention also relates to a workpiece carrier.
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Description

[0001] METHOD FOR COATING Spherical Bodies AND Spherical Bodies

[0002] The invention relates to a method for coating spherical bodies comprising the process steps of placing several spherical bodies on a workpiece carrier, inserting the workpiece carrier equipped with spherical bodies into a coating chamber and depositing a layer on the spherical bodies, wherein the spherical bodies undergo a controlled relative movement in relation to the workpiece carrier during the deposition process, as well as a spherical body.

[0003] State of the art

[0004] Rolling bearings reduce the frictional resistance of bearings in machines and equipment for transmitting rotational motion. The rolling elements are arranged between the inner and outer rings of a rolling bearing. Depending on the shape of their rolling elements, rolling bearings are classified into different designs, namely ball bearings, cylindrical roller bearings, needle roller bearings, tapered roller bearings, spherical roller bearings, and toroidal roller bearings. Ball bearings, whose rolling elements are spherical, are by far the most common. These spherical rolling elements are usually made of chrome steel, but plastic, glass, or ceramic are also possible materials.

[0005] The rolling elements can be surface-coated. For example, the coating is intended to ensure that industrial ball bearings can be used even without lubricants, with insufficient lubrication, or in start-stop operation under adverse load conditions. This is because conventional lubricants reach their limits in certain extreme situations, such as extreme temperatures or in strict hygiene environments. The absence or reduction of lubricant would previously lead to premature bearing failure. In such cases, coatings on the bearing components can improve performance and service life by reducing friction, increasing wear resistance, and protecting against corrosion. PVD coating is a thin metallic or ceramic layer deposited on a metal or plastic substrate to selectively modify the mechanical, tribological, and chemical properties.The PVD process is based on the vapor deposition of metallic layer components and takes place in a vacuum chamber. The solid coating material, also called the target, is either dissolved by heat (evaporated) or atomized by bombardment with ions (sputtering). The gaseous material is then guided to the workpiece by electric or magnetic fields. Simultaneously, a reactive gas is introduced, which then combines with the metal vapors and condenses on the workpiece surface as a thin, firmly adhering layer. A homogeneous coating is achieved by rotating the components around multiple axes at a constant speed.

[0006] The process typically takes place in batch systems, where workpieces are processed in batches, and is characterized by the sequential execution of production steps such as evacuation, heating, plasma etching, coating, and ventilation. The design of a batch system offers many advantages, particularly regarding the variety of components and thus the product range, as well as the high degree of freedom in the process sequence. A disadvantage lies in the limited scalability for large production runs and especially for small components in bulk form.

[0007] It is therefore an object of the invention to provide a method for coating spherical bodies with which a large number of spherical bodies can be coated cost-effectively and efficiently. It is also an object of the invention to provide a workpiece carrier with which a large number of spherical bodies can be coated cost-effectively and efficiently and which can simultaneously be manufactured cost-effectively.

[0008] The problem is solved by means of the inventive method for coating spherical bodies. Advantageous embodiments of the invention are set out in the dependent claims. The inventive method for coating spherical bodies comprises four process steps: In the first process step, the spherical bodies are introduced into a reaction chamber containing a source of a coating medium. Optionally, prior to introduction into the reaction chamber, the chamber is evacuated and heated; the spherical bodies are also optionally inspected and pretreated. Those skilled in the art also refer to the source of a coating medium as the target; therefore, the terms "source of a coating medium" and "target" are used synonymously in this document. The spherical bodies are optionally arranged on a workpiece carrier before being introduced.

[0009] In the second process step, the spherical bodies are coated in the reaction chamber using the coating medium. This coating can be carried out using various methods: Physical vapor deposition (PVD) and sputtering are preferred, while PACVD and CVD are optional. In principle, depositing a layer onto the spherical bodies is possible using any known coating method.

[0010] In the third process step, the spherical bodies are moved in a controlled motion in relation to the reaction space during the coating process, whereby the controlled motion changes the orientation of the spherical bodies to the source of the coating medium.

[0011] A controlled movement within the meaning of the invention is the movement of a spherical body at a controllable speed, i.e., rotational speed about one or more axes of rotation relative to the source of the coating medium. The controlled movement of the spherical bodies is therefore not random, but intentional, with adjustable motion parameters. This controlled movement relative to the reaction chamber ensures good adhesion of the coating, a trouble-free process, and uniform application to the spherical body. In the fourth process step, the spherical bodies are removed from the reaction chamber. Optionally, cooling and suction, pressure equalization, and inspection of the spherical bodies are performed.

[0012] In an alternative embodiment of the invention, several spherical bodies are placed on a workpiece carrier before being introduced into the reaction chamber. The workpiece carrier is optionally arranged horizontally, and the spherical bodies are preferably arranged such that they do not touch each other and are evenly distributed on the workpiece carrier.

[0013] In a further development of the invention, the coating of the spherical bodies takes place in a continuous process. This continuous process enables seamless coating of rotationally symmetrical components in high-volume production facilities. Optionally, the continuous process can be automated, thereby increasing production volumes and reducing coating costs.

[0014] In a further embodiment of the invention, the controlled movement comprises a first rotation about a first axis of rotation at a first rotational speed. The spherical bodies perform a rolling motion and, as a result, a first rotation of the spherical bodies on a workpiece carrier. The first rotation has a first axis of rotation and a first rotational speed.

[0015] In a further embodiment of the invention, the controlled movement comprises a second rotation about a second axis of rotation at a second rotational speed. The spherical bodies perform a rolling motion, resulting in a second rotation of the spherical bodies on the workpiece carrier. The second rotation has a second axis of rotation and a second rotational speed.

[0016] In another aspect of the invention, the first rotational speed differs from the second rotational speed. This ensures a uniform application of the coating during the coating process. In a further development of the invention, the first axis of rotation differs from the second axis of rotation. Optionally, the first and second rotations occur simultaneously. The simultaneous rotations around two different axes of rotation enable a uniform application of a layer over the entire surface of the spherical body.

[0017] In a further embodiment of the invention, the number of sphere rotations during the coating process in the first direction of rotation differs from the number of sphere rotations in the second direction of rotation. This also ensures a uniform application of the coating.

[0018] In a further embodiment of the invention, the number of sphere rotations in the first and / or second direction of rotation during coating is greater than or equal to ten, preferably greater than or equal to twenty, particularly preferably greater than or equal to forty, and especially preferably greater than or equal to sixty. A larger number of sphere rotations during the coating process results in a more uniform application and therefore a higher coating quality.

[0019] In a further embodiment of the invention, the controlled movement comprises a first translation in a first translational direction at a first translational velocity. The spherical bodies perform a rolling movement and, as a result, a first translation at a first translational velocity on the workpiece carrier. The spherical bodies thus perform a first linear movement on the workpiece carrier.

[0020] In a further embodiment of the invention, the first translation takes place relative to a workpiece carrier on which the spherical bodies are arranged during coating. The workpiece carrier has a plurality of recesses for receiving a plurality of spherical bodies. The spherical bodies arranged on the workpiece carrier perform the first translation relative to the workpiece carrier, wherein the first translation is a rolling movement. In addition to the first translation, the rolling movement simultaneously achieves first and second rotations of the spherical bodies. This results in a uniform application of a layer over the entire surface of the spherical body.

[0021] In a further embodiment of the invention, the first translation direction changes during the coating process. The first translation direction of the spherical bodies changes such that, after the change, the spherical bodies perform a translational movement antiparallel to the first translation direction.

[0022] In a further development of the invention, the first translation direction changes several times during the coating process. This achieves a uniform application of a layer over the entire surface of the spherical body by compensating for inconsistencies in the deposition rate due to different positions within the reaction chamber.

[0023] In a further embodiment of the invention, the first translation relative to the workpiece carrier is circular. In particular, the first translation is loop-shaped.

[0024] In a further embodiment of the invention, the controlled movement comprises a second translation in a second translational direction with a second translational velocity. The spherical bodies perform a rolling movement and, as a result, a second translation with a second translational velocity on the workpiece carrier. The spherical bodies thus perform a second linear movement on the workpiece carrier.

[0025] In a further embodiment of the invention, the second translation is achieved by the movement of the workpiece carrier. The workpiece carrier is moved linearly at a constant speed within the reaction space. The spherical bodies arranged on it therefore also undergo this second translation.

[0026] In a further development of the invention, the first translation direction differs from the second translation direction. Optionally, the first translation direction is arranged perpendicular to the second translation direction. This achieves a uniform deposition of a layer over the entire surface of the spherical body by compensating for inconsistencies in the deposition rate due to different positions within the reaction chamber.

[0027] In another aspect of the invention, the first translational speed differs from the second translational speed. This ensures a uniform application of a layer over the entire surface of the spherical body.

[0028] In a further embodiment of the invention, the first translation of the spherical bodies is carried out by a first driver. The first driver engages with the spherical bodies and performs a uniform translation. This results in a first translation of the spherical bodies on the workpiece carrier.

[0029] In another aspect of the invention, the first rotation is performed by the first driver. The first driver engages with spherical bodies and executes a uniform rotation. This results in the first rotation of the spherical bodies on the workpiece carrier.

[0030] In a further embodiment of the invention, the first rotation occurs about a first axis of rotation perpendicular to the longitudinal axis of a first shaft. The first shaft is optionally mounted to rotate about its longitudinal axis. During the deposition of a layer, spherical bodies are optionally arranged on the first shaft. The spherical bodies perform a rolling motion in the direction of the longitudinal axis of the first shaft. This results in a first rotation of the spherical bodies on the workpiece carrier, the first axis of rotation of which is oriented perpendicular to the longitudinal axis of the first shaft.

[0031] In an advantageous embodiment of the invention, the first driver is spirally shaped. The spirally shaped first driver engages with spherical bodies. During a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies. In a further development of the invention, the first driver is arranged spirally around the first shaft. The spirally shaped first driver engages with spherical bodies. During a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0032] In another embodiment of the invention, the first driver engages with the first shaft. The first shaft is optionally rotated about its longitudinal axis, and the spiral-shaped first driver therefore also rotates about its longitudinal axis. The first driver engages with spherical bodies; during a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0033] In a further embodiment of the invention, the first shaft rotates about its longitudinal axis. As the first shaft rotates about its longitudinal axis, the spiral-shaped first driver also rotates about its longitudinal axis. The first driver engages with spherical bodies; during rotation, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0034] In a further embodiment of the invention, the spherical bodies undergo a second rotation about an axis parallel to the longitudinal axis of the first shaft as a result of the rotation about the longitudinal axis of the first shaft. The second axis of rotation of the second rotation is therefore perpendicular to the first axis of rotation of the first rotation. The simultaneous rotations about two different axes of rotation enable a uniform application of a layer over the entire surface of the spherical body.

[0035] In a further embodiment of the invention, the spherical bodies are transferred via a deflecting element arranged at the end of the first shaft to a second shaft. The second shaft is arranged parallel to the first shaft and is also rotatably mounted. The deflecting element is optionally arranged on the first shaft such that it rotates at the same speed as the first shaft. During its rotation, the deflecting element engages with a spherical body and transfers the spherical body from the first shaft to the second shaft.

[0036] In a further embodiment of the invention, the second shaft rotates about its longitudinal axis. The second shaft optionally has a second helical driver. When rotating about its longitudinal axis, the helical second driver also rotates about its longitudinal axis. The second driver engages with spherical bodies; during rotation, the second driver optionally induces a second translation as well as a third and fourth rotation of the spherical bodies. The simultaneous rotations about two different axes of rotation enable a uniform application of a layer over the entire surface of the spherical body.

[0037] In a further embodiment of the invention, the directions of rotation of the first and second shafts are the same. The first and second shafts are rotatably mounted and driven such that their axes of rotation are the longitudinal axes of the first and second shafts. Their directions of rotation are identical.

[0038] In a further embodiment of the invention, the spherical bodies perform a third rotation through the rotation of the second shaft. The spherical bodies undergo a rolling motion and, as a result, a third rotation of the spherical bodies on the workpiece carrier. The third rotation has a third axis of rotation.

[0039] In a further embodiment of the invention, a second translation of the spherical bodies takes place along the longitudinal axis of a second shaft arranged on the workpiece carrier. The spherical bodies perform a rolling motion, resulting in a second translation of the spherical bodies on the second shaft. Thus, the spherical bodies execute a linear movement on the second shaft.

[0040] In a further embodiment of the invention, the second translation of the spherical bodies is performed by a second driver. The second driver engages with the spherical bodies and executes a uniform translation. This results in a second translation of the spherical bodies on the workpiece carrier. In a further development of the invention, a third rotation is performed by the second driver. The second driver engages with the spherical bodies and executes a uniform rotation. This results in a third rotation of the spherical bodies on the workpiece carrier.

[0041] In a further embodiment of the invention, the third rotation occurs about an axis of rotation perpendicular to the longitudinal axis of the second shaft. The second shaft is optionally mounted to rotate about its longitudinal axis. During the deposition of a layer, spherical bodies are optionally arranged on the second shaft. The spherical bodies perform a rolling motion in the direction of the longitudinal axis of the second shaft. This results in a third rotation of the spherical bodies on the workpiece carrier, the third axis of rotation of which is oriented perpendicular to the longitudinal axis of the second shaft.

[0042] In another aspect of the invention, the second driver is spirally shaped. This spirally shaped second driver engages with spherical bodies. During a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0043] In a further embodiment of the invention, the second driver is arranged spirally around the second shaft. The spirally shaped second driver engages with spherical bodies. During a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0044] In another aspect of the invention, the spiral of the second driver is designed in the opposite direction to the first spiral. The spirals of the first and second drivers are arranged in opposite directions to each other. For example, the spiral of the first driver is designed as a left-hand thread, the spiral of the second driver as a right-hand thread, or vice versa. When the spirals rotate with the same axis and direction of rotation, the spherical bodies engaging with the drivers are translated or rotated in opposite directions. In a further embodiment of the invention, the second driver engages with the second shaft. The second shaft is optionally rotated about its longitudinal axis, and the spiral-shaped second driver therefore also rotates about its longitudinal axis.The second driver engages with spherical bodies; during a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0045] In a further embodiment of the invention, the spherical bodies undergo a fourth rotation about an axis parallel to the longitudinal axis of the second shaft through a rotation about the longitudinal axis of the second shaft. The second shaft is rotated about its longitudinal axis, and the helical second driver therefore also performs a rotation about its longitudinal axis. The second driver is engaged with spherical bodies; during a rotational movement, the second driver induces a second transformation as well as a third and fourth rotation of the spherical bodies.

[0046] In a further embodiment of the invention, the spherical bodies rest on the first shaft or on the second shaft and a support. The arrangement of the spherical bodies is such that they are located either only on the first shaft and the support or on the second shaft and the support. This ensures that the spherical bodies located on the first shaft and the support exhibit a relative movement that differs from the relative movement of the spherical bodies located on the second shaft and support.

[0047] In a further embodiment of the invention, the support is designed as a third shaft. Like the first and second shafts, the support can be rotatably mounted and optionally driven.

[0048] In a further embodiment of the invention, the directions of rotation of the first and third shafts and / or the second and third shafts are the same. Therefore, the drive mechanism and the engagement means for driving the shafts can be designed simply and thus cost-effectively. In a further embodiment of the invention, the mean absolute deviation of the ratio of the first rotational speed to the coating deposition rate and / or the mean absolute deviation of the ratio of the second rotational speed to the coating deposition rate over the coating period is less than 20%, preferably less than 15%, particularly preferably less than 10%, and especially less than 8%.

[0049] The mean absolute deviation is a measure of dispersion and shows the distribution of values ​​around the arithmetic mean. The mean absolute deviation is calculated by subtracting the arithmetic mean of all data values, adding the absolute values ​​of these subtractions, and dividing the result by the number of data values.

[0050] The following equation is used to calculate the mean absolute deviation: Mean absolute deviation [%] = (( Z | Xi - X | / N ) / X) • 100 where:

[0051] Z = Sum of the terms

[0052] | Xi - X | = Absolute value of the difference between each data element and the arithmetic mean

[0053] X = mean of the data set

[0054] N = number of data points in the set. To calculate the mean absolute deviation, the absolute differences between each value in the data set and its mean are summed, and the result is divided by the total number of data points. This equation provides a measure of the average dispersion of the data in the data set relative to its mean.

[0055] A small mean absolute deviation in the ratio of rotational speeds to deposition rate indicates a constant rotational speed during the deposition process. This results in a uniform application of a layer over the entire surface of the spherical body. This objective is further achieved with the spherical body according to the invention, which is coated.

[0056] The spherical body according to the invention comprises a body and a layer system. The body is the workpiece to be coated and has the coating on its outer surface. The coating is designed as a layer system with one or more interconnected layers.

[0057] According to the invention, the layer system has a mean absolute deviation of the layer thickness of the layer system of less than 20% of the layer thickness, preferably less than 15% of the layer thickness, particularly preferably less than 10% of the layer thickness and particularly less than 8% of the layer thickness.

[0058] A low mean absolute deviation ensures that the spherical bodies are as spherical as possible, thus achieving high smoothness of running and wear resistance when the spherical bodies are used in a rolling bearing.

[0059] In a further development of the invention, the body is a metal body. The body is made, for example, of a steel such as 100Cr6 or 16MnCr5. The material 100Cr6 is a medium-alloy cold-work steel that can be used in many areas. As a classic bearing steel, it is particularly suitable for the manufacture of ball, needle, and roller bearings.

[0060] In a further embodiment of the invention, the coating is a wear-resistant layer, a sliding layer, and / or a hard coating. Depending on the type of coating, different properties and / or combinations of properties are achieved.

[0061] In a further embodiment of the invention, the layer system comprises several layers. The layer system consists of several layers of different materials, such as Cr, CrN, Si, W, WC-C, which are combined with a functional layer arranged on the outside. The functional layer on the outside is, for example, a wear-resistant protective layer, a sliding layer, and / or a hard coating layer and significantly determines the properties of the coated spherical body.

[0062] In a further embodiment of the invention, the different layers have different chemical compositions. The different layers of the layer system can, for example, be an outer functional layer and an intermediate layer arranged between the body and the functional layer. The intermediate layer serves, for example, to improve the adhesion of the functional layer. The intermediate layer can, for example, be composed of WC, and the functional layer of DLC.

[0063] In a further embodiment of the invention, the layer system has an outer functional layer consisting of MoS2, WSe2, Ag, Pb, Cu x Mon y N z The outer functional layer can therefore be a wear-resistant layer, a sliding layer, a hard coating layer, and / or a combination of these coating types. The outer functional layer can be a wear-resistant layer, a sliding layer, a hard coating layer, and / or a combination of these coating types.

[0064] In a further embodiment of the invention, the functional layer has a thickness of less than 5000 nm, preferably less than 3000 nm, particularly preferably less than 2000 nm, and most preferably less than 1500 nm. The smaller the thickness of the functional layer, the shorter the coating time can be. This choice of thickness of the functional layer ensures that the functional layer exhibits the desired properties with sufficient durability.

[0065] In a further embodiment of the invention, the functional layer has a thickness greater than 100 nm, preferably greater than 300 nm, particularly preferably greater than 500 nm, and most preferably greater than 750 nm. The smaller the thickness of the functional layer, the shorter the coating time can be. This choice of thickness of the functional layer ensures that the functional layer exhibits the desired properties with sufficient durability.

[0066] In a further embodiment of the invention, the functional layer has a mean absolute deviation of less than 20% of the layer thickness, preferably less than 15%, particularly preferably less than 10%, and especially less than 8%. A low mean absolute deviation ensures that the coated spherical bodies are as spherical as possible, thereby achieving smooth running and wear resistance when the coated spherical bodies are used in a rolling bearing.

[0067] In a further embodiment of the invention, the functional layer exhibits a mean absolute deviation of the Vickers hardness HV of less than 20% of the Vickers hardness HV, preferably less than 15% of the Vickers hardness HV, particularly preferably less than 10% of the Vickers hardness HV, and especially less than 8% of the Vickers hardness HV. A low mean absolute deviation of the Vickers hardness of the functional layer ensures uniform hardness and wear resistance across the entire surface of the coated spherical body when the coated spherical bodies are used in a rolling bearing.

[0068] In a further embodiment of the invention, the functional layer exhibits a mean absolute deviation of the roughness Ra of the functional layer of less than 20% of the roughness Ra, preferably less than 15% of the roughness Ra, particularly preferably less than 10% of the roughness Ra, and especially less than 8% of the roughness Ra. Particularly when the coated spherical bodies are used in a rolling bearing, a uniform, and optionally as low as possible, roughness of the functional layer across the entire surface of the coated spherical bodies is desirable. Such a small deviation of the roughness Ra of the functional layer ensures this uniform roughness Ra across the entire surface of the functional layer.

[0069] In this document, roughness Ra is the average roughness of the metal surface, including deviations from the centerline. Ra measures the peaks and dips within a specific measurement range and calculates the arithmetic mean. This can be done with a profilometer or a laser scanner. The greater the differences, the rougher the surface; conversely, a low Ra indicates a smooth surface. Numerous parameters exist for measuring the roughness of a profile, of which Ra is the most common. In a further embodiment of the invention, the layer system includes an intermediate layer between the functional layer and the spherical body, composed of MoS₂, WSe₂, Ag, Pb, CuxMoyNz, aC:H, aC:H:Me, a:C:H:X, ta-C, CrC, WC, TiN, CrN, TiAlN, and / or CrAlN. The intermediate layer can, for example, be a support layer and / or an adhesion promoter layer and is positioned between the body and the functional layer.The support layer is intended to increase fatigue strength, i.e., to prevent cracks and fractures in the functional layer yet to form. The adhesion promoter layer serves to improve the bond between the functional layer and the substrate.

[0070] In a further development of the invention, the intermediate layer has a thickness of less than 1000 nm, preferably less than 500 nm, particularly preferably less than 250 nm, and most preferably less than 150 nm. The thickness of the intermediate layer is preferably chosen to be as small as possible in order to achieve short coating times. On the other hand, the thickness of the intermediate layer must be large enough to achieve the desired properties.

[0071] In a further embodiment of the invention, the intermediate layer has a thickness greater than 10 nm, preferably greater than 30 nm, particularly preferably greater than 50 nm, and most preferably greater than 75 nm. The thickness of the intermediate layer is preferably chosen to be as small as possible in order to achieve short coating times. On the other hand, the thickness of the intermediate layer must be large enough to achieve the desired properties. An intermediate layer thickness between 75 nm and 150 nm ensures this.

[0072] In a further aspect of the invention, the intermediate layer has a mean absolute deviation in thickness of less than 20%, preferably less than 15%, particularly preferably less than 10%, and especially less than 8%. A low mean absolute deviation ensures that the coated spherical bodies are as spherical as possible, thus achieving smooth running and wear resistance when the coated spherical bodies are used in a rolling bearing. In a further embodiment of the invention, the intermediate layer has a mean absolute deviation in Vickers hardness HV of less than 20%, preferably less than 15%, particularly preferably less than 10%, and especially less than 8%.A small mean absolute deviation in the Vickers hardness HV of the intermediate layer ensures uniform fatigue strength and adhesion of the functional layer arranged above it to the intermediate layer.

[0073] In a further embodiment of the invention, the intermediate layer has a mean absolute deviation of the roughness Ra of less than 20% of the roughness Ra, preferably less than 15% of the roughness Ra, particularly preferably less than 10% of the roughness Ra, and especially less than 8% of the roughness Ra. A low mean absolute deviation of the roughness Ra of the intermediate layer also ensures uniform fatigue strength and adhesion of the functional layer arranged above it to the intermediate layer.

[0074] The problem is further solved by means of the inventive method for coating spherical bodies. Advantageous embodiments of the invention are set out in the following paragraphs.

[0075] The inventive method for coating spherical bodies comprises three process steps: In the first process step, several spherical bodies are placed on a workpiece carrier. The workpiece carrier is optionally arranged horizontally; the spherical bodies are preferably arranged such that they do not touch each other and are evenly distributed on the workpiece carrier.

[0076] In the second process step, the workpiece carrier, equipped with spherical bodies, is inserted into a coating chamber. Prior to insertion, the chamber is optionally evacuated and heated; the spherical bodies are also optionally inspected and pretreated. In the third process step, a coating is deposited onto the spherical bodies. This deposition can be achieved using various coating methods: Physical vapor deposition (PVD) and sputtering are preferred, while PACVD and CVD are optional. In principle, depositing a coating onto the spherical bodies is possible using any known coating method.

[0077] According to the invention, the spherical bodies undergo a controlled relative movement with respect to the workpiece carrier during deposition. In particular, the relative movement is achieved by a continuous and controlled movement of the spherical bodies on the workpiece carrier.

[0078] A controlled relative motion within the meaning of the invention is a motion of a spherical body with a controllable speed, rotational speed about one or more axes of rotation with respect to the workpiece carrier. The controlled relative motion of the spherical body is therefore not random, but intentional with adjustable motion parameters.

[0079] The controlled relative movement in relation to the workpiece carrier ensures good adhesion of the layer, a trouble-free process and a uniform application on the spherical body.

[0080] In a further development of the invention, part of the relative motion is a first rotation. The spherical bodies perform a rolling motion and, as a result, a first rotation of the spherical bodies on the workpiece carrier. The first rotation has a first axis of rotation.

[0081] In another aspect of the invention, part of the relative motion is a second rotation. The spherical bodies perform a rolling motion, resulting in a second rotation of the spherical bodies on the workpiece carrier. The second rotation has a second axis of rotation. In a further embodiment of the invention, the first rotation occurs about an axis of rotation that differs from the axis of rotation of the second rotation. Optionally, the first and second rotations occur simultaneously. The simultaneous rotations about two different axes of rotation enable a uniform application of a layer over the entire surface of the spherical body.

[0082] In a further embodiment of the invention, part of the relative motion is a first translation. The spherical bodies perform a rolling motion and, as a result, a first translation of the spherical bodies on the workpiece carrier. The spherical bodies thus perform a linear motion on the workpiece carrier.

[0083] In a further embodiment of the invention, the first translation of the spherical bodies is carried out by a first driver. The first driver engages with the spherical bodies and performs a uniform translation. This results in a first translation of the spherical bodies on the workpiece carrier.

[0084] In another aspect of the invention, the first rotation is performed by the first driver. The first driver engages with spherical bodies and executes a uniform rotation. This results in the first rotation of the spherical bodies on the workpiece carrier.

[0085] In a further embodiment of the invention, the first rotation occurs about a first axis of rotation perpendicular to the longitudinal axis of a first shaft. The first shaft is optionally mounted to rotate about its longitudinal axis. During the deposition of a layer, spherical bodies are optionally arranged on the first shaft. The spherical bodies perform a rolling motion in the direction of the longitudinal axis of the first shaft. This results in a first rotation of the spherical bodies on the workpiece carrier, the first axis of rotation of which is oriented perpendicular to the longitudinal axis of the first shaft.

[0086] In an advantageous embodiment of the invention, the first driver is spirally shaped. The spirally shaped first driver engages with spherical bodies. During a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0087] In a further development of the invention, the first driver is arranged spirally around the first shaft. The spirally shaped first driver engages with spherical bodies. During a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0088] In another embodiment of the invention, the first driver engages with the first shaft. The first shaft is optionally rotated about its longitudinal axis, and the spiral-shaped first driver therefore also rotates about its longitudinal axis. The first driver engages with spherical bodies; during a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0089] In a further embodiment of the invention, the first shaft rotates about its longitudinal axis. As the first shaft rotates about its longitudinal axis, the spiral-shaped first driver also rotates about its longitudinal axis. The first driver engages with spherical bodies; during rotation, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0090] In a further embodiment of the invention, the spherical bodies undergo a second rotation about an axis parallel to the longitudinal axis of the first shaft as a result of the rotation about the longitudinal axis of the first shaft. The second axis of rotation of the second rotation is therefore perpendicular to the first axis of rotation of the first rotation. The simultaneous rotations about two different axes of rotation enable a uniform application of a layer over the entire surface of the spherical body.

[0091] In a further embodiment of the invention, the spherical bodies are transferred via a deflecting element arranged at the end of the first shaft to a second shaft. The second shaft is arranged parallel to the first shaft and is also rotatably mounted. The deflecting element is optionally arranged on the first shaft such that it rotates at the same speed as the first shaft. During its rotation, the deflecting element engages with a spherical body and transfers the spherical body from the first shaft to the second shaft.

[0092] In a further embodiment of the invention, the second shaft rotates about its longitudinal axis. The second shaft optionally has a second helical driver. When rotating about its longitudinal axis, the helical second driver also rotates about its longitudinal axis. The second driver engages with spherical bodies; during rotation, the second driver optionally induces a second translation as well as a third and fourth rotation of the spherical bodies. The simultaneous rotations about two different axes of rotation enable a uniform application of a layer over the entire surface of the spherical body.

[0093] In a further embodiment of the invention, the directions of rotation of the first and second shafts are the same. The first and second shafts are rotatably mounted and driven such that their axes of rotation are the longitudinal axes of the first and second shafts. Their directions of rotation are identical.

[0094] In a further embodiment of the invention, the spherical bodies perform a third rotation through the rotation of the second shaft. The spherical bodies undergo a rolling motion and, as a result, a third rotation of the spherical bodies on the workpiece carrier. The third rotation has a third axis of rotation.

[0095] In a further embodiment of the invention, a second translation of the spherical bodies takes place along the longitudinal axis of a second shaft arranged on the workpiece carrier. The spherical bodies perform a rolling motion, resulting in a second translation of the spherical bodies on the second shaft. Thus, the spherical bodies perform a linear movement on the second shaft. In a further embodiment of the invention, the second translation of the spherical bodies is effected by a second driver. The second driver engages with the spherical bodies and performs a uniform translation. This results in a second translation of the spherical bodies on the workpiece carrier.

[0096] In a further development of the invention, a third rotation is performed by the second driver. The second driver engages with spherical bodies and executes a uniform rotation. This results in the third rotation of the spherical bodies on the workpiece carrier.

[0097] In a further embodiment of the invention, the third rotation occurs about an axis of rotation perpendicular to the longitudinal axis of the second shaft. The second shaft is optionally mounted to rotate about its longitudinal axis. During the deposition of a layer, spherical bodies are optionally arranged on the second shaft. The spherical bodies perform a rolling motion in the direction of the longitudinal axis of the second shaft. This results in a third rotation of the spherical bodies on the workpiece carrier, the third axis of rotation of which is oriented perpendicular to the longitudinal axis of the second shaft.

[0098] In another aspect of the invention, the second driver is spirally shaped. This spirally shaped second driver engages with spherical bodies. During a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0099] In a further embodiment of the invention, the second driver is arranged spirally around the second shaft. The spirally shaped second driver engages with spherical bodies. During a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0100] In another aspect of the invention, the spiral of the second driver is designed in the opposite direction to the first spiral. The spirals of the first and second drivers are arranged in opposite directions to each other. For example, the spiral of the first driver is designed as a left-hand thread, the spiral of the second driver as a right-hand thread, or vice versa. When the spirals are rotated with the same axis and direction of rotation, the spherical bodies engaging with the drivers are translated or rotated in opposite directions.

[0101] In a further embodiment of the invention, the second driver engages with the second shaft. The second shaft is optionally rotated about its longitudinal axis, and the spiral-shaped second driver therefore also rotates about its longitudinal axis. The second driver engages with spherical bodies; during a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0102] In a further embodiment of the invention, the spherical bodies undergo a fourth rotation about an axis parallel to the longitudinal axis of the second shaft through a rotation about the longitudinal axis of the second shaft. The second shaft is rotated about its longitudinal axis, and the helical second driver therefore also performs a rotation about its longitudinal axis. The second driver is engaged with spherical bodies; during a rotational movement, the second driver induces a second transformation as well as a third and fourth rotation of the spherical bodies.

[0103] In a further embodiment of the invention, the spherical bodies rest on the first shaft or on the second shaft and a support. The arrangement of the spherical bodies is such that they are located either only on the first shaft and the support or on the second shaft and the support. This ensures that the spherical bodies located on the first shaft and the support exhibit a relative movement that differs from the relative movement of the spherical bodies located on the second shaft and support.

[0104] In a further embodiment of the invention, the support is designed as a third shaft. Like the first and second shafts, the support can be rotatably mounted and optionally driven. In another embodiment of the invention, the directions of rotation of the first and third shafts, and / or the second and third shafts, are the same. Therefore, the drive mechanism and the engagement means for driving the shafts can be designed simply and thus cost-effectively.

[0105] The problem is further solved with the workpiece carrier according to the invention for receiving spherical bodies for a coating system.

[0106] The workpiece carrier according to the invention for receiving spherical bodies for a coating system has a frame, the frame having receptacles for receiving one and / or more shafts. The receptacles are arranged in pairs on opposite sides of the frame.

[0107] The workpiece carrier according to the invention further comprises a first shaft rotatably mounted in two of the receptacles and a support, wherein the first shaft together with the support forms a receptacle for spherical bodies. The first shaft and the support are arranged parallel to each other. Optionally, the support is rotatably mounted like the first shaft.

[0108] Furthermore, the workpiece carrier according to the invention has a first driver, wherein the driver is designed and suitable for moving a spherical body relative to the workpiece carrier. In particular, the relative movement is a continuous and controlled movement of the spherical body on the workpiece carrier. The workpiece carrier according to the invention is optionally used in a vacuum coating system. Vacuum coating systems are known from the prior art and include, for example, PVD and CVD vacuum coating systems. The controlled relative movement with respect to the workpiece carrier ensures good adhesion of the coating, a trouble-free process, and a uniform application on the spherical body.

[0109] In a further development of the invention, the first driver is arranged on the first shaft. The first driver engages with spherical bodies. During a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0110] In another aspect of the invention, the first driver engages with the first shaft. The first shaft is optionally rotated about its longitudinal axis; the helical first driver therefore also rotates about its longitudinal axis. The first driver engages with spherical bodies; during a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0111] In a further embodiment of the invention, the first driver is configured to move the spherical bodies along the longitudinal axis of the first shaft. The spherical bodies perform a rolling motion and, as a result, a first translation of the spherical bodies on the workpiece carrier. The spherical bodies thus perform a linear motion on the workpiece carrier.

[0112] In a further embodiment of the invention, the first driver is spirally shaped. The spirally shaped first driver engages with spherical bodies. During a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0113] In another aspect of the invention, the first driver is arranged spirally around the first shaft. The spirally shaped first driver engages with spherical bodies. During a rotational movement, the first driver induces a first translation as well as a first and second rotation of the spherical bodies.

[0114] In a further embodiment of the invention, the first shaft has a thread that serves as a drive element. The thread, shaped like a spiral, is designed to engage with spherical bodies and, upon rotation about the longitudinal axis of the first shaft, to generate translational and rotational motion of the spherical bodies. In a further embodiment of the invention, the first shaft has a deflecting element at one end, designed and suitable for transferring the spherical bodies via the support onto a second shaft. The second shaft is arranged parallel to the first shaft and is also rotatably mounted. Optionally, the deflecting element is arranged on the first shaft such that it rotates at the same speed as the first shaft.During the rotation of the deflection element, the deflection element engages with a spherical body and transports the spherical body from the first shaft to the second shaft.

[0115] In a further embodiment of the invention, the second shaft has a second driver. The second driver engages with spherical bodies and performs a uniform translation. This results in a second translation of the spherical bodies on the workpiece carrier.

[0116] In a further development of the invention, the second driver is arranged on the second shaft. The second driver engages with spherical bodies. During a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0117] In a further embodiment of the invention, the second driver engages with the second shaft. The second shaft is optionally rotated about its longitudinal axis, and the second driver therefore also rotates about its longitudinal axis. The second driver engages with spherical bodies; during a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0118] In a further embodiment of the invention, the second driver is configured to move the spherical bodies along the longitudinal axis of the second shaft. The second shaft is optionally rotated about its longitudinal axis, and the second driver therefore also rotates about its longitudinal axis. The second driver engages with the spherical bodies; during a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies. In a further embodiment of the invention, the second driver is spirally shaped. The spirally shaped second driver engages with the spherical bodies. During a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0119] In a further embodiment of the invention, the spiral of the second driver is designed in the opposite direction to the first spiral. The spirals of the first and second drivers are arranged in opposite directions to each other. For example, the spiral of the first driver is designed as a left-hand thread, the spiral of the second driver as a right-hand thread, or vice versa. When the spirals are rotated with the same axis and direction of rotation, the spherical bodies engaging with the drivers are translated or rotated in opposite directions.

[0120] In a further embodiment of the invention, the second driver is arranged spirally around the second shaft. The spirally shaped second driver engages with spherical bodies. During a rotational movement, the second driver induces a second translation as well as a third and fourth rotation of the spherical bodies.

[0121] In a further embodiment of the invention, the second shaft has a thread that functions as a second driver. The thread, shaped like a spiral, is suitable for engaging with spherical bodies and, when rotated about the longitudinal axis of the second shaft, generating translational and rotational movement of the spherical bodies.

[0122] In a further embodiment of the invention, the support is arranged parallel to the first shaft. The spherical bodies rest on the first shaft or on the second shaft and the support. The arrangement of the spherical bodies is such that they are located either only on the first shaft and the support or on the second shaft and the support. This ensures that the spherical bodies located on the first shaft and the support exhibit a relative movement that differs from the relative movement of the spherical bodies located on the second shaft and support.

[0123] In a further development of the invention, the support is designed as a third shaft. Like the first and second shafts, the support can be rotatably mounted and optionally driven.

[0124] In a further embodiment of the invention, the third shaft can be driven to rotate. This results in more efficient rotation and translation of the spherical bodies.

[0125] In another aspect of the invention, the direction of rotation of the third shaft is the same as the direction of rotation of the first and / or second shaft. Therefore, the drive mechanism and the engagement means for driving the shafts can be designed simply and thus cost-effectively.

[0126] In a further embodiment of the invention, the first, second and / or third shaft can be driven by an engagement means, wherein the engagement means is provided and suitable for engaging with an element of a coating system when the workpiece carrier moves.

[0127] Exemplary embodiments of the method and the workpiece carrier according to the invention are shown schematically simplified in the drawings and are explained in more detail in the following description.

[0128] They show:

[0129] Fig. 1: Inline PVD system for coating spherical bodies

[0130] Fig. 2: Frame of the workpiece carrier according to the invention

[0131] Fig. 3: Detail view of a workpiece carrier according to the invention

[0132] Fig. 4: Detail view of a workpiece carrier according to the invention, spherical bodies arranged in tracks

[0133] Fig. 5: Sectional view along the waves, deflection of the spherical bodies

[0134] Fig. 6a: Workpiece carrier for class 3

[0135] Fig. 6b: Workpiece carrier for class 4 Fig. 6c: Workpiece carrier for class 5 Fig. 6d: Workpiece carrier for class 6 Fig. 6e: Workpiece carrier for class 7 Fig. 7: Workpiece carrier

[0136] Fig. 8: Deflection element

[0137] Fig. 9: Threaded spindle as first and second shaft

[0138] Fig. 10: Threaded spindle arranged as first and second shaft in the workpiece carrier

[0139] Fig. 11: Shaft with grooves as first and second shaft

[0140] Fig. 12: Spherical body with layer system

[0141] Fig. 13a: Layer system

[0142] Fig. 13b: Layer system with an intermediate layer

[0143] Fig. 13c: Layer system with two intermediate layers

[0144] Fig. 1 shows an embodiment of an inline PVD system 200 for coating spherical bodies 100. As the spherical bodies 100 pass through the inline PVD system 200, they are arranged on the workpiece carrier 1. The inline PVD system 200 enables seamless PVD coating of the spherical bodies 100.

[0145] For loading 201, baskets containing cleaned spherical bodies 100 are emptied into a conveying bucket and positioned on the workpiece carrier 1 via a filling system. After loading 201, the workpiece carrier 1 is checked 202 by scanning its coding and verifying the type of spherical bodies 100. The spherical bodies 100 undergo a further check 203 by using a laser camera with an image data processing system to verify that the workpiece carrier 1 is fully loaded and that the spherical bodies 100 are correctly positioned. The workpiece carrier 1 moves into the load lock in area 204, behind the first airlock, and the pressure is equalized. The plasma etching process 205 then follows. During the transfer / heating phase 206, the transition between plasma etching 205 and layer deposition 207 takes place, including the heating process.

[0146] The deposition of 207 of a layer with six targets 207.1 , 207.2, 207.3, 207.4, 207.5,

[0147] 207.6 is carried out in the coating chamber 80. After the deposition 207 of a layer, the spherical bodies 100 are cooled 208. The workpiece carrier 1 moves from the coating chamber 80 into a lock chamber in the load lock out area 209, and the pressure is reduced to ambient pressure.

[0148] During cooling / vacuuming 210, the spherical bodies 100 are cooled to room temperature and vacuumed. The spherical bodies 100 are then checked again 211. A laser camera with an image data processing system verifies whether the workpiece carrier 1 is fully loaded and the spherical bodies 100 are correctly positioned. Finally, the workpiece carrier 1 is unloaded 212: The code of the workpiece carrier 1 is checked, representative samples of spherical bodies 100 are removed, measurements are taken, the inspected spherical bodies 100 are emptied, and the workpiece carriers 1 are checked and, if necessary, cleaned.

[0149] Fig. 2 shows an embodiment of the workpiece carrier 1 according to the invention for spherical bodies 100. The receptacles 41 are arranged in the frame 40. The shafts 10, 20, 30 lie on both sides in bronze guides 41 made of CuSn6, which ensure a secure fit and a constant distance between the shafts 10, 20, 30. To prevent the gears 42 from being coated during the deposition 207 of a layer, three protective covers made of X6CrNiTi18 are located over them. Coating the gears 42 can lead to undesirable changes in their dimensions and tolerances and impair their functionality.

[0150] Figures 3 and 4 show detailed views of an embodiment of the workpiece carrier 1 according to the invention. The workpiece carrier 1 has a plurality of parallel shafts 10, 20, 30 which are rotatably mounted in receptacles 41. Depending on the diameter of the spherical bodies 100, the shafts 10, 20, 30 have rollers 70. The rollers 70 are placed on the shafts 10, 20, 30 that are required for larger diameters of the spherical bodies 100.

[0151] Waves 10, 20, and 30 are arranged such that (from left to right) a first wave 10 is followed by a third wave 30, followed by a second wave 20. Waves 10, 20, and 30 are thus arranged parallel to each other in such a way that a first wave 10 never follows another first wave 10, a second wave 20 never follows another second wave 20, and a third wave 30 never follows another third wave 30. A third wave 30 is always positioned between a first wave 10 and a second wave 20.

[0152] Each shaft 10, 20, 30 has a gear 42 at one end, via which each individual shaft 10, 20, 30 can be driven. All gears 42 are identical to one another and mesh with the centrally arranged engagement element. During the deposition 207 of a layer (see Fig. 1), the centrally arranged engagement element is driven into uniform rotation and, via the gears 42, sets each individual shaft 10, 20, 30 into uniform rotation. The rotational movement of the shafts 10, 20, 30 is such that all shafts 10, 20, 30 rotate at the same speed around the same axis of rotation and in the same direction. To allow for the small distance between the shafts, the adjacent shafts 10, 20, 30 always have a certain offset at the gears 42, which is repeated over the entire workpiece carrier 1.

[0153] A first shaft 10 has a first driver 11, which is spirally formed around the first shaft 10 and engages with it. A first shaft 10 also has a deflecting element 50, designed as a vane, located at one end of the first shaft 10. The deflecting element 50 engages with and is rigidly connected to the first shaft 10. A second shaft 20 has a second driver 21, also spirally formed around the second shaft 20, which engages with it. A deflecting element 50 is located at one end of the second shaft 20, with the deflecting element 50 on the second shaft 20 being located at the opposite end from the deflecting element 50 on the first shaft 10. The deflecting element 50 on the second shaft 20 is also rigidly connected to and engages with it.The third shaft 30 has neither a driver nor a deflecting element and is designed as a support. The spirals of the first driver 11 and the second driver 21 are arranged in opposite directions. In this and the following embodiments (Figs. 4 to 8), the first drivers 11 and the second drivers 21 are designed as spiral springs, which are rigidly connected to a corresponding shaft 10, 20. For coating the spherical bodies 100, the spherical bodies 100 are arranged on the workpiece carrier 1 as shown in Fig. 1, such that the spherical bodies 100 are arranged in tracks between a first shaft 10 and a third shaft 30, and between a second shaft 20 and a third shaft 30.The workpiece carrier 1, thus equipped with the spherical bodies 100, is then introduced into the coating chamber 80 and a layer is deposited 207, wherein the spherical bodies 100 undergo a relative movement with respect to the workpiece carrier 1 during the deposition 207 of a layer.

[0154] In the coating chamber 80, the engagement element is driven at a constant rotational speed. Via gears 42, the engagement element also sets each shaft 10, 20, 30 into uniform rotation; all shafts 10, 20, 30 rotate at the same speed around the same axis of rotation and in the same direction.

[0155] The spherical bodies 100, arranged between a first shaft 10 and a third shaft 30, are driven by the first drive element 11 into a first translational motion along the longitudinal axis of the first shaft 10, whereby the spherical bodies 100 roll on the first shaft 10 and the third shaft 30 along the longitudinal axes of the shafts 10 and 30. The spherical bodies 100 are transferred by the deflecting element 50 located at the end of the first shaft 10, via the third shaft 30, to a second shaft 20 (see Fig. 5). The rolling motion results in a first rotation of the spherical bodies 100, the axis of rotation of the first rotation being at a right angle to the longitudinal axes of the shafts 10, 20, 30. Simultaneously, the spherical bodies 100 undergo a second rotation parallel to the longitudinal axis of the first shaft 10, the second rotation occurring about an axis of rotation differing from the axis of rotation of the first rotation.

[0156] Similarly, the spherical bodies 100, arranged between a second shaft 20 and a third shaft 30, are driven by the second driver 21 into a second translational movement along the longitudinal axis of the second shaft 20. This second translational movement occurs in the opposite direction, antiparallel to the first translational movement, due to the opposing arrangement of the drivers 11 and 21. The spherical bodies 100 are transferred by the deflecting element 50, located at the end of the second shaft 20, via the third shaft 30 to a first shaft 10 (see Fig. 5). The spherical bodies 100, arranged on the second shaft 20 and the third shaft 30, roll along the longitudinal axes of the shafts 20 and 30. This rolling motion results in a third rotation of the spherical bodies 100, the axis of rotation of which is at a right angle to the longitudinal axes of the shafts 10, 20, and 30.At the same time, the spherical bodies 100 undergo a fourth rotation parallel to the longitudinal axis of the second shaft 20, whereby the fourth rotation about an axis of rotation deviates from the axis of rotation of the third rotation.

[0157] Fig. 5 shows a sectional view of a section of the workpiece carrier 1 according to the invention along the shafts 10, 30.1, 30.2 to illustrate the deflection process during the deposition 207 of a layer. Spherical bodies 100 are arranged between a first 10 and a third shaft 30.1 on the one hand, and between a first 10 and a third shaft 30.2 on the other, and perform first and second translational movements as well as first, second, third, and fourth rotational movements. In this embodiment, a first shaft 10 is arranged between a third shaft 30.1 and a further third shaft 30.2. The shafts 10, 30.1, 30.2 are driven in the same direction of rotation, which in this embodiment is clockwise. In addition to the third wave 30.10, a second wave 20 (not shown) is arranged on its left side, and in addition to the third wave 30.22, another second wave 20 (not shown) is arranged on its right side (see Fig. 3).

[0158] A prototypical spherical body 100 is shown, which performs a first translational movement between the first wave 10 and the third wave 30.1 into the image plane. Another spherical body 100 also performs a first translational movement between the first wave 10 and the third wave 30.2 into the image plane.

[0159] At one end of the first shaft 10, the deflecting element 50 is arranged on the first shaft 10. This element engages with the first shaft 10 and therefore also performs the clockwise rotation. Upon reaching the deflecting element 50 at one end of the first shaft 10, it engages under the spherical body 100 and moves the spherical body 100 from its position between the first shaft 10 and the third shaft 30.1 to the left, to a position between the third shaft 30.1 and the adjacent second shaft 20 (not shown).

[0160] As the deflecting element 50 continues to rotate clockwise, the deflecting element 50 touches the spherical body 100 located between the first 10 and the third shaft 30.2 on its side and moves the spherical body 100 to the right to a position between the third shaft 30.2 and the adjacent second shaft 20 (not shown).

[0161] This deflection process is carried out continuously during the deposition 207 of a layer. The spherical bodies 100 move continuously in loop-like paths between first waves 10 and third waves 30, or between second waves 20 and third waves 30, during the deposition 207 of a layer. The spherical bodies 100 perform first and second translational movements as well as first, second, third, and fourth rotational movements. This ensures a uniform deposition 207 of a layer onto the spherical bodies 100.

[0162] Fig. 6 shows exemplary embodiments of workpiece carriers 1 for depositing a layer 207 for different diameters of the spherical bodies 100. Since manufacturing a workpiece carrier 1 for each individual diameter would be very costly, the diameters of the spherical bodies 100 are divided into classes. The diameters of the spherical bodies 100 are considered with the same parameters, such as shaft diameter, shaft spacing, and coil spacing of the drives 11, 21. The aim is to achieve maximum fill level of the workpiece carrier 1 as well as suitable rotational speeds of the shafts 10, 20, 30 and the spherical bodies 100. To ensure a uniform coating of the spherical bodies 100, the number of revolutions in the rotational direction must be similar to the number in the translational direction.

[0163] This results in seven classes, each with three to eight diameters of the spherical bodies 100 per class. For the first two classes, a suitable height for the deflection element 50 cannot be determined because, with the smaller diameters of the spherical bodies 100, the spacing between the shafts 10, 20, 30 is so small that there is insufficient space. For the subsequent classes, three different diameters of rollers 70 are required. In class 3, the diameter of the shafts 10, 20, 30 is 4 mm. However, from class 4 to 7, larger rollers are needed, firstly to ensure sufficient revolutions, and secondly to establish a suitable spacing between the shafts 10, 20, 30. The spacing between the shafts 10, 20, 30 is chosen so that the largest diameter of the spherical bodies 100 in each class fits between the windings.To determine the distance between waves 10, 20, 30, it must be ensured that, firstly, the spherical bodies 100 do not fall between waves 10, 20, 30 and, secondly, that the spherical bodies 100 do not collide with those on the adjacent track.

[0164] These parameters allow us to calculate the number of revolutions in both rotational and translational directions. The number of revolutions of the spherical body 100 results from several relationships:

[0165] Shaft revolutions per minute:

[0166] Revolutions of a ball per minute in the direction of rotation:

[0167] Revolutions of a ball per minute in the translational direction:

[0168] Shaft revolutions per unit length:

[0169] Revolutions of a ball per unit distance in the direction of rotation:

[0170] Rotations of a ball per unit distance in the translational direction: Here, v is the constant speed at which the workpiece carrier 1 travels through the inline PVD system 200. D w denotes the diameter of the existing shafts 10, 20, 30. The diameter of the roller D R , is the cross-section of a roller 70, which is fitted onto the shafts 10, 20, 30. Furthermore, the different diameters of the spherical bodies 100 D are used for the calculations. K and the winding spacing W is required. The distance s is a predetermined distance that the workpiece carrier 1 travels in the inline PVD system 200, for example the width of a target.

[0171] The distance between shafts 10, 20, 30, the diameter of the rollers 70 that can be placed on shafts 10, 20, 30, and the height of the deflection element are variable. The diameter of shafts 10, 20, 30, however, is fixed.

[0172]

[0173] The results show that with the selected parameters similar rotational speeds result in the first T translation and second T translation, thus ensuring a uniform coating of the spherical bodies 100.

[0174] The mean absolute deviation of the ratio of the first rotational speed to the coating deposition rate and / or the mean absolute deviation of the ratio of the second rotational speed to the coating deposition rate over the duration of the coating process 207 is less than 20%, preferably less than 15%, particularly preferably less than 10%, and especially less than 8%, in this embodiment 5%. A small mean absolute deviation of the ratios of rotational speeds to deposition rates thus indicates a constant rotational speed during the deposition process. This results in a uniform application of a layer system 120 over the entire surface of the spherical body 100.

[0175] For future cost calculations, the maximum number of spherical bodies per workpiece carrier is calculated to be 100 for the different ball classes. The CAD models with the corresponding components for ball classes 3 to 7 are shown in Figure 6. The figures illustrate the arrangement and spacing of the shafts 10, 20, 30 of class 3 (Fig. 6a), class 4 (Fig. 6b), class 5 (Fig. 6c), class 6 (Fig. 6d), and class 7 (Fig. 6e). The table can be used to estimate how many tracks and how many spherical bodies (100) can fit per track. Fig. 7 shows an embodiment of a workpiece carrier 1 according to the invention, comprising first shafts 10 and second shafts 20. The third shaft 30 is configured as a rigid partition between the first shafts 10 and the second shafts 20. The third shaft 30, configured as a rigid partition, is not rotatably mounted and is not driveable. The third shaft 30, configured as a rigid partition, has a recess at each of its two opposite ends, the diameters of which are larger than the diameters of the spherical bodies 100 for which the workpiece carrier 1 is designed. During operation of the workpiece carrier 1, the recesses allow the transition of the spherical bodies 100 arranged on the third shaft 30, configured as a rigid partition, to an arrangement of the spherical bodies 100 between the second shaft 20 and the third shaft 30, configured as a rigid partition, and vice versa (see Fig. 5).This design of the third wave 30 as a rigid partition therefore does not necessarily require a deflection element 50.

[0176] Fig. 8 shows an embodiment of a deflection element 50. In contrast to the deflection elements 50 shown previously (see Fig. 5), the deflection element 50 is not planar but has an elliptical cross-section. The deflection element 50 has a base 51 with a circular cross-section. The receptacle 52 is also circular and has a diameter corresponding to a shaft 10, 20. The deflection element 50 is placed onto a shaft 10, 20 such that the receptacle accommodates the shaft 10, 20. The derailleur 53 for carrying out the deflection process (see Fig. 5) has an elliptical cross-section and is arranged eccentrically on a shaft 10, 20.

[0177] Figures 9 and 10 show an embodiment of a first shaft 10 and second shaft 20, which has a thread. In the embodiments shown so far (Figures 2 to 7), the first shaft 10 and second shaft 20 each have a spiral 11, 21, which acts as a driver 11, 21 and is fitted over the shaft 10, 20 or roller 70, respectively. In this embodiment, the shaft 10, 20 is designed as a threaded spindle, with the circumferential thread acting as a driver 11, 21. The number and spacing of the turns are manufactured according to the diameter of the spherical bodies 100 (see Figure 6). Such a threaded spindle can be arranged as a first shaft 10 in the frame 40 by arranging a plurality of identically designed threaded spindles in parallel in the frame 40 (Figure 10). This eliminates the need for an arrangement of second waves 20 and third waves 30 within frame 40.With the same direction of rotation of all shafts 10, first and second translations of the spherical bodies 100 arranged on them are therefore achieved around a center point; the spherical bodies 100 “wobble” when the first and second or third and fourth rotations are performed simultaneously.

[0178] Fig. 11 shows an embodiment of a first shaft 10 and a second shaft 20, which has diagonally arranged grooves 90. The raised sections act as drivers 11, 21. The number and spacing of the grooves 90 are also manufactured according to the diameter of the spherical bodies 100 (see Fig. 6). This shaft 10 is also arranged as the first shaft 10 in the frame 40 by arranging a plurality of identically designed shafts 10 in parallel within the frame 40. This eliminates the need for a second shaft 20 and a third shaft 30. With all shafts 10 rotating in the same direction, as in the preceding embodiment, first and second translations of the spherical bodies 100 arranged on them about a center point are achieved; the spherical bodies 100 "wobble" during the simultaneous execution of the first and second, and third and fourth, rotations.

[0179] Fig. 12 shows an embodiment of the spherical body 100 according to the invention. The spherical body 100 comprises the inner body 110 and an outer layer system 120. The body 110 is made of the metallic material 100Cr6. The material 100Cr6 is a medium-alloy cold-work steel that can be used in many areas. As a classic bearing steel, the material is suitable for the manufacture of ball, needle, and roller bearings. However, other preferably metallic materials are also possible, in particular alloy steels, e.g., 16MnCr5. In further embodiments, the layer system 120 has a mean absolute deviation of the layer thickness of the layer system 120 of less than 20% of the layer thickness, preferably less than 15% of the layer thickness, particularly preferably less than 10% of the layer thickness, and particularly less than 8% of the layer thickness.

[0180] The thickness of the 120 layer system is determined by X-ray diffraction and optionally by the ball-and-socket method. For X-ray diffraction, primary X-rays are generated in an X-ray tube, optimized by a primary filter, and controlled by a shutter. This radiation reaches a measuring point monitored by a video camera. At this point, the radiation excites the atoms in the sample, which then emit characteristic fluorescence. The emitted radiation is detected and converted into a spectrum that identifies the elements in the sample. Software processes this information and calculates the layer thickness and / or the analytical results of the sample. The intensity of the element-specific fluorescence correlates with the mass and, taking the density into account, with the layer thickness of the material.This process enables precise and effective characterization of materials using X-ray spectroscopy.

[0181] For the spherical grinding process, a hardened steel ball with a precisely defined diameter is placed between the drive shaft and the sample and set in rotation by the motor-driven shaft. This ball acts as a carrier for an abrasive such as diamond suspension or diamond paste. This grinds a depression into the sample, which is called a spherical surface. The grinding time varies depending on the layer type in terms of thickness and wear resistance and ranges from a few seconds to several minutes.

[0182] When the layer system of the clamped sample is ground (with a grinding depth greater than the layer thickness), concentric rings (in the case of a flat sample) or ellipses (in the case of a cylindrical sample) are visible under the microscope. The spherical grinding method allows the analysis of both single and multilayer structures. Due to the significantly larger diameter of the hardened steel ball compared to the layer thicknesses, the grinding of the layer system is performed at a very shallow angle. This effectively widens the layer, with the diameter of the individual rings typically being about 200 times larger than the actual layer thickness. By using the diameter of the outer circle at the surface of the layer and the diameter of the inner circle, which is defined by the interfaces between the layer layers, the diameter of the individual rings can be determined.Since the layer and body 110 are defined, the thickness of the functional layer or the total layer thickness can be calculated. The layer system 120 comprises at least the functional layer 130, which is arranged on the outside of the spherical body 100 and forms the surface of the spherical body 100. According to the invention, the functional layer 130 is a wear-resistant layer, a sliding layer, and / or a hard material layer. In this and the following embodiment (see Fig. 11), the functional layer 130 is a DLC (diamond-like carbon) layer. The functional layer 130 can also consist of MoS₂, WSe₂, Ag, Pb, Cu. x . Mo y N z , aC:H:Me, a:C:H:X, ta-C, CrC, WC, TiN, CrN, TiAIN and / or CRAIN.

[0183] Compared to all other solids, diamond possesses exceptional properties, including the highest atomic density, greatest hardness, highest modulus of elasticity, and highest thermal conductivity at room temperature. Nevertheless, diamond is unsuitable as a coating material because it can only be deposited at high temperatures and on specific substrates. Hard amorphous carbon, commonly known as DLC (Diamond-Like Carbon), on the other hand, has the significant advantage over diamond of enabling cost-effective and large-area vacuum deposition processes at room temperature. Furthermore, films made of diamond-like carbon combine other outstanding properties such as high hardness, low coefficients of friction, chemical inertness, and wear resistance. DLC coatings are divided into two main groups: hydrogenated amorphous carbon (aC:H, ta-C:H) and hydrogen-free amorphous carbon (aC, ta-C).In this and the following embodiment (see Fig. 11), the functional layer 130 is an aC:H coating. By adding other elements such as metals (aC:H:Me) or non-metallic elements such as silicon, oxygen, fluorine or others (aC:H:X), it is possible to modify the properties of the coating for specific applications.

[0184] Carbon layers, which consist of carbon, hydrogen, and, when doped, a metal / nonmetal (Me / X), can exhibit various bonding states. These states arise due to different hybridization states of the electron orbitals. A carbon atom has a total of six electrons. Through excitation and redistribution of the electrons, carbon can exist in different hybridization states. In diamond, for example, the orbitals hybridize to form four energetically equivalent sp³ orbitals, which are arranged tetrahedrally in space. This leads to strong covalent bonds and the well-known properties such as high hardness, high melting point, and transparency. In contrast, in graphite, only two of the three orbitals hybridize to form three sp² orbitals. This results in a layered structure characterized by strong covalent bonds within the layers and weak van der Waals forces between the layers.Graphite is therefore less hard and exhibits good lubricating properties. The combination of these crystal structures enables the production of amorphous carbon layers. These consist of highly cross-linked three-dimensional networks with local structures of diamond and graphite. Amorphous carbon layers lack long-range order and are generally porous. Carbon layers can be a mixture of sp²- and sp³-bonded carbon atoms, with the sp³ proportion influencing the hardness. Increased hydrogen supply reduces the cross-linking and thus the hardness.

[0185] The functional layer 130 has a thickness of less than 5000 nm, preferably less than 3000 nm, particularly preferably less than 2000 nm, and especially preferably less than 1500 nm. The functional layer 130 also has a thickness greater than 100 nm, preferably greater than 300 nm, particularly preferably greater than 500 nm, and especially preferably greater than 750 nm. In this and the following embodiment (see Fig. 13), the functional layer 130 has a thickness of 1000 nm. The thickness of the functional layer 130 is also determined by X-ray fluorescence, as described. For this purpose, 4 different measuring points are selected on the functional layer of a spherical body 14, which are arranged at equal intervals from each other. The position of the measuring points is monitored with a camera.The mean absolute deviation of the layer thickness of the functional layer 130 is less than 20% of the layer thickness, preferably less than 15% of the layer thickness, particularly preferably less than 10% of the layer thickness and particularly less than 8% of the layer thickness.

[0186] The Vickers hardness HV of the functional layer (aC:H coating) 130 is 1028 HV in this embodiment. The functional layer 130 exhibits a mean absolute deviation of the Vickers hardness HV of less than 20% of the Vickers hardness HV, preferably less than 15% of the Vickers hardness HV, particularly preferably less than 10% of the Vickers hardness HV, and especially less than 8% of the Vickers hardness HV. The hardness of the functional layer 130 is determined by instrumented indentation testing according to DIN 14577. For this purpose, 4 different measuring points are selected on the functional layer of a spherical body 14, which are arranged at equal intervals from each other. The position of the measuring points is monitored with a camera. During the determination of the Vickers hardness HV, the indentation hardness is calculated via the indentation depth of the test specimen during the loading phase. A Vickers pyramid with an apex angle of 136° is used as the test specimen.

[0187] The functional layer 130 further exhibits a roughness Ra with a mean absolute deviation of less than 20% of the roughness Ra, preferably less than 15% of the roughness Ra, particularly preferably less than 10% of the roughness Ra, and especially less than 8% of the roughness Ra. Especially when the coated spherical bodies 100 are used in a rolling bearing, a uniform, and optionally the lowest possible, roughness Ra of the functional layer 130 across the entire surface of the coated spherical bodies 100 is desirable. Such a low mean absolute deviation of the roughness Ra of the functional layer 130 ensures this uniform roughness Ra across the entire surface of the functional layer 130.

[0188] The stylus method is used for the metrological measurement and description of roughness Ra. In the stylus method, the stylus tip is moved across the surface of a workpiece at a constant speed. In the tactile measuring method, the sensor of the roughness measuring instrument scans the surface of the functional layer 130 point by point at 14 different measuring areas, which are arranged at equal intervals from each other. With values ​​in the nanometer and micrometer range, the accuracies of tactile measuring systems are very high for roughness measurements. They are usually easy to operate and deliver reliable measured values. However, they are not particularly suitable for soft, compliant surfaces, as damage to the surface cannot be ruled out with tactile roughness measuring instruments. For these surfaces, optical, three-dimensional measuring methods are increasingly used, which measure surfaces without contact and therefore non-destructively. Fig.Figure 13 shows exemplary embodiments of the layer system 120. In its simplest form, the layer system 120 has a functional layer 130 that is applied directly to the body 110 of the spherical body 100 (Fig. 13a).

[0189] An intermediate layer 140 can be arranged between functional layer 130 and body 110 (Fig. 13b). The intermediate layer 140 consists of MoS2, WSe2, Ag, Pb, Cu x Mon y N z The intermediate layer 140 is composed of aC:H, a-C:H:Me, a:C:H:X, ta-C, CrC, WC, TiN, CrN, TiAIN and / or CRAIN. In this embodiment, the intermediate layer 140 is composed of WC. The WC intermediate layer 140 acts as both an adhesion promoter and a support layer, thus improving the adhesion of the aC:H functional layer 130 and reducing the risk of cracks and fractures in the functional layer 130.

[0190] For the coating process 207, two different types of targets 207.1, 207.2, 207.3, 207.4, 207.5, 207.6 are used. Targets 207.1 and 207.2 each have a WC target with a composition of 50% tungsten and 50% carbon, while targets 207.3, 207.4, 207.5, and 207.6 are each graphite targets with a purity of 99.9%.

[0191] The intermediate layer 140 can also have two different intermediate layers 140.1 and 140.2 (Fig. 13c). The intermediate layer 140.1 is also a WC intermediate layer, while the intermediate layer 140.2 is a CrAIN intermediate layer. The WC intermediate layer 140.1 acts as an adhesion promoter, and the CrAIN intermediate layer 140.2 acts as a support layer and reduces the risk of cracking and fractures in the functional layer 130.

[0192] The intermediate layers 140, 140.1, 140.2 each have a thickness of 100 nm. In a further embodiment, the intermediate layers 140, 140.1, 140.2 have a thickness of less than 1000 nm, preferably less than 500 nm, particularly preferably less than 250 nm, and especially preferably less than 150 nm. In a further embodiment, the intermediate layers 140, 140.1, 140.2 have a thickness greater than 10 nm, preferably greater than 30 nm, particularly preferably greater than 50 nm, and especially preferably greater than 75 nm. The determination of the thickness of the intermediate layers 140, 140.1, 140.2 is carried out as already described for the determination of the functional layer 130. The mean absolute deviation of the layer thickness of the intermediate layers 140, 140.1, 140.2 is less than 20% of the layer thickness, preferably less than 15% of the layer thickness, particularly preferably less than 10% of the layer thickness and particularly less than 8% of the layer thickness.

[0193] The intermediate layers 140, 140.1, 140.2 each exhibit a mean absolute deviation of the Vickers hardness HV of the intermediate layer of less than 20% of the Vickers hardness HV, preferably less than 15% of the Vickers hardness HV, particularly preferably less than 10% of the Vickers hardness HV, and especially less than 8% of the Vickers hardness HV. The determination of the Vickers hardness HV of the intermediate layers 140, 140.1, 140.2 is carried out as already described for the determination of the functional layer 130.

[0194] The intermediate layers 140, 140.1, 140.2 each exhibit a mean absolute deviation of the roughness Ra of the intermediate layer of less than 20% of the roughness Ra, preferably less than 15% of the roughness Ra, particularly preferably less than 10% of the roughness Ra, and especially less than 8% of the roughness Ra. The determination of the roughness Ra of the intermediate layers 140, 140.1, 140.2 is carried out as already described for the determination of the functional layer 130.

[0195] A small mean absolute deviation of these parameters ensures that the coated spherical bodies 100 have a shape that is as spherical as possible and that the functional layer 130 arranged above them has a uniform fatigue strength and adhesion.

[0196] Six different spherical bodies 100 (sphere 1 to sphere 6) with different functional layers were measured, with 14 measuring points on each spherical body 100.

[0197] The functional layers 130 were coated in the inline PVD system 200 described in Fig. 1 for coating spherical bodies 100. The temperature in the coating chamber was 350°C for test series sphere 1 and 180°C for all other test series. The pressure in the coating chamber varied from 1.8 × 10⁻³ mbar to 6.0 × 10⁻³ mbar. The spherical bodies 100 of test series sphere 2 have an intermediate layer 140 of CrAIN, while the spherical bodies 100 of test series sphere 3 and sphere 4 have an intermediate layer 140 of WC.

[0198] The rotational speeds of all spherical bodies 100 were 0.8 m / s in the first direction of rotation and 0.6 m / s in the second direction of rotation during coating 207. The translational speed of the coated spheres 100, which were coated on a workpiece carrier 1 with spiral drivers 11, 21, was also 0.6 m / s during coating 207.

[0199] The highest Vickers hardness (HV) measured (HV 2191) was found in the spherical specimens of test series 100, sphere 2 (CuMoN coating), with a mean absolute deviation (uniformity) of 8.5%. The lowest Vickers hardness (HV) measured was found in the spherical specimens of test series 100, sphere 3 (aC coating), with HV 796 and a mean absolute deviation (uniformity) of 6.6%. The Vickers hardness values ​​(HV) of the other test series lie between those mentioned above. The lowest mean absolute deviation of Vickers hardness (HV) was 5.0% for the spherical specimens of test series 100, sphere 1 (CrN coating), and the highest mean absolute deviation of Vickers hardness (HV) was 8.5% for the spherical specimens of test series 100, sphere 2 (CuMoN coating).

[0200]

[0201] The Vickers hardness (HV) of the functional layers 130 was determined by instrumented indentation testing according to DIN 14577, performed using the Picodentor HM500 from Helmut Fischer GmbH. In this test, the indentation hardness (HIT) is calculated during the loading phase based on the penetration depth of the test specimen. A Vickers pyramid with a tip angle of 136° was used as the test specimen. This instrument is specifically designed for ultrathin hard coatings with layer thicknesses from 1 pm to 4 pm. Penetration depths of up to 150 nm can be achieved with a maximum load of 500 mN.

[0202] Six different spherical bodies 100 (sphere 1 to sphere 6), each with different functional layers, were measured, with 14 measuring points recorded on each spherical body 100. The functional layers 130 were applied in the inline PVD system 200 described in Fig. 1 for coating spherical bodies 100. The temperature in the coating chamber was 350°C for sphere 1 in the test series and 180°C for all other test series. The pressure in the coating chamber varied from 1.8 × 10⁻³ mbar to 6.0 × 10⁻³ mbar. The spherical bodies 100 in test series sphere 2 have an intermediate layer 140 of CrAIN, while the spherical bodies 100 in test series sphere 3 and sphere 4 have an intermediate layer 140 of WC.

[0203] The rotational speeds of all spherical bodies 100 were 0.8 m / s in the first direction of rotation and 0.6 m / s in the second direction of rotation during coating 207. The translational speed of the coated spheres 100, which were coated on a workpiece carrier 1 with spiral drivers 11, 21, was also 0.6 m / s during coating 207.

[0204] The highest measured layer thickness (4.34 pm) is found in the spherical bodies 100 of test series sphere 1 (CrN coating), with a mean absolute deviation (uniformity) of 3.1%. The lowest measured layer thickness is found in the spherical bodies 100 of test series sphere 5 (aC:H coating), at 0.94 pm, with a mean absolute deviation (uniformity) of 13.6%. The layer thicknesses of the other test series lie between the aforementioned values. The lowest mean absolute deviation of the layer thicknesses is 3.1% for the spherical bodies 100 of test series sphere 1 (CrN coating), and the highest mean absolute deviation of the layer thickness is 13.6% for the spherical bodies 100 of test series sphere 5 (aC:H coating).

[0205] The thickness of the functional layers 130 was determined X-ray diffraction using the Fischerscope XRAL XDLM instrument. The emitted radiation is detected and converted into a spectrum that identifies the elements in the sample. The WinFTM software processes this information and calculates the layer thickness and / or the analytical results of the sample. The intensity of the element-specific fluorescence correlates with the mass and, taking the density into account, with the layer thickness of the material.

[0206] Six different spherical bodies 100 (sphere 1 to sphere 6), each with different functional layers, were measured, with 14 measuring points recorded on each spherical body 100. The layer systems 120 were applied in the inline PVD system 200 described in Fig. 1 for coating spherical bodies 100. The temperature in the coating chamber was 350°C for sphere 1 in the test series and 180°C for all other test series. The pressure in the coating chamber varied from 1.8 × 10⁻³ mbar to 6.0 × 10⁻³ mbar. The spherical bodies 100 in test series sphere 2 have an intermediate layer 140 of CrAIN, while the spherical bodies 100 in test series sphere 3 and sphere 4 have an intermediate layer 140 of WC.

[0207] The rotational speeds of all spherical bodies 100 were 0.8 m / s in the first direction of rotation and 0.6 m / s in the second direction of rotation during coating 207. The translational speed of the coated spheres 100, which were coated on a workpiece carrier 1 with spiral drivers 11, 21, was also 0.6 m / s during coating 207.

[0208] The highest measured layer thickness (4.34 pm) is found in the spherical bodies 100 of test series sphere 1 (CrN coating), with a mean absolute deviation (uniformity) of 3.1%. The lowest measured layer thickness is found in the spherical bodies 100 of test series sphere 5 (aC:H coating), at 1.12 pm, with a mean absolute deviation (uniformity) of 10.9%. The layer thicknesses of the other test series lie between the aforementioned values. The lowest mean absolute deviation of the layer thicknesses is 3.1% for the spherical bodies 100 of test series sphere 1 (CrN coating), and the highest mean absolute deviation of the layer thickness is 10.9% for the spherical bodies 100 of test series sphere 5 (aC:H coating).

[0209]

[0210] The layer thickness of the 120 coating systems was determined X-ray diffraction using the Fischerscope XRAL XDLM instrument. The emitted radiation is detected and converted into a spectrum that identifies the elements in the sample. The WinFTM software processes this information and calculates the layer thickness and / or the analytical results of the sample. The intensity of the element-specific fluorescence correlates with the mass and, taking the density into account, with the layer thickness of the material.

[0211] Six different spherical bodies 100 (sphere 1 to sphere 6), each with different functional layers, were measured, with 14 measuring points recorded on each spherical body 100. The intermediate layers 140 were applied in the inline PVD system 200 described in Fig. 1 for coating spherical bodies 100. The temperature in the coating chamber was 350°C for sphere 1 in the test series and 180°C for all other test series. The pressure in the coating chamber varied from 1.8 × 10⁻³ mbar to 6.0 × 10⁻³ mbar. The spherical bodies 100 in test series sphere 2 have an intermediate layer 140 of CrAIN, while the spherical bodies 100 in test series sphere 3 and sphere 4 have an intermediate layer 140 of WC.

[0212] The rotational speeds of all spherical bodies 100 were 0.8 m / s in the first direction of rotation and 0.6 m / s in the second direction of rotation during coating 207. The translational speed of the coated spheres 100, which were coated on a workpiece carrier 1 with spiral drivers 11, 21, was also 0.6 m / s during coating 207.

[0213] The highest measured layer thickness (0.49 pm) is found in the spherical bodies 100 of test series sphere 2 (CrAIN coating), with a mean absolute deviation (uniformity) of 7.4%. The lowest measured layer thickness (0.18 pm) is found in the spherical bodies 100 of test series sphere 5 (aC:H coating), with a mean absolute deviation (uniformity) of 10.0%. The layer thicknesses of the further test series sphere 3 lie between these values. The lowest mean absolute deviation in layer thickness is 7.4% for the spherical bodies 100 of test series sphere 2 (CrAIN coating), and the highest mean absolute deviation in layer thickness is 10.0% for the spherical bodies 100 of test series sphere 5 (aC:H coating).

[0214]

[0215] The thickness of the 140 interlayer layers was determined X-ray diffraction using the Fischerscope XRAL XDLM instrument. The emitted radiation is detected and converted into a spectrum that identifies the elements in the sample. The WinFTM software processes this information and calculates the layer thickness and / or the analytical results of the sample. The intensity of the element-specific fluorescence correlates with the mass and, taking the density into account, with the layer thickness of the material.

[0216] Six different spherical bodies 100 (sphere 1 to sphere 6), each with different functional layers, were measured, with 14 measuring points recorded on each spherical body 100. The functional layers 130 with the intermediate layers 140 were applied in the inline PVD system 200 described in Fig. 1 for coating spherical bodies 100. The temperature in the coating chamber was 350°C for sphere 1 in the test series and 180°C to 200°C in all other test series. The pressure in the coating chamber varied from 1.8 × 10⁻³ mbar to 6.0 × 10⁻³ mbar. The spherical bodies 100 in test series sphere 2 have an intermediate layer 140 of CrAIN, while the spherical bodies 100 in test series sphere 3 and sphere 4 have an intermediate layer 140 of WC.

[0217] The rotational speeds of all spherical bodies 100 were 0.8 m / s in the first direction of rotation and 0.6 m / s in the second direction of rotation during coating 207. The translational speed of the coated spheres 100, which were coated on a workpiece carrier 1 with spiral drivers 11, 21, was also 0.6 m / s during coating 207.

[0218] The measured roughness Ra is highest (0.03) for the spherical bodies 100 in test series sphere 1 (CrN coating), with a mean absolute deviation (uniformity) of 13.2%. The spherical bodies 100 in the other test series exhibit roughnesses Ra of 0.02. The lowest mean absolute deviation of the roughness Ra is 13.2% for the spherical bodies 100 in test series sphere 1 (CrN coating), and the highest mean absolute deviation of the roughness Ra is 17.8% for the spherical bodies 100 in test series sphere 4 (CrN coating).

[0219]

[0220] The stylus method is used to measure and describe the roughness Ra of the functional layers 130. In the stylus method, the probe tip is moved across the surface of a workpiece at a constant speed. During the tactile measurement, the sensor of the roughness measuring instrument scans the surface of the functional layer 130 point by point at 14 different measurement areas, which are equally spaced from each other. With values ​​in the nanometer and micrometer range, the accuracy of tactile measuring systems for roughness measurements is very high. They are usually easy to use and deliver reliable measured values. However, they are not particularly suitable for soft, pliable surfaces, as damage to the surface cannot be ruled out with tactile roughness measuring instruments.Therefore, optical, three-dimensional measurement methods are increasingly used for these applications, as they measure surfaces without contact and thus non-destructively. Six different spherical bodies 100 (sphere 1 to sphere 6), each with different functional layers 130, were measured, with 14 measurement points on each spherical body 100.

[0221] The intermediate layers 140 were applied to spherical bodies 100 in the inline PVD system 200 described in Fig. 1. The temperature in the coating chamber was 350°C for test series sphere 1, and 180°C to 200°C for all other test series. The pressure in the coating chamber varied from 1.8 × 10⁻³ mbar to 6.0 × 10⁻³ mbar. The spherical bodies 100 in test series sphere 2 have an intermediate layer 140 of CrAIN, while the spherical bodies 100 in test series sphere 3 and sphere 4 have an intermediate layer 140 of WC.

[0222] The rotational speeds of all spherical bodies 100 were 0.8 m / s in the first direction of rotation and 0.6 m / s in the second direction of rotation during coating 207. The translational speed of the coated spheres 100, which were coated on a workpiece carrier 1 with spiral drivers 11, 21, was also 0.6 m / s during coating 207.

[0223] The measured roughness Ra is highest (0.20) for the spherical bodies 100 in test series sphere 1 (CrN coating), sphere 5 (aC:H coating), and sphere 6 (CrN coating). The spherical bodies 100 in the other test series exhibit roughnesses Ra of 0.19. The lowest mean absolute deviation of the roughness Ra is 8.5% for the spherical bodies 100 in test series sphere 6 (CrN coating), and the highest mean absolute deviation of the roughness Ra is 17.3% for the spherical bodies 100 in test series sphere 3 (aC coating).

[0224] The stylus method is used to measure and describe the roughness Ra of the intermediate layers 140. In the stylus method, the stylus tip is moved across the surface of a workpiece at a constant speed.

[0225] In the tactile measuring method, the sensor of the roughness measuring instrument scans the surface of the intermediate layer 140 at 14 different measuring areas, which are arranged at equal intervals from each other, point by point. With values ​​in the nanometer and micrometer range, the accuracies of tactile measuring systems are very high for roughness measurements. They are usually easy to use and deliver reliable measured values. However, they are not particularly suitable for soft, pliable surfaces, as damage to the surface cannot be ruled out with tactile roughness measuring instruments. For these surfaces, optical, three-dimensional measuring methods are increasingly used, which measure surfaces without contact and therefore non-destructively. REFERENCE SIGN LIST

[0226] workpiece carrier

[0227] First wave

[0228] First drive wheel / spiral

[0229] Second wave

[0230] Second drive pin / spiral, 30.1, 30.2 Third shaft / support / rigid partition

[0231] Frame

[0232] Recording to record the waves

[0233] gear

[0234] deflection element

[0235] base

[0236] Recording

[0237] front derailleur

[0238] role

[0239] Coating chamber

[0240] Groove 0 Spherical body 0 Body 0 Layer system 0 Functional layer 0, 140.1, 140.2 Intermediate layer 0 Inline PVD system 1 Loading of the workpiece carrier 2 Inspection of the workpiece carrier 3 Inspection of the spherical bodies 4 Load Lock In 5 Plasma etching 6 Transfer / Heating Coating

[0241] Target

[0242] Cool

[0243] Load Lock Out

[0244] Cooling / Extraction

[0245] Examination of spherical bodies

[0246] Unloading the workpiece carrier

Claims

PATENTA SPECIALS 1. Method for coating (207) spherical bodies (100) comprising the process steps: • Introducing the spherical bodies (100) into a reaction chamber (80) with a source (207.1) for a coating medium, • Coating (207) the spherical bodies (100) in the reaction chamber (80) using the coating medium, • Moving the spherical bodies (100) in a controlled motion with respect to the reaction space (80) during the coating (207), wherein the controlled motion results in a change in the orientation of the spherical bodies (100) to the source (207.1) of the coating medium, • Removal of the spherical bodies (100) from the reaction chamber (80).

2. Method for coating (207) spherical bodies (100) according to claim 1 , characterized in that the coating (207) of the spherical bodies (100) is carried out in a continuous process.

3. Method for coating (207) spherical bodies (100) according to claim 1 or 2, characterized in that the controlled movement comprises a first rotation about a first axis of rotation with a first rotational speed, wherein the controlled movement comprises a second rotation about a second axis of rotation with a second rotational speed, wherein the first rotational speed is different from the second rotational speed, wherein the first axis of rotation is different from the second axis of rotation, wherein the number of sphere rotations during the coating process (207) in the first direction of rotation is different from the number of sphere rotations in the second direction of rotation, and wherein the number of sphere rotations in the first and / or in the second direction of rotation during the coating (207) is greater than or equal to ten, preferably greater than or equal to twenty, particularly preferably greater than or equal to forty and particularly preferably greater than or equal to sixty.

4. A method for coating (207) spherical bodies (100) according to one or more of the preceding claims, characterized in that the controlled movement comprises a first translation in a first translational direction with a first translational velocity, wherein the first translation is relative to a workpiece carrier (1) on which the spherical bodies (100) are arranged during the coating (207), wherein the first translational direction changes during the coating (207), wherein the first translational direction changes multiple times during the coating (207), and wherein the first translation is circular relative to the workpiece carrier (1).

5. Method for coating (207) spherical bodies (100) according to claim 4, characterized in that the controlled movement comprises a second translation in a second translation direction with a second translation speed, wherein the second translation is carried out by the movement of the workpiece carrier (1), wherein the first translation direction is different from the second translation direction, wherein the first translation speed is different from the second translation speed, and wherein the mean absolute deviation of the ratio of the first rotation speed to the deposition rate of the coating (207) and / or the mean absolute deviation of the ratio of the second rotation speed to the deposition rate of the coating (207) over the duration of the coating (207) is less than 20%, preferably less than 15%, particularly preferably less than 10% and particularly less than 8%.

6. Spherical body (100) with a coating of • a body (110) and • a layer system (120), characterized in that the layer system (120) has a mean absolute deviation of the layer thickness of the layer system (120) of less than 20% of the layer thickness, preferably less than 15% of the layer thickness, particularly preferably less than 10% of the layer thickness and particularly less than 8% of the layer thickness.

7. Spherical body (100) with a coating according to claim 6, characterized in that the body (110) is a metal body.

8. Spherical body (100) with a coating according to claim 6 or 7, characterized in that the coating is a wear-resistant layer, a sliding layer and / or a hard layer.

9. Spherical body (100) with a coating according to one or more of claims 6 to 8, characterized in that the layer system (120) has several layers (130, 140), wherein the different layers (130, 140) have different chemical compositions.

10. Spherical body (100) with a coating according to one or more of claims 6 to 9, characterized in that the layer system (120) has an outer functional layer (130) consisting of MoS2, WSe2, Ag, Pb, Cu x Mon y N z , aC:H, aC:H:Me, a:C:H:X, ta-C, CrC, WC, TiN, CrN, TiAIN and / or CRAIN is composed of, 11. Spherical body (100) with a coating according to one or more of claims 6 to 10, characterized in that the functional layer (130) has a thickness of less than 5000 nm, preferably less than 3000 nm, particularly preferably less than 2000 nm and particularly preferably less than 1500 nm, wherein the functional layer (130) has a thickness greater than 100 nm, preferably greater than 300 nm, particularly preferably greater than 500 nm and particularly preferably greater than 750 nm, wherein the functional layer (130) has a mean absolute deviation of the layer thickness of the functional layer (130) of less than 20% of the layer thickness, preferably less than 15% of the layer thickness, particularly preferably less than 10% of the layer thickness and particularly less than 8% of the layer thickness.

12. Spherical body (100) with a coating according to one or more of claims 6 to 11, characterized in that the functional layer (130) has a mean absolute deviation of the Vickers hardness HV of the functional layer (130) of less than 20% of the Vickers hardness HV, preferably less than 15% of the Vickers hardness HV, particularly preferably less than 10% of the Vickers hardness HV and particularly less than 8% of the Vickers hardness HV.

13. Spherical body (100) with a coating according to one or more of claims 6 to 12, characterized in that the functional layer (130) has a mean absolute deviation of the roughness Ra of the functional layer (130) of less than 20% of the roughness Ra, preferably less than 15% of the roughness Ra, particularly preferably less than 10% of the roughness Ra and particularly less than 8% of the roughness Ra.

14. Spherical body (100) with a coating according to one or more of claims 6 to 13, characterized in that the layer system (120) has an intermediate layer (140) between the functional layer (130) and the spherical body (110) consisting of MoS2, WSe2, Ag, Pb, Cu x Mon y N z, aC:H, aC:H:Me, a:C:H:X, ta-C, CrC, WC, TiN, CrN, TiAIN and / or CRAIN, wherein the intermediate layer (140) has a thickness of less than 1000 nm, preferably less than 500 nm, particularly preferably less than 250 nm and particularly preferably less than 150 nm, wherein the intermediate layer (140) has a thickness greater than 10 nm, preferably greater than 30 nm, particularly preferably greater than 50 nm and particularly preferably greater than 75 nm, wherein the intermediate layer (140) has a mean absolute deviation of the layer thickness of the intermediate layer (140) of less than 20% of the layer thickness, preferably less than 15% of the layer thickness, particularly preferably less than 10% of the layer thickness and particularly less than 8% of the layer thickness.

15. Spherical body (100) with a coating according to one or more of claims 6 to 14, characterized in that the intermediate layer (140) has a mean absolute deviation of the Vickers hardness HV of the intermediate layer (140) of less than 20% of the Vickers hardness HV, preferably less than 15% of the Vickers hardness HV, particularly preferably less than 10% of the Vickers hardness HV and particularly less than 8% of the Vickers hardness HV, wherein the intermediate layer (140) has a mean absolute deviation of roughness Ra of the intermediate layer (140) is less than 20% of the roughness Ra, preferably less than 15% of the roughness Ra, particularly preferably less than 10% of the roughness Ra and particularly less than 8% of the roughness Ra.

Citation Information

Patent Citations

  • Steel ball ion silver plating device

    CN202509131U

  • Deposition apparatus and method of coating spherical objects

    EP3567128A1

  • Bearing ball coating method

    JP2003239978A

  • Device for vacuum coating bulk material

    US6220203B1