Parameter for the power losses occurring in hydraulic systems, which can be noticed in the form of and leakage losses. There are also mechanical losses as a result of friction (Figure H 20).
A distinction is therefore made between hydromechanical efficiency η hm, which covers pressure losses and friction losses in components, and volumetric efficiency η vol, which is determined by any leakage losses which occur. Total efficiency (Figure H 21) is then expressed as follows:
![2d671cd1113be48faa20c853f58aefc9e8341cef hydraulischerwirkungsgrad_01.gif](/fileadmin/smc/files/2d671cd1113be48faa20c853f58aefc9e8341cef.gif)
![a31116dc963aa7058d81b051bff6e7ccbadb526d 0001_hydraulischerwirkungsgrad.gif](/fileadmin/smc/files/a31116dc963aa7058d81b051bff6e7ccbadb526d.gif)
Figure H 20: Losses in a pump
![9d5318cb6ccafce544bf36ee916e8edf4b8ed6a4 0002_hydraulischerwirkungsgrad.gif](/fileadmin/smc/files/9d5318cb6ccafce544bf36ee916e8edf4b8ed6a4.gif)
Figure H 21: Total efficiency of a pump