Pump device for a viscous fluid

Abstract: A pump device for a viscous fluid, comprising a unit provided with entry and exit mouths for the fluid, and relative fixed and rotating parts for moving the fluid within it, the unit consisting of a pair (14,15) of mutually facing plate elements, of which a first (14) rotates with the drive shaft of the device and the second (15) is fixed with respect to the first plate element, the second plate element having a central through hole to be mounted on the shaft and being provided on that lateral surface facing the first plate element with a helical recess which is eccentric to the hole for the shaft (11) and has its ends in the form of a first entry mouth (21) facing the bottom of the plate element and a second mouth (22) radially facing the central hole, between the central hole of the second plate element and the rotating shaft (11) there being provided a sleeve (23) element which is fixed to the second plate element (15) and is provided with at least one passageway (25) which at one end faces the second mouth (22) of the second plate element (15) and at the other end faces the outlet of the device.

Description: This invention relates to a pump device for a viscous fluid, for example a lubricating fluid. Viscous fluids, in particular lubricating fluids, are usually moved by various types of pumps or similar devices which are particularly costly or suffer from a certain constructional complexity. GB-A-1 400 531 shows a pump device according to the preamble of claim 1 which comprises a rotor surrounded by a two-part housing which are provided with shallow spiral pumping grooves. An object of the present invention is to provide a device of pump type for moving a viscous fluid, for example a lubricating fluid, which although being of excellent operation is extremely simple to construct, is of small overall size, is light in weight and is of low cost. A further object is to enable its parts to be easily removed and overhauled without high cost, and to provide extreme operational reliability. This object is attained according to the present invention by a pump device for a viscous fluid, for example a lubricating fluid, according to claim 1. The characteristics of, and the advantages deriving from, a plate element according to the present invention will be more apparent from the description of a non-limiting embodiment thereof given with reference to the accompanying drawings in which: Figure 1 is a longitudinal section showing one embodiment of a lifting pump device according to the present invention; and Figure 2 is a side view of only the plate element provided with the helical recess. With reference to the figures, a pump device for moving a viscous fluid, for example a lubricating fluid, within a vehicle, a machine tool or the like, comprises a drive shaft 11, partly shown, connected to a relative motor means, not shown. The shaft 11 extends into an element 12 containing a viscous fluid (Figure 1) and is supported at 13 rotatable relative to the element walls. Specifically, the pump device comprises a unit provided with an entry mouth for the fluid contained in the containing element 12 and a mouth for its exit to the outside. The unit consists of a first plate element or plate 14 rotating rigidly with the shaft 11 and facing a second plate element 15 fixed rigidly to the containing element 12. In the illustrated example the first plate element 14 has a lateral surface 16 facing the second plate element 15. The second plate element 15 has a through central hole 18 for mounting on the drive shaft 11 and is elongate towards its base, where it is fixed to the containing element 12. That surface 19 of the second plate element 15 facing the flat lateral surface 16 of the first plate element 14 comprises a helical recess 20 eccentric to the shaft 11. The ends of the helical recess 20 form a first downwardly-facing widened mouth 21 and a second mouth 22 radially facing inwards towards the shaft 11. The helical recess 20 narrows in the direction of the fluid flow, ie from the first mouth 21 to the second mouth 22, to favour the pumping effect of the device according to the invention. The diameter of the shaft 11 is less than the diameter of the central hole 18 of the second plate element 15. A sleeve element 23 is inserted into the interspace which is thus created between the shaft 11 and the second plate element 15. In the present embodiment the sleeve element 23 extends from the side wall of the containing element 12, acts as a support for the shaft 11 and abuts, fluid-tight under rotation, against the surface 16 of the first plate element 14. From the upper outer surface 24 of the sleeve element 23, which faces the second mouth 22 of the second plate element 15, there is provided at least one passageway or channel 25. The channel 25 passes into the body of the sleeve element 23 and emerges towards the outside, it being of suitable shape or inclination, for example in the form of a spiral. In this manner the rotation of the first plate element 14 causes the viscous fluid, for example oil, into which it dips in the containing element 12 and which is deposited on the lateral surface 16 of the first plate element 14, to be dragged towards the first mouth 21 of the second plate element 15. The oil is made to rise within the recess 20 by the rotation of the first plate element 14 and is dragged into proximity with the second mouth 22 of the second plate element 15. This flow is facilitated by the shape of the helical recess 20, which narrows towards the second mouth 22 to cause forward pumping of the viscous fluid. The second mouth 22 faces the channel 25, which provides feed into the interior of the sleeve element 23. The viscous fluid or oil passes through the channel 25, the form and/or inclination of which facilitates flow or pumping, and then passes to the outside of the pump device and containing element 12, for example to a height greater than the initial containing element 12 or into any other container into which the fluid has to be moved. This embodiment provides an upward movement or lifting of the fluid contained in the initial containing element 12. In contrast to the illustrated embodiment, the passageway or channel 25 can be replaced by a series of channels positioned offset from each other. A pump or like arrangement has hence been achieved within a first plate element, which enables a viscous fluid to be moved from an initial container to a different position or user.

Claims: A pump device for moving a viscous fluid, for example a lubricating fluid, comprising a unit provided with entry and exit mouths for said fluid, and relative fixed and rotating parts for moving said fluid within said unit between said entry and exit mouths wherein said unit consists of a pair of mutually facing plate elements (14,15), of which a first (14) rotates rigid with a drive shaft (11) of said device and a second (15) is fixed with respect to said first rotating plate element (14), said second plate element (15) having a central through hole (18) to be mounted on said shaft (11) and being provided on that lateral surface (19) facing said first plate element (14) with a helical recess (20) which has its ends in the form of a first mouth (21) facing said first plate element (14) and a second mouth (22) radially facing said central shaft (11), said helical recess (20) narrowing in the direction in which the fluid flows, there being provided at least one passageway (25) which at one end faces the second mouth (22) of said second plate element (15) and at the other end faces the outlet of said device, characterised in that said first and second plate elements (14,15) are inserted in a containing element (12) for said viscous fluid, said second plate element (15) being fixed rigidly to said containing element (12) so that said first mouth, which is the entry mouth (21) is positioned near to the bottom of said containing element (12), between said central hole (18) of said second plate element (15) and said rotating shaft (11), said fluid flowing from said first mouth (21) to said second mouth (22), there being provided a sleeve element (23) which is fixed to said second plate element (15) and in which is provided said at least one passageway (25), said helical recess (20) being eccentric to the hole for said shaft (11). A pump device for moving a viscous fluid as claimed in claim 1, characterised in that said at least one passageway is inclined relative to the direction of said shaft (11).

Inventors: GALDI PAOLO, GALDI, PAOLO
Applicants: FIAT AUTO SPA, FIAT AUTO S.P.A.
Application year: 1993
Main classification: F04D5
IPC codes: F04D1, F16N7, F04D5, F04D7, F04D29