A single-roller-based rocker arm structure

Abstract

The utility model discloses a kind of rocker structure based on single roller, belong to engine rocker technical field, solve the problem that existing roller and cam are easy to form point contact, the contact stress caused by point contact is easy to cause the damage of part.The rocker structure includes rocker shaft, the rocker shaft is rotatably provided with rocker, one end of the rocker is provided with pin shaft, the pin shaft is rotatably provided with roller, there is at least one non-linear cylindrical surface between the outer surface of the pin shaft and the inner surface of the roller, the outer surface of the pin shaft and the inner surface of the roller are provided with movable gap, the roller is provided with camshaft below, the camshaft is provided with cam and is in contact with the roller, the outer surface of the cam and the roller is contacted, lubrication channel is opened on the pin shaft and the roller.The rocker structure based on single roller of the utility model greatly reduces the contact stress between roller and cam, greatly improves the contact reliability and durability between roller and cam.

Description

Technical Field

[0001] This utility model relates to the field of engine rocker arm technology, and in particular to a rocker arm structure based on a single roller. Background Technology

[0002] In the valve train of an internal combustion engine, one type of valve train uses a roller rocker arm assembly. In practical applications of rocker arm assemblies with rollers, the valve load will create an eccentric additional torque between the camshaft 7 and the roller 4. In addition, in the transmission chain from the valve back to the camshaft, there are dimensional tolerances caused by manufacturing, clearances between contacting parts, deformation of parts under load and between contacting parts, clearances between the rocker arm shaft and the rocker arm shaft hole, clearances between the rocker arm shaft and the rocker arm shaft support, and clearances between the camshaft and the camshaft support. All of these can cause an angle between the plane of action of the valve reaction load and the plane of rocker arm movement. Due to the existence of the angle, the contact area between the camshaft 7 and the roller 4 is greatly reduced, resulting in a significant increase in the pressure between the camshaft 7 and the roller 4. This leads to abnormal contact failure between the camshaft 7 and the roller 4, easily causing roller wear and frequent malfunctions. Utility Model Content

[0003] The technical problem to be solved by this utility model is to address the above-mentioned shortcomings of the prior art by providing a rocker arm structure based on a single roller, which greatly reduces the contact stress between the roller and the cam, greatly improves the contact reliability and durability between the roller and the cam, and has the characteristics of being easy to use and highly practical.

[0004] The technical solution adopted by this utility model is: a rocker arm structure based on a single roller, including a rocker arm shaft, a rocker arm rotatably mounted on the rocker arm shaft, a pin shaft at one end of the rocker arm, a roller rotatably mounted on the pin shaft, at least one non-linear cylindrical surface between the outer surface of the pin shaft and the inner surface of the roller, a movable gap between the outer surface of the pin shaft and the inner surface of the roller, a cam shaft below the roller, a cam shaft with a cam in contact with the roller, the cam contacting the outer surface of the roller, and lubrication channels opened on the pin shaft and the roller.

[0005] As a further improvement, the outer surface of the pin is a non-linear cylindrical surface, the outer surface of the pin is barrel-shaped or drum-shaped, and the inner surface of the roller is a cylindrical surface.

[0006] Furthermore, the inner surface of the roller is a non-linear cylindrical surface, the inner surface of the roller is barrel-shaped or drum-shaped, and the middle position of the outer surface of the pin is a cylindrical surface.

[0007] Furthermore, both the inner surface of the roller and the outer surface of the pin are non-linear cylindrical surfaces, and both the inner surface of the roller and the outer surface of the pin are barrel-shaped or drum-shaped.

[0008] Furthermore, the rocker arm is provided with a first oil passage, the pin shaft is provided with an L-shaped oil passage, one end of the first oil passage is connected to the input end of the L-shaped oil passage, the other end of the first oil passage is connected to the main oil passage of the machine body, and the L-shaped oil passage is connected to the movable clearance.

[0009] Furthermore, two branch oil passages are provided on the pin shaft, which are arranged perpendicular to the L-shaped oil passages. The two branch oil passages are arranged on both sides of the contact surface between the pin shaft and the roller.

[0010] Furthermore, each of the L-shaped oil passage input ends is provided with a lubrication groove arranged around the outer surface of the pin.

[0011] Beneficial effects

[0012] Compared with the prior art, this utility model has the following advantages:

[0013] This invention relates to a rocker arm structure based on a single roller. A cam rotates around a camshaft, driving a roller via its inner surface. The roller then drives a pin, which in turn drives a rocker arm. The rocker arm, mounted on a rocker arm shaft, functions as a lever, oscillating and driving a valve screw to open the valve. During valve opening, the valve load reacts through the rocker arm, acting on the pin, roller, and ultimately the cam. This design incorporates at least one non-linear cylindrical element between the outer surface of the pin and the inner surface of the roller. Because the inner surface of the roller or the outer surface of the pin is barrel-shaped or drum-shaped, the roller and pin can adaptively change the point contact phenomenon that may exist between the roller and the cam under possible off-center load. This changes the theoretical point contact in the rocker arm motion plane into a theoretical line contact (actually, it changes the local small area surface contact into a larger area surface contact). This can greatly reduce the contact stress between the roller and the cam, effectively improve the contact reliability and durability between the roller and the cam, reduce the occurrence of failures, and has the characteristics of strong practicality and wide applicability. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure and operation of existing technology;

[0015] Figure 2 This is a schematic diagram of the main structure of the present invention;

[0016] Figure 3 This is a side view of the structure of the present invention;

[0017] Figure 4 This is an enlarged cross-sectional view of the present invention.

[0018] Figure 5 This is a schematic diagram of the motion in Embodiment 1 of this utility model;

[0019] Figure 6 This is a schematic diagram of the motion in Embodiment 2 of this utility model;

[0020] Figure 7 This is a schematic diagram of the motion in Embodiment 3 of this utility model.

[0021] Wherein: 1-rocker arm shaft, 2-rocker arm, 3-pin shaft, 4-roller, 5-movement clearance, 6-camshaft, 7-cam, 8-first oil passage, 9-L-shaped oil passage, 10-diverting oil passage, 11-lubrication groove. Detailed Implementation

[0022] The present invention will be further described below with reference to specific embodiments shown in the accompanying drawings.

[0023] See Figure 2-4 As shown, this utility model discloses a rocker arm structure based on a single roller, including a rocker arm shaft 1, a rocker arm 2 rotatably mounted on the rocker arm shaft 1, a pin 3 at one end of the rocker arm 2, and a roller 4 rotatably mounted on the pin 3. There is at least one non-linear cylindrical surface between the outer surface of the pin 3 and the inner surface of the roller 4. A movable gap 5 is provided between the outer surface of the pin 3 and the inner surface of the roller 4. A cam shaft 6 is located below the roller 4, and a cam 7 is mounted on the cam shaft 6 that contacts the roller 4. The cam 7 contacts the outer surface of the roller 4. Lubrication channels are provided on the pin 3 and the roller 4. The cam 7 rotates around the cam shaft 6. Under the action of rotation, the cam 7 drives the roller 4, and the roller 4 drives the pin 3 through its inner surface. The pin 3 drives the rocker arm 2 to achieve its function. The rocker arm 2, mounted on the rocker arm shaft 1, achieves a lever-like swinging function. The valve screw is driven by the rocker arm 2, which in turn drives the valve to open. During the valve opening process, the valve load is reflected by the rocker arm 2 onto the pin 3, roller 4, and ultimately the cam 7. This design provides at least one non-linear cylindrical surface between the outer surface of the pin 3 and the inner surface of the roller 4. Because the inner surface of the roller 4 or the outer surface of the pin 3 is barrel-shaped or drum-shaped, the roller 4 and the pin 3 can adaptively change the possible point contact phenomenon between the roller 4 and the cam 7 under possible off-center load. This changes the theoretical point contact in the rocker arm movement plane into a theoretical line contact (actually, it changes the local small area surface contact into a larger area surface contact). This can greatly reduce the contact stress between the roller and the cam, effectively improve the contact reliability and durability between the roller 4 and the cam 7, and reduce the occurrence of failures.

[0024] Example 1

[0025] See Figure 5The diagram shows a specific embodiment of this utility model. This embodiment features a rocker arm structure based on a single roller, including a rocker arm shaft 1, a rocker arm 2 rotatably mounted on the rocker arm shaft 1, and a pin 3 at one end of the rocker arm 2. The outer surface of the pin 3 is a non-linear cylindrical surface, either barrel-shaped or drum-shaped. The inner surface of the roller 4 is cylindrical. When there is an angle of inclination, the outer surface of the pin 3, under the action of the arc, can keep the roller 4 from tilting and maintain a horizontal state. It automatically adjusts the misalignment between the cam 7 and the roller 4 caused by the off-center load of the roller 4 or the pin 3, as well as the theoretical point contact caused by geometric and dimensional reasons such as processing and assembly. It always maintains a line contact between the outer surface of the roller 4 and the cam 6. According to Hertz stress theory, the stress of point contact is much greater than that of line contact or surface contact, thereby effectively reducing stress and greatly improving the contact reliability between the cam 7 and the roller 4.

[0026] Example 2

[0027] See Figure 6 As shown, this is a specific embodiment of the present invention. This embodiment has a rocker arm structure based on a single roller, including a rocker arm shaft 1, a rocker arm 2 rotatably mounted on the rocker arm shaft 1, a pin 3 at one end of the rocker arm 2, a non-linear cylindrical inner surface of the roller 4, and a barrel or drum-shaped inner surface. The middle position of the outer surface of the pin 3 is a cylindrical surface. When there is an angle of inclination, the roller 4 can be kept from tilting under the action of the curvature of the inner surface of the roller 4, and always remain in a horizontal state. The outer surface of the roller 4 and the cam 7 are always in line contact, which greatly reduces the contact stress between the roller 4 and the cam 7.

[0028] Example 3

[0029] See Figure 7 As shown, this is a specific embodiment of the present invention. This embodiment has a rocker arm structure based on a single roller, including a rocker arm shaft 1, a rocker arm 2 rotatably mounted on the rocker arm shaft 1, and a pin 3 at one end of the rocker arm 2. The inner surface of the roller 4 and the outer surface of the pin 3 are both non-linear cylindrical surfaces. The inner surface of the roller 4 and the outer surface of the pin 3 are both barrel-shaped or drum-shaped, and a double arc surface contact method is adopted. The movement gap 5 between the two is larger, which is more conducive to the adaptive movement of the pin 3. The outer surface of the roller 4 and the cam 7 are always in line contact, which greatly reduces the contact stress between the roller 4 and the cam 7.

[0030] Furthermore, the lubrication channel includes a first oil passage 8 and an L-shaped oil passage 9. The rocker arm 2 has a first oil passage 8, and the pin 3 has an L-shaped oil passage 9. One end of the first oil passage 8 is connected to the input end of the L-shaped oil passage 9, and the other end of the first oil passage 8 is connected to the main oil passage of the engine body. The L-shaped oil passage 9 is connected to the movable clearance 5. When the engine is running, the lubricating oil enters the radial oil outlet hole of the rocker arm shaft 2 through the main oil passage of the engine body, and then passes through the first oil passage 8 of the rocker arm. The lubricating oil in the first oil passage 8 flows to the L-shaped oil passage 9 of the pin 3, and passes through the movable clearance 5 between the pin 3 and the roller 4 at the outlet end, providing lubrication for the friction between the pin 3 and the roller 4, and improving the service life of the pin 3 and the roller 4.

[0031] Furthermore, two branch oil passages 10 are provided on the pin 3, which are arranged perpendicular to the L-shaped oil passages 9. The two branch oil passages 10 are arranged on both sides of the contact surface between the pin 3 and the roller 4. The lubricating oil flows from the branch oil passages 10 on both sides into the movable gaps 5 on both sides, so as to improve the lubrication effect.

[0032] Furthermore, each of the L-shaped oil passages 9 has a lubrication groove 11 arranged around the outer surface of the pin 3, so that the lubricating oil can flow smoothly from the first oil passage 8 to the L-shaped oil passage 9, and then from the L-shaped oil passage 9 to the branch oil passage 10.

[0033] The above description is only a preferred embodiment of the present utility model. It should be noted that for those skilled in the art, several modifications and improvements can be made without departing from the structure of the present utility model. These modifications and improvements will not affect the effectiveness of the present utility model or the practicality of the patent.

Claims

1. A rocker arm structure based on a single roller, characterized in that, The device includes a rocker arm shaft (1), on which a rocker arm (2) is rotatably mounted. One end of the rocker arm (2) is provided with a pin (3), and a roller (4) is rotatably mounted on the pin (3). There is at least one non-linear cylindrical surface between the outer surface of the pin (3) and the inner surface of the roller (4). There is a movable gap (5) between the outer surface of the pin (3) and the inner surface of the roller (4). A cam shaft (6) is provided below the roller (4). A cam (7) is provided on the cam shaft (6) that contacts the roller (4). The cam (7) contacts the outer surface of the roller (4). Lubrication channels are provided on the pin (3) and the roller (4).

2. The rocker arm structure based on a single roller according to claim 1, characterized in that, The outer surface of the pin (3) is a non-linear cylindrical surface, the outer surface of the pin (3) is barrel-shaped or drum-shaped, and the inner surface of the roller (4) is a cylindrical surface.

3. The rocker arm structure based on a single roller according to claim 1, characterized in that, The inner surface of the roller (4) is a non-linear cylindrical surface, the inner surface of the roller (4) is barrel-shaped or drum-shaped, and the middle position of the outer surface of the pin (3) is a cylindrical surface.

4. The rocker arm structure based on a single roller according to claim 1, characterized in that, The inner surface of the roller (4) and the outer surface of the pin (3) are both non-linear cylindrical surfaces, and the inner surface of the roller (4) and the outer surface of the pin (3) are both barrel-shaped or drum-shaped.

5. The rocker arm structure based on a single roller according to claim 1, characterized in that, The lubrication channel includes a first oil passage (8) and an L-shaped oil passage (9). The rocker arm (2) is provided with the first oil passage (8), and the pin (3) is provided with the L-shaped oil passage (9). One end of the first oil passage (8) is connected to the input end of the L-shaped oil passage (9), and the other end of the first oil passage (8) is connected to the main oil passage of the machine body. The L-shaped oil passage (9) is connected to the movable clearance (5).

6. The rocker arm structure based on a single roller according to claim 5, characterized in that, The pin (3) has two branch oil channels (10) arranged perpendicular to the L-shaped oil channel (9), and the two branch oil channels (10) are arranged on both sides of the contact surface between the pin (3) and the roller (4).

7. A rocker arm structure based on a single roller according to claim 6, characterized in that, The L-shaped oil passage (9) is provided with a lubrication groove (11) arranged around the outer surface of the pin (3) at the input end.

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