Improved VANE for a rotary VANE pump

Abstract

Vane for a positive-displacement pump, wherein the vane (1) comprises a front-side (2), a back-side (3), at least one contact surface (4), and at least two non-contact surfaces (5), and the contact surface (4) comprises at least one guiding surface (7) and at least one cutting surface (8).

Description

[0001] IMPROVED VANE FOR A ROTARY VANE PUMP

[0002] Technical field of the invention

[0003] The present invention relates to a vane for a positive-displacement pump, a rotor, and to a positive-displacement pump as such. In particular, the present invention relates to a vane for a positive-displacement pump which is capable of transporting or pumping a material from a material inlet to a material outlet, and which is capable of cutting or grinding at least part of the material to be pumped.

[0004] Background of the invention

[0005] A positive-displacement pump is a type of pump provided to move a material by trapping a fixed amount of said material and then forcing the trapped material into the pump's discharge or material outlet. These types of pumps may create a continuous flow of material by repeatedly capturing and expelling discrete volumes, providing a constant and predictable flow rate.

[0006] A rotary vane pump is one type of positive-displacement pump used to move materials, like fluids, solids or gases. It operates by using a series of vanes that rotate within a cylindrical cavity (a pump chamber). As the vanes rotate, they create expanding and contracting chambers within the pump chamber, which draw in and expel the material to be pumped.

[0007] A rotary vane pump generally comprising a pump chamber and a rotor. The rotor is provided with one or more vanes. The pump chamber comprising a material inlet and a material outlet.

[0008] The rotary vane pump comprises a cylindrical cavity (pump chamber) and a rotor (sometimes called an impeller) that is eccentrically mounted within the cylindrical cavity (pump chamber). The rotor is offset from the centre of the pump chamber, and may create a crescent-shaped space between the rotor and the inner-wall of the pump chamber.

[0009] The rotor of the rotary vane pump may comprise one or more slots that hold individual vanes. These vanes may often be made of metal or plastic, and the vanes may slide in and out of the slots and stay between the rotor and the inner-wall of the pump chamber. To avoid entrapment of material to be pumped by the rotary vane pump between the vane and the edges of the one or more slots in the rotor holding the individual vanes. The wear strips may be provided to protect the vane and for reducing the amount to material to be pumped is getting stuck.

[0010] The pump chamber may be provided with a material inlet and a material outlet. When the pump is in operation, the material inlet is connected to a material feeding device of the material that needs to be pumped, and the material outlet is connected to a device where the fluid needs to be delivered.

[0011] During operation, the rotor spins and the vanes may be tensioned to maintain contact with the inner-wall of the pump chamber as the rotor spins. This tension may be provided by springs, gravity, centrifugal force or a combination hereof, causing the vanes move in the slot provided and to slide outward against the inner surface of the pump chamber. This creates expanding chambers on the inlet side of the pump and contracting chambers on the outlet side.

[0012] As the rotor spins, material may be drawn into the expanding chambers through the material inlet, e.g. due to the vacuum created by the increasing volume or as material is fed to the chamber and captured by the vane. As the rotor continues to rotate, the expanding chambers move toward the outlet side of the pump. This movement reduces the volume of the chamber and compresses the material and forcing it out through the material outlet.

[0013] Due to the movement of the vanes in the slots, the vanes may provide a seal between the expanding and contracting chambers, preventing material from flowing backward within the pump chamber.

[0014] Rotary vane pumps are known for their efficiency, reliability, and ability to handle a wide range of materials, like fluids, solids, and gases. They are commonly used in applications such as automotive fuel systems, HVAC systems, vacuum packaging, printing presses, food or feed industry, beverage industry, fish processing industry, and rendering industry.

[0015] The construction of the vanes and the positive-displacement pumps presently available are however, difficult, cumbersome, time-consuming and costly. Furthermore, the vanes and the positive-displacement pumps presently available are not suitable for use in the fish processing industry or the rendering industry, since, in addition to the effect of pumping, some degree of cutting and grinding may also be desirable to improve flow of the material to be pumped.

[0016] Hence, there is a need in the industry to provide an improved vane for a positivedisplacement pump and a positive-displacement pump as such. In particular, there is a need in the industry for a vane for a positive-displacement pump (and a positivedisplacement pump as such) which may be faster, easier, more efficiently and cheaper produced and which vane (and a positive-displacement pump) may provide some degree of cutting and grinding of the material to be pumped, and which is suitable for use in the rendering industry.

[0017] Summary of the invention

[0018] Thus, an object of the present invention relates to a vane for a positive-displacement pump which is capable of transporting or pumping a material from a material inlet to a material outlet, and which is capable of cutting or grinding at least part of the material to be pumped, a rotor and a positive displacement pump as such.

[0019] In particular, it is an object of the present invention to provide a vane, a rotor and / or a positive displacement pump that solves the above mentioned problems of the prior art with speed, handling requirements, efficiency and capability of provide some degree of cutting or grinding of the material to be pumped, and which is suitable for use in the rendering industry.

[0020] Thus, one aspect of the present invention relates to a vane for a positive-displacement pump, wherein the vane comprises a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces, and the contact surface comprises at least one guiding surface and at least one cutting surface, wherein the vane may be provided from the same material throughout the vane.

[0021] A further aspect of the present invention relates to a vane for a positive-displacement pump, the vane comprising a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces, and the contact surface comprises at least one guiding surface and at least one cutting surface, wherein the vane may be provided from a single piece of material.

[0022] Yet an aspect of the present invention relates to a vane for a positive-displacement pump, wherein the vane consists essentially of a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces, and the contact surface comprises at least one guiding surface and at least one cutting surface.

[0023] A further aspect of the present invention relates to a vane for a positive-displacement pump, the vane comprising at least one contact surface, the contact surface comprises at least one guiding surface and at least one cutting surface, wherein a cutting-width of the at least one cutting surface is smaller than a guiding-width of the at least one guiding surface.

[0024] Another aspect of the present invention relates to a rotor comprising at least one through opening, wherein the at least one through opening is configured for receiving a vane.

[0025] Yet another aspect of the present invention relates to a positive displacement pump comprising a vane according to the present invention or a rotor according to the present invention.

[0026] A further aspect of the present invention relates to a positive displacement pump comprising a material inlet in fluid connection with a pump body comprising the pump chamber and the pump body may be in fluid connection with a material outlet, wherein the material outlet is a circular-shaped material outlet.

[0027] Another aspect of the present invention relates to a positive displacement pump comprising a material inlet in fluid connection with a pump body comprising the pump chamber and the pump body may be in fluid connection with a material outlet, wherein the pump body comprises an inspection hole.

[0028] Yet an aspect of the present invention relates to a system for processing a material, preferably a rendering system or a fish processing industry, wherein the system comprises a vane according to the present invention, a rotor according to the present invention, and / or a positive displacement pump according to the present invention.

[0029] The present invention will now be described in more detail in the following.

[0030] Brief description of the figures

[0031] Figure 1 shows a rotor (17) according to the present invention. The rotor (17) comprises a drive end (20), a rotor-body (21), and a non-drive end (23). The rotor-body is interposed between the drive end (20) and the non-drive end (23). The drive end (20) may be coupled to a moving element, e.g. a motor. The rotor-body (21) is the element of the rotor (17) that holds the two vanes (1) where the part of the vane (1) extending from the rotor body (21) constitutes the blades (19) of the vanes (1) and the rotor (17) presented in figure 1 comprises 2 vanes (1) and 4 blades (19) provided for moving the material to be pumped when the rotor (17) is installed in a positive-displacement pump (e.g. a rotary vane pump). The non-drive end (23) is placed in the opposite end of the drive end and elevates the rotor (17) and may support rotation of the rotor (17). The rotor (17) may be assembled by welding and without the use of screws or bolts. The non-drive end comprises one or more welding recesses (24) for welding the non-drive end to the rotor-body. The vanes (1) installed comprises a contact surface (4) and a non-contact surface (5) where the contact surface (4) is provided for moving the material to be pumped and which may be in contact with the inner-wall of the pump chamber of the positive-displacement pump (e.g. the rotary vane pump).

[0032] Figure 2 shows an explosion mode of the rotor (17) according to the present invention. The rotor (17) comprises a drive end (20), a rotor-body (21), and a non-drive end (23). The rotor-body is interposed between the drive end and the non-drive end. The rotor-body (21) is provided with two vanes (1), which vanes (1) comprising a front-side (2), a backside (3), two contact surfaces (4), and two non-contact surfaces (5). The vanes (1) are provided with a U-shaped cut-out resulting in an opening in the front-side and back-side of the vane. During installation the U-shapes of the two vanes (1) are assembled and when installed in the rotor and when the rotor is installed in the positive-displacement pump, the vanes (1) are allowed to move mutually relative to each other, as the vanes are rotated in the pump-chamber, without clashing with each other, without wearing each other down, and without blocking each other. The contact surfaces (4) comprise two guiding surfaces and one cutting surface located between the two guiding surfaces. The contact surface (4) is provided for moving the material to be pumped and which may be in contact with the inner-wall of the pump chamber of the positive-displacement pump (e.g. the rotary vane pump). As may be seen from figure 1 the vanes (1) comprise no wear strips between the vanes (1) and the through opening (18) as traditionally used.

[0033] When assembled the U-shapes of the two vanes (1) are merged and the assembled vanes (1) are pushed into the two through openings (18) of the rotor-body (21). The through openings (18) are going through the rotor-body perpendicular to the axial direction of the rotor and allows the vanes (1) to extend from two sides of the periphery of the rotor-body (21). The two through openings (18) are separated by 90° relative to each other. When assembling the rotor (17) a holding ring (22) may be placed in a groove (not shown) around the centreline of the rotor-body (21) which may assist in holding the vanes in the through openings (18). The non-drive end (23) is then put at the end of the rotor-body (21) and secured by welding in the welding recesses (24).

[0034] Figure 3 shows a subset of a vane (1) according to the present invention. The vane (1) comprises a front-side (2), a back-side (3), a contact surface (4), and a non-contact surface (5). The contact surface (4) comprises a contact-width (9), which may be the part of the vane (1) that may be in contact with the inner-wall of a positive displacement pump (not shown). The contact-width (9) may be the same or smaller than a vane-width (6). The contact surface (5) may comprise a cutting surface (8) and a guiding surface (7). The contact-width (9) of the contact surface (4) may comprise a cutting-width (10) of a cutting surface (8) and a guiding-width (11) of the guiding surface (7). The cutting-width (10) is smaller than the guiding-width (11).

[0035] Figure 4 shows a view of a subset of a vane (1) according to the present invention. The vane (1) comprises a front-side (2), a back-side (3), a contact surface (4), and a noncontact surface (5). The contact surface (4) comprises a contact-width (9), which may be the part of the vane (1) that may be in contact with the inner-wall of a positive displacement pump (not shown). The contact-width (9) is smaller than the vane-width (6). The contact-width (9) of the contact surface (4) may comprise a cutting-width (10) of a cutting surface (8) and a guiding-width (11) of the guiding surface (7). The contact surface (5) comprises a cutting surface (8) which is dislocated relative to the guiding surface (7) and relative to the centreline along the length of the contact surface (5). The cutting surface (8) is dislocated to flush with the front-side (2). The cutting surface (8) is not extending further from the vane (1) than the guiding surface (7).

[0036] Figure 5 shows a positive-displacement pump (25) having a rotor (17) according to the present invention installed. The positive-displacement pump (25) comprises a material inlet (27), a pump body comprising the pump chamber (not visible), and a material outlet (26). The positive displacement pump (25) comprises a square-shaped material inlet (27) and a circular-shaped material outlet (26). The pump body comprises an inspection hole (29) allowing easy access to the interior of the positive displacement pump (25), to the pump chamber (not visible), the material inlet (27), and / or the material outlet (26). The rotor (17) comprises a powdered-end (20) and a rolling end (23) and the rotor-body and the vanes are placed inside the pump-body.

[0037] Figure 6 shows a positive-displacement pump (25) without having a rotor installed. The positive displacement pump (25) comprising a material inlet (27) in fluid connection with a pump body comprising the pump chamber (28) and the pump body may be in fluid connection with a material outlet (26), wherein the material outlet (26) is a circularshaped material outlet. The pump body comprises an inspection hole (29) allowing easy access to the interior of the positive displacement pump (25), to the pump chamber (28), the material inlet (27), and / or the material outlet (26).

[0038] Detailed description of the invention

[0039] Accordingly, the inventors of the present invention found that by changing the construction of the vane for a positive-displacement pump it is possible to transport or pump a material from a material inlet to a material outlet, faster, easier, more efficiently and the pump may be cheaper produced and which vane (and a positive-displacement pump) may provide some degree of cutting and grinding of the material to be pumped, and which is suitable for use in the rendering industry.

[0040] The inventors also found that a simplified rotor construction would make construction and service of the rotor faster, more efficient, and cheaper.

[0041] By providing a new construction of the positive-displacement pump, the inventors of the present invention found that the pump could be produced and serviced cheaper, easier and that the instalment of the pump was much easier, and without compromising the functionalities, efficiency, and strength of the pump.

[0042] A preferred embodiment of the present invention relates to a vane for a positivedisplacement pump, wherein the vane comprises a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces, and the contact surface comprises at least one guiding surface and at least one cutting surface, wherein the vane may be provided from the same material throughout the vane.

[0043] Preferably, the vane may be provided from a single piece of material.

[0044] A preferred embodiment of the present invention relates to a vane for a positivedisplacement pump, wherein the vane consists essentially of a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces, and the contact surface comprises at least one guiding surface and at least one cutting surface.

[0045] Preferably, the present invention relates to a vane for a positive-displacement pump, wherein the vane consists of a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces, and the contact surface comprises at least one guiding surface and at least one cutting surface.

[0046] The vane according to the present invention may comprise a cutting-width of the at least one cutting surface which may be larger, the same or smaller than a guiding-width of the at least one guiding surface. Preferably, the vane according to the present invention may comprise a cutting-width of the at least one cutting surface which may be smaller than a guiding-width of the at least one guiding surface.

[0047] An embodiment of the present invention relates to a vane for a positive-displacement pump, the vane comprising a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces.

[0048] In yet an embodiment of the present invention the vane according to the present invention, may comprises a front-side, a back-side, a contact surface, and 3 non-contact surfaces.

[0049] In a further embodiment of the present invention the vane according to the present invention, may comprises a front-side, a back-side, two contact surfaces, and two noncontact surfaces.

[0050] The front-side and the back-side may be of same size. The front-side and the back-side may be of same shape.

[0051] The width of the at least one contact surface (the contact-width) may be the same or smaller than the width of the at least two non-contact surfaces (the vane-width).

[0052] The contact surface may comprise a cutting surface and at least one guiding surface.

[0053] The contact-width of the contact surface may comprise a cutting-width of a cutting surface and a guiding-width of the at least one guiding surface. Preferably, the cutting cuttingwidth is different from the guiding-width.

[0054] The cutting-width of the at least one cutting surface may preferably be smaller than the guiding-width of the at least one guiding surface.

[0055] In an embodiment of the present invention, the guiding-width may be the same as the vane-width or smaller. Preferably, the guiding-width may be the smaller than the vanewidth. A preferred embodiment of the present invention relates to a vane for a positivedisplacement pump, the vane comprising at least one contact surface, the contact surface comprises at least one guiding surface and at least one cutting surface, wherein a cuttingwidth of the at least one cutting surface may be smaller than a guiding-width of the at least one guiding surface.

[0056] The vane may be described as a three-dimensional structure having dimensions in three mutually perpendicular, or substantially mutually perpendicular, directions.

[0057] The vane according to the present invention may be defined as a three-dimensional structure, e.g. a plate or a plate shaped structure, having a width a length and a depth.

[0058] The vane of the present invention may be a plate or a plate shaped structure having a width a length and a depth.

[0059] Preferably, the vane comprising 6 sides, a front-side, a back-side, at least one contact surface, and at least two (or three) non-contact surfaces.

[0060] The depth of a vane, preferably a vane having two contact surfaces, may be determined by the distance from one contact-surface to the opposite contact surface of the vane.

[0061] The depth of the vane according to the present invention may be configured to be substantially as large as the diameter of pump chamber of the positive-displacement pump. Preferably the term "substantially as large as" may relate to a depth of the vane which may be in the range of 10-0.001% smaller than the diameter of the pump chamber of the positive-displacement pump, such as in the range of 8-0.05% smaller, e.g. in the range of 6-0.1% smaller, such as in the range of 4-0.5% smaller, e.g. in the range of 2- 0.75% smaller, such as about 1% smaller.

[0062] Preferably, the outer-edge of the vane according to the present invention may be the part of the vane being in contact with, or closest to, an inner-wall of a pump-chamber of a positive-displacement pump.

[0063] The outer-edge according to the present invention may comprise the contact surface. Preferably, the outer-edge of the vane may comprise the contact surface, and thus the guiding surface and / or the cutting surface. In an embodiment of the present invention the guiding surface and the cutting surface may be dislocated laterally relative to each other and / or the guiding surface and the cutting surface may be dislocated longitudinally relative to each other.

[0064] Preferably, the guiding surface and the cutting surface may not be dislocated laterally relative to each other and / or the guiding surface and the cutting surface may not be dislocated longitudinally relative to each other.

[0065] In an embodiment of the present invention the cutting surface and the guiding surface may be placed centrally along the length of the contact surface.

[0066] In yet an embodiment of the present invention, the cutting surface or the guiding surface may be placed centrally along the length of the contact surface.

[0067] In a further embodiment of the present invention the cutting surface or the guiding surface may be dislocated from the centreline along the length of the contact surface.

[0068] When the cutting surface or the guiding surface may be dislocated from the centreline along the length of the contact surface, the dislocation may be along the entire vane width.

[0069] When the vane comprises two contact surfaces the two contact surfaces may be identical (with no dislocation of cutting surface or guiding surface) or the cutting surface, the guiding surface, or both may be dislocated from the centreline along the length of the contact surface.

[0070] The length of the vane may preferably be the longer of the length of the vane when looking at the outer-edge of the vane. Preferably, the length of the vane may be determined as being in parallel or substantially in parallel with the axis of rotation of the rotor when the vane may be installed in the rotor and when the rotor may be installed in the positive-displacement pump.

[0071] The inventors of the present invention surprisingly found that the guiding-surface and the cutting surfaces provided different functions in a positive displacement pump, which may be independently and individually optimized to provide improved functionalities, like improved effect, improved productivity, improved strength, and a reduced impact on the environment (due to reduced energy consumption). Hence, the inventors of the present invention surprisingly found by providing at least one cutting surface having a cutting- width which is smaller than a guiding-width of the at least one guiding surface, improved production and applications of the vane may be provided.

[0072] In the present context the terms "guiding-width" and / or "cutting-width" may be used to describe the shorter side the guiding -surface and the cutting-surface of the vane, and the outer-edge of the vane.

[0073] In an embodiment of the present invention the vane may comprise two contact surfaces.

[0074] The two contact surfaces may be a first contact surface and a second contact surface.

[0075] Preferably, the first contact surface and the second contact surface are directed in opposite directions to each other.

[0076] In an embodiment of the present invention the contact surface (or each of the first contact surface and the second contact surface) according to the present invention may comprise two guiding surfaces and one cutting surface. Preferably, the cutting surface may be located between the two guiding surfaces.

[0077] In yet an embodiment of the present invention a length of the guiding surface may be shorter than a length of the cutting surfaces.

[0078] The length of the guiding surface may comprise the combined lengths of all (preferably both) of the guiding surfaces on an outer-edge of the vane.

[0079] In an embodiment of the present invention the guiding-width of the guiding surface may be smaller than a vane-width.

[0080] When the vane-width is larger than the guiding-width the vane may be provided with a shape that is not in contact with the inner-wall of a pump-chamber of a positivedisplacement pump, when used.

[0081] The vane-width may preferably be broader than the cutting width. Preferably, a cutting cavity may be provided between the cutting surface and the front-side and / or the backside of the vane.

[0082] The advantage of such cutting cavity may be that material cut during pumping may be easier removed from the contact between the cutting surface and a material-inlet into the pump-chamber of the positive-displacement pump. In an embodiment of the present invention, the vane comprises the same material throughout the vane.

[0083] By the same material may mean that the outer-edge of the vane according to the present invention may not be provided with a reenforced wear material applied to increase wear resistance of the contact surface(s) of the vane.

[0084] A preferred embodiment of the present invention relates to a vane for a positivedisplacement pump, wherein the vane comprising a front-side, a back-side, at least one contact surface, and at least two non-contact surfaces, and the contact surface comprises at least one guiding surface and at least one cutting surface, wherein the vane may be provided from the same material throughout the vane.

[0085] In an embodiment of the present invention the vane consists essentially of the same material throughout the vane.

[0086] In the context of the present invention the same material throughout the vane may relate to a single piece of material throughout the vane or a composite or layered material combined by welds or solders.

[0087] The vane according to the present invention may be made from a single piece of material.

[0088] The single piece of material may relate to a vane that are not composite or layered, but rather exist as a cohesive and homogeneous whole. Preferably, the single piece of material, according to the present invention, does not comprise any welds or solders. Preferably, the single piece of material may relate to a vane provided from the same material throughout the vane.

[0089] Preferably, the vane according to the present invention does not comprise any welds or solders.

[0090] The term "consists essentially of" may relate to a limitation of the scope of a feature or a claim to the specified features or steps, and those features or steps, not mentioned and which do not materially affect the basic and novel characteristic(s) of the claimed invention.

[0091] In an embodiment of the present invention, wherein the contact surface may be curved. Preferably the curved structure of the contact surface (and of the cutting-surface and / or the guiding-surface) may form a convex upward structure. Preferably, the convex upward structure may be convex upward over the entire length of the at least one guiding-surfaces (preferably over the 2 guiding-surfaces) and / or over the entire length of the cuttingsurfaces.

[0092] The convex upward structure may be formed from the front-side of the vane, over the contact surface to the back-side of the vane.

[0093] The cutting-width of the cutting surface may be curved. The guiding-width of the at least one guiding surface may be curved. The cutting-width of the cutting surface and the guiding-width of the at least one guiding surface may be curved.

[0094] When the contact surface is curved the contact surface may comprise: a base-width, describing the distance from a starting-point to an end-point, a starting-point defining the point where the curvature structure of the contact surface begins, an end-point defining the point where the curvature structure of the contact surface ends, a curvature length; and a curvature hight.

[0095] If the contact surface does not have a starting-point and an end-point at the front-side of the vane and the back-side of the vane, a connecting part may be provided to ensure a continuous smooth surface of the vane and the structure of the vane.

[0096] Preferably, the connecting part may provide an angle (relative to the front-side of the vane and / or the back-side of the vane) within the range of 90°-180°, such as in the range of 95°-170°, e.g. in the range of 100°-160°, such as in the range of 110°-150°, e.g. in the range of 120°-140°, such as in the range of 125°-135°.

[0097] In an embodiment of the present invention the base-width of the guiding surface may be larger than the base-width of the cutting surface.

[0098] In an embodiment of the present invention the curvature hight of the guiding surface is lower than the curvature hight of the cutting surface.

[0099] The curvature length of the guiding surface may be longer that the curvature length of the cutting surface. Preferably, the curve of the contact surface may be a circular-shaped contact surface or an oval-shaped contact surface.

[0100] The radius of the circular-shaped contact surface may be the same, or smaller than the radius of the inner-wall of a pump-chamber of a positive-displacement pump, to which the wane may be inserted. Preferably, the radius of the circular-shaped contact surface may be smaller than the radius of the inner-wall of a pump-chamber of a positive-displacement pump, to which the wane may be inserted.

[0101] The vane according to the present invention may be provided with a cut-out resulting in an opening in the front-side and back-side of the vane.

[0102] The cut-out allows at least two vanes, each having two opposed contact surfaces, to be installed in a rotor.

[0103] Due to the cut-out, the two (at least two) vanes installed in the rotor are, when the rotor is installed in the positive-displacement pump, allowed to move mutually relative to each other, as the vanes are rotated in the pump-chamber, without clashing with each other, without wearing each other down, and without blocking each other.

[0104] The cut-out provided may result in a U-shaped vane an opening in one of the non-contact surfaces and into the front- and back-sides.

[0105] Preferably, the vane according to the present invention may be made from a metal, or a ceramic material.

[0106] The rotor and / or the vane according to the present invention may preferably not comprise a wear strip.

[0107] Wear strips may be profiles, preferably metal profiles, conventionally placed between the vane and the edge of the slot for receiving the vane on the rotor, to reduce fouling of the open space left in the through opening of the rotor when the wane has been installed. Preferably, the wear strips are placed along the front-side and back-side in parallel, or substantially parallel, to the length of the contact surface of the vane, and preferably along the entire length of the contact surface of the vane.

[0108] In an embodiment of the present invention the rotor and / or the vane may not be provided with any wear strip. A preferred embodiment of the present invention relates to a rotor comprising at least one through opening, wherein the at least one through opening may be configured for receiving a vane.

[0109] The vane may, when installed in the rotor go through the through opening allowing the installed vane to extend from the periphery of the rotor, preferably extending from two openings of the rotor.

[0110] The rotor according to the present invention may comprise a drive end, a rotor-body, and a non-drive end. The rotor-body may be interposed between the drive end and the nondrive end.

[0111] In an embodiment of the present invention, the rotor may comprise a drive end, a rotorbody, a holding ring and a non-drive end. The rotor-body may be interposed between the drive end and the non-drive end. The holding ring may be placed between the rotor-body and the drive end, between the rotor-body and the non-drive end, or one holding ring may be placed between the rotor-body and the drive end and a holding ring may be placed between the rotor-body and the non-drive end. Preferably, holding ring may be placed between the rotor-body and the non-drive end.

[0112] The drive end may be provided for engaging with a moving element, e.g. a motor. The motor may preferably be an electrical motor.

[0113] The rotor-body may be an element of the rotor that holds the one or more vanes responsible for moving the material to be pumped.

[0114] The holding ring may be provided in the rotor for increases strength of the rotor body between the through openings and ensures the rotor body does not collapse and lock the vanes reduces the sliding function of the vanes in the through openings.

[0115] The non-drive end may be an end of the rotor opposite to the drive end. Preferably, the non-drive end may not be coupled to a motor, but may elevates the rotor and may support rotation of the rotor.

[0116] In an embodiment of the present invention the rotor may be assembled without the use of screws or bolts. Preferably, the drive end, the rotor-body, and the non-drive end may be assembled without the use of screws or bolts. Preferably, the drive end, the rotor-body, and the non-drive end may be assembled by welding.

[0117] Preferably, the drive end and / or the non-drive end may comprise one or more welding recesses for welding the drive end and / or the non-drive end to the rotor-body. Preferably, the drive end or the non-drive end may comprise the same number welding recesses as the number of blades of the rotor.

[0118] In an embodiment of the present invention the drive end or the non-drive end may comprise 2 welding recesses or more. In another embodiment of the present invention the drive end or the non-drive end may comprise 4 welding recesses or more. In another embodiment of the present invention the drive end or the non-drive end may comprise 6 welding recesses or more. Preferably, the drive end or the non-drive end may comprise 4 welding recesses. in a further embodiment of the present invention the at least one vane may be installed in the at least one through opening of the rotor.

[0119] Preferably, the vane installed in the through opening of the rotor may be a vane as described herein.

[0120] The at least one through opening may be configured for receiving at least one vane according to the present invention.

[0121] The rotor may be provided with one through opening for each vane to be inserted.

[0122] In an embodiment of the present invention the rotor comprises 1 through opening and having 1 vane installed. In another embodiment of the present invention the rotor comprises 2 through opening and having 2 vanes installed.

[0123] For each vane inserted into the through opening of the rotor, 2 blades for moving the material to be pumped may be provided. Thus, for a rotor comprising 2 through openings and 2 vanes (one in each through opening), 4 blades may be provided.

[0124] In the present context the terms "blade" or "blades" may be used in defining the portion(s) of the vane that extends from the rotor towards the inner surface of the pump-chamber. In an embodiment of the present invention the rotor may comprise 2 through openings for receiving vanes, a first through opening for receiving a first vane and a second through opening for receiving a second vane.

[0125] The rotor may comprise a first through opening for receiving a first vane and a second through opening for receiving a second vane, wherein the first vane and the second vane each comprises a cut-out, preferably the cut-out is located in one of the non-contact surfaces and into the front- and back-sides.

[0126] When the two vanes (each comprising a cut-out) is then installed in the rotor, the cut-out of the first vane are facing the cut-out of the second vane and the two vanes are merged, creating a 4-blade rotor.

[0127] The rotor according to the present invention may comprise two vanes, each vane comprises a cut-out, and the cut-outs may preferably be pointing in the longitudinal direction of the rotor (preferably relative to the rotation of the rotor).

[0128] In an embodiment of the present invention the vane according to the present invention provides two blades of the rotor. The two blades are extending from the centre of the of the rotor. Preferably, the two blades of the vane may be extending from the periphery of the rotor (e.g. towards the inner surface of the pump-chamber).

[0129] The cut-outs of the two vanes installed in the rotor allows, when the rotor is installed in the positive-displacement pump, the two vanes to move in and out of the through openings relative to each other as the rotor spins, without clashing with each other, without wearing each other down, and without blocking each other.

[0130] Preferably, the at least one through opening may comprise a through opening width and a through opening length configured to the width and the length of the vane according to the present invention.

[0131] In an embodiment of the present invention the through opening width is in the range of 0.1-50% larger than the width of the vane, such in the range of 0.3-40% larger, e.g. in the range of 0.5-30% larger, such in the range of 0.75-20% larger, e.g. in the range of 1.0-15% larger, such in the range of 1.5-10% larger, e.g. in the range of 2-7% larger, such in the range of 2.5-5% larger, e.g. in the range of 3-4% larger.

[0132] In a further embodiment of the present invention the through opening length is in the range of 0.1-50% larger than the length of the vane, such in the range of 0.3-40% larger, e.g. in the range of 0.5-30% larger, such in the range of 0.75-20% larger, e.g. in the range of 1.0-15% larger, such in the range of 1.5-10% larger, e.g. in the range of 2-7% larger, such in the range of 2.5-5% larger, e.g. in the range of 3-4% larger.

[0133] The rotor according to the present invention may comprises at least 1 through opening, such as at least 2 through openings, e.g. at least 3 through openings, such as at least 4 through openings.

[0134] In a preferred embodiment of the present invention the rotor may comprise two vanes.

[0135] The rotor according to the present invention may comprises at least 1 vane, such as at least 2 vanes, e.g. at least 3 vanes, such as at least 4 vanes.

[0136] The two vanes provided in the rotor may provide 4 blades for moving the material to be pumped.

[0137] In an embodiment of the present invention, the rotor may comprise at least one through opening, wherein at least one vane may be inserted into the at least one through opening and providing 2 blades extending from the rotor.

[0138] The at least one vane may preferably be movable installed in the rotor according to the present invention.

[0139] In an embodiment of the present invention the movement of the one or more vanes in the through openings of the rotor is not initiated, controlled or provided by a spring or the like.

[0140] The rotor according to the present invention may comprise lubrication inlet for introducing a grease to the through openings allowing a smooth and easy movement of the vanes. Preferably, the lubrication inlet may be placed at the non-drive end of the rotor.

[0141] A preferred embodiment of the present invention relates to a positive displacement pump comprising a vane as described herein, or a rotor as described herein.

[0142] The positive displacement pump according to the present invention may comprise a material inlet, a pump body comprising the pump chamber, and a material outlet.

[0143] The positive displacement pump may comprise a square-shaped material inlet and a circular-shaped material outlet, or a square-shaped material inlet and a square-shaped material outlet, or a circular-shaped material inlet and a circular-shaped material outlet. Preferably, the positive displacement pump may comprise a square-shaped material inlet and a circular-shaped material outlet.

[0144] A preferred embodiment of the present invention relates to a positive displacement pump comprising a material inlet in fluid connection with a pump body comprising the pump chamber and the pump body may be in fluid connection with a material outlet, wherein the material outlet is a circular-shaped material outlet.

[0145] A positive displacement pump comprising a material inlet in fluid connection with a pump body comprising the pump chamber and the pump body may be in fluid connection with a material outlet, wherein the material outlet is a circular-shaped material outlet.

[0146] In the present context the term "fluid connection" means that the material to be pumped may be transferred from the material inlet to the pump chamber and from the pump chamber to the material outlet.

[0147] In an embodiment of the present invention the pump body may comprise an inspection hole. The inspection hole may allow easy access to the interior of the positive displacement pump, to the pump chamber, the material inlet, and / or the material outlet.

[0148] A preferred embodiment of the present invention relates to a positive displacement pump comprising a material inlet in fluid connection with a pump body comprising the pump chamber and the pump body may be in fluid connection with a material outlet, wherein the pump body comprises an inspection hole.

[0149] When not in service, the inspection hole may be covered, e.g. by a removable plate.

[0150] In an embodiment of the present invention the cutting surface of the vane may be configured to have a length that equals or substantially equals the length of the material inlet of the positive-displacement pump.

[0151] The guiding surface(s) may of the vane may be configured to have a length that equals or substantially equals the length of the inner-wall of the pump chamber minus the length of the material inlet of the positive-displacement pump.

[0152] Substantial equals may relate to a difference from the material inlet of the positivedisplacement pump, by 10% or less, such as 8% or less, e.g. 6% or less, such as 4% or less, e.g. 2% or less, such as 1% or less. The positive-displacement pump may be a rotary vane pump or a lamella pump.

[0153] The positive displacement pump according to the present invention may preferably be used in the rendering industry.

[0154] Preferably, the positive displacement pump according to the present invention may be provided for moving waste food, offal from poultry, feathers, bone, fisk, meat or a combination hereof. A preferred embodiment of the present invention relates to a system for processing a material, preferably a rendering system, wherein the system comprises a vane according to the present invention, a rotor according to the present invention, and / or a positive displacement pump according to the present invention. It should be noted that embodiments and features described in the context of one of the aspects of the present invention also apply to the other aspects of the invention.

[0155] References

[0156] (1) Vane

[0157] (2) Front-side

[0158] (3) back-side

[0159] (4) Contact surface

[0160] (5) Non-contact surfaces

[0161] (6) Vane width

[0162] (7) Guiding surface

[0163] (8) Cutting surface

[0164] (9) Contact width

[0165] (10) Cutting-width

[0166] (11) Guiding-width

[0167] (12) Not used

[0168] (13) Not used

[0169] (14) Not used

[0170] (15) Not used

[0171] (16) Not used

[0172] (17) Rotor

[0173] (18) Through opening

[0174] (19) Blades

[0175] (20) Drive end

[0176] (21) Rotor body

[0177] (22) Holding ring

[0178] (23) Non-drive end

[0179] (24) Welding recess

[0180] (25) Positive displacement pump

[0181] (26) Material inlet

[0182] (27) Material outlet

[0183] (28) Pump chamber

[0184] (29) Inspection hole

Claims

Claims1. A vane (1) for a positive-displacement pump, wherein the vane (1) comprises a frontside (2), a back-side (3), at least one contact surface (4), and at least two non-contact surfaces (5), and the contact surface (4) comprises at least one guiding surface (7) and at least one cutting surface (8), wherein the vane (1) may be provided from the same material throughout the vane (1).

2. The vane (1) according to claim 1, wherein the vane (1) is provided from a single piece of material.

3. A vane (1) for a positive-displacement pump, wherein the vane (1) consists essentially of a front-side (2), a back-side (3), at least one contact surface (4), and at least two noncontact surfaces (5), and the contact surface (4) comprises at least one guiding surface (7) and at least one cutting surface (8).

4. The vane (1) according to anyone of the preceding claims, wherein a cutting-width (10) of the at least one cutting surface (8) is smaller than a guiding-width (11) of the at least one guiding surface (7).

5. A rotor (17) comprising at least one through opening (18), wherein the at least one through opening (18) is configured for receiving a vane (1).

6. The rotor (17) according to claim 5, wherein at least one vane (1) is installed in the at least one through opening (18) of the rotor (17).

7. The rotor (17) according to claim 5, wherein at least one vane (1) is a vane (1) according to anyone of claims 1-4.

8. The rotor (17) according to claim 5, wherein the rotor comprises at least one through opening (18), wherein at least one vane (1) is inserted into the at least one through opening (18) and providing 2 blades (19) extending from the rotor (17).

9. A positive displacement pump (25) comprising a vane (1) according to anyone of claims 1-4 or a rotor (17) according to anyone of claims 5-8.

10. A positive displacement pump (25) comprising a material inlet (27) in fluid connection with a pump body comprising the pump chamber (28) and the pump body may be in fluidconnection with a material outlet (26), wherein the material outlet (26) is a circularshaped material outlet (26).

11. The positive displacement pump (25) according to anyone of claims 9-10, wherein the pump body comprising a inspection hole (29).

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