The recirculating planetary roller screw mechanism (RPRSM) is a transmission mechanism that engages the screw and nut threaded by multiple grooved rollers. In this paper, firstly, the design method of RPRSM nut threadless area is proposed, and the equations related to the structural parameters of nut threadless area are derived. On this basis, the cross-section design method of roller, screw and nut is constructed according to the actual situation of engagements between the screw/nut and the roller. By adjusting the gap between the two beveled edges and that between the arc and the beveled edge, the accuracy of the thread engagements between the screw/nut and the roller can be improved. Secondly, to ensure the engagements of the screw/nut and the roller, the distance formula from the center surface of the different rollers to the end surface of cam ring is given. Thirdly, combined with the working principle and structural composition of RPRSM, the component model is established according to its relevant structural parameters, and the virtual assembly is completed. Finally, the 3D model is imported into the ADAMS simulation software for multi-rigid body dynamics. The dynamic characteristic is analyzed and the simulated values are compared with the theoretical values. The results show that the contact forces between the screw/nut and the roller are sinusoidal, mainly due to the existence of a small gap between the roller and the carrier. The maximum collision forces between the roller and cam ring are independent from load magnitude. Normally, the collision force between the roller and the carrier increases as the load increases. When RPRSM is in the transmission process, the roller angular speed in nut threadless area begins to appear abruptly, and the position of the maximum change is at the contact between the roller and the convex platform of cam ring. The design of the nut threadless area and the virtual assembly method proposed in this paper can provide a theoretical guidance for RPRSM research, as well as a reference for overall performance optimization.

Geometric error is the main obstacle that affects the quasi-static accuracy of horizontal boring machine tool. To improve quasi-static performance, the error terms that all PIGEs and PDGEs must be measurement and identified precisely. This study proposes a novel methodology for measuring and identifying that the above two types of geometric errors based on DBB for rotary axis. The error terms of linear axis are identified from measurement model based on exponential product method and a preset measure trajectory, and the measure coordinate system be unified together with reference coordinate to lower the uncertainty of identification accuracy, and then Elastic Net method and improved weight function IGG3-LTS method are established to identify the PIGEs and PDGEs of rotary and linear axes respectively. This method has the advantage that measurement with built in-sensors method that synchronously without interfering with the running state of the machine tool, and neither the inaccuracy of reference-frame misalignment nor installation error of the measuring instrument affects the geometric error identification results of linear axis. , the other is all PIGEs and PDGEs particular to rotary axis of horizontal boring machine tool are determinated accurately. The measurement and identify strategy is demonstrated by experimental comparison on a four-axis precision horizontal boring machine tool, the minimum compensation rate of each precision index of test specimen is 40.0%, the average compensation rate is 52.7%, and the maximum compensation rate is 62.5%. under the actual condition of machine tool.