Patent Application
20230287794
This application claims priority to European Patent Application No. 22461522.9 filed Mar. 9, 2022, the entire contents of which is incorporated herein by reference.
The methods and systems described herein relate to vanes and in particular vanes that may be used in rotary vane pumps.
Sliding rotary vane pumps may be used in a plurality of different mechanical and industrial applications (e.g. they may be used in both liquid and gas pumping applications) and can be invariable exposed to a wide range of environmental conditions. One type of rotary vane pump is a dry air pumps, which are dry vacuum pumps constructed of carbon vanes and rotors which are self-lubricating. Such dry air pumps may comprise mechanical carbon rots and vanes that operate in a hardened metal cavity. Such pumps may provide a power source in a multitude of applications such as to provide power to pneumatically operated flight instruments, for example.
Although such dry air pumps do not use a liquid lubricant, they do use other lubricating methods such as self-lubricating coatings, amongst other methods. Although such lubricating methods may work well to some extent, the nature of the vane lubrication technique is still destructive to the parts of the pump. Due to this, parts of the pump, such as the vanes, can wear down over time. This results in the lengths of the vanes eventually being too short to fit into the slot in which it is positioned in use and this can result in failure of the pump. If the pump is used in an aircraft, such failure can result in one or more of the aircraft systems becoming inoperative and, since this would most often occur during use, i.e. in flight, this can be quite problematic. It is therefore important to ensure that any wearing does not continue to such an extent that the vane exits the slot in use.
A vane for use in a rotary pump R is described herein wherein said vane comprises a first portion P1 having a first thickness T1 and a second portion P2 which has a second thickness T2 that is greater than the first thickness T1.
In some examples, the second portion P2 comprises a first ledge 20 provided on one side of the vane.
In some examples, said ledge protrudes from the first side of the vane and extends along the entire width W of the vane.
In some examples, said ledge does not protrude along the entire width W of the vane.
In some examples, said vane has an L-shaped cross-section.
In some examples, said second portion P2 comprises a ball shaped edge.
In some examples, said second portion P2 of said vane has a circular cross-section.
In some examples, said ball-shaped edge extends along the entire width W of the vane.
In some examples, said ball-shaped edge does not extend along the entire width W of the vane.
A rotary pump is also described herein, comprising at least one slot configured to receive said vane in use. In some examples, the rotary pump comprises a plurality of slots, each of which are configured to receive a vane
In some examples, said at least one slot comprises a first portion S1 that has a first slot width SW1 and a second portion S2 that has a second slot width SW2, wherein the second width SW2 of the second portion S2 of the slot is greater than the first slot width SW.
In some examples, the junction between the first slot portion S1 and the second slot portion S2 creates an end-stop, configured to contact said vane at the junction between said first vane portion P1 and said second vane portion P2 to thereby prevent the vane from exiting said slot.
In some examples, said vane has a length L that extends between a first edge of the vane and a second edge and wherein, use, the vane is provided within the slot of the rotor R such that the second edge is closer to a central axis of the rotor R than the first edge of the vane, and wherein said second portion P2 is provided at said second edge.
A known rotary vane pump prior to wear is shown in
Each vane 16 is made from a material that during use, wears and produces a form of dry lubrication for the pump when in use. For example, vanes 16 can be made from carbon material, graphite, and various organic binders. In some examples, a self-lubricating coating may be applied to the pump parts to inhibit wear between the slidable vanes 16 and pump rotor R.
A stator S is provided that surrounds the rotor R. The stator S has two symmetrically opposite lobes 18 and 19, the surfaces of which act as cams that regulate the two extension and retraction cycles for the vanes 16 during each rotation of the rotor R. As is known in the art, the longitudinal spaces defined by the adjacent vanes 16 and the external surface of the rotor R, as well as the surface of a stator lobe, and end plates of the pump serve as pumping pockets which are moved from an intake zone to an exhaust zone to accomplish the pumping action of the pump R.
During the lifetime of the pump, the vanes wear out and their length becomes shortened.
The new examples described herein and depicted in
In a first example, as shown in
As can be seen in
In known rotary pumps, such as shown in
In the example shown in
In combination with this, the slot 15 of the examples shown in
The second ledge 21 provided within the slot 15 should correspond in shape and size to the first ledge 20 of the vane, such that, when the vane 16 shortens in length, the first and second ledges 20, 21, form an end-stop in that they contact each other and prevent further movement of the vane out from the slot 15. This is depicted in
Although in the examples shown in
In the examples shown in
In this the new type of vane 16 therefore also has a first portion P1 having a first thickness T1 (which in this case is substantially uniform) and a second portion P2 which has a second thickness T2 that is greater than the first thickness T1 (i.e. the portion having the circular cross-section). In the examples shown in
In combination with this, the slot 15 of the examples shown in
As can be seen in
In the same way as described above with reference to
The term “about” is intended to include the degree of error associated with measurement of the particular quantity based upon the equipment available at the time of filing the application.
The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the present disclosure. As used herein, the singular forms “a”, “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, integers, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, integers, steps, operations, element components, and/or groups thereof.
While the present disclosure has been described with reference to an exemplary embodiment or embodiments, it will be understood by those skilled in the art that various changes may be made and equivalents may be substituted for elements thereof without departing from the scope of the present disclosure. In addition, many modifications may be made to adapt a particular situation or material to the teachings of the present disclosure without departing from the essential scope thereof. Therefore, it is intended that the present disclosure not be limited to the particular embodiment disclosed as the best mode contemplated for carrying out this present disclosure, but that the present disclosure will include all embodiments falling within the scope of the claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 22461522.9 | Mar 2022 | EP | regional |
