A kind of multi-gear pump based on Logix gear is proposed

and its flow uniformity is discussed.The Logix gear has minimum teeth number for no undercutting

and can be miniaturized easily

it’s suitable to be used in gear pump.The two-gear pump with 2 Logix gears is difficult to apply

because of its great flow fluctuation.The multi-gear pump is comprised of 3 Logix gears meshed successively

and with the middle one as the driving gear

two subsidiary pumps between the driving gear and the two driven gears are formed.The multi-gear pump flow increases more than one times by distributing proper channel flow.In the multi-gear pump

the situation of flow fluctuation is determined by teeth number of the driving gear.When the teeth number of driving gear is even number

the two subsidiary pumps flow fluctuate synchronously and be unable to compensate each other

the multi-gear pump has the same fluctuation as the two-gear pump.When the teeth number of driving gear is odd number

the subsidiary pumps can compensate one another

and the fluctuation of the multi-gear pump is greatly lesser than the two-gear pump.