Differential force rotary sprinkler

Abstract

A differential force rotary sprinkler comprises: a V-shaped rotary arm (1) having an arm body (11); a nozzle (2); a dust-resistant sealing cap (3) fixed and connected to the arm body (11); an upper oil seal (4) disposed at a lower end of an inner wall of the dust-resistant sealing cap (3); an upper bearing bush (5); a bearing housing (6); a lower bearing bush (7); a lower oil seal (8); a position-limiting screw nut (9); and a sealing O-ring (10). After the position-limiting screw nut (9) has been tightened, an axial gap of 0.5-1.5 mm is left between the position-limiting screw nut (9) and the lower bearing bush (7). An outer arm of the position-limiting screw nut (9) and the lower oil seal (8) realize a sealed smooth surface. The sprinkler realizes uniform spray of water and can be assembled and disassembled conveniently.

Claims

1. A differential force rotary sprinkler, comprising: a V-shaped rotary arm (1); a nozzle (2); a dust-resistant sealing cap (3); an upper oil seal (4); an upper bearing bush (5); a bearing housing (6); a lower bearing bush (7); a lower oil seal (8); a position-limiting screw nut (9); and a sealing O-ring (10), wherein the nozzle is symmetrically disposed at two top ends of the V-shaped rotary arm, the dust-resistant sealing cap (3) is fixed and connected to an arm body (11) of the V-shaped rotary arm (1), the arm body (11) has an annular position-limiting step (12), the annular position-limiting step (12) is concealed inside the dust-resistant sealing cap (3), the upper oil seal (4) is disposed at a lower end of an inner wall of the dust-resistant sealing cap (3), the upper bearing bush (5) is mounted at an upper end of the bearing housing (6), the lower bearing bush (7) and the lower oil seal (8) are sequentially disposed in the middle position inside bearing housing (6) from top to bottom, the upper bearing bush (5), the bearing housing (6), the lower bearing bush (7) and the lower oil seal (8) are assembled to constitute a bearing housing body (A), the bearing housing body (A) is sleeved over the arm body (11) of the V-shaped rotary arm (1), wherein the upper bearing bush (5) engages with and is positioned by the annular position-limiting step (12), the position-limiting screw nut (9) having the sealing O-ring (10) inside thereof is sleeved over the arm body (11) via a threaded connection and is located underside the bearing housing body (A), an axial gap of 0.5-1.5 mm is preserved between the position-limiting screw nut (9) and the lower bearing bush (7) after the position-limiting screw nut (9) has been tightened, and an outer arm of the position-limiting screw nut (9) and the lower oil seal (8) realize a sealed smooth surface, wherein the dust-resistant sealing cap (3), the upper oil seal (4) and the arm body (11) define a first oil storage cavity (15).

2. The differential force rotary sprinkler according to claim 1, wherein the nozzle (2) is provided with a front spray hole (13) and a back spray hole (14), where the front spray hole (13) has a smaller diameter than that of the back spray hole (14), and there is an angle of 90 to 120 between the front spray hole (13) and the back spray hole (14).

3. The differential force rotary sprinkler according to claim 1, wherein the upper bearing bush (5), the bearing housing (6), the lower bearing housing (7) and the arm body (11) define a second oil storage cavity (16).

4. The differential force rotary sprinkler according to claim 1, wherein a gap of at least 0.15 mm in a radial direction is provided between the upper bearing bush (5) and the lower bearing bush (7) and the arm body (11) to facilitate lubrication for rotation.

5. The differential force rotary sprinkler according to claim 1, wherein the inner wall of the dust-resistant sealing cap (3) has two steps, wherein an upper step (3-1) provides an engaging platform for the upper oil seal (4), and a lower step (3-2) provides a sealing platform for the dust-resistant sealing cap (3) and the bearing housing (6).

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 is a schematic view of an overall structure of the present invention.

(2) FIG. 2 is an exploded view of an assembly in FIG. 1 of the present invention.

(3) FIG. 3 is an assembled view of components in FIG. 2 of the present invention.

(4) FIG. 4 is a cross-sectional view of the structure of a sprinkler of the present invention.

(5) FIG. 5 is a cross-sectional view taken along line A-A of FIG. 4 of the present invention.

(6) Reference numerals in the above drawings: 1. V-shaped rotary arm; 2. nozzle; 3. dust-resistant sealing cap; 4. upper oil seal; 5. upper bearing bush; 6. bearing housing; 7. lower bearing bush; 8. lower oil seal; 9. position-limiting screw nut; 10. sealing O-ring; 11. arm body; 12. annular position-limiting step; 13 front spray hole; 14. rear spray hole; 15. first oil storage cavity; 16. second oil storage cavity 16.

DETAILED DESCRIPTION OF THE EMBODIMENTS

(7) As shown in FIGS. 1 and 2, the sprinkler includes: a V-shaped rotary arm (1); a nozzle (2); a dust-resistant sealing cap (3); an upper oil seal (4); an upper bearing bush (5); a bearing housing (6); a lower bearing bush (7); a lower oil seal (8); a position-limiting screw nut (9); and a sealing O-ring (10), wherein the nozzle is symmetrically disposed at two top ends of the V-shaped rotary arm, the dust-resistant sealing cap (3) is fixed and connected to an arm body (11) of the V-shaped rotary arm (1), the arm body (11) has an annular position-limiting step (12), the annular position-limiting step (12) is concealed inside the dust-resistant sealing cap (3), the upper oil seal (4) is disposed at a lower end of an inner wall of the dust-resistant sealing cap (3), the upper bearing bush (5) is mounted at an upper end of the bearing housing (6), the lower bearing bush (7) and the lower oil seal (8) are sequentially disposed in the middle position inside bearing housing (6) from top to bottom, the upper bearing bush (5), the bearing housing (6), the lower bearing bush (7) and the lower oil seal (8) are assembled to constitute a bearing housing body, the main body of the bearing housing (6) is sleeved over the arm body (11) of the V-shaped rotary arm (1), wherein the upper bearing bush (5) engages with and is positioned by the annular position-limiting step (12), the position-limiting screw nut (9) having the sealing O-ring (10) inside thereof is sleeved over the arm body (11) via a threaded connection and is located underside the bearing housing body, an axial gap of 0.5-1.5 mm is preserved between the position-limiting screw nut (9) and the lower bearing bush (7) after the position-limiting screw nut (9) has been tightened, and an outer arm of the position-limiting screw nut (9) and the lower oil seal (8) realize a sealed smooth surface.

(8) The inner wall of the dust-resistant sealing cap (3) has two steps, wherein an upper step (3-1) provides an engaging platform for the upper oil seal (4), and a lower step (3-2) provides a sealing platform for the dust-resistant sealing cap (3) and the bearing housing (6).

(9) The nozzle (2) is provided with a front spray hole (13) and a back spray hole (14), wherein the front spray hole (13) has a smaller diameter than that of the back spray hole (14), and there is an angle of 90 to 120 between the front spray hole (13) and the back spray hole (14).

(10) The dust-resistant sealing cap (3), the upper oil seal (4) and the arm body (11) define a first oil storage cavity (15); and the upper bearing bush (5), the bearing housing (6), the lower bearing bush (7) and the arm body (11) define a second oil storage cavity (16).

(11) A gap of at least 0.15 mm in a radial direction is provided between the upper bearing bush (5) and the lower bearing bush (7) and the arm body (11) to facilitate lubrication for rotation.

(12) Operating Process:

(13) When in use, a water inlet pipeline is connected to the internal thread beneath the bearing housing. Since two spray holes, the front spray hole (13) and the back spray hole (14) disposed on the nozzles (2) at the top end of the V-shaped rotary arm (1) are in opposite directions, when a water pump pressurizes water and send it via a pipeline to the sprinkler, the water flow will be sprayed from the front spray hole (13) and the back spray hole (14) on the nozzle (2), where the water sprayed from the front spray hole (13) will fall into a range near the sprinkler, while the water sprayed from the back spray hole (14) covers a further range. Functions of the back spray hole (14) are not only to spray the water to a distant place, but also to generate a force for rotation of the sprinkler.

(14) Operating Principle:

(15) When a force driving the sprinkler to rotate is F, and a frictional resistance is F.sub.1, a driving force for the front spray hole is F.sub.2, a driving force for the back spray hole (14) is F.sub.3, then the force driving the sprinkler to rotate is F=F.sub.3F.sub.1F.sub.2. Since F.sub.1 is constant while F.sub.2 and F.sub.3 are changeable via adjustment. When the sprinkler is such manufactured (leaves factory) that when the front spray hole and the back spray hole are all at a 30 horizontal elevation angle, F.sub.3 is greater than F.sub.1 plus F.sub.2. When the sprinkler is working, the sprinkler is in a state of a constant medium rotation speed. When the rotation speed needs to be increased, the angle of the back spray hole can be adjusted downwards, so that its horizontal elevation angle is lower than 30, and meanwhile the horizontal elevation angle of the front spray hole will be greater than 30. Since a thrust generated by reverse thrust of air on rotation of the sprinkler is that the smaller the angle is, the larger the thrust is and vice versa, the larger the angle is, the smaller the thrust is. Therefore, when the back spray hole is adjusted to a horizontal elevation angle of 0, the front spray hole reaches its maximum horizontal elevation angle of 60. At this time, F.sub.3 is the largest, the driving force for the front spray hole F.sub.2 is the smallest, the sprinkler rotates fastest, and F has a maximum value. Conversely, when lower rotation speed is required, the front spray hole is adjusted downward. When the front spray hole is adjusted to a horizontal elevation angle of 0, the horizontal elevation angle of the back spray hole will be 60. At this time, the difference F.sub.3F.sub.1F.sub.2 is the smallest, and the force F driving the sprinkler to rotate is minimized, then the sprinkler is in the state of the lowest speed rotation.

(16) When the sprinkler is not working and in a static state, the space inside the bearing housing (6) and the oil storage cavity in the dust-resistant sealing cap (3) are all filled with grease. Now, an upper end surface of the upper bearing bush (5) is loaded in close contact due to gravity, and the gap between the lower bearing bush (7) and the position-limiting screw nut (9) opens, allowing the grease to automatically flow into the axial gap of 0.5-1.5 mm preserved between the lower bearing bush (7) and the position-limiting screw nut (9).

(17) At the beginning of the work, the pressurized water is pumped by a water pump into a water feeding pipe and then is ejected out of the nozzle (2). Since the back thrust generated by the water sprayed from the back spray hole (14) is greater than the front thrust generated by the water sprayed from the front spray hole (13), the sprinkler rotates by the back thrust while the water pressure rapidly reaches a peak. Since the pressurized water imparts an upward thrust on the sprinkler, the gap between the upper bearing bush (5) and the annular position-limiting step (12) is opened. Since the oil storage cavity is at a high position, the lubricating grease may automatically fill the gap. Now, the gap between the lower bearing bush (7) and the position-limiting screw nut (9) is closed. When the irrigation work is completed, the water pressure disappears, and the force generated by self-weight of the upper bearing bush (5) causes its gap to close, and the gap between the lower bearing bush (7) and the position-limiting screw nut (9) is to open, allowing the grease to automatically fill the gap between the lower bearing bush (7) and the position-limiting screw nut (9). This cycle is repeated, realizing lubrication and maintenance without need to disassemble the sprinkler, while ensuring a more even and reliable rotation over the design of prior application.