Kinetic analysis method for marine valve camshaft system in consideration of friction effect

Patent metadata

Field	Value
Publication number	US-2025389622-A1
Application number	US-202418944419-A
Country	US
Kind code	A1
Filing date	Nov 12, 2024
Priority date	Jun 21, 2024
Publication date	Dec 25, 2025
Grant date	—

Abstract

Disclosed is a kinetic analysis method for a marine valve camshaft system in consideration of a friction effect. The method includes the following steps: S1, computing load torque of a camshaft: computing the load torque of the camshaft during the operation on the basis of composition and an operation condition of a valve train; S2, computing torsional vibration of the valve camshaft system: analyzing, on the basis of an excitation condition of the load torque of the valve camshaft, a torsional vibration phenomenon of the camshaft system and influence of the friction effect on vibration characteristics in combination with physical properties including stiffness, damping and a moment of inertia of the camshaft system; and S3, conducting comprehensive result analysis and influence evaluation: comprehensively analyzing and evaluating a torsional vibration result, and paying attention to influence of the friction effect on the camshaft system.

First claim

What is claimed is:

1 . A kinetic analysis method for a marine valve camshaft system in consideration of a friction effect, comprising the following steps:
S1, computing load torque of a camshaft: computing the load torque borne by the camshaft during the operation on the basis of composition and an operation condition of a valve train; S2, computing torsional vibration of the valve camshaft system: analyzing, on the basis of an excitation condition of the load torque of the valve camshaft, a torsional vibration phenomenon of the camshaft system and influence of the friction effect on vibration characteristics in combination with physical properties comprising stiffness, damping and a moment of inertia of the camshaft system; and S3, conducting comprehensive result analysis and influence evaluation: comprehensively analyzing and evaluating a torsional vibration result, and paying attention to influence of the friction effect on the camshaft system.

2 . The kinetic analysis method for a marine valve camshaft system in consideration of a friction effect according to claim 1 , wherein the computing load torque of a camshaft in S1 comprises:
S11, computing the force of the valve train: computing a force F 1 between a cam and a tappet, wherein a computation formula is as follows:

F
1

=

F

T
⁢
1

+

F

N
⁢
1

+

i
·

F
G

,

wherein
F T1 denotes a valve spring force, F N1 denotes a part inertia force, F G denotes a gas force, i denotes an air intake and exhaust indicator, i=0 indicates air intake, and i=1 indicates air exhaust;
S12, computing a gear transmission force: analyzing torque excitation of a tooth surface meshing force between gear pairs, and computing a gear meshing excitation force in a torsion direction;
S13, computing a valve cam pair contact friction force: evaluating a friction force and oil film performance of a cam pair through kinematics and friction and lubrication analysis; and
S14, computing valve cam load torque: computing load torque of a single valve camshaft on the basis of the force between the cam and the tappet and a force arm corresponding to the force.

3 . The kinetic analysis method for a marine valve camshaft system in consideration of a friction effect according to claim 2 , wherein a computation formula of the valve spring force F T1 is as follows:

F

T
⁢
1

=

k
r

[

F

0
⁢
1

+

k

s
⁢
1

·

h

α
⁢
1

]

,

k r denotes a rocker-arm ratio, F 01 denotes a valve spring pretightening force, k s1 denotes valve spring stiffness, and h a i denotes valve cam lift;
a computation formula of the part inertia force F N1 is as follows:

F

N
⁢
1

=

M
1

·

d
2

⁢

h

α
⁢
1

dt
2

=

M
1

·

ω
0
2

·

d
2

⁢

h

α
⁢
1

d
⁢

α
2

,

M 1 denotes a lumped mass of the valve train, and ω 0 denotes a valve cam angular speed; and
a computation formula of the gas force F G is as follows:

F
G

=

π
·

d
v
2

4

·

p
g

·

10
5

,

wherein
d v denotes a valve disc diameter, and p g denotes in-cylinder pressure.

4 . The kinetic analysis method for a marine valve camshaft system in cons

Assignees

• Univ Harbin Eng

Inventors

• Shi Xiujiang
• Hua Deliang
• Li Wanyou
• Lu Xiqun
• Lv Zhijun
• Guo Yibin
• Ma Xuan
• Wang Donghua
• Zhao Bin
• Sun Pengfei

Classifications

• G01M15/042

  by monitoring a single specific parameter not covered by groups G01M15/06 - G01M15/12 · CPC title

• G01M15/05 Primary

  by combined monitoring of two or more different engine parameters · CPC title

• F01L1/047 Primary

  Camshafts · CPC title

• G06F2119/14

  Force analysis or force optimisation, e.g. static or dynamic forces · CPC title

• G06F2113/08

  Fluids · CPC title