please-translate-the-next-statement-into-a-formal-academic-essay增材制造的抗扭配油盖中心通过双键和螺栓与摆动缸转轴连接外圈通过螺栓与大腿壳体连接起到传输髋关节扭矩的作用。同时内嵌的弯曲流道连通了从摆动缸转轴到大腿壳体的油路。n为了精简大腿结构使其像大部分电驱四足机器人一样将所有部件置于完全防护的壳体之内本文引入了一种增材制造的一体化大腿结构。采用内嵌在大腿壳体中的直线活塞缸作为膝关节的液压执行器通过滑块曲柄机构推动小腿摆动小腿作为曲

The anti-torsion oil cap center of the additive manufacturing is connected to the swing cylinder shaft through double joints and bolts, and the outer ring is connected to the thigh shell through bolts, serving to transmit the hip joint torque. Meanwhile, the embedded curved flow channel connects the oil circuit from the swing cylinder shaft to the thigh shell.

In order to simplify the structure of the thigh and place all components inside a fully protected shell, like most electrically driven quadruped robots, this article introduces an additive manufacturing integrated thigh structure. A straight piston cylinder embedded in the thigh shell is used as the hydraulic actuator of the knee joint, pushing the calf swing through a slider crank mechanism, where the calf acts as a crank and the piston rod end acts as a slider.

Thanks to the design flexibility brought by additive manufacturing, as well as the high hardness of titanium alloy materials, the traditional hydraulic cylinder body can be discarded. The cylindrical inner cavity of the thigh shell (blue part in the figure) is used as the oil chamber of the hydraulic cylinder. The oil ports at both ends of the oil chamber are connected to the anti-torsion oil cap (green part in the figure) by the built-in oil passage. During additive manufacturing, the oil passage and oil chamber are integrated, and the inner wall of the oil chamber that matches the piston needs to be machined to ensure surface roughness and dimensional fit accuracy, while the inner wall of the oil passage needs to be polished by abrasive flow to remove burrs.

The end of the piston rod is connected to the connecting rod through a special piston hinge sleeve (gray part in the figure). This part is essentially a slider in the cavity of the thigh shell, providing radial support and limiting movement while pushing the connecting rod. Together with the guiding sleeve at one end of the cylinder, it forms a double-end support for the piston rod.

In order to make this embedded structure assembly feasible, unlike traditional guiding sleeves, the guiding sleeve of the embedded hydraulic cylinder extends axially to the end of the thigh shell cavity, sliding and frictionally matching with the piston hinge sleeve to form a long bucket-shaped structure (transparent part in the figure). During assembly, the piston hinge sleeve is pre-assembled with the connecting rod, the piston rod passes through the guiding sleeve, and the rod end is fixed to the piston hinge sleeve through a thread. Then the whole assembly is filled into the cavity of the thigh shell, and the guiding sleeve is fixed to the shell through a thread.

In summary, this paper proposes an additive manufacturing integrated thigh structure that simplifies the structure of the thigh and places all components inside a fully protected shell. The structure adopts a straight piston cylinder embedded in the thigh shell as the hydraulic actuator of the knee joint, and uses the cylindrical inner cavity of the thigh shell as the oil chamber of the hydraulic cylinder, which is connected to the anti-torsion oil cap by the built-in oil passage. The special piston hinge sleeve provides radial support and limiting movement while pushing the connecting rod, and the guiding sleeve of the embedded hydraulic cylinder extends axially to the end of the thigh shell cavity to form a long bucket-shaped structure, making the assembly feasible.