Electric energy recovery system for a hydraulic forklift

This thesis studies the possibilities to recover energy in a hydraulic forklift system. Controlling of the system is done directly with an electric servo motor drive and a hydraulic pump. A real system was built and tested and simulations of the system were made with Matlab. Results of the system and simulations were analysed and compared and according to them, energy can be recovered efficiently from the hydraulic forklift system. Also new ideas and directions of further research were obtained with the help of this research.

Towards a better energy efficiency through a systems approach in an industrial forklift

The purpose of this study is to improve the potential energy recovery to electric energy in an electrohydraulic forklift system. The initial achieved result for energy saving ratio after structural optimization is 40 %. Component optimization is applied to the tested drive which consists of a DTC controlled electric servo motor directly running a reversible hydraulic pump. According to the study the energy efficiency and the energy recovery from the electro-hydraulic forklift system can be increased by 11 % units. New ideas and directions of further research were obtained during the study.

Operator's manual : truck, forklift, DED, pneumatic tire, articulated, frame steer, 4,000 lb. capacity, rough terrain, Army model MHE 237 (J.I. Case model M4K) (NSN 3930-01-076-4237).

"May 1980."

Unit, direct support, and general support maintenance manual : truck, forklift, 6000 lbs, variable reach, rough terrain, model 6000M, NSN 3930-01-158-0849 (Army model MHE 269).

"October 1989."

Unit, direct support, and general support maintenance repair parts and special tools lists (including depot maintenance repair parts and special tools lists) : truck, forklift, power shift GED, 6000 lb capacity, SRT, 180 in. lift height, Army model MHE-212 (NSN 3930-00-489-0263), Allis Chalmers model F-60-24PS-180.

"October 1992."

Direct support and general support maintenance manual for truck, forklift, 6,000 lb., variable reach, rough terrain, NSN 3930-01-158-0849.

"March 1993."

Unit, direct support, and general support maintenance repair parts and special tools lists : truck, forklift, electric, solid rubber tires, 6000 lb capacity, 180 in. lift (Drexel Dynamics model FL60-EE5600) (Army model MHE206), NSN 3930-00-935-7867.

"November 1992."

Operator, organizational, direct and general support, and depot maintenance manual : loader, scoop type, DED, 4-wheel drive, pneumatic tires, hinged frame steer, w/forklift, front mounted, hydraulic operated, 10,500-lb capacity (Eaton, Yale & Towne Trojan model 3000M) FSN 3805-074-6378.

Includes index.

Technical manual, maintenance instructions, organizational maintenance : truck, forklift, DED, pneumatic tire, 10,000 lb. capacity, rough terrain, articulated frame steer (Dresser Industries model M10A, MHE 236) (NSN 3930-01-054-3833).

Includes index.

Unit maintenance, direct support, and general support maintenance repair parts and special tools lists : truck, forklift, DED, pneumatic tire, articulated, frame steer, 4000 lb capacity, rough terrain, Army model MHE 237, NSN 3930-01-076-4237, J.I. Case model M4K.

"April 1992."

Unit, direct support, and general support repair parts manual : truck, forklift, 6000 lbs, variable reach, rough terrain, model 6000M, NSN 3930-01-158-0849 (Army model MHE 269).

"October 1989."

Operator's manual : truck, forklift, 6000 lbs, variable reach, rough terrain, model 6000M, NSN 3930-01-158-0849 (Army model MHE 269).

"October 1989."

Direct support and general support maintenance repair parts and special tools lists : truck, forklift, gasoline engine driven, pneumatic-tired, 4,000 lbs capacity, 144" lift height Army model MHE-221, NSN 3930-00-151-4428 Baker model FJF-040.

Includes index.

Organizational maintenance repair parts and special tools lists : truck, forklift, gasoline engine driven, pneumatic-tired, 4,000 lbs capacity, 144" lift height, Army model MHE-221, 3930-00-151-4428, Baker model FJF-040.

Includes index.

Unit, direct support, and general support maintenance repair parts and special tools lists : truck, forklift, EMD, solid rubber tired wheels, 2000 lb capacity, 144 in. lift, Army model MHE 219, (NSN 3930-00-151-4432) : Allis-Chalmers model FE20-24EE.

"March 1992."