Split type cam shaft for engine of medium-speed four-stroke high-pressure common-rail ship

Abstract

The utility model belongs to the field of marine engines, and particularly relates to a split type cam shaft for a medium-speed four-stroke high-pressure common-rail marine engine, which comprises a shaft body, a plurality of cam groups integrally formed at specified positions on the shaft body, and sliding bearings arranged between two adjacent cam groups. When the cam shaft rotates by 360 degrees, a common rail pump of a high-pressure common rail engine can pump oil for eight times, the oil pumping frequency is improved, the oil pumping quantity of fuel oil of the engine can be effectively improved, and the fuel oil pressure is stabilized.

Description

Technical Field

[0001] The utility model belongs to the field of camshafts for marine engines, in particular to a split camshaft for medium-speed four-stroke high-pressure common rail marine engines. Background Art

[0002] The camshaft used in traditional marine engines has only one protruding part, namely one vertex, or one wave crest. The corresponding parts of four of the eight fuel cams on the camshaft are equipped with the engine's common rail pump. As the camshaft rotates, the four fuel cams' wave crests push the engine's common rail pump once, and the common rail pump pumps oil once. Therefore, when the camshaft rotates 360°, the 8-cylinder engine can pump oil four times. Since the medium-speed four-stroke engine has a low speed and the camshaft rotates only 360° for every 720° rotation of the engine, the common rail pump has a low pumping frequency and a small oil supply, and cannot continuously stabilize the fuel pressure in the common rail pipe. Utility Model Content

[0003] In view of the various deficiencies in the prior art, the inventors have researched and designed a split camshaft for a medium-speed four-stroke high-pressure common rail marine engine through long-term practice. The shapes of four of the fuel cams are changed into elliptical shapes. When the camshaft rotates 360°, the 8-cylinder engine can pump oil 8 times, thereby increasing the oil pumping frequency and amount.

[0004] In order to achieve the above purpose, the utility model provides the following technical solutions:

[0005] A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine comprises a shaft body, a plurality of cam groups integrally formed at a predetermined position on the shaft body, and a sliding bearing arranged between two adjacent cam groups. The plurality of cam groups are arranged in sequence along a first direction, including a first cam group, a second cam group, a third cam group, a fourth cam group, a fifth cam group, a sixth cam group, a seventh cam group, and an eighth cam group.

[0006] The first group of cams is provided with a first exhaust cam, a first intake cam and a first fuel cam in sequence along a first direction. The second group of cams is provided with a second exhaust cam, a second intake cam and a second fuel cam in sequence along a first direction. The third group of cams is provided with a third exhaust cam, a third intake cam and a third fuel cam in sequence along a first direction. The fourth group of cams is provided with a fourth exhaust cam, a fourth intake cam and a fourth fuel cam in sequence along a first direction. The fifth group of cams is provided with a fifth exhaust cam, a fifth intake cam and a fifth fuel cam in sequence along a first direction. The sixth group of cams is provided with a sixth exhaust cam, a sixth intake cam and a sixth fuel cam in sequence along a first direction. The seventh group of cams is provided with a seventh exhaust cam, a seventh intake cam and a seventh fuel cam in sequence along a first direction. The eighth group of cams is provided with an eighth exhaust cam, an eighth intake cam and an eighth fuel cam in sequence along a first direction.

[0007] The first fuel cam, the third fuel cam, the fifth fuel cam and the seventh fuel cam have the same structure. The second fuel cam, the fourth fuel cam, the sixth fuel cam and the eighth fuel cam have the same structure and are all elliptical.

[0008] Furthermore, each of the sliding bearings cooperates with a bearing bush, and a wedge-shaped oil film gap is formed after the two bearings rotate relative to each other.

[0009] Furthermore, the shaft body, each cam group and each sliding bearing are an integrated structure, and are made of alloy steel material.

[0010] Further, a third sliding bearing is arranged between the first group of cams and the second group of cams, a fourth sliding bearing is arranged between the second group of cams and the third group of cams, a fifth sliding bearing is arranged between the third group of cams and the fourth group of cams, a sixth sliding bearing is arranged between the fourth group of cams and the fifth group of cams, a seventh sliding bearing is arranged between the fifth group of cams and the sixth group of cams, an eighth sliding bearing is arranged between the sixth group of cams and the seventh group of cams, and a ninth sliding bearing is arranged between the seventh group of cams and the eighth group of cams.

[0011] Furthermore, a first sliding bearing is provided at one end of the shaft body close to the first exhaust cam.

[0012] Furthermore, a second sliding bearing is provided at one end of the shaft body close to the eighth fuel cam.

[0013] Furthermore, an extension line of a line connecting two vertices of the first fuel cam and an extension line of a line connecting two vertices of the fourth fuel cam intersect at a right angle.

[0014] Furthermore, an extension line of a line connecting two vertices of the fourth fuel cam and an extension line of a line connecting two vertices of the sixth fuel cam intersect at a right angle.

[0015] Furthermore, an extension line of a line connecting two vertices of the sixth fuel cam intersects with an extension line of a line connecting two vertices of the eighth fuel cam at a right angle.

[0016] The beneficial effects of the utility model are:

[0017] The fuel cam profile is designed to be elliptical, and the four elliptical fuel cams have a total of eight peaks, evenly distributed within a 360° range, with a peak every 45°, ensuring the uniformity and sustainability of oil pumping. When the camshaft rotates 360°, the common rail pump of the high-pressure common rail engine can pump oil eight times. The increase in the pumping frequency can effectively increase the amount of oil pumped by the engine fuel and stabilize the fuel pressure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 It is a structural schematic diagram of the utility model;

[0019] Figure 2 It is a schematic diagram of the structure of the first to fourth groups of cams of the camshaft of the utility model;

[0020] Figure 3 It is a schematic diagram of the structure of the fifth to eighth groups of cams of the camshaft of the utility model;

[0021] Figure 4 It is a schematic diagram of the state of each cam of the first to fourth groups of the utility model in the initial state;

[0022] Figure 5 It is a schematic diagram of the states of the fifth to eighth groups of cams of the utility model in the initial state.

[0023] In the attached figure:

[0024] 10- shaft body;

[0025] 1-first group of cams, 2-second group of cams, 3-third group of cams, 4-fourth group of cams, 5-fifth group of cams, 6-sixth group of cams, 7-seventh group of cams, 8-eighth group of cams;

[0026] 11-first exhaust cam, 12-first intake cam, 13-first fuel cam;

[0027] 21-second exhaust cam, 22-second intake cam, 23-second fuel cam;

[0028] 31- third exhaust cam, 32- third intake cam, 33- third fuel cam;

[0029] 41-fourth exhaust cam, 42-fourth intake cam, 43-fourth fuel cam;

[0030] 51-fifth exhaust cam, 52-fifth intake cam, 53-fifth fuel cam;

[0031] 61-sixth exhaust cam, 62-sixth intake cam, 63-sixth fuel cam;

[0032] 71-seventh exhaust cam, 72-seventh intake cam, 73-seventh fuel cam;

[0033] 81-eighth exhaust cam, 82-eighth intake cam, 83-eighth fuel cam;

[0034] 101 - a first sliding bearing, 102 - a second sliding bearing, 103 - a third sliding bearing, 104 - a fourth sliding bearing, 105 - a fifth sliding bearing, 106 - a sixth sliding bearing, 107 - a seventh sliding bearing, 108 - an eighth sliding bearing, 109 - a ninth sliding bearing. DETAILED DESCRIPTION

[0035] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is clearly and completely described below in conjunction with the accompanying drawings of the present invention. Based on the embodiments in this application, other similar embodiments obtained by ordinary technicians in this field without making creative work should all fall within the scope of protection of this application. In addition, the directional words mentioned in the following embodiments, such as "up", "down", "left", "right", etc., are only reference to the directions of the accompanying drawings. Therefore, the directional words used are used to illustrate rather than limit the creation of the present invention.

[0036] The utility model is further described below in conjunction with the accompanying drawings and preferred embodiments.

[0037] See also Figure 1-Figure 5 The utility model discloses a split camshaft for a medium-speed four-stroke high-pressure common rail marine engine, comprising a shaft body 10, a plurality of cam groups integrally formed at a predetermined position on the shaft body 10, and a sliding bearing arranged between two adjacent cam groups. Each sliding bearing of the embodiment cooperates with a bearing bush, and a wedge-shaped oil film gap is formed after mutual rotation to achieve a lubrication effect. The shaft body 10, each cam group and each sliding bearing are an integrated structure, and are made of alloy steel material.

[0038] Multiple cam groups are arranged in sequence along the first direction, including a first cam group 1, a second cam group 2, a third cam group 3, a fourth cam group 4, a fifth cam group 5, a sixth cam group 6, a seventh cam group 7 and an eighth cam group 8.

[0039] In this embodiment, a third sliding bearing 103 is arranged between the first group of cams 1 and the second group of cams 2, a fourth sliding bearing 104 is arranged between the second group of cams 2 and the third group of cams 3, a fifth sliding bearing 105 is arranged between the third group of cams 3 and the fourth group of cams 4, a sixth sliding bearing 106 is arranged between the fourth group of cams 4 and the fifth group of cams 5, a seventh sliding bearing 107 is arranged between the fifth group of cams 5 and the sixth group of cams 6, an eighth sliding bearing 108 is arranged between the sixth group of cams 6 and the seventh group of cams 7, and a ninth sliding bearing 109 is arranged between the seventh group of cams 7 and the eighth group of cams 8.

[0040] See also Figure 2 and Figure 3 In this embodiment, the first cam group 1 is provided with a first exhaust cam 11, a first intake cam 12 and a first fuel cam 13 in sequence along the first direction. The second cam group 2 is provided with a second exhaust cam 21, a second intake cam 22 and a second fuel cam 23 in sequence along the first direction. The third cam group 3 is provided with a third exhaust cam 31, a third intake cam 32 and a third fuel cam 33 in sequence along the first direction. The fourth cam group 4 is provided with a fourth exhaust cam 41, a fourth intake cam 42 and a fourth fuel cam 43 in sequence along the first direction. The fifth cam group 5 is provided with a fifth exhaust cam 51, a fifth intake cam 52 and a fifth fuel cam 53 in sequence along the first direction. The sixth cam group 6 is provided with a sixth exhaust cam 61, a sixth intake cam 62 and a sixth fuel cam 63 in sequence along the first direction. The seventh cam group 7 is provided with a seventh exhaust cam 71, a seventh intake cam 72 and a seventh fuel cam 73 in sequence along the first direction. The eighth cam group 8 is provided with an eighth exhaust cam 81, an eighth intake cam 82 and an eighth fuel cam 83 in sequence along the first direction.

[0041] The camshaft of this embodiment has the direction of the cam apex in the initial state as shown in FIG. Figure 4 and Figure 5 The intake cams and exhaust cams have the same structure. The first fuel cam 13, the third fuel cam 33, the fifth fuel cam 53 and the seventh fuel cam 73 have the same structure. The second fuel cam 23, the fourth fuel cam 43, the sixth fuel cam 63 and the eighth fuel cam 83 have the same structure and are all elliptical.

[0042] See also Figure 4 and Figure 5 The extended line of the connection line between the two vertices of the first fuel cam 13 intersects with the extended line of the connection line between the two vertices of the fourth fuel cam 43 at a right angle, the extended line of the connection line between the two vertices of the fourth fuel cam 43 intersects with the extended line of the connection line between the two vertices of the sixth fuel cam 63 at a right angle, and the extended line of the connection line between the two vertices of the sixth fuel cam 63 intersects with the extended line of the connection line between the two vertices of the eighth fuel cam 83 at a right angle.

[0043] In this embodiment, a first sliding bearing 101 is provided at one end of the shaft body 10 close to the first exhaust cam 11, and a keyway (not shown in the figure) is designed on the shaft body 10 close to one end of the first sliding bearing 101, which is connected to a rotation drive source gear outside the figure, and the gear drives the shaft body 10 to rotate the camshaft around its axis. A second sliding bearing 102 is also provided at one end of the shaft body 10 close to the eighth fuel cam 83.

[0044] In the utility model, since the second fuel cam 23, the fourth fuel cam 43, the sixth fuel cam 63 and the eighth fuel cam 83 are elliptical in shape, when they rotate 360°, the two apexes of the ellipse can push the common rail pump of the engine twice. The common rail pump of the utility model is a single pump, which provides high-pressure fuel for the engine. One common rail pump is installed for every two cylinders and is driven by the camshaft. Therefore, the four elliptical fuel cams can push the common rail pump 8 times, that is, the four elliptical fuel cams have a total of 8 peaks, and these 8 peaks are evenly distributed within the range of 360°, and a peak is encountered every 45°, which ensures the uniformity and sustainability of the pumping oil. The common rail pump of the engine is pushed once, and the oil is pumped once. Therefore, when the camshaft of the utility model rotates 360°, the common rail pump is pushed 8 times, and the oil can be pumped 8 times. The increase in the pumping frequency can effectively increase the oil volume of the engine fuel pump and better stabilize the fuel pressure.

[0045] The present invention has been described in detail above. The above description is only a preferred embodiment of the present invention and should not limit the scope of implementation of the present invention. That is, all equivalent changes and modifications made within the scope of this application should still fall within the scope of the present invention.

Claims

1. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine, characterized in that: It comprises a shaft body (10), a plurality of cam groups integrally formed at specified positions on the shaft body (10), and a sliding bearing arranged between two adjacent cam groups; The plurality of cam groups are arranged in sequence along a first direction, including a first group of cams (1), a second group of cams (2), a third group of cams (3), a fourth group of cams (4), a fifth group of cams (5), a sixth group of cams (6), a seventh group of cams (7) and an eighth group of cams (8); The first group of cams (1) are provided with a first exhaust cam (11), a first intake cam (12) and a first fuel cam (13) in sequence along a first direction; the second group of cams (2) are provided with a second exhaust cam (21), a second intake cam (22) and a second fuel cam (23) in sequence along the first direction; the third group of cams (3) are provided with a third exhaust cam (31), a third intake cam (32) and a third fuel cam (33) in sequence along the first direction; the fourth group of cams (4) are provided with a fourth exhaust cam (41), a fourth intake cam (42) and a fourth fuel cam (43) in sequence along the first direction; The fifth group of cams (5) are provided with a fifth exhaust cam (51), a fifth intake cam (52) and a fifth fuel cam (53) in sequence along the first direction; the sixth group of cams (6) are provided with a sixth exhaust cam (61), a sixth intake cam (62) and a sixth fuel cam (63) in sequence along the first direction; the seventh group of cams (7) are provided with a seventh exhaust cam (71), a seventh intake cam (72) and a seventh fuel cam (73) in sequence along the first direction; and the eighth group of cams (8) are provided with an eighth exhaust cam (81), an eighth intake cam (82) and an eighth fuel cam (83) in sequence along the first direction; The first fuel cam (13), the third fuel cam (33), the fifth fuel cam (53) and the seventh fuel cam (73) have the same structure; The second fuel cam (23), the fourth fuel cam (43), the sixth fuel cam (63) and the eighth fuel cam (83) have the same structure and are all elliptical.

2. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 1, characterized in that: Each of the sliding bearings cooperates with the bearing bush, and a wedge-shaped oil film gap is formed after rotating relative to each other.

3. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 2, characterized in that: The shaft body (10), each of the cam groups and each of the sliding bearings are an integrated structure and are made of alloy steel material.

4. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 1, characterized in that: A third sliding bearing (103) is arranged between the first group of cams (1) and the second group of cams (2), a fourth sliding bearing (104) is arranged between the second group of cams (2) and the third group of cams (3), a fifth sliding bearing (105) is arranged between the third group of cams (3) and the fourth group of cams (4), a sixth sliding bearing (106) is arranged between the fourth group of cams (4) and the fifth group of cams (5), a seventh sliding bearing (107) is arranged between the fifth group of cams (5) and the sixth group of cams (6), an eighth sliding bearing (108) is arranged between the sixth group of cams (6) and the seventh group of cams (7), and a ninth sliding bearing (109) is arranged between the seventh group of cams (7) and the eighth group of cams (8).

5. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 4, characterized in that: A first sliding bearing (101) is provided at one end of the shaft body (10) close to the first exhaust cam (11).

6. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 5, characterized in that: The shaft body (10) is also provided with a second sliding bearing (102) at one end close to the eighth fuel cam (83).

7. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 1, characterized in that: An extension line of a line connecting two vertices of the first fuel cam (13) and an extension line of a line connecting two vertices of the fourth fuel cam (43) intersect at a right angle.

8. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 7, characterized in that: An extension line of a line connecting two vertices of the fourth fuel cam (43) and an extension line of a line connecting two vertices of the sixth fuel cam (63) intersect at a right angle.

9. A split camshaft for a medium-speed four-stroke high-pressure common rail marine engine according to claim 8, characterized in that: An extension line of a line connecting two vertices of the sixth fuel cam (63) and an extension line of a line connecting two vertices of the eighth fuel cam (83) intersect at a right angle.

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