PUMP UNIT

The invention is purposed to increase the endurance of the pump unit by way of reduction of the shaft flexural vibrations, radial movements of the wheels and guaranteed provision of the axial waisting of ball-bearings when runout. This is reached due to that the wheel 5 is fixed at the shaft 2 and the wheel 6 at the wheel 5 hub. The wheel 5 is placed with stop and the ball-bearing 3. Circular flange of the wheel 6 is placed at the larger diameter that the same flange of the wheel 5. Opposite to the flanges in the case offset rings 7 made of antifriction material are mounted. At such arrangement of the wheels the size of arm is smaller and the flexural vibrations become lower, the rings 7 receiving loading at the bearings runout have the same function.