144
4 Structure and Mechanism Technology of Lunar Lander
Fig. 4.25 Composition of the lunar rover transfer mechanism of the Chang’E-3 lunar lander. 1Deployment and hold down mechanism for ladders; 2-Ladders assembly; 3-Hold down and release
mechanism; 4-Four-bar linkage assembly; 5-Slow release mechanism
(1) From launch to soft-landing: The transfer mechanism was folded and held
down on the lateral side of the lunar lander to withstand the launch and landing
loads.
(2) Operation on lunar surface:
1. After the lunar lander was landed, the ladders of transfer mechanism was
released, deployed and held down.
2. The lunar rover drove to a predetermined position on the ladders of transfer
mechanism, then stopped.
3. The four-bar linkage assembly of transfer mechanism was released. Then the
four-bar linkage assembly was deployed by the slow release mechanism under
the effect of lunar gravity to touch lunar surface with the lunar rover on the
ladders.
4. After the transfer mechanism touched lunar surface, the transfer mechanism
stopped and the lunar rover drove from the ladders of transfer mechanism to
lunar surface.
The transfer process is shown in Fig. 4.26.
4. Transfer Mechanism Analysis
The analysis of the transfer mechanism included structural modal analysis, static analysis, frequency response analysis, and mechanism dynamics analysis at hold down
status. For structural analysis such as modal analysis, static analysis and frequency
response analysis, the analysis method was the same as the analysis method of
general spacecraft structure. Therefore, the structural analysis of the transfer mechanism will not be introduced here. Because the movement of the transfer mechanism
4 Structure and Mechanism Technology of Lunar Lander
Fig. 4.25 Composition of the lunar rover transfer mechanism of the Chang’E-3 lunar lander. 1Deployment and hold down mechanism for ladders; 2-Ladders assembly; 3-Hold down and release
mechanism; 4-Four-bar linkage assembly; 5-Slow release mechanism
(1) From launch to soft-landing: The transfer mechanism was folded and held
down on the lateral side of the lunar lander to withstand the launch and landing
loads.
(2) Operation on lunar surface:
1. After the lunar lander was landed, the ladders of transfer mechanism was
released, deployed and held down.
2. The lunar rover drove to a predetermined position on the ladders of transfer
mechanism, then stopped.
3. The four-bar linkage assembly of transfer mechanism was released. Then the
four-bar linkage assembly was deployed by the slow release mechanism under
the effect of lunar gravity to touch lunar surface with the lunar rover on the
ladders.
4. After the transfer mechanism touched lunar surface, the transfer mechanism
stopped and the lunar rover drove from the ladders of transfer mechanism to
lunar surface.
The transfer process is shown in Fig. 4.26.
4. Transfer Mechanism Analysis
The analysis of the transfer mechanism included structural modal analysis, static analysis, frequency response analysis, and mechanism dynamics analysis at hold down
status. For structural analysis such as modal analysis, static analysis and frequency
response analysis, the analysis method was the same as the analysis method of
general spacecraft structure. Therefore, the structural analysis of the transfer mechanism will not be introduced here. Because the movement of the transfer mechanism