ROLLER OF A SUPPORT ARRANGEMENT FOR A ROTARY MILKING PLATFORM

Abstract

A roller of a support arrangement for a rotary milking platform, where the support arrangement includes a first rail member fixedly connected to the rotary platform, a second rail member stationarily arranged in a position below the platform, and a plurality of rollers arranged in a vertical space between the first rail member and the second rail member. Each roller includes a peripheral surface comprising a contact surface to be in contact with a contact portion of the first rail member and a contact portion of the second rail member. The peripheral surface of the roller includes two beveled surfaces arranged at opposite sides of the contact surface which are located at a smaller distance from a rotary axis of the roller than the contact surface.

Claims

1. A roller of a support arrangement for a rotary milking platform, wherein the support arrangement comprises a first rail member (4) fixedly connected to the rotary platform (1), a second rail member (5) stationarily arranged in a position below the platform (1), and a plurality of rollers arranged in a vertical space between the first rail member (4) and the second rail member (5), wherein said roller (8) is one of said plurality of rollers, and comprises a peripheral surface (8c) comprising a contact surface (8c.sub.1) to be in contact with a contact portion (4d) of the first rail member (4) and a contact portion (5d) of the second rail member (5), wherein the peripheral surface (8c) of the roller (8) comprises two beveled surfaces (8c.sub.2) arranged at opposite sides of the contact surface (8c), the two beveled surfaces (8c2) being located at a smaller distance (d) from a rotary axis (8g) of the roller (8) than the contact surface (8c.sub.1).

2. The roller according to claim 1, further comprising a transition area between the contact surface (8c1) and each of the two beveled surfaces (8c2), wherein an angle in each transition area between the contact surface (8c.sub.1) and each of the two beveled surfaces (8c.sub.2) is at least 135 degrees.

3. The roller according to claim 1, wherein the contact surface (8c.sub.1) is located at a longest distance (d.sub.max) from the rotation axis (8g) of the roller (8) in a midway position between the two beveled surfaces (8c.sub.2).

4. The roller according to claim 1, wherein the contact surface (8c.sub.1) has a convex shape.

5. The roller according to claim 4, wherein the two beveled surfaces (8c.sub.2) have a convex shape.

6. The roller according to claim 5, wherein the two beveled surfaces (8c.sub.2) have a smaller radius of curvature than a radius of curvature of the convex contact surface (8c.sub.1).

7. The roller according to claim 1, wherein all of the contact surface (8c.sub.1) of the peripheral surface (8c) is located at a same distance from the rotation axis (8g) of the roller (8).

8. The roller according to claim 7, wherein each of the two beveled surfaces (8c.sub.2) is located at a distance (d) from the rotation axis (8g) which increases linearly from an outer end to an inner end located adjacent to the contact surface (8c.sub.1).

9. The roller according to claim 1, further comprising flange portions (8a, 8b), each flange portion having a radial outer surface located at a longer distance from the rotation axis (8g) than the peripheral surface (8c).

10. The roller according to claim 9, wherein each of the two beveled surfaces (8c.sub.2) of the roller (8) is connected to the flange portions (8a, 8b) via a curved connection portion (8c.sub.4).

11. The roller according to claim 1, further comprising a center hole (8f) defining the rotation axis (8g) of the roller (8).

12. The roller according to claim 11, the center hole (8f) is configured to receive a shaft (10, 13) connecting the roller (8) to two support elements (9a, 9b, 12a) arranged on opposite sides of the roller (8).

13. The roller according to claim 1, wherein the roller (8) is a material body in one piece.

14. The roller according to claim 13, wherein the roller (8) is comprised of a nylon material.

15. The roller according to claim 5, wherein the two beveled surfaces (8c.sub.2) have a more curved shape than a curved shape of the contact surface (8c.sub.1).

16. The roller according to claim 1, further comprising: a center hole (8f) defining the rotation axis (8g) of the roller (8); a transition area between the contact surface (8c1) and each of the two beveled surfaces (8c2); and two flange portions (8a, 8b), each flange portion having a radial outer surface located at a longer distance from the rotation axis (8g) than the peripheral surface (8c), wherein an angle in each transition area between the contact surface (8c.sub.1) and each of the two beveled surfaces (8c.sub.2) is at least 135 degrees, wherein the contact surface (8c.sub.1) is located at a longest distance (d.sub.max) from the rotation axis (8g) of the roller (8) in a midway position between the two beveled surfaces (8c.sub.2), wherein the contact surface (8c.sub.1) has a convex shape, wherein the two beveled surfaces (8c.sub.2) have a convex shape, wherein the two beveled surfaces (8c.sub.2) have a smaller radius of curvature than a radius of curvature of the convex contact surface (8c.sub.1), wherein each of the two beveled surfaces (8c.sub.2) of the roller (8) is connected to the flange portions (8a, 8b) via a curved connection portion (8c.sub.4), and the center hole (8f) is configured to receive a shaft (10, 13) connecting the roller (8) to two support elements (9a, 9b, 12a) arranged on opposite sides of the roller (8).

17. The roller according to claim 1, further comprising: a center hole (8f) defining the rotation axis (8g) of the roller (8); a transition area between the contact surface (8c1) and each of the two beveled surfaces (8c2); and two flange portions (8a, 8b), each flange portion having a radial outer surface located at a longer distance from the rotation axis (8g) than the peripheral surface (8c), a transition area between the contact surface (8c1) and each of the two beveled surfaces (8c2), wherein an angle in each transition area between the contact surface (8c.sub.1) and each of the two beveled surfaces (8c.sub.2) is at least 135 degrees, wherein the contact surface (8c.sub.1) is located at a longest distance (d.sub.max) from the rotation axis (8g) of the roller (8) in a midway position between the two beveled surfaces (8c.sub.2), wherein all of the contact surface (8c.sub.1) of the peripheral surface (8c) is located at a same distance from the rotation axis (8g) of the roller (8), wherein each of the two beveled surfaces (8c.sub.2) is located at a distance (d) from the rotation axis (8g) which increases linearly from an outer end to an inner end located adjacent to the contact surface (8c.sub.1), wherein each of the two beveled surfaces (8c.sub.2) of the roller (8) is connected to the flange portions (8a, 8b) via a curved connection portion (8c.sub.4), and the center hole (8f) is configured to receive a shaft (10, 13) connecting the roller (8) to two support elements (9a, 9b, 12a) arranged on opposite sides of the roller (8).

18. The roller according to claim 1, in combination with the support arrangement for the rotary milking platform, wherein the first rail member (4) is fixedly connected to the rotary platform (1), the second rail member (5) is stationarily arranged in the position below the platform (1), and the plurality of rollers are arranged in the vertical space between the first rail member (4) and the second rail member (5), wherein said roller (8) is one of said plurality of rollers.

19. The roller according to claim 16, in combination with the support arrangement for the rotary milking platform, wherein the first rail member (4) is fixedly connected to the rotary platform (1), the second rail member (5) is stationarily arranged in the position below the platform (1), and the plurality of rollers are arranged in the vertical space between the first rail member (4) and the second rail member (5), wherein said roller (8) is one of said plurality of rollers.

20. The roller according to claim 17, in combination with the support arrangement for the rotary milking platform, wherein the first rail member (4) is fixedly connected to the rotary platform (1), the second rail member (5) is stationarily arranged in the position below the platform (1), and the plurality of rollers are arranged in the vertical space between the first rail member (4) and the second rail member (5), wherein said roller (8) is one of said plurality of rollers.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The present invention is now to be explained more closely by means of preferred embodiments, which are disclosed as examples, and with reference to the attached drawings.

[0015] FIG. 1 shows a view of a rotary milking platform from below,

[0016] FIG. 2 shows a perspective view of a part of a support arrangement for a platform according to the invention,

[0017] FIG. 3 shows a sectional view of the support arrangement in FIG. 2 along the plane A-A,

[0018] FIG. 4 shows the peripheral surface of the roller in FIG. 3 in more detail,

[0019] FIG. 5 shows a support structure for a single roller according to the invention,

[0020] FIG. 6 shows the roller In FIG. 6 in contact with a rail member and

[0021] FIG. 7 shows a support structure for two side rollers.

BRIEF DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0022] FIG. 1 shows a rotary milking platform 1 for milking of cows, from below. The platform 1 is rotatably arranged around a vertical axis 2. The platform 1 has an outer edge portion 1a and an inner edge portion 1b. The platform 1 is driven by a drive unit 3. The drive unit 3 comprises an electric motor 3a, an integrated reduction gear box 3b and a drive wheel 3c mounted in contact with a lower surface of the platform 1. The drive wheel 3c may be a pneumatic tyre. Such a drive wheel 3 makes the drive unit shock resistant as the tyre provides a cushioning effect. The drive unit 3 has a smooth start and stop action. The drive unit 3 may be infinitely variable in speed in either a clockwise or counter-clockwise direction. A first circular rail member 4 is fixedly attached to a lower surface of the platform 1. The first circular rail member 4 may by attached to the platform by welding. The first circular rail member 4 may be directly connected to a lower surface of the platform 1 or indirectly via a suitable connection.

[0023] FIG. 2 shows a part of a support arrangement for the platform 1. The first circular rail member 4 comprises a beam with an I-shaped cross section. The first circular rail member 4 comprises an upper horizontal portion 4a, a lower horizontal portion 4b and a vertical portion 4c connecting the upper horizontal portion 4a and the lower horizontal portion 4b. The first circular rail member 4 comprises an elongated contact portion 4d mounted on a lower surface of the lower horizontal portion 4b. The contact portion 4d may be welded to the lower horizontal portion 4b. The support arrangement comprises a second circular rail member 5 arranged on a stationary surface 6 below the rotary platform 1 by means of a suitable number of support legs 7. The second rail member 5 also comprises a beam with an I-shaped cross section. The second rail member 5 comprises an upper horizontal portion 5a, a lower horizontal portion 5b and a vertical portion 5c connecting the upper horizontal portion 5a and the lower horizontal portion 5b. The second rail member 5 also comprises a contact portion 5d mounted on an upper surface of the upper horizontal portion 5a. The contact portion 5d may be welded to the upper horizontal portion 5a. The second rail member 5 is arranged vertically below the first circular rail member 4.

[0024] The support arrangement comprises a number of rollers 8 arranged in a vertical space between the first circular rail member 4 and the second circular rail member 5. Each roller 8 is provided with a first side flange 8a, a second side flange 8b and a peripheral surface 8c arranged between the side flanges 8a, 8b. A first elongated connection element 9a and a second elongated connection element 9b are arranged on opposite sides on the rollers 8. The connection elements 9a, 9b have a corresponding circular extension as the rail members 4, 5, either as circular elements or each as a number of interconnected elements which each extends between only a few of the rollers. The connection elements 9a, 9b are provided with holes at constant intervals. The rollers 8 are rotatably arranged around bolts 10 arranged in said holes. The distance between two adjacent holes of the elongated connection elements 9a, 9b defines the distance between two adjacent rollers 8.

[0025] FIG. 3 shows a cross section view of the support arrangement and one of the rollers 8 in FIG. 2. The roller 8 comprises a first side surface 8d and a second side surface 8e. The roller 8 comprises a centrally arranged hole 8f extending between the side surfaces 8d, 8e. The centre hole 8f defines a rotation axis 8g of the roller 8. The peripheral surface 8c of the roller 8 is in contact with a lower flat surface 4d.sub.1 of the contact portion 4d of the first rail member 4 and an upper flat surface 5d.sub.1 of the contact portion 5d of the second rail member 5. The peripheral surface 8c of the roller 8 is located at a smaller radial distance from the rotation axis 8g than a peripheral surface of the first side flange 8a and a peripheral surface of the second side flange 8b. Thus, at least a part of the contact portions 4d, 5d of the rail members 4, 5 are located in a space between the side flanges 8a, 8b of the roller 8.

[0026] During rotation of the platform 1, the side flanges 8a, 8b prevent side movements of the first rail member 4 and the platform 1 in relation to the rolling member 8 and the stationary rail member 5. The side flanges 8a, 8b position the first rail member 4 vertically above the second rail member 5 and the platform 1 in a horizontal plane such that it rotates around the fixed vertical axis 2. The roller 8 is rotatably arranged around a non-rotatable shaft in the form of the centre bolt 10. The centre bolt 10 has a head arranged outside the first elongated element 9a. The centre bolt 10 has an elongated body extending through a hole in the first elongated element 9a, the centre hole 8f of the roller 8 and a hole in the second elongated element 9b. The centre bolt 10 is fastened by means of a nut 11 arranged on the outside of the second elongated element 9b.

[0027] FIG. 4 shows the peripheral surface 8c of the roller 8 in an axial plane through the roller 8. The peripheral surface 8c comprises a contact surface 8c.sub.1. The contact surface 8c.sub.1 is surrounded by two beveled surfaces 8c.sub.2. The contact surface 8c.sub.1 has a larger width than the two beveled surfaces 8c.sub.2. The contact surface 8c.sub.1 is located at a longer distance d from a rotation axis 8g of the roller 8 than the two beveled surfaces 8c.sub.2. The contact surface 8c.sub.1 has a convex shape. The contact surface 8c.sub.1 is located at the longest distance from the rotation axis 8g of the roller 8 in a midway position 8c.sub.3 between the two beveled surfaces 8c.sub.2. Each beveled surface 8c.sub.2 also has a convex shape. The convex beveled surfaces 8c.sub.2 have a smaller radius of curvature than the convex contact surface 8c.sub.1. Thus, the beveled surfaces 8c.sub.2 have a more curved shape than the contact surface 8c.sub.1. However, the beveled surfaces 8c.sub.2 are shaped such that they are located at a successively longer distance d from the rotation axis 8g from an outer end of the beveled surface 8c.sub.2 to an inner end of the beveled surface 8c.sub.1 located adjacent to the contact surface 8c.sub.1. The roller 8 comprises flange portions 8a, 8b having an outer surface located at a longer distance from the rotation axis 8g than the peripheral surface 8c. Each beveled surface 8c.sub.2 is connected to the flange portions 8a, 8b via concave curved connection portions 8c.sub.4.

[0028] The contact surface 8c.sub.1 of the roller 8 is in contact with a flat surface 4d.sub.1, 5d.sub.1 of the contact portions 4d, 5d. The convex shape of the contact surface 8c.sub.1 allows a small misalignment of the roller 8 in relation to the flat contact surfaces 4d.sub.1, 5d.sub.1 of the contact portions 4, 5. Furthermore, the parts of the contact surface 8c.sub.1 located adjacent to the beveled surfaces 8c.sub.2 will be less loaded than a more central part of the contact surface 8c.sub.1. Due to the convex curved shape of the beveled surfaces 8c.sub.2, it is possible to provide a smooth transition area between the beveled surfaces 8c.sub.2 and the contact surface 8c.sub.1. Such a transition area has substantially no edge portions in which stress concentrations can be created.

[0029] Consequently, the convex beveled surfaces 8c.sub.2 prevents stress concentrations in the transition area between the contact surface 8c.sub.1 and the beveled surfaces 8c.sub.2. Furthermore, the curved portions 8c.sub.4 between the flange portions 8a, 8b and the beveled surfaces 8c.sub.2 reduces stress concentrations in an area located between the vertical surfaces of the flange portions 8a, 8b and the beveled surfaces 8c.sub.2. Consequently, the peripheral surface 8c of the roller 8 has a design without sharp edge portions and substantially without stress concentrations.

[0030] FIGS. 5 and 6 shows a stationary support structure 12 to be arranged in a position under a rotary platform 1. The support structure 12 supports one roller 8. The roller 8 is rotatably arranged around a centre shaft 13 and a horizontal axis 8g. The roller 8 comprises a contact surface 8c.sub.1 having a flat shape in an axial direction. Thus, the entire contact surface 8c.sub.1 is located at the same distance from the rotation axis 8g of the roller 8. The contact surface 8c.sub.1 is located between two beveled surfaces 8c.sub.2. In this case, each beveled surface 8c.sub.2 is located at a distance d from the rotation axis 8g which increases linearly from an outer end to an inner end located adjacent to the contact surface 8c.sub.1. Such a roller 8 has a simple design and it is easy to manufacture.

[0031] The beveled surfaces 8c.sub.2 connect the contact surface 8c.sub.1 and the side surfaces 8d, 8e of the roller 8. In this case, the transition areas between the contact surface 8c.sub.1 and the beveled surfaces 8c.sub.2 comprise an edge portion. A conventional cylindrical roller without beveled surfaces 8c.sub.2 has transition areas between the contact surface 8c.sub.1 and the side surfaces 8d, 8e in which said surfaces form an angle of 90 degrees in relation to each other. However, the edge portions of the present roller 8 include a larger angle than 90 degrees in the transition area between the contact surface 8c.sub.1 and the beveled surface 8c.sub.2. Since the stress concentration is higher in a sharp edge portion than in a less sharp edge portion, the stress concentration will be lesser in the transition areas of the present roller 8 than in the corresponding transition areas of a conventional cylindrical roller. Due to the less stress concentration in the present roller 8, it provides advantages regarding strength and life time in relation to a conventional roller.

[0032] FIG. 7 shows a stationary support structure 14 to be arranged in a position under a rotary platform 1. The support structure 14 supports two side rollers 8i. Each side roller 8i is rotatably arranged around a vertical axis 8h. The side rollers 8i are configured to come in contact with a vertical surface of a rail member fixedly connected to the platform 1. The object of the side rollers 8i is to prevent side moments of the platform 1 such that it rotates around a fixed vertical axis. The side rollers 8i constitute a complement to the support rollers 8 shown in FIG. 5 and FIG. 6, which have no flange portions. The load on the side rollers 8is much smaller than the load on the support rollers 8. Therefore, it is not necessary to provide the contact surfaces of the side rollers 8i with beveled surfaces.

[0033] The above mentioned rollers 8 may be manufactured of a material body in one piece. The material may be a nylon material. Such a material has suitable properties for supporting a heavy rotary platform. However, it is possible to manufacture the rollers 8 of other materials. Furthermore, the rollers 8 may comprise different materials in different parts.

[0034] The invention is not restricted to the described embodiment in the figures, but may be varied freely within the scope of the claims. A roller may, for example, comprise a flat contact surface 8c.sub.1 surrounded by two convex beveled surfaces 8c.sub.2. On the other hand, the roller may comprise a convex contact surface 8c.sub.1 surrounded by beveled surfaces located at a distance d from the rotation axis 8g which increases linearly from an outer end to an inner end located adjacent to the contact surface 8c.sub.1.