Novel fastening of support assemblies for food applications

Abstract

A support assembly (1) for a live, rotating or sliding shaft (5) has a bearing unit (2), a housing (3) and a cover (10) for a fluid-tight opening (11) of an inner seat (4) of the housing; the cover has an annular coupling portion (14) of a radially external lateral surface (16) facing the housing, provided on the radially inner side with at least one pair of teeth (20) projecting radially towards the inner side of the cover and circumferentially spaced apart from each other; the radially external lateral surface of the housing is provided with an annular groove (22) for receiving the teeth of the cover, which in turn is circumferentially provided with an alternation of recesses (26) and protrusions (27); the annular groove has at least one pair of mechanical stops (32) for the at least one pair of teeth of the cover, which extend in the radial direction up to flush with the lateral surface of the housing with respect to the corresponding recesses.

Description

Technical Field

[0001] This invention relates to a novel fastening system between the housing and the lid of a support assembly for food applications. Specifically, the support assembly is fixed to a machine frame and serves to support movable shafts, such as rotating shafts, by means of suitable bearing units.

[0002] The novel fastening system improves the installation of the cover on the housing, especially improving the sealing performance. Background Technology

[0003] It is well known that in the food industry (also known as "food and beverage ( / catering)", or simply "F&B"), there is a growing interest in developing new machines and machine designs to improve food safety and quality.

[0004] In addition, it is well known that machines used in the food industry have many moving parts supported by rotating or sliding shafts, such as conveyor belts, mixers, and machines for cleaning fresh food.

[0005] All these machines must be cleaned frequently, typically with water already treated with detergent and / or disinfectant, to control the growth of any bacterial colonies that could contaminate food. In particular, these machines must be free of any gaps or other areas where dirt or even wash water can penetrate and stagnate. This is because stagnation of liquid or moisture promotes the potential proliferation of bacteria.

[0006] This problem is particularly severe for support assemblies used for moving shafts, which can be terminal type, shaft-receiving end, or through type. These support assemblies consist of a housing, bearing unit, and cover. The housing is typically annular and has a base or flange for securing to the machine. The bearing unit is located inside the housing and connected to the moving shaft. The cover is typically cup-shaped and press-fitted to the housing.

[0007] For known types of forced mounting, the cover must be fitted onto the outside of the housing via, for example, a snap-fit, or by engaging a groove formed on the radially outer lateral surface of the housing. The cover has multiple teeth in the groove engaging the housing. Within the groove of the housing, there are protrusions in the form of rising and falling ramps for locking the teeth of the cover in the circumferential direction.

[0008] In other words, during the installation process, the cover is positioned on the housing, and the teeth of the cover reach the groove of the housing through the corresponding opening on the outer surface of the housing. Then, in a typical bayonet coupling, the cover is rotated and the teeth of the cover move along the groove of the housing past the corresponding protrusion. The cover is thus locked, although it can still be rotated through a circumferential arc until the next protrusion. Two consecutive protrusions are angularly spaced so that the teeth of the cover are not located near an opening on the outer surface of the housing through which the teeth of the cover could disengage, thus causing the cover to be demounted.

[0009] However, this installation process has certain uncertainties and insecurities. First, during installation, the angular positioning of the cap's teeth within the housing's groove is not precisely defined. Users may become confused and over-rotate the cap until the next protrusion also encounters and passes the teeth, leading to inevitable and undesirable disassembly / removal of the cap. Second, while two consecutive protrusions form a barrier to prevent accidental cap disassembly, this does not guarantee that the cap's teeth will not ride over the protrusions due to excessive vibrations caused by specific applications, in which case undesirable cap disassembly will also occur. Finally, even without accidental disassembly, the fact that the cap still has a certain degree of angular freedom relative to the housing poses a problem for the safety of the fluid seal.

[0010] Therefore, it is necessary to define a support component that provides a novel design solution that can solve or at least mitigate the aforementioned drawbacks. Summary of the Invention

[0011] In order to fundamentally solve the above-mentioned technical problems, one object of the present invention is to define a novel support assembly for food applications, particularly a support assembly for a rotating shaft and a corresponding bearing unit fixed to a machine frame.

[0012] To this end, according to one aspect of the invention, in order to improve the operation of mounting the cover onto the housing and the fluid sealing performance of the entire support assembly, the cover is provided with mechanical stops for the teeth of the cover and with ramp-shaped protrusions having an improved shape (especially an asymmetrical shape) to facilitate installation and make accidental removal of the cover from the housing more difficult.

[0013] Advantageously, along the groove of the outer shell housing the teeth of the cover, there are four mechanical stops and eight protrusions in the circumferential direction. In practice, two protrusions will be positioned circumferentially on opposite sides of each mechanical stop, and the ramp will have a greater inclination on the side closer to the mechanical stop.

[0014] Therefore, according to the present invention, a support component for food applications is provided, having the features set forth in the independent claims appended to this specification.

[0015] Further preferred and / or particularly advantageous embodiments of the invention are described in accordance with the features set forth in the appended dependent claims. Attached Figure Description

[0016] The invention will now be described with reference to the accompanying drawings, which illustrate non-limiting examples of embodiments of the invention, wherein: - Figure 1 A cross-section of a support assembly according to an embodiment of the present invention is shown. - Figure 2 It shows Figure 1 A front view of the housing of the supporting components. - Figure 3 Shown at magnified scale Figure 2 Details - Figure 4 Shown at a larger scale Figure 2 Details - Figure 5 It shows Figure 1 A front view of the cover of the supporting components, and - Figure 6 Shown at magnified scale Figure 5 Details. Detailed Implementation

[0017] By way of non-limiting example only and with reference to the above figures, the number 1 indicates the whole of the support assembly for a movable axis, a rotating axis or a sliding axis (the axis is not shown for simplicity).

[0018] The support assembly 1 also includes a bearing unit 2 and a housing 3. For example, the bearing unit 2 is a rolling bearing of a known type, capable of accommodating the movable shaft 5, such as a rotating shaft, in a known manner. The housing 3 has a through seat 4 in which the bearing unit 2 is stably and knownly accommodated.

[0019] Support component 1 is specifically designed for mounting on machinery used in the food industry. For this purpose, housing 3 (in...) Figure 2 (As shown in the front view) It has a type for fixed mounting on a frame of a known machine (particularly for machines used in the food industry, not shown for simplicity).

[0020] The housing 3 has an integral annular shape and is designed to accommodate the bearing unit 2 therein in a known manner, particularly in the through seat 4. The housing also includes a base or flange 8 for fixing to the frame of the machine; the seat 4 has a total axis of symmetry X, which is also the axis of symmetry of the housing 3.

[0021] Obviously, Figure 2 The embodiment of the housing 3 shown is only one of the possible embodiments; for example, the square base or flange 8 in the illustrated example may have other symmetrical or asymmetrical shapes.

[0022] In any case, the support assembly 1 also includes a cover 10 for the opening 11 of the through seat 4 of the fluid-sealed housing 3.

[0023] The cover 10 for the housing 3 is generally bowl-shaped and includes a bottom wall 12, an annular side wall 13 extending laterally relative to the bottom wall 12, and a connecting portion 14 facing the housing 3.

[0024] The connecting portion 14 is annular and designed to be laterally connected to the housing 3 on the outside of the housing during use. In particular, the connecting portion 14 is shaped as a socket joint and is radially and laterally connected to the outer side of the radially outer lateral surface 16 of the housing 3.

[0025] Lateral surface 16 and connecting portion 14 are defined by a solid of revolution and share a common axis of symmetry, which in the illustrated example is the same as the axis of symmetry X of cover 10. Figure 1 ) overlaps and is also the axis of symmetry between the outer shell 3 and the through seat 4.

[0026] The connecting portion 14 of the cover 10 is provided with at least a pair of teeth 20 on its radially inner side. These teeth 20 project radially toward the inner side of the cover 10 and are spaced apart from each other in the circumferential direction. Each tooth extends on a defined circumferential portion of the connecting portion. Figure 5 In the non-limiting example shown, the number of teeth 20 is four and they are spaced apart from each other at 90°.

[0027] In combination with the presence of teeth 20 on the connecting cover 10, the radially outer lateral surface 16 of the housing 3 is provided with an annular seat 21 for receiving the teeth 20 of the cover 10. The annular seat 21 includes an annular groove 22, which is configured to be axially spaced relative to the front edge 23 of the defining opening 11 of the housing 3 and is provided with axial grooves 24, the number of which is equal to the number of teeth 20 present on the cover 10, and these grooves 24 radially interrupt at least a portion of the front edge 23 of the housing 3.

[0028] The bottom wall 25 of the annular groove 22 is provided with a plurality of alternating recesses 26 and protrusions 27 in the circumferential direction, the protrusions 27 being configured to be offset (or staggered) relative to the axial groove 24 in the circumferential direction.

[0029] The radial depth of the axial groove 24 is equal to the radial depth of the annular groove 22 at the position of the axial groove 24, so that the corresponding bottom wall of the axial groove is flush with the bottom wall 25 of the radial groove 22.

[0030] In the preferred example of the illustrated embodiment, the cover 10 has two pairs of teeth 20 configured to be symmetrically spaced and offset by 90° in the circumferential direction. In this case, the radially outer lateral surface 16 of the outer casing 3 has two pairs of axial grooves 24 symmetrically spaced and offset by 90° in the circumferential direction. The bottom wall 25 of the annular groove 22 has a plurality of circumferential sectors of equal angular size, including eight recesses 26 and eight protrusions. Four of the eight recesses 26 are axially defined by edges 23, and the other four are free and disposed at the location of the groove 24. The recesses 26 are defined by curved surfaces flush with the bottom wall 25 of the annular groove 22, while the protrusions 27 protrude radially relative to the bottom wall 25 of the annular groove 22 and are alternately arranged with the recesses 26.

[0031] According to one aspect of the invention, the annular groove 22 ( Figure 3 and Figure 4 The protrusions 27 of the annular groove 22 each include a first circumferential portion 29 with a flat surface that rises (or is raised) relative to the bottom wall 25 of the annular groove 22, and second and third circumferential portions 30 and 31 with flat surfaces, respectively. The second and third circumferential portions 30 and 31 are located on either side of the first circumferential portion 29 and form two inclined planes connecting the first surface portion 29 to the bottom wall 25 of the annular groove 22. These two inclined planes are characterized by having different sloping angles, thus the protrusions 27 take the form of asymmetrical slopes. Specifically, as... Figure 3 and Figure 4 As shown, the inclination of the second circumferential portion 30, which has a flat surface (in other words, it is less steep), is less than the inclination of the third circumferential portion 31, which has a flat surface (it is steeper). The importance of having different inclinations will be explained more fully below.

[0032] According to another aspect of the invention, the annular groove 22 has at least one pair of mechanical stops 32, which are further protrusions relative to the bottom wall 25 of the annular groove 22. The protrusions 32 project radially relative to the corresponding recesses 26 and extend to be flush with the lateral surface 16 of the housing 3. The introduction of this feature forms end stops for the teeth 20 of the cover 10 during the installation process; therefore, the number of mechanical stops 32 is equal to the number of teeth 20 of the cover 10.

[0033] In the described non-limiting example, the number of mechanical stops 32 is four, equal to the number of teeth 20 of the cover 10. Advantageously, according to the non-limiting example, in the circumferential direction, along the groove of the outer shell receiving the teeth of the cover, the number of mechanical stops 32 is four, while the number of asymmetrical protrusions 27 is eight; in other words, the number of asymmetrical protrusions 27 is twice the number of mechanical stops 32. In fact, two protrusions 27 will be positioned circumferentially on opposite sides of each mechanical stop 32, and a third circumferential portion 31 with a flat surface (the portion with a larger inclination) will be circumferentially closer to the mechanical stop 32 on one side.

[0034] The presence of the mechanical stop 32 and the protrusion 27 with asymmetrical ramps allows for a new process to be defined for mounting the cover 10 onto the housing 3, making it simpler for the operator and, most importantly, preventing accidental disassembly.

[0035] In fact, the asymmetrical inclination of the protrusion 27 is related to the different forces required to overcome the protrusion. The smaller the inclination, the easier it will be to install the cover 10 and ensure that the cover 10 is inserted into the final tightened position. In fact, compared with known installation processes (where the groove of the housing is provided with a protrusion with a symmetrical ramp), in this case, the process always requires the teeth 20 to slide along the groove 24 in any rotational direction using a typical bayonet connection. During installation, the teeth 20 of the cover 10 encounter the second circumferential portion 30 with a flat surface (with a smaller inclination), and the sliding of the teeth over the protrusion 27 occurs with a small force. When the teeth 20 of the cover 10 have passed the protrusion 27, the teeth 20 of the cover 10 will be finally locked in the recess 26 by the corresponding mechanical stop 32 and will occupy a well-defined position.

[0036] Therefore, the cover can only be removed in the opposite rotational direction to its installation. In this case, the teeth 20 of the cover 10 will encounter the third circumferential portion 31 (with a large inclination) with a flat surface. Obviously, the greater the inclination, the greater the force required to remove the cover, thus significantly hindering the sliding of the teeth 20 above the protrusion 27 and preventing accidental removal.

[0037] Taking into account the size of the teeth 20 of the cover 10 and the circumferential space available between the two consecutive protrusions 27 in the annular groove 22, the design of the mechanical stop 32 has been optimized to have a sufficiently large thickness S in the circumferential direction.

[0038] The thickness S can be calculated using the following formula: S = A - 2xB - G.

[0039] in: A ( Figure 2() is the circumferential distance between two consecutive protrusions 27 in the annular groove 22. B ( Figure 6 () is the circumferential width of the 20 teeth of the cover 10. G is the circumferential clearance between the mechanical stop 32, the tooth 20, and the protrusion 27, which allows for manufacturing tolerances of the parts.

[0040] The radial height H of the mechanical stop 32 is determined taking into account the fact that the protrusion projects radially relative to the bottom wall 25 of the annular groove 22 and extends to be flush with the lateral surface 16 of the housing 3. Therefore, H = (D le –D h ) / 2 in: D le ( Figure 2 () is the diameter of the side surface 16 of the outer casing 3. D h ( Figure 2 ) is the diameter of the bottom wall 25 of the annular groove 22.

[0041] The second circumferential portion 30 and the third circumferential portion 31 of the protrusion 27, which have flat surfaces (in other words, two inclined planes with different inclinations), are designed by subdividing the circumferential length W of the entire protrusion 27 so that the inclination of the second circumferential portion 30 (the portion used during installation) is less than the inclination of the third circumferential portion 31 (the portion used during disassembly). The circumferential length of the second circumferential portion 30 plus half the circumferential length of the first circumferential portion 29 (the raised ( / protruding) flat surface) equals W. m Furthermore, the circumferential length of the third circumferential portion 31 plus half the circumferential length of the first circumferential portion 29 equals W. d Experiments have shown that optimal performance is achieved when the following conditions are met: W m = 0.6 W W d = 0.4 W In summary, the introduction of the mechanical stop simplifies installation and improves sealing performance due to the well-defined mechanical stop where the teeth of the cover meet. This also results in better protection against accidental disassembly, which could occur in a particular application due to excessive vibration.

[0042] The second feature (i.e., the asymmetrical shape of the protrusions) also provides benefits in terms of both installation and accidental disassembly. During installation, the teeth of the cap must overcome a smaller angle of inclination, making operation easier. However, the larger angle encountered by the teeth of the cap in the disassembly direction makes accidental disassembly much less likely, thereby improving the sealing performance of the support assembly.

[0043] In addition to the embodiments of the present invention described above, it should be understood that many other variations exist. It should also be understood that these embodiments are described by way of example only and do not limit the purpose of the invention, its application, or its possible constructions. Rather, while the above description enables those skilled in the art to practice the invention according to at least one example of its embodiments, it should be understood that many variations of the described components are possible without departing from the purpose of the invention, which is defined by the appended claims, and interpreted literally and / or according to their legal equivalents.

Claims

1. A support assembly (1) for a movable shaft, a rotating shaft or a sliding shaft (5), the support assembly (1) comprising a bearing unit (2) adapted to receive the movable shaft, a housing (3) and a cover (10) for fluid sealing an opening (11) of an inner seat (4) of the housing (3). - The cover (10) includes an annular connecting portion (14) facing the radially outer lateral surface (16) of the outer shell (3), the annular connecting portion (14) having at least one pair of teeth (20) on the radially inner side, the at least one pair of teeth (20) protruding radially toward the inner side of the cover and spaced apart from each other in the circumferential direction. - The radially outer lateral surface (16) of the outer shell (3) is provided with an annular seat (21) for receiving the teeth (20) of the cover. - The annular seat (21) includes an annular groove (22) configured to be spaced axially relative to the front edge (23) of the housing (3) defining the opening (11) and connected to an axial groove (24), the number of which is equal to the number of teeth (20) present on the cover, and the axial groove (24) interrupts at least a portion of the front edge (23) radially; in the bottom wall (25) of the annular groove (22) having alternating recesses (26) and protrusions (27) in the circumferential direction, the protrusions are configured to be offset circumferentially relative to the axial groove (24); The support assembly (1) is characterized in that the annular groove (22) has at least one pair of mechanical stops (32) for at least one pair of teeth (20) of the cover (10), the mechanical stops (32) extending in the radial direction relative to the corresponding recess (26) to be flush with the lateral surface (16) of the housing (3).

2. The support component (1) according to claim 1, characterized in that, The protrusions (27) of the annular groove (22) include a first circumferential portion (29) with a flat surface that protrudes relative to the bottom wall (25) of the annular groove (22), and a second circumferential portion (30) and a third circumferential portion (31) with flat surfaces. The second circumferential portion (30) and the third circumferential portion (31) are on both sides of the first circumferential portion (29) and form two inclined planes that connect the first circumferential portion (29) with the surface to the bottom wall (25) of the annular groove (22). The inclination of the second circumferential portion (30) is less than that of the third circumferential portion (31), thereby making the protrusions (27) have an asymmetrical shape.

3. The support component (1) according to claim 1, characterized in that, The number of mechanical stop parts (32) is equal to the number of teeth (20) of the cover (10).

4. The support component (1) according to claim 2 or 3, characterized in that, The number of asymmetric protrusions (27) is twice the number of mechanical stops (32).

5. The support component (1) according to claim 4, characterized in that, Two asymmetrical protrusions (27) are configured to originate from opposite segments relative to each mechanical stop (32) in the circumferential direction, and the third circumferential portion (31) having a flat surface faces the mechanical stop (32) in the circumferential direction.

6. The support component (1) according to claim 4, characterized in that, The number of mechanical stop parts (32) is four, and the number of asymmetrical protrusions (27) is eight.

7. The support component (1) according to any one of claims 1 to 3, characterized in that, The thickness (S) of the mechanical stop (32) in the circumferential direction is equal to: S = A - 2xB - G: in: A is the circumferential distance between two consecutive protrusions (27) on the annular groove (22). B is the circumferential width of the teeth (20) of the cover (10). G is the circumferential clearance between the mechanical stop (32), the tooth (20), and the protrusion (27).

8. The support component (1) according to any one of claims 1 to 3, characterized in that, The height (H) of the mechanical stop (32) in the radial direction is equal to: H = (D le –D h ) / 2 in: D le It is the diameter of the lateral surface (16) of the outer shell (3). D h It is the diameter of the bottom wall (25) of the annular groove (22).

9. The support component (1) according to claim 2 or 3, characterized in that, W is the circumferential length of the asymmetric protrusion (27), and the circumferential length (W) of the second circumferential portion (30) of the protrusion (27) m ) equals 0.6 x W.

10. The support component (1) according to claim 9, characterized in that, The circumferential length (W) of the third circumferential portion (31) of the protrusion (27) d ) equals 0.4 x W.

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