Cam shaft

Abstract

The utility model discloses a cam shaft, which relates to the technical field of engines, and comprises two gas distribution cam shafts and an oil pump cam shaft positioned between the two gas distribution cam shafts, each gas distribution cam shaft comprises a gas distribution cam shaft main body and gas distribution cams arranged at two ends of the gas distribution cam shaft main body, the oil pump cam shaft comprises an oil pump cam shaft body and an oil pump cam arranged in the middle of the oil pump cam shaft body, and the two ends of the oil pump cam shaft body are detachably connected with the gas distribution cams of the two gas distribution cam shafts respectively. According to the cam shaft, the oil pump cam can be directly replaced in the cam shaft box, the workload of maintenance work is reduced, the convenience of maintenance is improved, and the maintenance cost is reduced.

Description

TECHNICAL FIELD

[0001] The utility model relates to the technical field of engine, concretely relates to a camshaft. BACKGROUND

[0002] The camshaft is a component in the piston engine. Its function is to control the opening and closing action of the valve, and in the single pump engine, it also controls the opening and closing of the oil pump. Because the camshaft rotates at a high speed and needs to bear a large torque, it has high requirements for strength and support.

[0003] In the camshaft, the oil pump cam has a large Hertz stress (i.e. a large pressure on the unit area of the contact surface), which easily leads to sticking and wear of the oil pump cam. Therefore, the oil pump cam needs to be regularly disassembled and repaired. However, the shaft body of the existing camshaft is mostly of an integral structure, and the oil pump cam needs to be disassembled and repaired by dismounting the entire camshaft, which involves multiple key components and is a very complex work. Not only is the work load large, but also the repair is inconvenient, and the repair cost is increased. SUMMARY

[0004] In view of the above defects in the prior art, the utility model provides a camshaft, which can directly replace the oil pump cam in the camshaft box, reduces the work load of the repair work, improves the convenience of the repair, and reduces the repair cost.

[0005] To solve the above technical problems, the utility model adopts the technical scheme of:

[0006] A camshaft, comprising two valve cams and an oil pump cam located between the two valve cams, wherein the valve cam comprises a valve cam body and a valve cam arranged at both ends of the valve cam body, the oil pump cam comprises an oil pump cam body and an oil pump cam arranged in the middle of the oil pump cam body, and both ends of the oil pump cam body are detachably connected with the valve cams of the two valve cams respectively.

[0007] Among them, both ends of the oil pump cam body are provided with connecting flanges, and the connecting flanges are fastened and connected with the corresponding valve cams through bolts respectively.

[0008] Among them, the connecting flanges and the valve cams are provided with positioning structures.

[0009] Among them, the positioning structure comprises a positioning stop.

[0010] Among them, the positioning stop comprises a concave stop arranged on the connecting flange and a convex stop arranged on the valve cam and matched with the concave stop.

[0011] The positioning structure comprises a positioning pin.

[0012] The installation hole is in interference fit with the positioning pin, and the positioning hole is in clearance fit with the positioning pin.

[0013] The main journal of the camshaft is arranged on the valve timing camshaft body, and is located between the two valve timing cams.

[0014] The valve timing camshaft body, the main journal and the two valve timing cams are integrally arranged.

[0015] The oil pump camshaft body, the oil pump cam and the two connecting flanges are integrally arranged.

[0016] The beneficial effects of the camshaft are as follows:

[0017] The camshaft provided by the utility model adopts a split structure, the oil pump camshaft with the greatest wear risk is separated, the oil pump cam can be directly replaced in the camshaft box without disassembling the whole camshaft from the camshaft box, the work load of maintenance work is effectively reduced, the convenience of maintenance is improved, and the maintenance cost is reduced. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a structure schematic view of the camshaft of the utility model;

[0019] Figure 2 is a partial sectional view of Figure 1 ;

[0020] Figure 3 is a use state reference view of Figure 1 ;

[0021] In the drawing: 1, valve timing camshaft; 11, valve timing camshaft body; 12, valve timing cam; 121, convex stop; 13, main journal; 2, oil pump camshaft; 21, oil pump camshaft body; 22, oil pump cam; 23, connecting flange; 231, concave stop; 3, camshaft box; 4, bolt; 5, positioning pin. DETAILED DESCRIPTION

[0022] In order to make the purpose, technical scheme and advantages of the utility model more clear and obvious, the utility model is further described in detail below by combining with the drawings and examples, and it should be understood that the specific examples described herein are only used for explaining the utility model, and are not used for limiting the utility model.

[0023] As Figures 1 to 3As shown, the embodiment provides a camshaft, which comprises two valve cams 1 and an oil pump camshaft 2 located between the two valve cams 1, the valve cam 1 comprises a valve camshaft body 11 and a valve cam 12 arranged at both ends of the valve camshaft body 11, the oil pump camshaft 2 comprises an oil pump camshaft body 21 and an oil pump cam 22 arranged in the middle of the oil pump camshaft body 21, and both ends of the oil pump camshaft body 21 are detachably connected with the valve cams 12 of the two valve cams 1 respectively.

[0024] The camshaft in the embodiment adopts a split structure, by separating out the oil pump camshaft 2 with the highest risk of wear, the purpose of directly replacing the oil pump cam 22 in the camshaft box 3 without having to disassemble the entire camshaft from the camshaft box 3 is achieved, effectively reducing the workload of maintenance work, improving the convenience of maintenance, and reducing maintenance costs.

[0025] In order to facilitate connection, the embodiment is provided with a connecting flange 23 at both ends of the oil pump camshaft body 21, and the two connecting flanges 23 are fastened and connected with the corresponding valve cams 12 through bolts 4.

[0026] In order to ensure that the oil pump camshaft body 21 and the valve camshaft body 11 can be accurately aligned on the same axis, while enhancing the stability and reliability of the entire camshaft, the embodiment is provided with a positioning structure between the connecting flange 23 and the valve cam 12.

[0027] The positioning structure in the embodiment comprises a positioning stop.

[0028] In order to facilitate the smooth removal of the oil pump camshaft 2 from the camshaft box 3, the positioning stop in the embodiment comprises a concave stop 231 arranged on the connecting flange 23 and a convex stop 121 arranged on the valve cam 12 and matched with the concave stop 231. Of course, the convex stop 121 can also be arranged on the connecting flange 23, and the concave stop 231 can be arranged on the valve cam 12, which is determined according to the actual situation, and the embodiment does not limit this.

[0029] The positioning structure in the embodiment further comprises a positioning pin 5.

[0030] In order to facilitate the smooth removal of the oil pump camshaft 2 from the camshaft box 3, the embodiment is provided with a mounting hole on the valve cam 12 and matched with the positioning pin 5, and a positioning hole on the connecting flange 23 and matched with the positioning pin 5, and one end of the positioning pin 5 is arranged in the mounting hole, and the other end of the positioning pin 5 is arranged in the positioning hole. Of course, the mounting hole can also be arranged on the connecting flange 23, and the positioning hole can be arranged on the valve cam 12, which is determined according to the actual situation, and the embodiment does not limit this.

[0031] In the embodiment, the important reference position main journal 13 on the camshaft is arranged on the valve camshaft body 11, and the main journal 13 is located between the two valve cams 12.

[0032] In order to improve the strength of the valve camshaft 1, the valve camshaft body 11, the main journal 13 and the two valve cams 12 are preferably arranged integrally in the embodiment.

[0033] In order to improve the strength of the oil pump camshaft 2, the oil pump camshaft body 21, the oil pump cam 22 and the two connecting flanges 23 are preferably arranged integrally in the embodiment.

[0034] The dismounting method of the oil pump camshaft 2 in the camshaft box 3 is as follows:

[0035] Step one: remove the thrust structure of the camshaft at the free end a of the engine, remove the bolts 4 between the valve camshaft 1 and the oil pump camshaft 2 close to the free end a, and prevent the camshaft from rotating by fixing the flywheel at the flywheel end b of the engine during the removal, and if the angle of the camshaft needs to be adjusted, the camshaft can be rotated by the cranking;

[0036] Step two: pull out the valve camshaft 1 close to the free end a by a certain distance (about the length of a positioning pin 5), so that the valve camshaft 1 is separated from the oil pump camshaft 2;

[0037] Step three: remove the bolts 4 between the valve camshaft 1 and the oil pump camshaft 2 close to the flywheel end b;

[0038] Step four: pull out the oil pump camshaft 2 towards the free end a (about the length of a positioning pin 5), so that it is separated from the valve camshaft 1 close to the flywheel end b;

[0039] Step five: take out the oil pump camshaft 2 from the window of the camshaft box 3.

[0040] The installation steps are in the reverse order of the above steps, and the above steps can be executed in the reverse order.

[0041] In summary, the camshaft in the utility model realizes the purpose of directly replacing the oil pump cam 22 in the camshaft box 3 without dismounting the entire camshaft from the camshaft box 3, effectively reduces the workload of the maintenance work, improves the convenience of the maintenance, and reduces the maintenance cost.

[0042] The utility model is not limited to the above specific embodiments, and various modifications made by ordinary skilled persons in the art without creative labor are within the protection scope of the utility model.

Claims

1. A camshaft, characterized in that The camshaft (1) comprises a camshaft body (11) and a cam (12) arranged at both ends of the camshaft body (11), and the oil pump camshaft (2) comprises an oil pump camshaft body (21) and an oil pump cam (22) arranged in the middle of the oil pump camshaft body (21), and both ends of the oil pump camshaft body (21) are detachably connected with the cams (12) of the two camshafts (1) respectively. Both ends of the oil pump camshaft body (21) are provided with connecting flanges (23), and the two connecting flanges (23) are fastened and connected with the corresponding cams (12) through bolts (4) respectively.

2. The camshaft of claim 1, wherein, The connecting flanges (23) and the cams (12) are provided with positioning structures.

3. The camshaft of claim 2, wherein, The positioning structure comprises a positioning stop.

4. The camshaft of claim 3, wherein, The positioning stop comprises a recessed stop (231) arranged on the connecting flange (23) and a protruding stop (121) arranged on the cam (12) and matched with the recessed stop (231).

5. The camshaft of claim 4, wherein, The positioning structure comprises a positioning pin (5).

6. The camshaft of claim 3, wherein, The cam (12) is provided with a mounting hole matched with the positioning pin (5) in interference fit, the connecting flange (23) is provided with a positioning hole matched with the positioning pin (5) in clearance fit, one end of the positioning pin (5) is arranged in the mounting hole, and the other end of the positioning pin (5) is arranged in the positioning hole.

7. The camshaft of claim 6, wherein, The main journal (13) of the camshaft is arranged on the camshaft body (11), and the main journal (13) is located between the two cams (12).

8. The camshaft of claim 1, wherein, The camshaft body (11), the main journal (13) and the two cams (12) are integrally arranged.

9. The camshaft of claim 8, wherein, The oil pump camshaft body (21), the oil pump cam (22) and the two connecting flanges (23) are integrally arranged.

10. The camshaft of claim 2, wherein, ​

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