At present, there are few harvesters for dandelion (Taraxacum mongolicum) seeds, which limits the large-area planting of dandelion. Furthermore, manual harvesting is characterized by huge labor intensity, low efficiency, and high costs. Combining the material characteristics of dandelion plants and seeds with agronomic requirements for harvesting dandelion seeds, a self-propelled dandelion seed harvester was designed. The harvester is mainly composed of collection devices, separation devices, transmission devices, and a rack. It can facilitate seed collection from plants, seed transportation, and seed–pappus separation in one operation. The collection and separation processes of dandelion seeds were studied to ascertain the main factors that affect the collection rate. Then, the collection and separation devices were designed, and their parameters were analyzed. Taking the forward speed, wind velocity of blowers, and rate of rotation of the drum as test factors and the collection rate as the evaluation index, quadratic regression orthogonal rotating field tests were performed. In this way, the optimal combination of operation parameters was determined: the collection rate is optimal when the forward speed is 0.8 m·s⁻¹, the air velocity from the blowers is 1.63 m·s⁻¹, and the rate of rotation of the drum is 419 rpm. Field test results showed that a favorable harvesting effect was achieved after operation of the harvester, and only small amounts of dandelion seeds remained unharvested. Under the optimal parameter combination, the collection rate reached 89.1%, which could meet requirements for practical field harvesting of dandelion seeds. The test results satisfy the design requirement.

In order to solve the problems that arise from poor fruit–soil separation, a high fruit burial rate, and a high crushing rate during peanut harvesting under clay-heavy soil conditions, a multistage roller peanut harvester that is suitable for operation in these environments was designed. Considering the growth conditions of peanuts and the agronomic requirements of planting, the movement process and separation operation mechanism of the seedling and fruit–soil were analyzed, coupled with the vibrating excavation device and the conveying roller group. A dynamic model of seedling fruit–soil coupled throwing and soil collisions on the conveyor roller was constructed. The structure and maximum swing angle of the vibrating excavation device, the number of stages of the conveying roller group, the diameter of the throwing roller, and other parameters were determined through analyses. Utilizing the design results, a prototype was built, and a multifactor test for the operation parameters was carried out. The forward speed of the machine, the excavation depth, and the speed of the conveyor roller were used as the test factors. The fruit burial rate and the peanut crushing rate were used as the test indexes. The Box–Behnken test method was used to establish a regression equation between the factors and the test indexes, and the influence law of each factor on the peanut harvest index was determined. When the optimal parameters were combined, i.e., 1.0 m/s, 150 mm, and 80 r/min, the fruit burial rate and crushing rate of peanuts were 6.2% and 6.4%, respectively. The performance of the machine meets the design requirements, and our research results can provide a reference for the research of mechanized peanut harvesting technology and equipment.