Rotary dust screen

Abstract

A rotary dust screen for a cooling unit of an agricultural vehicle includes a frame having a ring shape, wherein a dust screen is mounted in the frame and wherein the frame includes a seal extending along the ring and comprising a lip adapted to abut, when the rotary dust screen is mounted on the cooling unit, against a housing of the cooling unit to prevent contaminants from entering the cooling unit at an edge of the dust screen, wherein the rotary dust screen further has a driving belt adapted to be driven by a rotary actuator to rotate the dust screen, wherein the driving belt engages with the rotary dust screen at an outer surface of the seal.

Claims

1. Rotary dust screen assembly for a cooling unit of a vehicle, the rotary dust screen comprising: a frame having a ring shape, wherein a dust screen is mounted in the frame and wherein the frame comprises a seal extending around the outer surface of the ring and comprising a lip adapted to abut, when the rotary dust screen is mounted on the cooling unit, against a housing of the cooling unit to prevent contaminants from entering the cooling unit at an edge of the dust screen, a driving belt adapted to be driven by a rotary actuator to rotate the dust screen, wherein the driving belt is engaged at an outer surface of the seal to rotate the dust screen through the seal.

2. The rotary dust screen assembly according to claim 1, wherein the frame comprises an outer frame surface and wherein the seal is mounted with an inner seal surface against the outer frame surface.

3. The rotary dust screen assembly according to claim 1, wherein the seal is made of a resilient plastic material.

4. The rotary dust screen assembly according to claim 1, wherein the seal comprises a groove at the outer surface of the seal, and the groove is adapted for engagement with the driving belt.

5. The rotary dust screen assembly according to claim 4, wherein the driving belt is a V-shaped belt adapted to engage in the groove of the seal.

6. The rotary dust screen assembly according to claim 1, wherein the frame comprises a protrusion extending to an inner side of the ring-shaped frame and the protrusion is adapted to engage with positioning elements at the cooling unit.

7. The rotary dust screen assembly according to claim 1, wherein the dust screen is mounted at a first segment of the frame.

8. The rotary dust screen assembly according to claim 1, wherein the dust screen is formed by a perforated metal plate.

9. The rotary dust screen assembly according to claim 1, wherein the dust screen comprises a cylindrical part and a closing part, wherein one end of the cylindrical part is connected to the frame and another end of the cylindrical part is closed by the closing part.

10. The rotary dust screen assembly according to claim 1, further comprising a dust cleaning module adapted to be mounted to the housing of the cooling unit to cover a segment of the rotary dust screen that extends between an area at the frame and an area at the center of the rotary dust screen.

11. A Cooling unit comprising a housing and at least one rotary dust screen assembly comprising a frame having a ring shape, wherein a dust screen is mounted in the frame and wherein the frame comprises a seal extending around the outer surface of the ring and comprising a lip adapted to abut, when the rotary dust screen is mounted on the cooling unit, against a housing of the cooling unit to prevent contaminants from entering the cooling unit at an edge of the dust screen, a driving belt adapted to be driven by a rotary actuator to rotate the dust screen, wherein the driving belt is engaged at an outer surface of the seal to rotate the dust screen through the seal a rotary actuator, which rotary actuator engages with the driving belt for rotating the dust screen.

12. Cooling unit according to claim 11, wherein the at least one rotary dust screen assembly comprises multiple rotary dust assemblies, and wherein the multiple rotary dust assemblies are driven by a single driving belt that engages with each of the outer surfaces of the seals of the multiple rotary dust assemblies.

13. The cooling unit of claim 11 in combination with an agricultural vehicle wherein the cooling unit forms part of a cooling system of the agricultural vehicle.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will now be described in more details with respect to the drawings illustrating some preferred embodiments of the invention. In the drawings:

(2) FIG. 1 illustrates an agricultural vehicle with a cooling unit according to an embodiment of the invention;

(3) FIG. 2 illustrates a cooling unit according to an embodiment of the invention;

(4) FIG. 3A shows a first embodiment of a cross section of a rotary dust screen mounted in a cooling unit housing according to an embodiment of the invention,

(5) FIG. 3B shows a second embodiment of a cross section of a rotary dust screen mounted in a cooling unit housing according to an embodiment of the invention; and

(6) shows a cross section of a rotary dust screen mounted in a cooling unit housing according to an embodiment of the invention; and

(7) FIG. 4 illustrates a top view of a cooling unit according to an embodiment of the invention.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

(8) In the drawings a same reference number has been allocated to a same or analogous element.

(9) FIG. 1 shows an agricultural vehicle 1 with a cooling unit 2. The shown agricultural vehicle 1 is an agricultural combine, however, it will be clear that the cooling unit 2 according to the invention is suitable for various agricultural vehicles, preferably self-propelled agricultural vehicles. Self-propelled agricultural vehicles typically require a significant cooling capacity. To achieve such cooling capacity in dusty environments, the cooling unit of the present invention can be used.

(10) Cooling unit 2 is adapted for drawing air from an environment of the agricultural vehicle into the cooling unit where it is typically guided over one or multiple heat exchangers and/or over other elements that require cooling. The present invention particularly relates to the part of the cooling unit 2, where the environmental air enters the cooling unit 2.

(11) Since agricultural vehicles typically operate in dusty environments, the openings of the cooling unit 2 are provided with respective rotary dust screens 3. The rotary dust screen 3 is mounted in an opening of a housing 4 of the cooling unit 2 to cover the opening. The rotary dust screen 3 is provided with perforations so that air can flow through the rotary dust screen 3 into the cooling unit 2. Thereby, the perforations have predetermined dimensions which are chosen to prevent dust particles from entering the cooling unit 2. In this manner, the rotary dust screen 3 operates as a filter for filtering environmental air that is drawn into the cooling unit 2.

(12) To prevent the rotary dust screen 3 from getting clogged up with dust particles, a cleaning element 5 is provided, which is typically pie-shaped and extends over a part of the rotary dust screen 3 between an area at the edge or frame of the rotary dust screen 3 and a central area of the rotary dust screen 3. The cleaning element is preferably formed as a suction element that operates as a vacuum cleaner for cleaning the outer surface of the rotary dust screen. The cleaning element 5 is preferably mounted in a fixed position, and the dust screen 3 is rotated so that by rotation of the dust screen 3 substantially the complete rotary dust screen 3 passes by the cleaning element 5. In this manner the outer surface of the rotary dust screen is suction cleaned every time the rotary dust screen makes a full rotation, so that the rotary dust screen is prevented from getting clogged up with dust particles.

(13) In the example of FIG. 1 three rotary dust screens 3a, 3b, 3c are provided to cover three corresponding openings in a housing 4 of the cooling unit 2. Each of the rotary dust screens 3a, 3b, 3c is provided with a suction cleaning element 5a, 5b, 5c. It will be clear that the cooling unit 2 can also be designed with different numbers of rotary dust screens 3 and corresponding suction cleaners 5. Therefore, the invention is not limited to a cooling unit 2 having three rotary dust screens 3a, 3b, 3c.

(14) FIG. 2 shows a cooling unit 2 according to an embodiment of the invention. Thereby, FIG. 2 shows the housing 4 of the cooling unit, and shows the openings in which rotary dust screens are mounted. For clarity, and for showing inner parts of the cooling unit 2, the dust screens are not shown in FIG. 2. FIG. 2 shows the heat exchangers 6 that are mounted inside the cooling unit 2. FIG. 2 further shows the suction device 7 that is operationally connected to the suction elements 5a, 5b and 5c for cleaning the outer surface of the rotary dust screens.

(15) FIGS. 3A and 3B shows a cross section of an edge of a rotary dust screen according to a first and a second embodiment of the present invention. In the first embodiment, shown in FIG. 3a, the rotary dust screen is substantially flat, meaning that the dust screen 12 is not provided with a cylindrical part. In the second embodiment shown in FIG. 3b, the dust screen has a cylindrical part 12a and a closing part 12b, which allows to significantly increase the surface area of the dust screen. Thereby one end of the cylindrical part 12a is closed with the closing part 12b while the other end is mounted in the frame, which is described hereunder. The techniques for mounting the dust screen, for sealing the edges of the dust screen with respect to the housing 4 of the cooling unit and for driving the rotary dust screen are substantially the same for the first and second embodiment, as is described hereunder.

(16) The rotary dust screen comprises at least four main elements being a frame 8, a dust screen 12, a seal 13 and a driving belt 17. These elements of the rotary dust screen 3 cooperate with the housing 4 of the cooling unit, and optionally with positioning elements 18 that are connected to the housing 4 in order to filter the air entering the cooling unit 2. In this context it is noted that the connection between the positioning element 18 and the housing 4 is not shown in FIGS. 3A and 3B.

(17) The frame 8, of which a cross section is shown in FIG. 3a, is ring-shaped with a diameter that corresponds with the diameter of the opening in the housing 4 of the cooling unit 2. The ring-shaped frame 8 comprises a first part 9 for connection of the dust screen 12. This first part 9 is preferably formed with a U-shaped cross section that allows to clamp the dust screen 12 between the legs of the U-shape. This allows to mount the dust screen in the ring-shaped frame 8 in a convenient manner. The U-shape can, after positioning of the dust screen, be deformed to bring the legs of the U-shape together to thereby clamp the dust screen 12 in the frame 8. In this manner, the frame 8 is rigidly connected to the dust screen 12. The skilled person will understand that other ways of connecting the dust screen 12 to the ring-shaped frame 8 are also possible, for example by gluing or welding.

(18) The frame 8 further comprises a second part with an outer surface 10 that is adapted for receiving a seal 13. The outer surface 10 allows the seal 13 to be stretched and clamped around the ring-shaped frame 8 so that the seal 13 is mounted against the frame 8 along the entire outer surface 10.

(19) Frame 8 further preferably comprises a third part being a protrusion 11 that extends to an inner side of the ring-shaped frame. This protrusion 11 is in the example of FIG. 3a formed as a partly tube-shaped protrusion. The protrusion 11 facilitates engagement of positioning elements 18 with the rotary dust screen 3. The rotary dust screen 3 can then via the protrusion 11 be held in place by the positioning elements 18.

(20) The seal 13 is ring-shaped with a diameter that matches the diameter of the ring-shaped frame 8 so that the seal 13 can be stretched and clamped around the ring-shaped frame 8 to obtain a rigid connection between the seal 13 and the frame 8. Thereby it will be clear that in the shown example the rigid connection is solely obtained by friction between the frame 8 and the seal 13, particularly between the outer surface 10 of the frame 8 and the inner surface 14 of the seal. Other ways of connecting the seal to the frame are also possible. The seal 13 comprises a lip 15 that is adapted to abut against the housing 4 of the cooling unit 2, when the rotary dust screen is mounted onto the cooling unit 2. Preferably, the seal 13 abuts against a protrusion of the frame 8 at one end of the seal, in the example of FIGS. 3A and 3B the protrusion is the first part 9, while the lip 15 is formed at the other end of the seal 13. In this manner, when the frame 8 is correctly positioned with respect to the opening in the housing 4, the lip 15 will always push against the housing 4 thereby obtaining a reliable and tight sealing between the edge of the rotary dust screen 3 and the housing 4. In the shown example, when the rotary dust screen is mounted to the cooling unit, the seal is trapped between on the one hand the first part 9 of the frame, extending outward from the outer surface, and on the other hand the housing 4. This sealing prevents contaminants from entering the cooling unit 2 via the edge of the rotary dust screen 3.

(21) The seal 13 comprises a V-shaped groove 16 at an outer surface of the seal 13. The outer surface of the seal 13 is a surface opposite to the inner side 14 of the seal 13. The groove 16 is preferably V-shaped, and is preferably optimized for cooperating with a V-shaped driving belt 17. Via this driving belt 17, the rotary dust screen 3 can be driven. The seal 13 is preferably made from a resilient material, more preferably a resilient plastic material. The resilient material can for example be rubber or a synthetic rubber. Resilient materials are known for having a high friction coefficient, so that mounting the seal 13 onto the frame 8 will result in a rigid connection, and so that engagement with the driving belt 17 will result in a high friction between the driving belt 17 and the seal 13. The advantage of this high friction is explained hereunder in relation to FIG. 4.

(22) FIG. 4 shows a schematical top view of a cooling unit 2 provided with three rotary dust screen 3a, 3b, 3c. For clarity purposes, only a single cleaning unit 5a is shown, however, it will be clear that rotary dust screen 3b and rotary dust screen 3c are also provided with a cleaning unit 5. The figure shows how each rotary dust screen 3a, 3b, 3c is held in place via three positioning elements 18a, 18b, 18c. These positioning elements 18 can for example be formed by wheels as shown in FIGS. 3A and 3B, which cooperate with the protrusion 11 of the frame 8 to hold the rotary dust screens 3a, 3b, 3c in position with respect to the housing 4 of the cooling unit 2.

(23) FIG. 4 shows how the three rotary dust screen 3a, 3b and 3c are driven by a single driving belt 17. The driving belt 17 is driven by a rotary actuator 19 which is mounted at an outer side of the housing 4 of the cooling unit 2. Since the rotary actuator 19 is mounted at an outer side, as well as the driving belt 17 is mounted at an outer side, maintenance of these elements is easy to perform. Driving belt guiding wheels 20 are provided to guide the driving belt in a predetermined path around the multiple rotary dust screens. These guiding wheels 20 can be further provided with tensioning elements (not shown) to provide a predetermined tension to the driving belt 17. FIG. 4 shows how the driving belt 17 engages with the middle rotary dust screen 3b only over a limited angular segment of the outer surface of the rotary dust screen. However, since the friction between the seal 13 and the driving belt 17 is high, tests have shown that this limited engagement area is sufficient for the driving belt 17 to be able to drive the middle rotary dust screen 3b.

(24) The above described embodiments and the shown figures are illustrative and serve only for a better understanding of the invention. The invention is not limited to the described embodiments. Different alternatives, and preferred features described in the text can be freely combined by a skilled person and developed in more detail to form an operational whole without departing from the claimed invention. The scope of protection of the invention will therefore be defined solely by the claims.