Pumping assembly for feeding oil under pressure to a user

Abstract

A pumping assembly for feeding oil under pressure to a user is defined by a gear pump, which is actuated by an electric motor, and has a pair of gears, which are coupled to each other within a pump body, and are each provided with a respective plurality of teeth facing radially to a respective lateral surface of the pump body and axially to two recesses formed on two side elements of the pump body itself; the radial distance of the teeth from the respective lateral surface increasing in the direction of rotation of the gears around their own rotation axes.

1 . Pumping assembly for feeding oil under pressure to a user, the pumping assembly comprising a gear pump, and an electric motor for actuating the gear pump; the gear pump comprising, in turn, two toothed members, which are coupled to each other, are assembled so as to rotate around respective rotation axes parallel to each other, and present respective teeth; and a pump body defining a containing chamber, which houses in its inside the two toothed members, presents, for each toothed member, a respective first lateral surface extending around, and at a given radial distance (Dr) from, the teeth of the respective toothed member, and is, furthermore, axially limited by two side elements parallel to each other and perpendicular to said rotation axes; the radial distance (Dr) increasing in the direction of rotation of the toothed members around respective rotation axes, and each side element being limited by a second lateral surface perpendicular to said rotation axes and facing the toothed members; wherein each side element presents, for each toothed member, a respective recess, which is formed on the relative second lateral surface, is facing the teeth of the respective toothed member, and is limited by a bottom wall arranged at a given axial distance from the teeth of the respective toothed member. 
     
     
         2 . Pumping assembly according to  claim 1 , wherein the axial distance is constant in the direction of rotation of the toothed members around respective rotation axes. 
     
     
         3 . Pumping assembly according to  claim 1 , wherein the axial distance increases in the direction of rotation of the toothed members around respective rotation axes. 
     
     
         4 . Pumping assembly according to  claim 1 , wherein the two recesses are connected to each other, so as to define a cavity. 
     
     
         5 . Pumping assembly according to  claim 1 , wherein the two recesses are separated from each other. 
     
     
         6 . Pumping assembly according to  claim 1 , wherein each said first lateral surface presents a coupling end coupled in fluid-tight manner to the teeth of the relative toothed member and wherein each said second lateral surface is coupled in fluid-tight manner with the teeth ( 8 ) of the toothed members. 
     
     
         7 . Pumping assembly according to  claim 6 , wherein the pump body presents an oil inlet to the containing chamber and an outlet of the oil under pressure from the containing chamber itself; the radial distance being substantially null in correspondence to each said coupling end and each said second lateral surface being arranged substantially in contact with the teeth of the toothed members so as to separate in a fluid-tight manner said inlet and said outlet from each other. 
     
     
         8 . Pumping assembly according to  claim 7 , wherein each recess extends around the respective rotation axis downstream of said inlet the direction of rotation of the respective toothed member. 
     
     
         9 . Pumping assembly according to  claim 1 , wherein each said first lateral surface presents a cylindrical shape, and is wound in a spiral around the respective toothed member. 
     
     
         10 . Pumping assembly according to  claim 9 , wherein each said first lateral surface presents a longitudinal axis parallel to, and distinct from, said rotation axis of the relative toothed member. 
     
     
         11 . Pumping assembly according to  claim 9 , wherein the pump body presents an oil inlet to the containing chamber and an outlet of the oil under pressure out of the containing chamber itself; each said first lateral surface presenting a coupling end substantially tangent to the teeth of the respective toothed member so as to separate in a fluid-tight manner said inlet and said outlet from each other. 
     
     
         12 . Pumping assembly according to  claim 1 , wherein each toothed member is an externally toothed gear wheel, each said first lateral surface presenting a substantially cylindrical shape, a given radius of curvature, and a longitudinal axis arranged at a distance from the longitudinal axis of the other said first lateral surface less than the sum of the radii of curvature of the two said first lateral surfaces.