The textbook presents information on the types, constructional features, working, and essential terms and definitions of semi-rotary actuators and hydraulic motors. Many solved, and unsolved numerical exercise problems are given in the textbook. The book uses the SI system of units. The language of the book is simple, the topics are logically arranged, and information is most up-to-date.A fluid power professional should possess exceptional knowledge about hydraulic motors for his/her continuing professional development and career advancement. A faculty or a student in an engineering institution must acquire the knowledge of hydraulic motors to upgrade his/her knowledge. As the knowledge and skill of the reader improve, professional life is undoubtedly going to be more outstanding and comfortable.The book has been written by a professional trainer who has trained thousands of professionals and students, over 25 years. If you are looking for a more in-depth knowledge into fluid power, then this book is a valuable resource that will assist you in your quest for professional development.