Blade for blade unit machine, method for producing blade, and blade unit machine

Abstract

The invention relates to a vane for a vane unit machine. The vane includes a body extending in a longitudinal direction, a transverse direction, and a thickness direction, wherein all directions are at least substantially perpendicular to one another. The main body includes two opposite longitudinal end surfaces along the longitudinal direction and includes an outer side for abutting against an inner circumferential wall surface of the stator for sealing, wherein the outer side constitutes one end of the main body in the transverse direction. In order to optimize the mechanical efficiency of the vane unit and improve the manufacturability of the vane, the main body is made of a solid fibrous polymer composite material and the vane comprises at least one counterweight insert, in which at least one cavity for inserting the at least one counterweight insert into the main body is formed in the main body. The invention also relates to a vane unit machine and a method for producing a vane.

Description

Technical Field

[0001] This invention relates to blades for vane cell machines, wherein the vane cell machine includes a stator having a stator bore and a rotor rotatably arranged in the stator bore, the stator having an inner circumferential wall surface. Furthermore, this invention relates to vane cell machines and methods for producing vanes. Background Technology

[0002] For example, a blade unit machine is described in US 10,415,565 B2.

[0003] The blade unit machine comprises a rotor and a stator. The rotor is located within a stator bore of the stator. The axis of rotation of the rotor is at a distance from the central axis of the stator bore. The external constraint of the stator bore is formed by the circumferential walls of the stator and the two axial end faces of the stator. Several blades are rotatably connected to the rotor. During operation of the blade unit machine, the outer sides of the blades slide along the circumferential walls of the stator, and more specifically, along the inner circumferential wall surfaces of the stator. A fluid chamber (sometimes also called a pressure chamber) is formed within the stator bore between the rotor, the blades, and the circumferential walls of the stator bore. The chamber is constrained along the axial direction of the rotor (and the stator bore) by the axial end faces of the stator.

[0004] During operation, the blades rotate together with the rotor about the rotor's axis of rotation. Furthermore, the blades move radially inward and outward relative to the rotor, and more specifically, radially inward and outward relative to the axis of rotation. During each rotation of the rotor, the chambers increase and decrease in volume. During each rotation, each pressure chamber experiences a period of volume increase (increase period) and a period of volume decrease (decrease period).

[0005] If this bladed unit machine is used as a pump, fluid is supplied to the bladed unit machine. During the enlargement period of the respective chamber, fluid is drawn into the chamber from the fluid inlet of the bladed unit machine. At least during and at the end of the decrease period, fluid is expelled from the chamber toward the outlet of the bladed unit machine. Furthermore, during the decrease period, the fluid may be compressed.

[0006] If this blade unit machine is used as a fluid motor, pressurized fluid is supplied to the blade unit machine. The pressurized fluid flows into the chamber and expands within the chamber during the amplification period, thereby driving the rotation of the rotor. The fluid is then discharged from the blade unit machine.

[0007] Blades for bladed unit machinery are known to be formed by first providing a steel core and then molding it by overcoating the steel core with a polymer. The steel core provides mechanical stability. The polymer can improve frictional properties and protect the steel core from damage, such as due to corrosion. However, the manufacturing process for such blades is costly and offers very little flexibility. Summary of the Invention

[0008] The problem of the present invention is to provide blades for optimizing the efficiency of blade unit machinery and to improve the manufacturability of blades.

[0009] This problem is solved by a blade having the features of claim 1.

[0010] The blade is used in blade unit machinery, wherein the blade unit machinery includes a stator having a stator bore and a rotor rotatably arranged in the stator bore, the stator having an inner circumferential wall surface.

[0011] The blade includes a body. The body extends in a longitudinal direction, a transverse direction, and a thickness direction. All directions may be at least substantially perpendicular to each other. The body (and therefore the blade) includes two opposite longitudinal end surfaces along the longitudinal direction and includes an outer side for sliding against the inner circumferential wall surface of the stator, wherein the outer side constitutes one end of the body (and therefore the blade) in the transverse direction.

[0012] According to the invention, the body is made of a solid or solid fiber polymer composite material, and the blade includes at least one counterweight insert, wherein at least one cavity for inserting the at least one counterweight insert into the body is formed in the body.

[0013] In other words, the body includes at least one cavity for inserting at least one counterweight insert.

[0014] This invention allows for the provision of blades for optimizing the efficiency of blade unit machinery. Furthermore, this invention improves the manufacturability of the blades. These aspects will be described in more detail below.

[0015] As explained above, conventional blades can be formed by providing a steel core and overmolding it with a polymer. However, specific overmolding tools must be provided for each blade type to be used for overmolding the steel core with polymer. These overmolding tools must be specifically adapted to the size and shape of each blade type. In other words, a separate overmolding tool must be designed and manufactured for each blade type. It often takes a long time to obtain the appropriate overmolding tool for a new blade type. This significantly reduces the flexibility of manufacturing different blade types. Furthermore, such overmolding tools are expensive. This is an economic disadvantage, especially for blade types that are produced in small quantities, such as particularly large blades.

[0016] This invention allows for the manufacture of blades without overmolding. The blades may not have any overmolded portions.

[0017] The entire body is made solely of fiber polymer composite material. In particular, the entire blade, except for one or more counterweight inserts, and, if applicable, the corresponding fastening devices for one or more counterweight inserts, may be made solely of fiber polymer material.

[0018] The fibrous portion enhances the mechanical stability and reliability of the body and therefore the blades. The fiber-polymer composite material exhibits high corrosion resistance. In particular, the blades can be configured for use with seawater.

[0019] Blades can be easily manufactured, are low in cost, and offer high flexibility.

[0020] In particular, the entire body can be easily formed by using flexible and inexpensive manufacturing methods.

[0021] According to one aspect, the body can be manufactured by providing a single precursor body made of a fiber polymer material and forming the body from the precursor body by machining. For example, the precursor can be of a simple geometry, such as (at least approximately) a cuboid shape. Such a precursor can be manufactured cost-effectively and offers high flexibility in terms of its dimensions.

[0022] With this invention, the desired (final) shape of the body can be obtained through machining, for example, from such a precursor. This allows for considerably higher cost-effectiveness and flexibility compared to overmolding, especially if blades of different sizes and / or shapes are being produced. For example, machining may include CNC milling.

[0023] In particular, the shape of the body can be obtained by machining to match the corresponding geometry (e.g., length, width, and thickness) of the blade unit mechanism. Additionally or alternatively, other geometric features of the body, such as grooves, outer shapes, etc., can be obtained with high flexibility and low cost.

[0024] The following describes some other possible aspects of manufacturing methods.

[0025] The omission of the steel core reduces the mass of the blades. The mass density of the fiber polymer composite is lower than that of steel. This helps reduce friction and wear. Furthermore, it contributes to better efficiency in the blade unit machinery. The rotor rotation can be started and stopped with less effort.

[0026] However, the research upon which this disclosure is based shows that if the quality of the blades used in a blade unit machine is particularly low, the volumetric efficiency of the blade unit machine may be reduced. This is likely to occur if the entire body is formed solely of fiber-reinforced composite material without any other measures.

[0027] In a blade unit machine, a rotor blade mount rotatably secures the blade to the rotor, but allows limited radial displacement of the blade (relative to the rotor's axis of rotation). The blade is rotatably coupled to the rotor and rotates / moves circumferentially during operation. The outer side of the blade is configured to slide against and seal against the inner circumferential wall surface of the stator. Two adjacent blades (viewed circumferentially) form part of the housing of one (pressure) chamber of the blade unit machine. To allow for an increase in chamber volume, the blade mount allows the blade to move radially outward relative to the axis of rotation. To allow for a decrease in chamber volume, the mount allows the blade to move radially inward relative to the axis of rotation. At least a portion of the sealing force required to seal the outer side of the blade against the inner circumferential wall surface of the stator is provided by a centrifugal force acting on the blade due to its rotation about the axis of rotation. This centrifugal force (relative to the rotor's axis of rotation) pushes the blade radially outward. Therefore, the centrifugal force helps to push the outer side of the blade against the inner circumferential wall surface of the stator. In this way, the centrifugal force generated by the mass (weight) of the blade and its rotation at least contributes to a proper seal between the blade and the inner circumferential wall surface.

[0028] If the mass of a single blade is too low, the centrifugal force forcing the blade radially outward during operation will be too low. A proper seal between the outer edge of the blade and the inner circumferential surface of the stator cannot be guaranteed. Internal leakage between adjacent fluid chambers will lead to reduced volumetric efficiency. This is particularly important in blade unit machinery without additional bias springs to force the blades radially outward relative to the rotor's axis of rotation. It is worth noting that such additional bias springs complicate production, increase production costs, require space, and constitute an additional source of failure. Naturally, if the contact force between the blade and the inner circumferential wall surface is higher than the contact force required for a proper seal, this will cause unnecessarily high friction and thus reduce efficiency.

[0029] In addition, thicker blades affect the resistance to fluid entering and leaving the pump, especially when the corresponding passage is located in the axial end face of the stator.

[0030] Furthermore, it is advantageous if all blades in the blade unit machine have the same mass. This benefits the smooth operation of the rotor. If the blades in the same blade unit machine have different masses, this may cause vibration during operation and potentially reduce their lifespan.

[0031] However, during the manufacturing process of the main body, it is difficult to ensure that all blade bodies have uniform quality.

[0032] This is no longer an issue through the disclosed approach. As described above, the blade includes at least one counterweight insert, wherein a cavity is formed in the body for inserting the counterweight insert into the body.

[0033] The mass of the blade can be precisely adjusted using one or more counterweight inserts. In other words, the mass of the blade is adjusted using one or more counterweight inserts. This allows for obtaining a blade with optimized mass. There is an optimal point for the mass of the blade, where the mass is as low as possible on the one hand, but high enough on the other hand to ensure proper sealing during operation (by generating a sufficiently strong centrifugal force).

[0034] By adjusting the mass of the counterweight insert and then inserting it into the impeller, more specifically into the cavity, the mass of the impeller can be adjusted to a predetermined target mass. In this way, the individual masses of all impellers in the impeller unit machine can be easily adjusted to the same target mass. For example, the mass of each body is measured, and the counterweight insert is provided with a mass that at least approximately corresponds to the difference between the body mass and the target mass of the impeller. Another approach is to provide small counterweight inserts, in which several counterweight inserts can be inserted into at least one cavity. In this case, the mass of the impeller can be easily adjusted by inserting multiple counterweight inserts into at least one cavity such that the (total) mass of the impeller (i.e., the body and(one or more) inserts) is matched as closely as possible to the target mass. This can also be advantageous if the individual old impellers in the impeller pump need to be replaced. Even if there is a weight difference between the old and replacement impellers, the weight of the replacement impeller according to the invention can be easily adapted.

[0035] Another advantage of this solution is its particularly easy separation of different materials, for example, at the end of the life of the impeller unit pump. In the case of a steel core molded with a polymer overlay, it is difficult to separate the polymer from the steel core. Therefore, this invention facilitates the proper handling and recycling of the impeller material.

[0036] According to one aspect, at least one cavity can be formed in the body by partially removing the fiber polymer composite material, for example, by machining. For instance, at least one cavity is drilled into the body. This allows for the cost-effective production of bodies with cavities.

[0037] In one embodiment, the at least one cavity comprises a circular cross-section of an arch. This is particularly easy to manufacture.

[0038] The at least one cavity has an opening. This opening facilitates the insertion of at least one counterweight insert into the empty at least one cavity.

[0039] The cavity can extend along its axis. The cavity axis can be at least approximately parallel to the longitudinal axis.

[0040] According to one aspect, the minimum wall thickness of the body around the at least one cavity is 1 mm (except at the opening of the cavity). This ensures sufficient structural integrity of the body.

[0041] In one embodiment, at least one counterweight insert is already inserted into at least one cavity. Therefore, the customer does not need to insert the counterweight insert into at least one cavity, nor does the customer need to secure the counterweight insert within the cavity. This improves user-friendliness.

[0042] The at least one counterweight insert may be rod-shaped. This shape is easy to manufacture and easy to insert into the cavity. Furthermore, the mass of the counterweight insert can be easily changed by manufacturing longer or shorter rods. Adjusting the mass of at least one counterweight insert may include: selecting a counterweight insert from a set of rods of different lengths, and / or shortening the rod to an appropriate length.

[0043] In one embodiment, the at least one cavity is arranged off-center and outward relative to the central longitudinal axis of the body. In other words, the at least one cavity is located near a sealing surface configured to provide a sliding seal between the impeller and the circumferential wall of the stator. Specifically, if the impeller is mounted in an impeller unit machine, the at least one cavity is arranged in the radially outer end of the impeller. This increases the effect of at least one counterweight insert (which is inserted into at least one cavity) on centrifugal force, and on the sealing of the impeller against the inner circumferential sidewall of the stator during operation. The longitudinal axis can be parallel to the longitudinal direction. In particular, "longitudinal axis" can refer to an intermediate axis / central axis extending parallel to the longitudinal direction of the impeller body. The longitudinal axis can extend between the two longitudinal end faces of the body.

[0044] According to one aspect, at least one cavity is open at one of the longitudinal end faces (e.g., at a first longitudinal end face). In other words, the at least one cavity has an opening at one of the longitudinal end faces. At least one counterweight insert can be inserted (or has been inserted) from one of the longitudinal end faces. The at least one counterweight insert will not be forced out of the opening of the cavity by centrifugal force and / or by the force caused by the forward and backward radial displacement of the blade relative to the axis of rotation.

[0045] In one embodiment, at least one cavity extends longitudinally into the body from one of the longitudinal end faces. Each longitudinal end face is configured to interact with a corresponding axial end face of the stator bore of the blade unit mechanism. As described above, the blade is configured to radially move into and out of the rotor of the blade unit mechanism. This movement is perpendicular to the orientation of the cavity, particularly perpendicular to the cavity axis, such that the blade does not move in the direction of the cavity axis. Therefore, even if the counterweight insert becomes loose, it cannot dislodge from the cavity. Furthermore, the additional centrifugal force exerted by at least one counterweight insert is more evenly distributed along the longitudinal direction. This improves sealing and reduces internal stress in the body during operation.

[0046] In one embodiment, the length of at least one cavity (e.g., along the longitudinal direction) is at least 0.2 mm longer than the length of the counterweight insert. Additionally or alternatively, the at least one counterweight insert may already be inserted into the at least one cavity and may be recessed relative to one of the longitudinal end faces of the body, for example, recessed by at least 0.2 mm. This reduces the risk of the at least one counterweight insert colliding with stator components during operation (e.g., colliding with one of the axial end faces of the stator bore).

[0047] According to one aspect, the blade may include a plurality of counterweight inserts. For example, the blade may include at least two or at least four counterweight inserts.

[0048] If the blade includes several counterweight inserts, each counterweight insert can conform to any of the features, embodiments, and modifications described with respect to at least one counterweight insert. Accordingly, advantages also apply. Different counterweight inserts can conform to different features, implementations, and modifications described with respect to at least one counterweight insert. However, at least some, and even all, of the counterweight inserts can be of the same type.

[0049] Additionally or alternatively, a plurality of cavities for inserting counterweight inserts into the body may be formed in the body. For example, at least two or at least four cavities for inserting counterweight inserts (e.g., at least one corresponding counterweight insert) may be formed in the body. This increases the degree of freedom in adjusting the blade mass. The cavities may be formed in different sections of the blade.

[0050] If a plurality of cavities for inserting counterweight inserts into the body are formed within the body, each cavity can conform to any of the features, embodiments, and modifications described with respect to at least one cavity. Accordingly, advantages also apply. Different cavities can conform to different features, implementation methods, and modifications described with respect to at least one cavity. However, at least some, and even all, of the cavities can be of the same type.

[0051] Cavities and / or counterweight inserts can be used to influence the position of the blade's center of mass.

[0052] By providing multiple cavities, several counterweight inserts can be placed in different cavities. This allows the blades to be balanced according to predefined requirements.

[0053] One or more counterweight inserts provide sufficient additional mass to the blades, ensuring a proper seal between the blades and the circumferential surfaces of the stator bores due to the increased centrifugal force generated during operation. Depending on the characteristics of the blades and the corresponding blade unit mechanics, counterweight inserts with a predetermined weight can be provided to achieve the required sealing contact. Clearly, the mass of the blades can be adapted by using counterweight inserts with corresponding weights. This allows for easy adaptation of sealing pressures.

[0054] By incorporating at least one counterweight insert (or several counterweight inserts) into the body of the blade, particularly into at least one cavity (or several cavities), the blade is particularly suitable for use in blade unit machinery, wherein the blade is pressed against the stator bore solely by centrifugal force.

[0055] In one embodiment, the body (at least) includes another cavity (a second cavity) extending longitudinally from another longitudinal end face in the body. The at least one cavity and the other cavity may be spaced apart or separated by a distance along the longitudinal direction. This arrangement results in blade balance because counterweight inserts can be positioned near two opposite longitudinal end faces. In other words, the body includes at least two cavities extending longitudinally from opposite longitudinal end faces of the body, wherein the cavities are spaced apart from each other. For example, the at least one cavity (a first cavity) is located at a first longitudinal end face of the body, while the second cavity is located at another longitudinal end face in the body. The two cavities may extend along a shared axis. The shared axis may be parallel to the longitudinal direction. In one embodiment, these cavities do not intersect each other.

[0056] According to one aspect, the body includes a groove extending in the transverse direction on a side surface forming one end of the body in the thickness direction. This invention improves flexibility regarding the design of the groove.

[0057] The depth of the groove can be at least 31%, for example, at least 35%, of the thickness of the body along the thickness direction. Additionally or alternatively, the depth of the groove can be up to 45%, possibly up to 40%, of the body thickness. The groove can be formed by partially removing the fiber polymer composite material (e.g., from the precursor), for example by machining. Ridges can be formed between adjacent grooves. In the assembled state where the blade is arranged within the rotor of a blade unit machine, the groove forms a fluid connection between one of the adjacent fluid chambers and a displacement space arranged radially between the blade and the axis of rotation. The displacement space is required to allow the blade to shift radially inward during the reduction period. A larger depth reduces the flow resistance between the displacement space and the adjacent fluid chamber. Therefore, when the blade is pushed radially toward the axis of rotation (during the reduction period), fluid can easily overflow from the displacement space into the pressure chamber through the groove. In conventional blades, the maximum depth of the groove is limited. It is quite difficult to form a groove with such a large depth by machining. The large depth would exceed the thickness of the overmolded polymer cover. Therefore, both the polymer and the steel core must be machined. Furthermore, large pores in the created polymer cover can impair the mechanical stability of the impeller. Grooves with greater depth, and thus with an "effective area" that increases fluid flow, reduce torque pulsation on the rotor during operation. This is beneficial. For example, the operation of the impeller unit as a impeller pump places lower demands on the motor driving the rotor.

[0058] According to one aspect, the at least one counterweight insert is formed of a material having a higher mass density than that of a fiber-polymer composite. For example, the mass density of the material of the counterweight insert may be at least 4 g / cm³. 3 As described above, the blade mass is adjusted by at least one counterweight insert. In particular, if the mass density of the counterweight insert material is particularly high compared to fiber polymer composites, a significant percentage increase in blade mass can be achieved even using small-sized counterweight inserts.

[0059] The at least one counterweight insert can be made of steel, bronze, highly filled plastic, etc. The material is selected based on the fluid used with the blade unit, the required weight, and space requirements. In one embodiment, at least one counterweight insert is formed of stainless steel, particularly salt-resistant stainless steel. Stainless steel has a sufficiently high mass density.

[0060] According to one aspect, fiber polymer composites include polyetheretherketone (PEEK). PEEK has good tribological properties, especially when used in conjunction with water or other fluids.

[0061] Additionally or alternatively, fiber polymer composites include carbon fibers. Carbon fibers contribute to good structural strength.

[0062] In one embodiment, the fiber-polymer composite material comprises PEEK and carbon fibers. In particular, the fiber-polymer composite material may (at least substantially) consist of PEEK and carbon fibers. The combination of PEEK and carbon fibers allows for good sliding contact while providing high stability and reliability.

[0063] According to one aspect, fiber-polymer composites are laminated composites.

[0064] In one embodiment, the fiber-polymer composite is formed from a laminate with fiber directions offset from each other by 90°. The two fiber directions can be parallel to a plane defined by a longitudinal and a transverse direction. This orientation results in stable blades. For example, the first fiber direction is longitudinal, while the second fiber direction is transverse. Several different manufacturing methods are available for processing the laminate. Depending on the number and size of the blades, the lamination process can be performed manually, automatically, or partially manually and partially automatically. This offers a high degree of flexibility.

[0065] Laminates can be made from crosswise oriented unidirectional fiber layers and / or from woven fiber layers with two orthogonal fiber directions.

[0066] In one embodiment, the at least one counterweight insert is secured within at least one cavity, particularly by an adhesive. The term "adhesive" can be used synonymously for any bonding agent. The at least one counterweight insert is held, for example, by an adhesive that forms a connection between the body and the at least one counterweight insert. Other means of retention include, for example, form-fitting or press-fitting of a threaded counterweight insert. A thermo-press fit is also possible. By securing the at least one counterweight insert to the body, movement of the at least one counterweight insert within the at least one cavity is prevented, and detachment from the body is also prevented.

[0067] According to one aspect, the mass of the at least one counterweight insert may correspond to at least 8% of the mass of the blade without any counterweight insert. Additionally or alternatively, the mass of the at least one counterweight insert for the blade may correspond to at most 80% of the mass of the blade without any counterweight insert.

[0068] According to one aspect, the total mass of all counterweight inserts used for the blade may correspond to at least 30% of the mass of the blade without any counterweight inserts. Additionally or alternatively, the total mass of all counterweight inserts used for the blade may correspond to 120% of the mass of the blade without any counterweight inserts.

[0069] Furthermore, the aforementioned problem is solved by a blade unit having the features described in claim 11.

[0070] The blade unit mechanical components include: A housing having a stator with stator holes; A rotor, which is mounted in the stator bore and configured to rotate about a rotation axis relative to the stator; and Multiple blades are mounted to the rotor such that the blades are fixed to the rotor in a rotatable manner, but the blades are allowed to have limited displacement in the radial direction; At least one of the blades is a blade according to the invention.

[0071] The embodiments, modifications, and advantages described with respect to the blade can be applied accordingly to blade unit machinery, and vice versa.

[0072] Preferably, some or even all of the blades are blades according to the invention. In particular, some or all of the blades may be of the same type.

[0073] In one embodiment, the relative weight difference between the blades is less than 5% by weight. This allows the rotor-blade imbalance to be minimized during operation. Furthermore, the blades wear evenly, enabling all blades to be replaced at once. This reduces maintenance workload.

[0074] Furthermore, the aforementioned problem is solved by a method for manufacturing a blade, preferably according to the invention, having the features of claim 13.

[0075] The method includes the following steps: - Provide the body of the blade, wherein the body is made of a solid fiber polymer composite material; - At least one cavity is formed in the body for inserting at least one counterweight insert; and - Insert the at least one counterweight insert into at least one empty cavity.

[0076] This method offers high flexibility for the rapid and cost-effective production of different types of blades (e.g., different sizes and / or shapes). Furthermore, the method allows for the production of blades to optimize the efficiency of blade unit machinery by adjusting the quality of the blades.

[0077] The embodiments, modifications, and advantages described with respect to the blades and / or blade unit assemblies can be applied accordingly to the method, and vice versa.

[0078] In addition, the method may include, for example, the step of fixing at least one counterweight insert into at least one cavity by means of an adhesive.

[0079] This method may include machining the body.

[0080] In particular, the method may include forming a body from a single precursor made of a fiber polymer composite material by machining.

[0081] The method may include providing a single precursor made of a fibrous polymer material. For example, the precursor may be of a simple geometry, such as (at least approximately) a cuboid shape.

[0082] This method may include lamination, for example, to produce fibrous polymer materials using prepreg. Alternatively, providing the body may include injection molding or any other manufacturing method capable of providing a body (or precursor) formed from a fibrous polymer composite.

[0083] The at least one cavity can be formed to extend from the longitudinal end face of the body along the longitudinal direction of the body.

[0084] The method may include, for example, machining at least one cavity in the body by drilling. Alternatively, the at least one cavity may be manufactured during the production of the fiber polymer composite, for example, during the production of the precursor.

[0085] In one embodiment, the mass (weight of the blade) of the blade is adjusted or oriented toward a target mass by inserting at least one counterweight insert. At least one counterweight insert may be provided based on the difference between the mass of the body and the target mass and / or to match the mass of the blade (including the mass of the body and all counterweight inserts) to the target mass of the blade.

[0086] The method may include one, several, or all of the following steps: - Determine the mass of the body equipped with at least one cavity (multiple cavities) having at least one counterweight insert (multiple counterweight inserts), for example by counterweighting the body; - Determine the mass difference between the target mass of the blade and the mass of the main body; and - Provide at least one counterweight insert (or multiple counterweight inserts) based on this quality difference.

[0087] The corresponding counterweight inserts can be provided using one, several, or all of the following methods: - Select from a set of counterweight inserts with different masses (e.g., different sizes and / or different materials with different mass densities); - Adjust the mass of the counterweight insert, for example, by reducing the mass through machining the counterweight insert; and - Produce counterweight inserts of this quality as required.

[0088] The method may include using at least one counterweight insert, and more particularly at least two counterweight inserts, to balance the blades. Balancing helps optimize the position of the blade's center of mass, and thereby ensures that the abutment force on the inner circumferential wall surface of the stator is particularly uniform in the longitudinal direction on the outer side.

[0089] Balance may include any, some, or all of the following: - Adjust the position of at least one cavity within the main body; - Adjust the position of at least one counterweight insert within at least one cavity; and - Adjust the mass of the counterweight insert inserted into the cavity / in multiple cavities in the body that are located at different positions relative to each other.

[0090] In one embodiment, the groove is machined into the body. Depending on the mechanical characteristics of the blade unit, the groove can be easily adapted. This allows for the formation of different blades from a single type of (precursor) body. This is cost-effective and allows for good flexibility.

[0091] Additional features, advantages, and possible applications of the invention will be derived from the following description of exemplary embodiments and the accompanying drawings. All features described and / or illustrated herein, individually or in any desired combination, form the subject matter of the invention, regardless of how they are combined in the claims or in their references to preceding claims. Attached Figure Description

[0092] The present invention will now be described with reference to preferred embodiments and the accompanying drawings. The drawings show:

[0093] Figure 1 It is a blade unit machine;

[0094] Figure 2 Is Figure 1 A perspective view of the blades used in the blade unit machinery;

[0095] Figure 3 yes Figure 2 A view of the side surface of the blade;

[0096] Figure 4 yes Figure 3 A cross-sectional view of the blade at section BB in the middle;

[0097] Figure 5 yes Figure 2 A view of the longitudinal end face of the blade; and

[0098] Figure 6 yes Figure 5 The cross-sectional view of the blade at section AA. Detailed Implementation

[0099] Figure 1 A blade unit machine 1 with a housing 2 is shown. The blade unit machine 1 can be configured for use with a fluid (e.g., brine / seawater). The blade unit machine 1 can be configured to operate as a fluid pump and / or a fluid motor. The housing 2 includes a stator 10 with a stator bore 11. The radially outer constraint of the stator bore 11 is formed by the circumferential wall of the stator 10, and more specifically, by the inner circumferential wall surface 12 of the stator 10 and the two axial end faces (not shown) of the stator 10.

[0100] The blade unit mechanism 1 includes a first fluid port 7 and a second fluid port (not shown). Depending on whether the blade unit mechanism 1 operates as a fluid pump or a fluid motor, the first fluid port 7 is used as a fluid inlet and the second fluid port is used as a fluid outlet, or vice versa.

[0101] The rotor 20 is rotatably mounted in the stator bore 11. The rotor 20 is configured to rotate about a rotation axis RA. The rotation axis RA is parallel to the longitudinal axis LD of the blade 30 and parallel to the intermediate axis MA of the stator bore 11. The rotation axis RA of the rotor 20 is offset relative to the intermediate axis MA of the stator bore 11. The blade unit mechanism 1 includes a rotor shaft 21 for connecting the rotor 20 to a motor (not shown) for driving the rotor 20, and / or to a power-consuming device (e.g., a generator) driven by the rotor 20. The rotor shaft 21 may be integrally formed with the rotor 20.

[0102] Multiple blades 30 are mounted to the rotor 20. For each blade 30, the rotor 20 includes a corresponding blade mount 22. The blade mount 22 allows the blade 30 to have limited displacement relative to the axis of rotation RA in the radial direction RD, but fixes the blade 30 to the rotor 20 in a rotatable manner. Each blade mount 22 includes a displacement space 23 formed in the rotor 20 at the radially inner side of the blade 30 (the radially inner side corresponds to...). Figures 3 to 6 The inner side 34 of the blade 30 in the transverse direction of TVD.

[0103] In the operation of the blade unit machine 1, the blade 30 and the rotor 20 rotate together about the rotation axis RA. Therefore, the blade 30 rotates / moves in the circumferential direction CD. The outer side of the blade 30 slides along the circumferential wall of the stator 10, especially along the inner circumferential wall surface 12 of the stator 10.

[0104] Pressure chamber 24 (fluid chamber 24) is formed between two adjacent blades 30 (adjacent in the circumferential direction CD), the circumferential walls (particularly the inner circumferential wall surface 12) of the rotor 20 and stator 10. During rotation, depending on the rotational position of the blades 30, the blades 30 partially retract into the displacement space 23, while the volume of the adjacent pressure chamber 24 decreases, and the blades 30 move radially outward relative to the rotation axis RA to maintain sealing contact with the inner circumferential wall surface 12, while the volume of the adjacent pressure chamber 24 increases.

[0105] Figure 2 A schematic perspective view of the blade 30 is shown. The blade 30 consists of a main body 31 and a counterweight insert 42.

[0106] The main body 31 and therefore the blade 30 extend along the longitudinal direction LD, the transverse direction TVD, and the thickness direction THD. The transverse direction TVD and the thickness direction THD are perpendicular to the longitudinal direction LD, respectively. The thickness direction THD is perpendicular to the transverse direction TVD.

[0107] At the side surface 35 of the body 31 along the thickness direction THD, the body 31 includes a groove 37 and a ridge 36 extending along the transverse direction TVD of the body 31.

[0108] The main body 31 has two longitudinal end faces 32 along the longitudinal direction LD. Figure 2 Only one of the longitudinal end faces 32 can be seen (referred to as the first longitudinal end face 32).

[0109] Each of the longitudinal end faces 32 is provided with an opening for two cavities 41 formed in the body 31. Each cavity 41 is at least generally cylindrical; each cavity 41 extends along the longitudinal direction LD from the corresponding longitudinal end face 32.

[0110] The blade 30 also includes an outer side 33 that extends in the longitudinal direction LD and generally along the thickness direction THD. For example, as shown in the exemplary embodiment, the outer side 33 may be bent along the thickness direction THD. Figure 1 Reference numeral 33 is not shown, but the outermost 33 is the radially outer end of the corresponding blade 30 and slides against the inner circumferential wall surface 12. The outermost 33 and innermost 34 of the body 31 constitute opposite sides of the body 31 in the transverse direction TVD.

[0111] Figure 3 A schematic side view of the blade 30 is shown, with a more detailed view of the side surface 35 with grooves 37 and ridges 36 (see [link]). Figure 2 , Figure 4 and Figure 5The view shows that the grooves 37 and ridges 36 are arranged in an alternating manner. Each groove 37 and ridge 36 extends linearly along the transverse direction TVD on the side surface 35. The groove width GRW (along the longitudinal direction LD) of the groove 37 can be approximately twice (±10%) the ridge width RW (along the longitudinal direction LD) of the ridge 12.

[0112] Figure 5 A schematic side view of the first longitudinal end face 32 of the blade 30 is shown. The (first) longitudinal end face 32 is equipped with two cavities 41. These two cavities 41 are arranged off-center in the transverse direction TVD relative to the longitudinal axis LA of the body 31, particularly towards the outer side 33. Figure 2 The longitudinal axis LA can be better seen in the middle. More specifically, the cavity 41 is arranged in the end portion of the body 31 with the outer side 33 along the transverse direction of the TVD.

[0113] Furthermore, the cavity 41 is arranged off-center in the thickness direction (THD), particularly away from the side surface 35. This avoids the cavity 41 intersecting with the groove 37. The remaining "wall thickness" of the body 31 around the corresponding cavity 41 is greater than 1 mm everywhere (except at the opening of the cavity 41 located in the longitudinal end face 41), especially at the side surface 35.

[0114] Figure 4 It shows Figure 3 The cross-sectional view of section BB is shown. The cavity 41 is arranged at a certain distance from the external geometry of the body 31 (outer side 33, side surface 35, groove 37, ridge 36, etc.). Except for the opening at the longitudinal end face 32, the cavity is completely surrounded by the body 31 and is therefore surrounded by a fiber polymer material.

[0115] The groove 37 allows for fluid communication between the displacement space 23 for the blade and the adjacent pressure chamber 24. When the blade 30 is pushed into the corresponding displacement space 23, the fluid accumulated in the displacement space 23 is displaced by the blade 30. As the blade 30 moves radially outward, fluid needs to flow into the displacement space 23. The groove 37 allows fluid to flow into the displacement space 23.

[0116] By setting the groove 37 to have a depth GRD of at least 31% or at least 35% of the thickness BTH of the body 31 and / or a groove width GRW that is twice the width RW of the ridge 12, the effective flow cross section of the groove 37 is large enough to ensure that fluid can flow easily between the displacement space 23 and the corresponding pressure chamber 24.

[0117] In one example, the groove 37 has a depth GRD of approximately 40% of the thickness BTH of the body 31 (in the thickness direction THD). In the longitudinal section of both the groove 37 and at least one cavity 41 in the body 31, the cavity 41 is arranged within the remaining 60% of the thickness BTH of the body 31.

[0118] The groove 37 should be as large as possible to allow good flow between the displacement space 23 and the pressure chamber 24, while the blade 30 should be as robust or solid as possible to ensure the performance and reliability provided by the blade unit mechanism 1. Furthermore, the ridge 36 needs to provide good guidance for the blade 30 in the corresponding blade mount 22 with low friction. Therefore, a trade-off is required between the size of the groove 37, the strength of the blade 30, and manufacturing cost. This is possible in this invention.

[0119] Figure 6 It shows Figure 3 The blade 30 has a cross-section BB. The main body 31 comprises a total of four cavities 41. Two cavities 41 extend from each of the two longitudinal end faces 32 along the longitudinal direction LD.

[0120] exist Figure 4 In the middle, the cavity axes of the upper cavity 41 coincide, and the cavity axes of the lower cavity 41 coincide. All cavity axes are parallel to the longitudinal direction LD.

[0121] In this example, all cavities 41 are completely separated from each other within the body 31.

[0122] Each cavity 41 is equipped with a counterweight insert 42. The counterweight insert 42 is inserted into the corresponding cavity 41. The counterweight insert 42 can be additionally fixed in the corresponding cavity 41, for example, by using adhesive.

[0123] The counterweight insert 42 is made of a denser material than the material of the body 31. In other words, the counterweight insert 42 is made of a material with a higher mass density than the fibrous polymer material of the body 31.

[0124] By inserting the counterweight insert 42, the mass of the blade 30 (including the body 31 and the counterweight insert 42) increases and adapts to the desired target mass. The target mass is as low as possible on the one hand, but high enough on the other hand, that the blade 30 is subjected to sufficient centrifugal force during operation of the blade unit mechanism 1, thereby ensuring a proper seal between the outer side 33 and the inner circumferential wall surface 12 of the stator 10. Therefore, the blade unit mechanism 1 may be without biasing elements (such as springs) for elastically forcing the blade 30 against the inner circumferential wall surface 12 (i.e., radially outward).

[0125] For example, the counterweight insert 42 may be formed of materials from the group consisting of: steel, stainless steel, bronze, other metals, polymers filled with particles denser than fibers (e.g., metal particles), etc. In particular, the counterweight insert 42 may be made of stainless steel. This ensures good corrosion resistance (e.g., resistance to salt water / seawater) and sufficiently high density.

[0126] The counterweight inserts 42 are arranged to be spaced apart from or recessed from their respective longitudinal end faces 32, for example, spaced apart from or recessed by at least 0.2 mm.

[0127] The counterweight insert 42 is protected by the fiber polymer composite material surrounding the cavity 41 of the body 31 (except for the opening of the cavity 41 at the longitudinal end face 32).

[0128] Regarding blade 30, only the main body 31 slides against other parts of blade unit mechanism 1 during operation. The counterweight insert 42 does not slide against other parts.

[0129] All blades 30 within the same blade unit machine 1 can differ in weight by up to 5%. This allows the blade unit machine 1 to operate smoothly. The technique of inserting suitable counterweight inserts 42 allows the mass of all blades 30 to be adjusted precisely to the same common target mass.

[0130] Naturally, embodiments with other numbers of cavities 41 and / or other numbers of counterweight inserts 42 are also possible.

[0131] For example, in another embodiment (not shown), six cavities 41 for inserting counterweight inserts 42 are formed in the body 31, and the blade 30 includes six counterweight inserts 42.

[0132] In one modification (not shown), the body 31 includes two cavities 41 extending between two longitudinal end faces 32, for example, as if... Figure 6 The two upper cavities 41 extend and merge, and Figure 6 The two lower cavities 41 extend and merge in the same manner. Two counterweight inserts 42 can be inserted into each elongated cavity, such that the arrangement of the counterweight inserts 42 is similar to... Figure 6 Alternatively, a longer counterweight insert can be inserted into each elongated cavity.

[0133] Blade 30 can be relatively large. For example, the length of blade 30 in the longitudinal direction LD can be greater than 100 mm, such as at least 130 mm. Additionally or alternatively, the thickness BRT of blade can be greater than 10 mm, such as at least 12 mm.

[0134] Of course, other sizes are also possible.

[0135] As an example, the blade 30 can be manufactured as follows:

[0136] Provide precursors (green blanks) for solid or solid fiber polymer composites.

[0137] Polymers used in fiber-polymer composites include, for example, polyetheretherketone (PEEK). This material exhibits good sliding properties when combined with fluids such as water and steel.

[0138] The fibers can be provided in the form of fabrics, prepregs, chopped strands, etc. In one embodiment, the fibers include carbon fibers. In particular, all fibers can be carbon fibers. For example, carbon fiber reinforced polymers are less susceptible to performance degradation due to the effects of fluids such as water compared to polymers reinforced with aramid fibers.

[0139] For example, the precursor is made of a fiber-reinforced polymer laminate, wherein the two fibers are oriented 90° off from each other. In one embodiment, manufacturing the precursor may include: - Laminated unidirectional carbon fiber reinforcement layers (e.g., prepreg layers); and / or - Laminated braided carbon fiber reinforcement layers (e.g., prepreg layers), especially those with orthogonal fiber orientations.

[0140] The external shape of the body 31 is formed by machining, for example by milling and / or drilling.

[0141] The final dimensions (e.g., the length of the longitudinal direction LD, the width of the transverse direction TVD, and the thickness of the thickness direction THD BTH) can be obtained by machining.

[0142] The shapes of the outer side 33 and / or the inner side 34 can be formed by machining.

[0143] Groove 37 can be formed by machining.

[0144] The cavity 41 in the body 31 can be formed directly during the production of the fiber polymer composite. However, forming the cavity 41 by machining (e.g., by drilling) is particularly cost-effective and easy.

[0145] In the insertion step, the counterweight insert is inserted into the cavity 41. The method may additionally include securing the counterweight insert 42 to the body 31, for example by means of an adhesive; in other words, the counterweight insert 42 is glued in place.

[0146] The method may include, for example, forming processing features 39 in the precursor and / or body 31 by machining to facilitate processing during further manufacturing of the blade 30 and / or during mounting of the blade 30 to the rotor 20. List of reference numerals in the attached figures 1 Blade unit machinery 2. Outer shell 7 (First) Fluid Port 10 stators 11 Stator Holes 12 Inner circumferential wall surface 20 rotors 21 Rotor shaft 22 Blade mounting components 23. Displacement space (part of the blade mounting assembly) 24. Pressure Chamber (Fluid Chamber) 30 blades 31 Main Body 32 Longitudinal end face 33 Outer side 34 Inner side 35 side surfaces 36. Spine 37 Grooves 39 Processing Features 41 Cavities 42 counterweight inserts BTH (body thickness) GRW Groove Width GRD Groove Depth LA longitudinal axis LD longitudinal direction MA intermediate axis RA rotation axis RD Radial direction RW Ridge Width THD thickness direction TVD (Horizontal Direction)

Claims

1. A vane (30) for a vane cell machine (1), wherein, The vane cell machine (1) comprises a stator (10) having a stator bore (11) and a rotor (20) rotatably arranged in the stator bore (11), the stator (10) having an inner circumferential wall surface (12), wherein the vane (30) comprises a main body (31) extending in a longitudinal direction (LD), a transverse direction (TVD) and a thickness direction (THD), wherein all directions (LD, TVD, THD) are at least approximately perpendicular to each other, wherein the main body (31) comprises two opposite longitudinal end surfaces (32) along the longitudinal direction (LD) and comprises an outer side (33) for sealing against the inner circumferential wall surface (12) of the stator (10), wherein the outer side (33) constitutes one end of the main body (31) in the transverse direction (TVD), characterized in that the main body (31) is made of a solid fiber polymer composite material, and in that the vane (30) comprises at least one weight insert (42), wherein at least one cavity (41) for inserting the at least one weight insert (42) into the main body (31) is formed in the main body (31).

2. The vane (30) of claim 1, wherein The at least one cavity (41) is arranged off-center with respect to a central longitudinal axis (LA) of the main body (31) towards the outer side (33).

3. The vane (30) according to claim 1 or 2, wherein The at least one cavity (41) extends into the main body (31) from one of the longitudinal end surfaces (32) along the longitudinal direction (LD).

4. The vane (30) of claim 3, wherein, The length of the at least one cavity (41) is at least 0.2 mm longer than the length of the at least one weight insert (42).

5. The vane (30) according to claim 3 or 4, wherein The main body (31) comprises a further cavity (41) extending into the main body (31) from the other one of the longitudinal end surfaces (32) along the longitudinal direction (LD), wherein the at least one cavity (41) and the further cavity (41) are at a distance from each other along the longitudinal direction (LD).

6. The vane (30) according to any one of the preceding claims, wherein The main body (31) comprises a groove (37) extending in the transverse direction (TVD) on a side (35) forming one end of the main body (31) in the thickness direction (THD), wherein the depth (GRD) of the groove (37) is at least 31% of the thickness (BTH) of the main body (31) along the thickness direction (THD).

7. The vane (30) according to any one of the preceding claims, wherein The at least one weight insert (42) is formed of a material having a higher mass density than the fiber polymer composite material, and / or wherein the at least one weight insert (42) is formed of stainless steel.

8. The vane (30) according to any one of the preceding claims, wherein The fiber polymer composite material comprises polyether ether ketone and carbon fibers.

9. The vane (30) according to any one of the preceding claims, wherein The fiber polymer composite material is formed of a laminate, preferably of a laminate having two fiber directions offset by 90° with respect to each other.

10. The vane (30) according to any one of the preceding claims, wherein The at least one weight insert (42) is fixed within the at least one cavity (41), preferably by an adhesive.

11. A vane cell machine (1) comprising: a housing (2) having a stator (10) with a stator bore (11); a rotor (20) mounted in the stator bore (11) and configured to rotate relative to the stator (10) about a rotation axis (RA); and a plurality of vanes (30) mounted to the rotor (20) such that the vanes (30) are rotatably fixed to the rotor (20) but allow the vanes (30) to have a limited displacement in radial direction; characterized in that at least one of the vanes (30) is a vane (30) according to any one of the preceding claims.

12. The vane cell mechanism (1) according to claim 11, wherein The relative weight difference between the vanes (30) is less than 5%.

13. A method for producing a blade (30), preferably a blade (30) according to any one of claims 1 to 10, wherein The method comprises the following steps: - providing a body (31) of the vane (30), wherein the body (31) is made of a solid fiber polymer composite material; - forming at least one cavity (41) for inserting at least one weight insert (42) in the body (31); and - inserting the at least one weight insert (42) into the empty at least one cavity (41).

14. The method of claim 13, wherein, By inserting the at least one weight insert (42), the mass of the vane (30) is adjusted towards a target mass.

15. The method of claim 13 or 14, wherein, A groove (37) is machined into the body (31).

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