FORWARD SUPPORT ROTATING ASSEMBLY FOR A SNAPPING ROLL OF A SNAPPING UNIT OF A COMBINE HARVESTING MACHINE

Abstract

A forward support rotating assembly for a snapping roll of a snapping unit of a combine harvesting machine is provided. The assembly comprises:—a frontally open axial seat provided in the snapping roll and having an inner circumferential abutment edge;—a cylindrical support pin extending axially in the seat and being integral with a support bracket for fixing the assembly to a snapping unit;—a sliding element interposed between the support pin and the seat;—a labyrinth seal element comprising a cylindrical ferrule, which has a labyrinth cross-section and in which there is defined an inner annular seat, and an annular packing seal received in the annular seat and radially contacting the outer surface of the cylindrical support pin, wherein the labyrinth seal element frontally seals the seat with respect to the outside.

Claims

1. Forward support rotating assembly (11) for a snapping roll (13) of a snapping unit (23) of a combine harvesting machine, comprising: a frontally open axial seat (15) provided in the snapping roll (13) and having an inner circumferential abutment edge (17); a cylindrical support pin (19) extending axially in the seat (15) and being integral with a support bracket (21) for fixing the assembly (11) to a snapping unit (23); a sliding element (25) interposed between the support pin (19) and the seat (15); a labyrinth seal element (37) comprising a cylindrical ferrule (39), which has a labyrinth cross-section and in which there is defined an inner annular seat (39a), and an annular packing seal (41) received in the annular seat (39a) and radially contacting the outer surface (29) of the cylindrical support pin (19), wherein the labyrinth seal element (37) frontally seals the seat (15) with respect to the outside.

2. Assembly according to claim 1, comprising an elastic annular seal (35) between the cylindrical support pin (19) and the inner wall (27) of the seat (15).

3. Assembly according to claim 1, wherein the sliding element (25) is a ball bearing axially contacting the abutment edge (17).

4. Assembly according to claim 3, comprising an elastic ring (33) adapted for locking the bearing (25) and housed in a radial annular slot (31) formed in the inner wall (27) of the seat (15) and wherein the bearing (25) axially contacts the elastic ring (33).

5. Assembly according to claim 2, wherein the elastic annular seal (35) is a double-lip gasket having a U-shaped cross-section in which there are defined an outer annular portion (35a), an inner annular portion (35b) having a double lip (35c,35d) and extending radially toward the inside, and a transverse connecting portion (35e) between the outer portion (35a) and the inner portion (35b).

6. Assembly according to claim 5, wherein the double lip comprises two corresponding elastic flaps (35c,35d) radially diverging at an angle comprised between 60° and 120°.

7. Assembly according to claim 1, wherein the cylindrical ferrule (39) has a substantially F-shaped cross-section in which there is defined an outer annular portion (39b) and two parallel inner radial portions between which the seat (39a) for the packing seal (41) is defined.

8. Assembly according to claim 1, wherein the cylindrical ferrule (39) is made of carbon steel.

9. Assembly according to claim 1, wherein the packing seal (41) comprises a braid of synthetic yarn impregnated with graphite powder, a corrosion inhibitor and a lubricant.

10. Assembly according to claim 1, characterized in that it does not require maintenance.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Some preferred embodiments of the invention will be described below by way of non-limiting examples with reference to the annexed figures, in which:

[0012] FIG. 1 is a longitudinal section of a snapping roll provided with a forward support rotating assembly according to a preferred embodiment of the invention;

[0013] FIG. 2 is an enlarged view of the support assembly of FIG. 1;

[0014] FIG. 3 is a top plan view of a snapping unit equipped with two snapping rolls provided with a support assembly according to FIG. 1.

DESCRIPTION OF SOME PREFERRED EMBODIMENTS OF THE INVENTION

[0015] Referring to FIGS. 1 to 3, the support rotating assembly 11 of a snapping roll 13 comprises an axial seat 15 in the roll 13. The seat 15 is frontally open and has an inner circumferential abutment edge 17. The seat 15 is frontally arranged in the roll 13. The support assembly 11 further comprises a cylindrical support pin 19 extending axially in the seat 15. The pin 19 is integral to a support bracket 21 for fixing the assembly 11 to a snapping unit 23 of a combine harvesting machine. The support assembly 11 comprises a sliding element 25 interposed between the support pin 19 and the seat 15. In the illustrated embodiment, the sliding element 25 is a ball bearing. The outer ring 25a of the bearing 25 is radially in contact with the inner wall 27 of the seat 15. The inner ring 25b of the bearing 25 is radially in contact with the outer wall 29 of the pin 19. The bearing 25 is further axially in contact with the abutment edge 17 of the seat 15. A radial annular slot 31 housing an elastic ring 33 for locking the sliding element 25 is formed in the wall 27. In the illustrated embodiment, the elastic ring 33 consists of a Seeger ring. An elastic annular seal 35 is provided between the support pin 19 and the inner wall 27 of the seat 15. In the illustrated embodiment, the seal 35 consists of a double-lip gasket having a substantially U-shaped cross-section. An outer annular portion 35a, an inner annular portion 35b having a double lip 35c,35d and extending radially toward the inside, and a transverse connecting portion 35e arranged between the outer portion 35a and the inner portion 35b are defined in the seal 35. In the illustrated embodiment, the double lip comprises two corresponding elastic flaps 35c,35d, radially diverging and forming between them an angle comprised between 60° and 120°, preferably an angle of 90°. The seal 35 is further axially in contact with the elastic ring 33. According to the invention, the support assembly 11 is further provided with a labyrinth seal element 37. The labyrinth seal element 37 comprises a cylindrical ferrule 39 and an annular packing seal 41. The ferrule 39 has a labyrinth cross-section in which an inner annular groove 39a housing the packing seal 41 is defined. The packing seal 41 is radially in contact with the outer surface 29 of the support pin 19. The cylindrical ferrule 39 has a substantially F-shaped cross-section in which there is defined an outer annular portion 39b and two parallel inner radial portions 39c,39d between which the groove 39a for the packing 41 is defined. According to a preferred embodiment of the invention the cylindrical ferrule 39 is made of carbon steel. The packing seal 41 comprises for instance a braid of synthetic yarn impregnated with graphite powder, a corrosion inhibitor and a lubricant. The assembly 11 according to the invention is substantially maintenance-free, i.e. it does not require maintenance interventions, practically for the entire service life of the snapping roll 13. In the shown example, the snapping roll 13 comprises a helical surface 51 at its front end supported by the support assembly 11. The snapping roll 13 extends longitudinally inside a support chamber 53 and is rotated by a support and motion transmitting unit 55. The snapping roll 13 is preferably hollow and further comprises a sealing plug 57 isolating the sliding element 25 from the chamber inside the roll 13, on the side opposite to the labyrinth seal 39. The snapping unit 23 will not be described further as it is part of the prior art known to the person skilled in the art.

INDUSTRIAL APPLICABILITY

[0016] The invention is adapted to be applied to the industry of agricultural mechanics, namely to snapping units of either new produced or already existing combine harvesting machines. Indeed, it is advantageously possible to provide with the support rotating assembly also combine machines having conventional support assemblies.

[0017] The invention as described and illustrated may undergo several changes and modifications falling within the same inventive principle.