GB2528037A - Building element for a bearing, bearing and method of producing - Google Patents

Abstract

A building element 102 for a bearing 202 and a method of manufacturing the building element are provided. The building element 102 comprises a plurality of pockets 140 for securing a position of rolling elements 120 in the bearing 202. In use, the pockets 140 are configured for at least partially surrounding the rolling elements 120. The building element 102 further comprises a seal 150, 152 configured for at least partially sealing the rolling elements 120 from environmental influence. At least a part of the seal 150, 152 comprises printed material being printed to a first construction comprising the plurality of pockets 140 for producing the building element 102 using an additive manufacturing process. Alternatively, at least a part of the plurality of pockets 140 comprises printed material being printed to a second construction comprising the seal 150, 152 for producing the building element 102 using the additive manufacturing process.

Description

BUILDING ELEMENT FOR A BEARING, BEARING AND METHOD OF PRODUCING

FIELD OF THE INVENTION

The invention relates to a building element for a bearing. The invention further relates to a bearing and to a method of producing the building element.

BACKGROUND ART

Additive manufacturing or more commonly called 3D printing is a known production technique in which a three-dmensional solid object is generated from a digital model. The process of additive manufacturing starts with generating the digital model via any known digital modeling methods, for example, using a CAD program.

Next, the digital model is divided into slices in which each slice indicates for this layer of the digital model where the printed material should be located. The individual slices are sequentially fed into an additive manufacturing tool or 3D printer which deposits the material according to the individual slices and as such generates the complete three-dimensional solid object layer by layer.

In the early days of additive manufacturing, mainly plastic materials or resins have been used as printed material for generating the three-dimensional solid object. However, nowadays, also other processes have been developed in which also other materials, including different types of metal may be deposited in layers using this additive manufacturing technique. A major benefit of this 3D printing manufacturing technique is that it allows the designer to produce virtually any three-dimensional object in a relatively simple production method. This may be especially beneficial when, for example, only a few models are required of a product before, for example, mass production starts. These few models may beneficially be produced using 3D printing.

Alternatively, when only a limited number of products are required 3D printing may also be a viable production method.

The use of additive manufacturing in high-quality bearings has been limited.

This is caused by material requirements for such high-quality bearings which in the past have been insufficient for producing high-quality bearings.

SUMMARY OF THE INVENTION

One of the objects of the invention is to provide a multi-function building element for a bearing.

A first aspect of the invention provides the building element for the bearing according to claim 1. A second aspect of the invention provides the bearing according to claim 10. A third aspect of the invention provides a method of producing the building element according to claim 11. Embodiments are defined in the dependent claims.

The building element in accordance with the first aspect of the invention comprises a plurality of pockets for securing a position of rolling elements in the bearing, in use, the pockets being configured for at least partially surrounding the rolling elements. The building element further comprises a seal configured for at least partially sealing the rolling elements of the bearing from environmental influence. At least a part of the seal comprises printed material being printed to a first construction comprising the plurality of pockets for constituting the building element using an additive manufacturing process. Alternatively, at least a part of the plurality of pockets comprises printed material being printed to a second construction comprising the seal for constituting the building element using the additive manufacturing process.

The inventors have realized that material requirements for a seal near the rolling elements at least partially may be different compared to material requirements used for the plurality of pockets constituting at least a part of a cage of a bearing. So generating the building element according to the invention, which basically combines the seal and cage into a single building element for a bearing, has been a great challenge due to these differences in material requirements. It often is relatively costly or even nearly impossible to glue or otherwise connect the different materials required to produce the building element according to the invention using production methods typically used for producing bearings. Methods to connect different types of materials to generate a sufficiently secure connection which is able to withstand the long-term wear and the forces acting upon such building element during long-time use in a bearing has been virtually impossible.

Generating the building element according to the invention in which the seal comprises printed material which is material printed using 3D printing techniques onto the first construction which comprises the plurality of pockets would result in a single building element configured to act both as the cage and as the seal. Due to the use of the 3D printing process, the connection between different materials in the building element to produce the seal onto the cage is significantly improved, enabling the generation of the building element according to the invention which can withstand the harsh requirements for long-term use of the building element in a high-quality bearing.

In this embodiment, the first construction may be a previously produced cage which comprises the plurality of pockets, onto which the seal is printed using the 3D printing process. The pockets may be evenly or unevenly distributed along the length of the building element; alternatively, the first construction may also comprise additional elements next to the cage.

A further advantage when the seal at least partially comprises printed material which is printed onto the first construction to create the building element, is that it provides a high degree of freedom in the seal geometry and the possibility of placing specific materials only where they are really needed and not across the bulk of the seal or the building element. The additional freedom comes from the fact that the geometrical distribution of the elements that make up a seal are not limited as would be when using the traditional construction processes for the seal, e.g. injection molding and casting. Injection molding and casting impose limitations related to the flow of non-molten materials into the cast as well as the passage of such materials through narrow section of the seal. Furthermore, specialized materials may be required in parts of the seal, for example, for reducing wear. Such specialized materials are often relatively expensive. Using the additive manufacturing process to apply the printed material only at the location where needed generates a significant cost reduction. Furthermore, the surface of the seal may be built as part of the process to build the whole seal and the whole building element. This further enables to optimize or tune, for example, surface roughness, wetting, heat exchange and other performance parameters wthout having additional processes to control these performance parameters. These other performance parameter may, for example, include magnetic materials and properties and include specific 3 dimensional top layers without having to use specific coating processes and. All may be done in a single additive manufacturing production step.

In the alternatively embodiment, the building element according to the inventon is generated by printing (using 3D printing techniques) the plurality of pockets to the second construction comprising the seal. Also this embodiment would result in the single building element configured to act both as the cage and as the seal. And again, due to the use of the 3D printing process, the connection between different materials in the building element to produce the cage onto the seal is significantly improved, enabling the generation of the building element according to the invention which can withstand the harsh requirements for long-term use of the building element in a high-quality bearing. In this embodiment, the second construction may be a previously produced seal, onto which the plurality of pockets are printed using the 3D printing process to include the cage into the building element; alternatively, the second construction may also comprise additional elements next to the seal.

A further advantage when printing the cage onto the second construction to create the building element is that it provides a high degree of freedom in the cage geometry and the possibility of placing specific materials only where they are really needed in the design of the cage and not across the bulk of the cage or building element. Also here, the additional freedom comes from the fact that the geometrical distribution of the elements that make up a cage are not limited as would be when using the traditional construction processes for the cage, e.g. injection molding and casting. As indicated before, injection molding and casting impose limitations related to the flow of non-molten materials into the cast as well as the passage of such materials through narrow section of the cage. Furthermore, specialized materials may be required in the pockets of the cage, for example, for reducing wear. Such specialized materials are often relatively expensive and their deposition requires an additional/separated process also relatively expensive and increasing the degree of complexity of the manufacturing process. Using the additive manufacturing process to apply the printed material only at the location where needed generates a significant cost reduction. Furthermore, the surface in the pockets of the cage can be built as part of the process to attach the whole cage to the second construction. This further enables to optimize or tune surface roughness, wetting, heat exchange, magnetic and other performance parameters without having additional processes to control these performance parameters. All may be done in a single additive manufacturing production step.

A further benefit of using the building element according to the invention is that fewer production steps may be required to produce the bearing which reduces the overall cost of the bearing. Finally, using the 3D printing techniques to produce the building element according to the invention also allows to further integrate other functionality into the building element, as any shape can be produced using such 3D printing technique.

The seal may at least partialy seal the rolling elements from environmental influence, because whether the seal fully or partially seals the rolling elements from the environment depends on the design of the bearing. The design of the bearing may be such that a second seal may be arranged on an opposite side of the rolling element such that the second seal and the seal included in the building element together substantially completely seal the rolling elements from environmental influence.

Alternatively, the building element may comprise a seal part comprising printed material which is printed on either side of the cage such that the rolling elements are substantially completely shielded from environmental influence by the building element according to the invention.

In an embodiment of the building element, at least a part of the first construction or at least a part of the second construction comprises printed material being material printed using the additive manufacturing process. In this embodiment, the first construction may be produced wholly or partially using the 3D printing process.

As such, the complete building element may be produced using the 3D printing process. The first construction may at least partially comprise printed material which is different from the printed material used for the seal, and the second construction may at least partially comprise printed materal which is different from the printed material used for the plurality of pockets. Using 3D printing, the combination of different materials for the seal and the cage part of the building element is beneficial as the connection between these different materials may be relatively strong, especially when a so called graded interface layer is used between the different printed materials. In such graded interface layer, a first printed material gradually changes to a second (different) printed material by gradually increasing the mixing of the second printed material into the first printed material until there is only the second printed material left.

This gradual mixing of the different materials creates a very strong bond between elements of the building element produced from the first material and the second material, respectively. For instance you may have materials with different (even opposed) thermal expansion behavior to provide dimensional stability to the system profiting from differentiated heating and tribology of cage and seal lip. For the same reason the second construction may be produced wholly or partially using the 3D printing process, onto which the plurality of pockets representing the cage is printed.

Again, in this embodiment, the complete building element may be produced using the 3D printing process, enabling the strong bond between the different elements of the building element, for example, due to the use of a graded interface layer.

In an embodiment of the building element, the seal comprises a first printed material and the plurality of pockets comprises a second material, different from the first printed material, or wherein the seal comprises a first material and the plurality of pockets comprises a second printed material, different from the first material. The seal may, for example, require a specific material, for example, having a specific flexibility, which is not required or present in the material from which the plurality of pockets is C, produced. In such an embodiment, the first printed material is not present in the cage-part of the building element. Vice versa the second material may have a predefined stiffness or may have a specific self-lubricating property which may be required at the location where the building element touches or possibly touches the rolling elements to reduce wear. However, this second material being relatively stiff material having, for example, self-lubricating property may not be present at the seal-part of the building element.

The first printed material or the first material may, for example be a material selected from a list comprising: a low-friction material and a self-lubricating material.

Such low-friction materials may enable noise reduction of the bearing comprising the building elements including the seal according to the invention. Self-lubricant materials may be rather difficult to apply locally and may be rather difficult to apply n a relatively homogeneous layer. Furthermore, these self-lubricant materials are also relatively expensive. Using this additive manufacturing technique, the self-lubricating material may be applied exactly locally there where it is needed and at a layer thickness as required. This results in a good local concentration of the self-lubricant material in a cost-effective manner. Furthermore, known seals are constructed and design to build a film (or layer) of lubricant (oil) between them and the other moving body. The film is built dynamically -so when the parts are moving relative to each other. This means that during the non-steady states -for example, accelerations, start-ups, etc -the film is either perturbed, destroyed or not yet created. At these moments during the use of the bearing most wear takes place. Using low-frictional materials and/or self-lubricated materials, for example, at the seal lip ensures lubricity at the seal lip in any condition.

Due to this, overall friction performance is enhanced and wear reduced. Reduction of wear is important as it is due to wear that contaminants (water/dust) could enter into the bearing leading to most of the life-reducing damage. Furthermore, a damaged seal will leak oil/grease outside the intended volume which will lead to environmental contamination.

Using different materials in the building block not only allows for the distribution of self-lubricating materials but also, for example, to enhance mechanical reinforcement or heat conductive characteristics of the building block.

Also the second printed material or the second material may comprise low-frictional and/or self-lubricating material: for example, printed at locations inside the cage or inside pockets near the rolling elements. This second printed material or second material may, for example, only be present at a contact surface of the cage, the contact surface being a part of the surface of the cage where, in use, at least occasionally a frictional force is applied to the cage, for example by the rolling element.

The contacts between the moving rolling elements (sphere or rollers) against the cage create a contact force opposite to the movement of the rollers and therefore increasing the internal friction of the bearing. This could also lead to phenomena like wear and energy inefficiency in the system and could lead to additional noise. By applying this low-friction material and/or self-lubricating material only at the contact surface of the cage one or more of the above problems may be solved. The surface wettability may be controlled by applying a specific second printed material or specific second material at the contact surface of the cage, enabling to have the lubricant in the desired quantities only where needed. An important advantage of having the tuned wetting behavior at the contact surface is that it results in a significant reduction of the amount of lubricant inside the bearing. This reduces the friction, for example, associated with churning the grease as the bearing turns. Furthermore, less lubricants reduces any impact such lubricants may have on the environment.

In an embodiment of the building element, the seal comprises a first seal-part and a second seal-part, in use, the first seal-part being configured for being arranged on an opposite side of the rolling elements compared to the second seal-part.

A bearing typically exists of an inner ring, an outer ring and rolling elements arranged between the inner ring and the outer ring to allow the inner ring and outer ring to rotate relative to each other at relatively low friction while all elements substantially reside in a plane perpendicular to a rotation axis. Such bearings typically require two seals each arranged on opposite sides of the plane to seal the inside of the bearing from environmental influences. However, when the seal is printed onto the first construction, the seal may be constituted of the first seal-part and the second seal-part, each being arranged on opposite sides of the rolling element. As such, the seal may be configured to completely protect the inside of the bearing from environmental influences. An advantage of this embodiment is that the integration of the second seal-part obviates the need for mounting the second seal to the bearing. A further advantage is that the printing of the second seal-part enables a tighter clearance -as mounting is not needed, which reduces the overall dimensions of the second seal-part -which may free space to include other functionality such as sensors, batteries, etc, inside the bearing and reducing the required volume of lubricant. Furthermore, when printing the complete building element, the printing may start with a first seal-part onto which the plurality of pockets is printed, constituting the cage. Finally, the second seal-part may be applied completely sealing the inside of the bearing. So the first seal-part and the second seal part do not need to be connected, but may be separate elements printed on either side of a cage. Such printing process to print the complete building element preferably is applied by directly printing around the rolling elements.

In an embodiment of the building element, the building element comprises a hollow structure. A hollow structure may be used to reduce the weight of the building element. Furthermore, the hollow structure may create space without the need for additional volume. As such, this created hollow structure, for example, created during the printing of the building element in the additive manufacturing process, may now be used for other tunctionalities, such as the containing of lubricants or sensors or even built-in batteries. The hollow structure may, for example, comprise an opening towards the rolling element. When, for example, the hallow structure is filled with lubricant, the lubricant may, in use, be delivered to the rolling elements from the hollow structure.

The hollow structure may also comprise a sensor and the opening towards the rolling element may generate a connection to the lubricants near the rolling element and provide an indication of the quality of the lubricant near the rolling element. This may, for example, be used to monitor the condition of the bearing and only start, for example, maintenance work when really necessary -for example, resulting from parameters measured by the sensor. Of course, the hollow structures may also be used to reduce the overall weight of the building element.

In an embodiment of the building element, the building element comprises a predefined distribution of magnetic particles. This predefined distribution of magnetic particles may, for example, be configured and constructed for maintaining or guiding, in use, a magnetic lubricant. Magnetic particles may, for example, be arranged in a pattern to guide or hold magnetic lubricants such that they will be located at a position where they are actually needed. As such, the amount of lubricant necessary for lubricating the bearing and/or building element may be reduced. The pattern may have any form suitable for maintaining the magnetic lubricant in its place, and even may be substantially random for merely confining the magnetic lubricant to one place.

Alternatively, the pattern may comprise a system of channels for guiding the magnetic lubricant through the system and allowing the magnetic lubricant to flow through the system. The guiding and holding of lubrcants in a system in which the building element moves relative to other elements of the bearing may be a challenge. Often lubricants tend to migrate through such a system which may result in a shortage of lubricant at the interface between two relative moving elements. Using the predefined distribution of magnetic particles, for example, printed during the production of the building element, enables to guide or hold the magnetic lubricant at the position where it is needed such that a shortage of lubricant may be avoided. This would improve the overall reliability of such bearing. It woud also obviate the need to use an access of lubricant in such bearing. Some circulaton of magnetic lubricant may be allowed or even stimulated by using a specific pattern of magnetic particles, for example, comprising grooves. Such a pattern may also be used to replenish the lubricants gradually such that the magnetic lubricants migrate from an entrance part of the pattern to an exit part of the pattern. At the exit part of the pattern, the magnetic lubricant may be colected, checked for contaminations and, for example, recycled back to the entrance part of the pattern. Furthermore, the contaminations found in the collected magnetic lubricant may also be used as an indicator whether maintenance of the bearing would be required.

In an embodiment of the building element, the first printed material or the first material is chosen from a list comprising ceramics, polymers, elastomer, and wherein the second printed material or the second material comprises a hydrophobic material.

In an embodiment of the building element, an interface between the first printed material and the second printed material comprises a functionally graded interface layer, a composition of the functionally graded interface layer being configured to gradually change from the first printed material via a mixture of the first printed material and the second printed material to the second printed material. An important benefit of using functionally graded interface layers is that the bonding characteristics of the two materials is significantly improved without the need for additional bonding materials, structures or layers which may degrade the specific material characteristics required for either the first printed material or the second printed material. Coatings typically create an abrupt interphase between the bulk (base) material and the deposited layer. This interface is a weak point as it acts as stress concentrator and defines a sharp transition in terms of properties, e.g. thermal expansion, stiffness, elastic properties, chemical gradients, etc. Using an intermediate layer with intermediate properties reduces the abruptness of the properties changes but doubles the number of interfaces. A graded interface layer may be produced using other processes than 3D printing, but these interface layers are very difficult to make.

The two materials must be deposited in coating processes, and both of the materials used need to be compatible with the coating process. However, using the additive manufacturing process in which material is deposited in a layer by layer almost pixelated fashion, mixing of different materials and even gradual changing the mixing ratio layer by layer is relatively simple.

In an embodiment of the building element, at least a part of the building element is configured for being printed around the rolling elements using the additive manufacturing process. For example, the seal may be constituted of the first seal-part and the second seal-part such that the first seal-part and the second seal-part may be printed on either side of an existing cage inside the bearing to generate the building element according to the current embodiment. Alternative, the complete building element may be printed around the rolling elements, for example, starting with the first seal-part. Next the cage is printed directly on the first seal-part and finally, the second seal-part is printed onto the cage to form the overall building element. Of course during the printing process of the building element around the rolling elements dfferent materials may be used to print the first seal-part, the cage and the second seal-part, depending on the requirements of the d[fferent elements. And, as indicated before, other elements may be included in the building element, such as hollow structures -which of course may be printed all at the same time around the rolling elements.

Known seals often have to be joined together with the remainder of the bearing to form a closed seal around the bearing. At the position where the seals are joined with the bearing, the known seal may have a weaker construction and wear at the rolling elements may be increased locally. When producing the building element according to the current embodiment, the seal is printed around the rolling elements which prevents any weakness in the construction and prevents increased local wear.

Furthermore, clearance between the rolling elements, the cage and the seal are often derived from the mounting compromise which is required when the seal and cage are built separately and mounted later. When printing the seal and/or cage around the rolling elements of the bearing, at least some of the clearance between the rolling elements, cage and seal may be optimized without the need for mounting concessions.

The bearing in accordance with the second aspect of the invention comprises the building element according to the invention.

The method in accordance with the third aspect of the invention comprises a step of adding at least a part of the seal to a first construction comprising the plurality of pockets for producing the building element using an additive manufacturing process, or comprises a step of adding at least a part of the plurality of pockets to a second construction comprising the seal for producing the building element using the additive manufacturing process. As indicated before, the first construction may be a cage onto which a seal is printed using the method according to the invention. Alternatively the first construction may comprise more elements including the cage onto which the plurality of pockets constituting the cage is printed. The second construction may be a seal onto which a cage is printed using the method according to the invention.

Alternatively, the second construction may comprise more elements including the seal onto which the plurality of pockets constituting the cage is printed. Any of the two method steps generate a building element according to the invention. The use of additive manufacturing, also known as 3D printing, enables a high degree of freedom in the shape of the building element and enables a strong bond between the seal and the cage inside the bearing. Furthermore, accurate deposition of specific materials at specific locations at or inside the building element is possible using 3D printing techniques which results in a limited use of the specific materials and typically a reduction of the cost.

In an embodiment of the method, the method further comprises the step of printing at least a part of the first construction using the additive manufacturing process, or comprises a step of printing at least a part of the second construction using the additive manufacturing process.

In an embodiment of the method, the method is configured for printing the building element around the rolling elements using the additive manufacturing process.

In an embodiment of the method, the method further comprises a step of locally applying a distribution of magnetc particles. The distribution of magnetic particles may be configured and constructed for maintaining or guiding, in use, magnetic lubricant. This applying of the magnetic particles may be done using the additive manufacturing process, or using any other manufacturing process for applying magnetic particles to the building element.

In an embodiment of the method, the additive manufacturing process is selected from a list comprising stereolithography, selective laser sintering, laminated object manufacturing, fused deposition modeling, selective binding, laser engineering net shaping, photo polymerization and selective electron beam sintering, 3D nesting.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other aspects of the invention are apparent from and will be elucidated with reference to the embodiments described hereinafter. In the drawings, Figs. 1 A to 1 C show different schematic cross-sectional views of embodiments of a building element according to the invention, Figs. 2A to 2D show different stages in printing a further embodiment of the building element according to the invention directly printed around a rolling element, Fig. 3 shows a schematic plan view of a bearing according to the invention, Fig. 4A shows a first embodiment of an additive manufacturing tool in which a liquid resin is used for applying the printed material in the additive manufacturing process, Fig. 4fl shows a second embodiment of the additive manufacturing tool in which a liquid resin is dispensed from a dispenser for applying the printed material in the additive manufacturing process, Fig. 5A shows a third embodiment of the additive manufacturing tool in which the material is granulated into small solid particles which are used for applying the printed material in the additive manufacturing process, Fig. SB shows a fourth embodiment of the additive manufacturing tool in which the granulated solid material is dispensed from a dispenser for applying the printed material in the additive manufacturing process, Fig. 6 shows a fifth embodiment of the additive manufacturing tool in which a melted plastic material is dispensed for applying the printed material in the additive manufacturing process, and Figs. 7A to 7C show different flow diagrams illustrating different manufacturing methods for producing the building element according to the invention.

It should be noted that items which have the same reference numbers in different Figures, have the same structural features and the same functions, or are the same signals. Where the function and/or structure of such an item has been explained, there is no necessity for repeated explanation thereof in the detailed description.

DETAILED DESCRIPTION OF EMBODIMENTS

Figs. 1 A to 1 C show different schematic cross-sectional views of embodiments of a building element 101, 102, 103 according to the invention. In the embodiment of Fig. 1A, a schematic cross-sectional view of a first embodiment of a bearing 201 is shown comprising an outer ring 110, and inner ring 115 and a rolling element 120 in the form of a sphere 120. To keep the plurality of spheres 120 at a predefined location at a peripheral position around a rotation axis (not shown) of the bearing 201, the bearing 201 comprises a cage 140. Attached to the cage 140 a seal is present.

In the embodiment of the bearing 201 as shown in Fig. 1A, the seal 150 comprises printed material which is printed onto the first construction 140, which in the current embodiment only contains the cage 140 comprising the plurality of pockets 140.

The seal 150 comprising printed material, together with the plurality of pockets 140 constituting the cage 140 form a first embodiment of the building element 101 according to the invention. In the current embodiment, the seal 150 is printed onto the plurality of pockets 140 constituting the cage 140. This cage 140 may also be wholly or partially produced of printed material being material printed using a 3D printing or additive manufacturing process. Of course, the printed material used for the plurality of pockets 140 constituting the cage 140 may be different printed material compared to the printed material used for printing the seal 150 onto the cage 140.

In the embodiment of the bearing 202 as shown in Fig. 1B, again the bearing 202 comprises the outer ring 110, inner ring 115 and the rolling element 120.

Now the building element 102 comprises of the seal 150, 152 and the plurality of pockets 140 constituting the cage 140 in which the seal 150, 152 is constituted of two different materials 150, 152 of which at east one of the different material 150, 152 is printed material 150, 152. In such an embodiment, the edge part 152 of the seal 150, 152 may comprise different material 152 compared to the remainder 150 of the seal 150, 152 to ensure that the rotational movement of the seal 150, 152 relative to the inner ring 110 or outer ring 115 may not generate too much wear.

In the embodiment shown in Fig. 1 B, the part of the seal 150, 152 facing the outer ring 110 is identical to the part of the seal 150, 152 facing the inner ring 115.

However, this need not be the case, as the seal 150, 152 typically only moves relative to either the inner ring 115 or the outer ring 110. So the part of the seal 150, 152 which does not move relative to the inner ring 115 or outer ring 110 may have a different shape compared to the part of the seal 150, 152 which does move relative to the inner ring 115 or outer ring 110 to ensure an efficient sealing of the rolling elements 120 from environmental influence while reducing the overall wear inside the bearing 202.

In the embodiment of the bearing 203 as shown in Fig. 1C, the bearing 203 again comprises an outer ring 110, and inner ring 115 and a rolling element 120. The building element 103 comprises of a plurality of pockets 140 and a seal 150. The cage now includes both the plurality of pockets 140 an a further cage element 180 which, in the current embodiment, is a separate cage element 180 which together with the plurality of pockets 140 ensure that the rolling elements 120 have a predefined location at the peripheral ring around the rotation axis (not shown) of the bearing 203.

In the embodiment of the building element 103 as shown in Fig. 1 C, the building element 103 comprises a plurality of structures 142 or channels 142 comprising a predefined distribution of magnetic particles configured and constructed for maintaining or guiding, in use, a magnetic lubricant 170. The predefined distribution or pattern 142 may have any form suitable for maintaining the magnetic lubricant 170 in its place, and even may be substantially random for merely confining the magnetic lubricant 170 to one place. Alternatively, the pattern 142 may comprise a system of channels 142 for guiding the magnetic lubricant 170 through the bearing 203 and allowing the magnetic lubricant 170 to flow through the bearing 203. The pattern 142, or channels 142 are only applied to the plurality of pockets 140, but alternatively, the pattern 142, or channels 142 may also be applied to the seal 150 (see Fig. 2). The distribution of magnetic particles is indicated in Fig. 1 C with the letters "N" and "5", representing the magnetic poles "North" and "South", respectively. The magnetic particles may also be omitted from the pattern 142 or channels 142 while the pattern 142 or channels 142 may still be able to maintain or guide lubricant 170 inside the bearing 203.

Also the further cage element 180 comprises a pattern 182 or channels 182, similar to the plurality of pockets 140 of the building element 103. Also this pattern 182 or these channels 182 are configured for allowing the magnetic lubricant 170 to flow through the bearing 203 or to maintain the magnetic lubricant 170 in the required location within the bearing 203.

Figs. 2A to 2D show different stages in printing a further embodiment of the building element 104 for a bearing 204 according to the invention directly printed around a rolling element 120 of the bearing 204. Each of the different stages shown in Figs. 2A to 2D represent a schematic cross-sectional view of the building element 104 according to the invention. Fig. 2A shows a first part of the production of the building element 104 in which a first seal-part 150A is provided. This first seal-part 150A may be an existing first seal-part 150A, for example, produced via known injection molding processes, or may alternatively comprise or be constituted of printed material or a plurality of different printed materials. In the first step shown in Fig. 2A the first seal-part 1SOA also comprises a pattern 154 or a plurality of channels 154 which may comprise magnetic particles and which may be used for guiding the magnetic lubricant 170 (not indicated in Fig. 2). On top of this first seal-part 150A a plurality of pockets 140 is printed using a 3D printing process. In the case that the first seal-part 1SOA at least partially comprises printed material, the interface between the first seal-part 150A and the plurality of pockets 140 may be a functionally graded interface layer 190. A composition of the functionally graded interface layer 190 gradually changes from a first printed material, for example, of the first seal-part 1 50A via a mixture of the first printed material and a second printed material to the second printed material, for example, of the plurality of pockets 140. The plurality of pockets 140, for example, constitutes a cage 140 for the bearing 204. Also the plurality of pockets 140 or the cage comprises a pattern 142 or a plurality of channels 142 which may comprises magnetic particles and which may be used for guiding the magnetic lubricant 170 (not indicated in Fig. 2). In the stage of the construction of the building element 104 shown in Fig. 2B, the building element 104 comprises a hollow structure 1 BOA. This hollow structure 1 BOA may, for example, be used for storing or applying lubricants to the rolling elements 120, or which may, for example, be used for including sensors (not shown) or even batteries (not shown) to allow sensors to operate. Such sensors may, for example, be used to register the temperature inside the bearing 204 or may be used to register any other parameter inside the bearing 204.

Fig. 2C shows an embodiment of the building element 104 in which the plurality of pockets 140 have been printed around the rolling element 120. More channels 142, for example, containing magnetic particles, have been printed at different locations on the building element 104 to ensure that the magnetic lubricant (not shown) is maintained at the correct location, in use. Fig. 2D shows the finished building element 104 in which the second seal-part 1 50B is printed on the plurality of pockets 140. This second seal-part 1509 may again be printed onto the plurality of pockets 140 or onto the cage 140 via a functionally graded interface layer 190. This second seal-part 1509 again may comprise a plurality of channels 154, for example, containing magnetic particles to ensure that the magnetic lubricant (not shown) is maintained at the correct location. As indicated before, the magnetic particles may also be omitted from the pattern 154 or plurality of channels 154 while the pattern 154 or plurality of channels 154 may still maintain or guide the lubricant within the bearing 204 in use.

In the embodiment of the building element 104 as shown in Fig. 2D, also the second seal-part 1509 comprises a hollow structure 1609. Also this hollow structure 1609 may be used to store lubricant (not shown) or to provide space for a sensor (not shown) or battery (not shown). Alternatively, the hollow structures 160A, 1 BOB may also be used for reducing the overall weight of the building element 104 or bearing 204. The hollow structures 1 60A, 1609 as shown in Figs. 28, 2C and 2D may be provided in the first seal-part 150A and/or second seal-part 1509. However, alternatively such hollow structures (not shown) may also be generated in the cage part or near the plurality of pockets 140 without departing from the scope of the inventon. Alternatively, the first seal-part 1 50A and/or the second seal-part 1 SOB may be directly applied onto the plurality of pockets 140 or the cage 140 without the presence of the hollow structures 1 BOA, 1609.

Fig. 3 shows a schematic plan view of a bearing 205 according to the inventon. The bearing 205 shown in Fig. 3 also comprises an outer ring 110, and inner ring 115 and a plurality of rolling elements 120 in the shape of rolling spheres 120. Of course any shape of the rolling elements 120, in this and any of the previous embodiments may be used without departing from the scope of the invention. In the cut-away part of the outer ring 110 the rolling elements 120 are visible, together with a part of the cage 140 constituted by the plurality of pockets 140. The first seal-part 1 50A and second seal-part 1 SOB are indicated as partially transparent seals 150 for at least partially sealing the plurality of rolling elements 120 from environmental influence. As indicated before, the cage 140 may comprise printed material and may be produced using a 3D printing process. In addition, also the first seal-part 150A and/ar the second seal-part 1509 may comprise printed material and may be produced using the 3D printing process. In a preferred embodiment, the whole building element 105 is produced using the 3D printing process.

Whether a part of the building element 101, 102, 103, 104, 105, 105 comprises printed material, may be clearly visible due to the nature of the 3D printing process. The deposition of droplets of resin or the deposition and melting of small material pellets generate an overall material structure from which the printed material may easily be identified after the printed material has hardened.

Fig. 4A shows a first embodiment of an additive manufacturing tool 400 in which a liquid resin 450 is used for applying the printed material 460 in the additive manufacturing process. Such additive manufacturing tool 400 comprises resin container 430 comprising the liquid resin 450. Inside the resin container 430 a platform 470 is positioned which is configured to slowly move down into the resin container 430.

The additive manufacturing tool 400 further comprises a laser 410 which emits a laser beam 412 having a wavelength for curing the liquid resin 450 at the locations on the printed material 460 where additional printed material 460 should be added. A re-coating bar 440 is drawn over the printed material 460 before a new layer of printed material 460 is to be applied to ensure that a thin layer of liquid resin 450 is on top of the printed material 460. Emitting using the laser 410 those parts of the thin layer of liquid resin 450 where the additional printed material 460 should be applied will locally cure the resin 450. In the embodiment as shown in Fig. 4A the laser beam 412 is reflected across the layer of liquid resin 450 using a scanning mirror 420. When in the current layer all parts that need to be cured, have been illuminated with the laser beam 412, the platform 470 lowers the printed material 460 further into the liquid resin 450 to allow the re-coating bar 460 to apply another layer of liquid resin 450 on top of the printed material 460 to continue the additive manufacturing process.

Fig. 4B shows a second embodiment of the additive manufacturing tool 401 in which a liquid resin 450 is dispensed from a dispenser 405 or print head 405 for applying the printed material 460 in the additive manufacturing process. The additive manufacturing tool 401 again comprises the resin container 430 comprising the liquid resin 450 which is fed via a feed 455 towards the print head 405. The print head 405 further comprises a print nozzle 415 from which droplets of liquid resin 450 are emitted towards the printed material 460. These droplets may fall under gravity from the print head 405 to the printed material 460 or may be ejected from the print nozzle 415 using some ejection mechanism (not shown) towards the printed material 460. The print head 405 further comprises a laser 410 emitting a laser beam 412 for immediately cure the droplet of liquid resin 450 when it hits the printed material 460 to fix the droplet of liquid resin 450 to the already printed material 460. The printed material 460 forming a solid object may be located on a platform 470.

Fig. SA shows a third embodiment of the additive manufacturing tool 500 in which the material is granulated into small solid particles 550 which are used for applying the printed material 560 in the additive manufacturing process. Now, the additive manufacturing tool 500, also known as a Selective Laser Sintering tool 500, or SLS tool 500 comprises a granulate container 530 comprising the granulated small solid particles 550. The printed material 560 is located again on a platform 570 and is completely surrounded by the granulated small solid particles 550. Lowering the platform allows a granulate feed roller 540 to apply another layer of granulated solid particles 550 on the printed material 560. Subsequently locally applying the laser beam 512 using the laser 510 and the scanning mirror 520 will locally melt the granulated solid particles 550 and connects them with each other and with the printed material 560 to generate the next layer of the solid object to be created. Next, the platform 570 moves down further to allow a next layer of granulated solid particles 550 to be applied via the granulate feed roller 540 to continue the next layer in the additive manufacturing process.

Fig. SB shows a fourth embodiment of the additive manufacturing tool 501 or SLS tool 501 in which the granulated solid material 550 is dispensed from a dispenser 505 or print head 505 for applying the printed material 560 in the additive manufacturing process. The additive manufacturing tool 501 again comprises the granulate container 530 comprising the granulated solid particles 550 which are fed via a feed 555 towards the print head 505. The print head 505 further comprises a print nozzle 515 from which granulated solid particles 550 are emitted towards the printed material 560. These solid particles 550 may fall under gravity from the print head 505 to the printed material 560 or may be ejected from the print nozzle 515 using some ejection mechanism (not shown) towards the printed material 560. The print head 505 further comprises a laser 510 emitting a laser beam 512 for immediately melting or sintering the solid particle 550 when it hits the printed material 560 to fix the solid particle 550 to the already printed material 560. The printed material 560 forming a solid object may be located on a platform 570.

Fig. 6 shows a fifth embodiment of the additive manufacturing tool 600 in which a melted plastic material 650 is dispensed for applying the printed material 660 in the additive manufacturing process. The additive manufacturing tool 600 shown in Fig. 6 is also known as Fused Deposition Modeling tool 600 or FDM tool 600. Now a plastic filament 630 is fed into a dispenser 610 or melter 610 via a filament feeder 640.

The dispenser 610 or melter 610 comprises an extrusion nozzle 615 for melting the plastic filament 630 to form a droplet of melted plastic material 650 which is applied to the printed material 660 where it hardens and connects to the already printed material 660. The dispenser 610 may be configured and constructed to apply the droplet of melted plastic 650 to the printed material 660 under gravity or via an ejection mechanism (not shown). The additive manufacturing tool 600 further comprises a positioning system 620 for positioning the dispenser 610 across the printed material 660.

Figs. 7A to 7C show different flow diagrams illustrating different manufacturing methods for producing the building element according to the invention.

In the flow diagram of Fig. 7A, the first step in the process of producing the building element comprises a step of "provide seal" 701 in which a seal is provided. This seal may be produced using any known seal manufacturing method. Next the step of printing the cage or the plurality of pockets constituting the cage on the seal in the step of "print cage" 702. In this step, the plurality of pockets or the cage is directly printed on the provided seal. In an optional intermediate step between the step of "providing seal" 701 and "print cage" 702, another material or layer may be printed onto the seal provided in the optional intermediate step "print other" 704. During this step, an intermediate layer of, for example, low friction material may be applied to the seal provided to reduce the wear. During this step, also a local pattern or a plurality of channels may be printed on the seal provided, with our without magnetic particles present, to guide and/or maintain lubricant and possibly magnetic lubricant at the required location on the building element. After the step of "print cage" 702, the method of producing the building block may comprise a further optional step of print seal" 703 during which a second seal is printed on the building element to fully seal the rolling elements from environmental influence. This step is optional which is indicated in Fig. 7A using the dash-doffed box around the optional steps. Between the step of "print cage" 702 and the step of "print seal" 703 another step of "print further" 705 may be present in which also a pattern or a plurality of channels may be printed to guide and/or maintain the lubricant and possibly magnetic lubricant at the required location on the building element.

In the flow diagram of Fig. 79, the first step in the process of producing the building element comprises a step of "provide cage" 711 in which a cage or a plurality of pockets is provided. This cage may be produced using any known cage manufacturing method. Next the printing the seal on the cage is done in the step of "print seal" 712. In this step, the seal is directly printed on the provided cage. In an optional intermediate step between the step of "providing cage" 711 and "print seal" 712, another material or layer may be printed onto the cage provided in the optional intermediate step "print other" 714. During this step, an intermediate layer of, for example, low friction material may be applied to the inside of the pockets in the cage provided to, for example, reduce wear. During this step, also a local pattern or a plurality of channels may be printed on the cage provided, with our without magnetic particles present, to guide and/or maintain lubricant and possibly magnetic lubricant at the required location on the building element. After the step of "print seal" 712, the method of producing the building block may comprise a further optional steps which is indicated by the dashed arrow. Alternatively, after printing the seal in the step of "print seal" 712, also another optional step may be present of "print further" 715 in which again different materials may be printed on the printed seal and in which also a pattern or a plurality of channels may be printed to guide and/or maintain the lubricant and possibly magnetic lubricant at the required location on the building element. Again, after this step of "print further" 715 other optional steps may follow which s indicated by the dashed arrow.

Finally, in the flow diagram of Fig. 7C, the first step in the process of producing the building element comprises a step of "print seal 1" 721 in which a first seal-part is printed using a 3D printing process. Next the printing of the cage on the seal is done in the step of "print cage" 722. In this step, the cage is directly printed on the printed seal, for example, using a functionally graded interface layer. In an optional intermediate step between the step of "print seal" 721 and "print cage" 722, another material or layer may be printed onto the printed first seal-part in the optional intermediate step print other" 724. During this step, an intermediate layer of, for example, low friction material may be applied to the printed first seal-part, for example, to reduce wear. During this step, also a local pattern or a plurality of channels may be printed on the printed first seal-part, with our without magnetic particles present, to guide and/or maintain lubricant and possibly magnetic lubricant at the required location on the building element. After the step of "print cage" 722, the method of producing the building block may comprise a further optional step of "print seal 2" 723 during which a second seal-part is printed on the building element to fully seal the rolling elements from environmental influence. This step is optional which is indicated in Fig. 7C using the dash-doffed box around the optiona steps. Between the step of "print cage" 722 and the step of "print seal 2" 723 another step of "print further" 725 may be present in which again different materials may be printed on the printed second seal-part and in which also a pattern or a plurality of channels may be printed to guide and/or maintain the lubricant and possibly magnetic lubricant at the required location on the building element. Again, after this step of "print seal 2" 723 other optional steps may follow which is indicated by the dashed arrow.

Summarizing, the invention provides a building element 101,102, 103, 104, for a bearing. The invention further provides the bearing and a method of producing the building element. The building element comprises a plurality of pockets for securing a position of rolling elements 120 in the bearing. In use, the pockets are configured for at least partially surrounding the rolling elements. The building element further comprises a seal 150, 150A, 1506, 152 configured for at least partially sealing the rolling elements from environmental influence. At least a part of the seal comprises printed material being printed to a first construction comprising the plurality of pockets for producing the building element using an additive manufacturing process.

Alternatively, at least a part of the plurality of pockets comprises printed material being printed to a second construction comprising the seal for producing the building element using the additive manufacturing process.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments.

In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. Use of the verb "comprise" and its conjugations does not exclude the presence of elements or steps other than those stated in a claim. The article "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. The invention may be implemented by means of hardware comprising several distinct elements, and by means of a suitably programmed computer. In the device claim enumerating several means, several of these means may be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

LISTING OF REFERENCE NUMBERS

Building element 101, 102,103, Scanning mirror 420, 520 104, 105 Resin container 430 Seal 150, 152, 154 Re-coating bar 440 Cage 140, 142 Liquid resin 450 Functionally graded layer 190 Feed 455, 555 Rolling element 120 Platform 470, 570, 670 Hollow structure 160A, 160B SLS-tool 500, 501 Bearing 201, 202, 203 Granulate container 530 204 Granulate feed roller 540 Outer ring 110 Granulate material 550 Inner ring 115 FDM-tool 600 Magnetic structure 142, 154 Melter 610 Magnetic lubricant 170 Extrusion nozzle 615 Additive manufacturing tool 400, 401 Positioning construction 620 Print head 405, 505 Filament 630 Print nozzle 415, 515 Filament feeder 640 Laser 410, 510 Liquid plastic 650 Laser beam 412, 512

Claims (15)

1. CLAIMS1. A building element (101, 102, 103, 104, 105) for a bearing (201, 202, 203, 204), the building element (101, 102, 103, 104, 105) comprising a plurality of pockets (140) for securing a position of rolling elements (120) in the bearing (201,202, 203, 204), in use, the pockets (140) being configured for at least partially surrounding the rolling elements (120), the building element (101, 102, 103, 104, 105) further comprising a seal (150, 1 50A, 1 SOB, 152) configured for at least partially sealing the rolling elements (120) of the bearing (201, 202, 203, 204) from environmental influence, wherein at least a part of the seal (150, 150A, 1506, 152) comprises printed material being printed to a first construction comprising the plurality of pockets (140) for constituting the building element (101, 102, 103, 104, 105) using an additive manufacturing process, or wherein at least a part of the plurality of pockets (140) comprises printed material being printed to a second construction comprising the seal (150, 150A, 1 SOB, 152) for constituting the building element (101, 102, 103, 104, 105) using the additive manufacturing process.
2. 2. The building element (101, 102, 103, 104, 105) according to claim 1, wherein at least a part of the first construction or at least a part of the second construction comprises printed material being material printed using the additive manufacturing process.
3. 3. The building element (101, 102, 103, 104, 105) according to claim 1, wherein the seal (150, 150A, 15DB, 152) comprises a first printed material and the plurality of pockets (140) comprises a second material, different from the first printed material, or wherein the seal comprises a first material and the plurality of pockets comprises a second printed material, different from the first material.
4. 4. The building element (101, 102, 103, 104, 105) according to claim 1, wherein the seal (150, 150A, 15DB, 152) comprises a first seal-part (1SOA) and a second seal-part (1506), in use, the first seal-part (150A) being configured for being arranged on an opposite side of the rolling elements (120) compared to the second seal-part (1506).
5. 5. The building element (101, 102, 103, 104, 105) according to any of the previous claims, wherein the building element (101, 102, 103, 104, 105) comprises a hollow structure (160A, 160B).
6. 6. The building element (101, 102, 103, 104, 105) according to any of the previous claims, wherein the building element (101, 102, 103, 104, 105) comprises a predefined distribution of magnetic particles (142, 154).
7. 7. The building element (101, 102, 103, 104, 105) according to any of the claims 3 to 6, wherein the first printed material or the first material is chosen from a list comprising ceramics, polymers, elastomer, and wherein the second printed material or the second material comprises a hydrophobic material.
8. 8. The building element (101, 102, 103, 104, 105) according to any of the claims 3 to 7, wherein an interface between the first printed material and the second printed material comprises a functionally graded interface layer (190), a composition of the functionally graded interface layer (190) being configured to gradually change from the first printed material via a mixture of the first printed material and the second printed material to the second printed material.
9. 9. The building element (101, 102, 103, 104, 105) according to any of the previous claims, wherein at least a part of the building element (101, 102, 103, 104, 105) is configured for being printed around the rolling elements (120) using the additive manufacturing process.
10. 10. A bearing (200) comprising the building element (101, 102, 103, 104, 105) according to any of the previous claims.
11. 11. A method of producing the building element (101, 102, 103, 104, 105) according to any of the claims ito 9, wherein the step of producing the building element (101, 102, 103, 104, 105) comprises a step of: -adding at least a part of the seal (150, i5OA, 1 506, 152) to a first construction comprising the plurality of pockets (140) for producing the building element (101, 102, 103, 104, 105) using an additive manufacturing process, or comprises a step of -adding at least a part of the plurality of pockets (140) to a second construction comprising the seal (150, 150A, 15DB, 152) for producing the building element (101, 102, 103, 104, 105) using the additive manufacturing process.
12. 12. The method according to claim II, wherein the method further comprises the step of: -printing at least a part of the first construction using the additive manufacturing process, or comprises a step of -printing at least a part of the second construction () using the additive manufacturing process.
13. 13. The method according to claim 12, wherein the method is configured for printing the building element (101, 102, 103, 104, 105) around the rolling elements (120) using the additive manufacturing process.
14. 14. The method according to claim 13, wherein the method further comprises a step of: -locally applying a predefined distribution of magnetic particles 0.
15. 15. The method according to any of the claims 11 to 14, wherein the additive manufacturing process is selected from a list comprising stereolithography, selective laser sintering, laminated object manufacturing, fused deposition modeling, selective binding, laser engineering net shaping, photo polymerization and selective electron beam sintering, 3D nesting.