Annotation: In the present-day rocket engineering, the liquid rocket engines with pump feed system have gained wide acceptance. As a rule, the pumps used in liquid rocket engines are screw-axifugal. The screw serves to increase pressure upstream of the axifugal wheel, thus ensuring its cavitation-free operation. The screws used in the screw-axifugal pumps of liquid rocket engines may be of two types: with constant and variable step. The screws with constant step are easier to calculate, profile and manufacture as compared to the screws with variable step. As known from the literature, the use of the screw with variable step increases power characteristics of the screw-axifugal pump. The purpose of investigation is comparative analysis of cavitation and power characteristics of the following high-speed low-consumption screw-axifugal pumps of liquid rocket engines with jointed screws, screws of constant and variable step:  RD868 engine oxidizer and fuel pumps;  RD859 engine fuel pumps;  RD861K engine fuel pumps. Besides, the analysis has been made of the impact of design features and geometrical dimensions of the screws with variable and constant step on power characteristics of the screw-axifugal high-speed lowconsumption pumps of liquid rocket engines. Special attention has been given to the analysis of anticavitation properties of the pumps with screws of variable step and pumps with jointed screws. Based on the results of investigation, it has been ascertained that when using the joint screws and screws with variable step instead of the screws with constant step in the high-speed low-consumption screw-axifugal pumps of liquid rocket engines, the pump delivery head increases from 0.65 to 3.83%, the efficiency increases up to 1.7%. The use of jointed screw and screw of variable step as compared with the screw of constant step does not have any impact on cavitation properties of low-consumption crew-axifugal pumps of liquid rocket engines.

Annotation: The article presents the experience of creating LRE turbopump units by the Rocket Engines Design Office (DO-4) at Yuzhnoye SDO. The best known turbopump units designs developed by DO are described. Both earlier developments of DO and the turbopump unit being now in final testing phase are considered. The design evolution of both separate assemblies and of entire unit is shown. The design evolution allowed increasing the unit’s lifetime dozens times. For example, the lifetime of the first turbopump units developed by DO did not exceed 150 s. Currently, the DO has in stock the engines with lifetime of ~19000 s. The information is presented on the problems that the designers faced in testing the turbopumop unit and the ways to solve them. The unique achievement are presented. At present, there are no analogs of some units in the world. The article presents the information on the latest achievements of DO, such as the face seal on pump vane discs whose use fully excludes unwanted leaks. Having analyzed the data presented, one may conclude that the Rocket Engines Design Office and Yuzhnoye SDO as a whole accumulated sufficient experience and knowledge allowing solving any problems that may arise when developing a new LRE turbopump unit, and successfully operating LRE with turbopump units, including those in the engines with generator gas afterburning created in recent years testify to a great value of accumulated experience.