附件24.4 Experiment 1 Experiment of assembling gear pump of CB type 1.General description The greatest advantages of gear pumps are:small size.light weight,reliable.easy to manufacture,low cost and less sensitive to pollution of hydraulic oil,convenient maintenance and repair,etc.Consequently,gear pumps are found widely applications in low-pressure hydraulic system(general in 25 kg/cm2 or less).The shortages of gear pumps are that it has more leakage-level and the gear bearing undertake larger pressure which lead the gear pump to be only applicable to low-pressure hydraulic system.As a result of large flow pulsation and pressure pulsation,very favorable low sound levels can not be achieved.what's more,it can only be used as a fixed delivery pump.But,as some structural improvement measures are taken in the gear pumps.it can reach a higher working pressure CB-type gear pump is designed and manufactured by own designers and manufacturing engineers in our country.It's working pressure is 25 kg/cm2.We make a little improvement in the structure to accommodate the needs of the high-pressure hydraulic system (to realize the automatic compensation of the axial clearance such as a floating bushing or a floating sideboard is set between the gears and the front and rear covers in the gear pumps with high pressure).So we can make the outlet pressure of the gear pumps to reach 70~140kg/cm2 By considering the structure of gear pumpsWe can satisfactorily resolve the problem of axial clearance.Unbalanced hydraulic radial force,Phenomenon of surrounded oil and so on. 2.The purpose of the experiment Understand the Principle of assembly and structural characteristics of CB-type gear pumps 3.Equipment of experimental CB-type gear pump,OB-B-type gear pump,CB-G-type gear pump,CB-H-type gear pump 附件 24.4 2 Experiment 1 Experiment of assembling gear pump of CB type 1、General description The greatest advantages of gear pumps are: small size, light weight, reliable, easy to manufacture, low cost and less sensitive to pollution of hydraulic oil, convenient maintenance and repair, etc. Consequently, gear pumps are found widely applications in low-pressure hydraulic system( general in 25 kg / cm 2 or less) .The shortages of gear pumps are that it has more leakage-level and the gear bearing undertake larger pressure which lead the gear pump to be only applicable to low-pressure hydraulic system. As a result of large flow pulsation and pressure pulsation ,very favorable low sound levels can not be achieved. what’s more , it can only be used as a fixed delivery pump.But ,as some structural improvement measures are taken in the gear pumps,it can reach a higher working pressure. CB-type gear pump is designed and manufactured by own designers and manufacturing engineers in our country.It’s working pressure is 25 kg / cm 2 . We make a little improvement in the structure to accommodate the needs of the high-pressure hydraulic system (to realize the automatic compensation of the axial clearance such as a floating bushing or a floating sideboard is set between the gears and the front and rear covers in the gear pumps with high pressure). So we can make the outlet pressure of the gear pumps to reach 70～140kg / cm 2. By considering the structure of gear pumps ,We can satisfactorily resolve the problem of axial clearance, Unbalanced hydraulic radial force ，Phenomenon of surrounded oil and so on. 2、The purpose of the experiment Understand the Principle of assembly and structural characteristics of CB-type gear pumps. 3、Equipment of experimental CB-type gear pump, OB-B-type gear pump ,CB-G-type gear pump, CB-H-type gear pump