Rotary lobe pump with angular gear

#This application claims the benefit of German Patent Application No. 20 2009 009 093.0 filed on Jul. 1, 2009, the contents of which are incorporated herein by reference.

#The invention relates to a rotary lobe pump for a tank truck, in particular for solids-laden fluids engendered in agriculture, comprising a drive flange which is connectable to a horizontally extending cardan shaft of a towing vehicle and rotatable in the installed position about a horizontal axis, at least one pair of cooperating rotary lobes, each pair being disposed in a pump chamber which is enclosed by a pump housing, wherein each pair is coupled to the drive flange to transfer a torque, and first and second openings which are formed in the pump housing at each pump chamber and which are in fluid communication with the respective pump chamber.

#Such rotary lobe pumps are provided, for example, to convey solids-laden fluids engendered in agriculture. In such a case, the rotary lobe pump performs the function of filling the tank of a tank truck, or of conveying the fluid out of the tank of a tank truck, for example. The rotary lobe pump is driven, for example, via a cardan shaft of a towing vehicle, said shaft being provided in the form of a horizontally extending power take-off shaft. In this case, a preferred mounting position for the rotary lobe pump is between the towing vehicle and the tank, for example in the region of a drawbar of a tank truck.

#With reference to the embodiments shown in the Figures, the invention shall now be described, and in particular the maintenance of the rotary lobes, which can be carried in such a way that the rotary lobe pump can restart well after maintenance has been carried out, thanks to improved self-priming.

#FIG. 1 shows a rotary lobe pump according to the invention and ready for operation, with the angular gear disposed below the pump housing.

#FIG. 2 shows the inventive rotary lobe pump in FIG. 1, with its topside cover dismantled and with dismantled rotary lobes, the angular gear being disposed under the pump housing.

#Rotary lobe pump 1 according to the invention, shown in FIG. 1, has an angular gear 11 disposed on underside cover 18. Two cuboidal fluid storage volumes 4, 5 are also provided on pump housing 14. A first pipeline 8 connectable to the tank 3 and a second pipeline 9 are connected to pump housing 14 via fluid storage volumes 4, 5. A force or torque for transfer onto the rotary lobes (not shown) can be introduced via drive flange 10 on angular gear 11. The fluid conveying direction when tank 3 is being filled is indicated by arrows on pipelines 8, 9. Angular gear 11 is mounted at approximately the height of drawbar 2 and is somewhat protected by the latter or by a mechanical shield, for example in the form of a crossbar 22, from the ground, for example from a stony or uneven field.

#FIG. 2 shows the rotary lobe pump 1 in FIG. 1, specifically with dismantled rotary lobes 121, 122. Rotary lobes 121, 122 are shown after they have been vertically removed from pump housing 14, where rotary lobes 121, 122 may remain coupled to topside cover 17. Pump housing 14 is opened on its upper side only. The fluid (not shown) remains substantially in pump chamber 13.

#The rotary lobe pump 1 according to the invention, as shown in FIG. 3, has an angular gear 11 disposed on topside cover 17, where pump housing 14 can be mounted at approximately the same height as drawbar 2, i.e. about the height of the angular gear lower than in the embodiment shown in FIGS. 1 and 2. The pump housing is protected here by a mechanical shield, for example in the form of a crossbar (not shown), for example from a stony or uneven field. Due to the lower position, the first pipeline 8 connectable to tank 3 can easily be connected to the lowest point of tank 3, which means that tank 3 can easily be drained substantially completely. In addition, if there is a reduction in the pressure differential or suction lift that must be overcome on self-priming, the self-priming function requires less time. If self-priming takes less time, the maintenance intervals can also be extended due to shorter dry-cycle times. Due to the fact that the second pipeline 9 can be laid substantially horizontally to fluid storage volume 5, the risk of fluid leaving fluid storage volume 5 via the second pipeline 9 is also reduced.