Ejector rod mechanism for measuring pitch of variable pitch propeller

Abstract

The invention relates to the technical field of mechanical structure optimization, in particular to an ejector rod mechanism for variable pitch propeller pitch measurement, which comprises a self-lubricating roller bearing, a displacement rod, a support, a reset mechanism and a dustproof limiting assembly. Through rolling contact between the self-lubricating roller bearing and the cam, angular displacement is accurately converted into axial linear displacement of the displacement rod, through cooperation with double-point radial constraint of the linear motion bearing and the category limiting assembly, it is ensured that the motion trail is stable, and the propeller pitch measurement precision is improved, and through interference fit between a dustproof ring in the dustproof limiting assembly and the displacement rod, the propeller pitch measurement precision is improved. Foreign matters such as dust and carbon powder are effectively prevented from entering the cavity, clamping stagnation caused by movement is avoided, the reliability of the mechanism in a severe environment is guaranteed, a reset spring in the reset mechanism provides reset elastic force, a displacement rod can rapidly and reversely move when the pitch of a propeller is decreased by adopting a piano steel wire material, real-time dynamic response is achieved, and the reliability of the mechanism is improved. And the real-time measurement requirement of the blade angle is met.

Description

Technical Field

[0001] This application relates to the field of mechanical structure optimization technology, and in particular to a push rod mechanism for measuring the pitch of a variable pitch propeller. Background Technology

[0002] In aviation, shipbuilding, and other fields, variable-pitch propellers control propulsion efficiency by adjusting the blade angle (pitch). Existing pitch measurement devices often employ a combination of a cam-push-rod mechanism and a Hall sensor: the cam rotates with the blade as the pitch changes, the push-rod mechanism converts the cam's angular displacement into linear displacement, and the Hall sensor then converts the displacement signal into the blade angle. For example, a previous patent application with publication number CN107941142A disclosed a real-time propeller blade pitch angle measurement device, including a cam, a push-rod assembly, and a displacement sensor; the cam is located at the root of the propeller blade and rotates integrally with the blade; the push-rod assembly includes a push-rod, a universal ball bearing, a housing, and a spring; one end of the push-rod is fitted with the universal ball bearing, and the other end is located inside the housing, with the push-rod slidingly engaging with the housing; the spring is positioned between the push-rod and the housing, applying an elastic thrust to the push-rod; under the action of this elastic thrust, the universal ball bearing at one end of the push-rod always presses against the cam; the displacement sensor monitors the sliding displacement of the push-rod in real time. A contact-type measurement scheme of "cam-push rod-indicator-displacement sensor" is adopted, and an eddy current sensor is used for pitch measurement. However, the traditional push rod mechanism is also prone to the following drawbacks:

[0003] Risk of motion jamming: The displacement rod lacks effective radial constraint and is easily jammed by centrifugal force or foreign objects (such as dust and carbon powder), which affects the accuracy of measurement.

[0004] High frictional loss: The friction coefficient between ordinary bearings and push rods is high, which makes them prone to wear and reduces their service life after long-term operation.

[0005] Dynamic response lag: The ordinary spring has insufficient restoring force or insufficient structural rigidity, which cannot meet the real-time measurement requirements of the propeller's rapid pitch change in a timely manner.

[0006] Insufficient sealing: There is no dedicated dustproof design, and external contaminants can easily enter the cavity, which will aggravate the wear of moving parts.

[0007] Therefore, there is an urgent need to develop a high-precision, anti-jamming, corrosion-resistant, and fast dynamic response push rod mechanism to improve the accuracy and stability of propeller pitch measurement. Summary of the Invention

[0008] This application provides a push rod mechanism for measuring the pitch of a variable pitch propeller, which overcomes the shortcomings of traditional push rods and improves the accuracy and stability of propeller pitch measurement.

[0009] This application provides a push rod mechanism for measuring the pitch of a variable-pitch propeller, comprising:

[0010] Self-lubricating roller bearings contact the cam and rotate with it;

[0011] The displacement rod has one end connected to the self-lubricating roller bearing via a bearing joint, and the other end is fixed with a sensing disk;

[0012] The support has an inner cavity that houses a linear motion bearing and a retaining ring for the bore. One end of the displacement rod passes through the inner cavity of the support and is connected to the induction disk.

[0013] A reset mechanism is located at one end of the support and is connected to the support by bolts.

[0014] A dustproof limiting component is located between the reset mechanism and the displacement rod.

[0015] Preferably, the displacement rod is made of high-temperature alloy material, and the displacement rod is divided into a large end and a small end, wherein the end closest to the bearing joint is the large end of the displacement rod;

[0016] An abutment ring is also provided between the large end and the small end of the displacement rod.

[0017] Preferably, the reset mechanism includes a spring seat and a reset spring, wherein:

[0018] One end of the spring seat is inserted into the inside of the support, and the spring seat is sleeved on the small end of the displacement rod;

[0019] The return spring is made of piano wire and is placed inside the cavity of the support. One end of the spring abuts against the outer surface of the abutment ring, and the other end abuts against the inner wall of the spring seat.

[0020] Preferably, a receiving groove is provided on the side of the spring seat that connects with the displacement rod, the dustproof limiting component is located inside the receiving groove, and the inner surface of the dustproof limiting component is in close contact with the outer surface of the small end of the displacement rod.

[0021] Preferably, the dustproof limiting component includes a limiting bushing and a dustproof ring, wherein the inner surface of the limiting bushing is in close contact with the outer surface of the small end of the displacement rod, and the dustproof ring and the displacement rod are interference fit.

[0022] Preferably, the limiting bushing is made of polyamide-imide material, the linear motion bearing and the large end of the displacement rod form a rolling friction pair, and the limiting bushing and the small end of the displacement rod form a sliding friction pair.

[0023] Preferably, the support is made of titanium alloy, and the axial displacement of the linear motion bearing is limited by an elastic retaining ring through the hole.

[0024] Preferably, the self-lubricating roller bearing has a molded gasket made of self-lubricating composite material between its inner and outer rings, and the outer ring is made of high-nitrogen stainless steel.

[0025] Preferably, one end of the bearing joint is rotatably connected to the self-lubricating roller bearing via a bearing rod, and the other end is threadedly connected to the large end of the displacement rod.

[0026] Preferably, the induction disk is made of strong magnetic steel, and the induction disk is connected to the small end of the displacement rod by an elastic cylindrical pin.

[0027] The beneficial effects of this application are as follows:

[0028] The push rod mechanism for measuring the pitch of a variable-pitch propeller disclosed in this application accurately converts angular displacement into axial linear displacement of the displacement rod through the rolling contact between a self-lubricating roller bearing and a cam. Combined with the dual-point radial constraint of the linear motion bearing and the range limiting assembly, it ensures stable motion trajectory and improves pitch measurement accuracy. The interference fit between the dustproof ring in the dustproof limiting assembly and the displacement rod effectively prevents dust, carbon powder, and other foreign matter from entering the cavity, avoiding jamming and ensuring the reliability of the mechanism in harsh environments. The reset spring in the reset mechanism provides reset force, and the use of piano wire allows the displacement rod to quickly reverse when the propeller pitch decreases, achieving real-time dynamic response and meeting the real-time measurement requirements of the blade angle. Attached Figure Description

[0029] To more clearly illustrate the technical solutions in the specific embodiments of this application or the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this application. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0030] Figure 1 This is a schematic diagram of the overall structure of the push rod mechanism for measuring the pitch of a variable-pitch propeller, provided in an embodiment of this application.

[0031] Figure label:

[0032] 1. Self-lubricating roller bearing; 2. Bearing joint; 3. Bearing rod; 4. Displacement rod; 5. Support; 6. Elastic retaining ring for bore; 7. Linear motion bearing; 8. Return spring; 9. Spring seat; 10. Limit bushing; 11. Dustproof ring; 12. Induction plate. Detailed Implementation

[0033] The technical solutions of this application will be clearly and completely described below with reference to the embodiments. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0034] The following is combined with Figure 1 This application describes a push rod mechanism for measuring the pitch of a variable-pitch propeller, as provided in an embodiment of the present application.

[0035] Reference Figure 1 As shown in the embodiment of this application, the push rod mechanism for measuring the pitch of a variable-pitch propeller includes a self-lubricating roller bearing 1, a displacement rod 4, a support 5, a reset mechanism, and a dustproof limiting component. The self-lubricating roller bearing 1 is installed at the front end of the push rod mechanism and contacts the cam, allowing it to rotate with the cam. One end of the displacement rod 4 is connected to the self-lubricating roller bearing 1 via a bearing joint 2, and the other end is fixed to a sensing disk 12. The support 5 has an internal cavity that houses a linear motion bearing 7 and a retaining ring 6 for the bore. The reset mechanism is located at one end of the support 5 and is connected to the support 5 via bolts. The dustproof limiting component is located between the reset mechanism and the displacement rod 4, and one end of the displacement rod 4 passes through the support 5, the reset mechanism, and the dustproof limiting component in sequence before connecting to the sensing disk 12.

[0036] The angular displacement is precisely converted into the axial linear displacement of the displacement rod 4 through the rolling contact between the self-lubricating roller bearing 1 and the cam. The linear motion bearing 7 and the range limit component provide dual-point radial constraint to ensure stable motion trajectory and improve the accuracy of blade pitch measurement. The dustproof ring 11 in the dustproof limit component and the interference fit between the displacement rod 4 effectively prevent dust, carbon powder and other foreign objects from entering the cavity, avoid motion jamming, and ensure the reliability of the mechanism in harsh environments (such as ocean and high dust). The reset spring 8 in the reset mechanism provides reset elasticity, and the use of piano wire material allows the displacement rod 4 to move quickly in the opposite direction when the propeller pitch decreases, realizing real-time dynamic response and meeting the real-time measurement requirements of blade angle.

[0037] In some specific embodiments, the displacement rod 4 is made of high-temperature alloy material to enhance its adaptability to harsh environments while maintaining sufficient strength. The displacement rod 4 is divided into a large end and a small end, wherein the end near the bearing joint 2 is the large end of the displacement rod 4.

[0038] An abutment ring is also provided between the large end and the small end of the displacement rod 4.

[0039] Specifically, the displacement rod 4 is a rod-shaped component with different thicknesses at both ends, made of high-temperature alloy material. It is divided into a thicker large end and a thinner small end by an abutment ring near the middle of the rod. The end closer to the self-lubricating roller bearing 1 is the large end, and the end closer to the induction disk 12 is the small end.

[0040] In some specific embodiments, the reset mechanism includes a spring seat 9 and a reset spring 8, wherein:

[0041] One end of the spring seat 9 is inserted into the inside of the support 5, and the spring seat 9 is sleeved on the small end of the displacement rod 4;

[0042] The return spring 8 is made of piano wire and is placed inside the cavity of the support 5. One end of it abuts against the outer surface of the abutment ring, and the other end abuts against the inner wall of the spring seat 9. It is used to provide a reverse return force so that when the propeller pitch decreases, the elastic force of the return spring 8 causes the displacement rod 4 to move in the opposite linear direction. By using piano wire, which has excellent fatigue life and extremely high strength and tensile strength, the overall stiffness and service life of the return spring 8 are improved. While achieving miniaturization and weight reduction, its return capability is enhanced, enabling it to quickly return to its original position. It also ensures that the outer surface of the self-lubricating roller bearing 1 is always in contact with the outer surface of the corresponding cam, preventing it from separating and causing adverse effects on the accuracy of the data.

[0043] In some specific embodiments, a receiving groove is provided on the side of the spring seat 9 that is connected to the displacement rod 4, and the dustproof limiting component is located inside the receiving groove. The inner surface of the dustproof limiting component is in close contact with the outer surface of the small end of the displacement rod 4.

[0044] The dustproof limiting component provides support and sealing for the small end of the displacement rod 4, limiting its radial direction while preventing external dust and other impurities from entering the cavity of the support 5 and affecting the operation of the displacement rod 4.

[0045] In some specific embodiments, the dustproof limiting assembly includes a limiting bushing 10 and a dustproof ring 11, wherein the inner surface of the limiting bushing 10 is in close contact with the outer surface of the small end of the displacement rod 4, the dustproof ring 11 is in an interference fit with the displacement rod 4, and the dustproof ring 11 is disposed on the outside of the limiting bushing 10 to seal the cavity.

[0046] Specifically, the dustproof ring 11 is placed in the receiving groove opened in the spring seat 9 and is interference-fitted with the small end of the displacement rod 4 to prevent external dust from entering the cavity and causing the displacement rod 4 to jam. The dustproof ring 11 is made of fluorosilicone rubber to facilitate its installation. The elongation and compression ratio can be set to 1.02 and 6.1-13.3% respectively to ensure that it can effectively prevent dust while improving its service life.

[0047] In some specific embodiments, the limiting bushing 10 is made of polyamide-imide material, the linear motion bearing 7 and the large end of the displacement rod 4 form a rolling friction pair, and the limiting bushing 10 and the small end of the displacement rod 4 form a sliding friction pair.

[0048] The support 5 constrains the radial displacement of the displacement rod 4 by means of the linear motion bearing 7 and the limiting bushing 10 set at both ends of the displacement rod 4, thereby reducing the jamming caused by centrifugal force or foreign objects (such as dust and carbon powder) and affecting the measurement accuracy.

[0049] The limiting bushing 10 is made of polyamide-imide material with low friction coefficient and self-lubricating function, such as TORLON 4301 material. While limiting and supporting the small end of the displacement rod 4, it reduces the self-friction between itself and the outer surface of the displacement rod 4, so as to extend its service life and avoid hindering the displacement of the displacement rod 4.

[0050] In some specific embodiments, the support 5 is made of titanium alloy, and the axial displacement of the linear motion bearing 7 is limited by the elastic retaining ring 6 through the hole, so as to prevent the linear motion bearing 7 from axially displacing with the large end of the displacement rod 4, causing additional friction between it and the displacement rod 4, and reducing its service life.

[0051] In some specific embodiments, a molded gasket made of a self-lubricating composite material is provided between the inner and outer rings of the self-lubricating roller bearing 1, and the outer ring is made of high-nitrogen stainless steel.

[0052] By using a molded gasket made of self-lubricating composite material, such as SLACM-96 molded gasket, between the inner and outer rings of the self-lubricating roller bearing 1, the coefficient of friction during operation is reduced. Furthermore, by selecting high-nitrogen stainless steel to make its outer ring, the strength and hardness of the outer ring of the self-lubricating roller bearing 1 are significantly improved without sacrificing corrosion resistance, enabling it to operate normally in harsh environments.

[0053] In some specific embodiments, one end of the bearing joint 2 is rotatably connected to the self-lubricating roller bearing 1 via the bearing rod 3, and the other end is threadedly connected to the large end of the displacement rod 4.

[0054] Specifically, the displacement rod 4 and the bearing joint 2 are both provided with screw threads so that the two can be quickly connected by threads, and the top of the displacement rod 4 is also provided with a shoulder structure to prevent it from rotating unnecessarily.

[0055] In some specific embodiments, the inside of the induction disk 12 is made of a strong magnetic steel material such as samarium cobalt or neodymium iron boron, which can directly resist seawater and salt spray corrosion without additional protection. The induction disk 12 and the small end of the displacement rod 4 are connected by an elastic cylindrical pin.

[0056] In some specific embodiments, the working principle of the push rod mechanism for measuring the pitch of a variable-pitch propeller provided in this application is as follows:

[0057] The self-lubricating roller bearing 1 is installed at the front end of the push rod mechanism, in contact with the cam, and rotates with the cam. SLACM-96 molded gaskets are used between the inner and outer rings of the self-lubricating roller bearing 1 to reduce the coefficient of friction during operation. The outer ring of the bearing is made of high-nitrogen stainless steel. The bearing joint 2 is fixedly connected to the self-lubricating roller bearing 1 via the bearing rod 3, and also to the displacement rod 4 via threads. The displacement rod 4 is placed in the cavity of the support 5, with one end connected to the bearing joint 2 and the other end connected to the induction plate 12. Its radial displacement is limited by the linear motion bearing 7 and the polyamide-imide limiting bushing 10. The inner wall of the displacement rod 4 in the axial direction contacts the return spring 8 through a set abutment ring. To reduce the friction experienced by the displacement rod 4 during operation, the displacement rod 4 has been designed for weight reduction and strength enhancement to meet the usage requirements. Furthermore, to prevent the displacement rod 4 from rotating during the push rod mechanism's movement, causing damage to the self-lubricating roller... The bearing 1 deflects, and a shoulder structure is designed at the top of the displacement rod 4 to prevent rotation. One end of the support 5 is fixedly connected to the propeller by bolts, and the other end is fixedly connected to the spring seat 9 by bolts. A linear motion bearing 7 is placed in the inner cavity of the support 5, and its axial displacement is limited by an elastic retaining ring 6 through a hole. The return spring 8 is also placed in the cavity of the support 5 and sleeved on the outer surface of the displacement rod 4. One end of the spring 8 contacts the inner wall of the displacement rod 4 in the axial direction, and the other end contacts the inner wall of the spring seat 9. When the propeller pitch decreases, the spring force causes the displacement rod 4 to move in the opposite linear direction. The inner diameter of the spring seat 9 is equipped with a limiting bushing 10 and a dustproof ring 11 to support and seal the displacement rod 4 to prevent the displacement rod 4 from moving inflexibly. The dustproof ring 11 is interference-fitted with the displacement rod 4 to prevent external dust from entering the cavity and causing the displacement rod 4 to jam. The induction disk 12 is fixed to the displacement rod 4 by an elastic cylindrical pin. The inside is made of strong magnetic steel to provide a strong magnetic signal to the propeller pitch measurement sensor.

[0058] To meet the complex operating conditions on board, a two-point constraint method using linear motion bearing 7 and limiting bushing 10 was adopted within the limited space. Since the push rod mechanism bears a centrifugal force of nearly 800N during propeller operation, the displacement rod 4 structure was designed to reduce weight. A polyamide-imide bushing with good self-lubricating properties was used to reduce friction during the movement of the displacement rod 4. The entire structure fully considers marine environmental conditions, using a variety of highly corrosion-resistant materials such as high-temperature alloys, titanium alloys, and high-nitrogen stainless steel. To prevent external dust, propeller brush dust, carbon powder, and other foreign matter from entering the structural cavity and affecting the displacement rod 4... To prevent jamming during operation, a dustproof ring 11 is designed to seal its port. When the propeller pitch changes, it drives the cam to rotate, causing relative rolling between the self-lubricating roller bearing 1 on the push rod mechanism and the cam, compressing the spring and causing the displacement rod 4 with the sensing disk 12 to move forward along the axis. When the propeller pitch decreases, the self-lubricating roller bearing 1 disengages from the cam, and the return spring 8 rebounds, causing the displacement rod 4 with the sensing disk 12 to move in the opposite direction along the axis. This converts the angular change during the pitch change into a linear change, allowing the displacement rod 4 to move quickly in the opposite direction when the propeller pitch decreases, thus achieving real-time dynamic response and meeting the requirements for real-time blade angle measurement.

[0059] In the description of this application, it should be understood that the terms "center", "longitudinal", "lateral", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential", etc., indicating the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this application.

[0060] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this application, "multiple" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0061] In this application, unless otherwise expressly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between components; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise expressly limited. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0062] In this application, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of this application. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0063] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A push rod mechanism for measuring the pitch of a variable-pitch propeller, characterized in that, include: Self-lubricating roller bearings contact the cam and rotate with it; The displacement rod has one end connected to the self-lubricating roller bearing via a bearing joint, and the other end is fixed with a sensing disk; The support has an inner cavity that houses a linear motion bearing and a retaining ring for the bore. One end of the displacement rod passes through the inner cavity of the support and is connected to the induction disk. A reset mechanism is located at one end of the support and is connected to the support by bolts. A dustproof limiting component is located between the reset mechanism and the displacement rod.

2. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 1, characterized in that, The displacement rod is made of high-temperature alloy material. The displacement rod is divided into a large end and a small end, wherein the end near the bearing joint is the large end of the displacement rod. An abutment ring is also provided between the large end and the small end of the displacement rod.

3. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 2, characterized in that, The reset mechanism includes a spring seat and a reset spring, wherein: One end of the spring seat is inserted into the inside of the support, and the spring seat is sleeved on the small end of the displacement rod; The return spring is made of piano wire and is placed inside the cavity of the support. One end of the spring abuts against the outer surface of the abutment ring, and the other end abuts against the inner wall of the spring seat.

4. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 3, characterized in that, A receiving groove is provided on the side of the spring seat that connects with the displacement rod. The dustproof limiting component is located inside the receiving groove, and the inner surface of the dustproof limiting component is in close contact with the outer surface of the small end of the displacement rod.

5. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 4, characterized in that, The dustproof limiting assembly includes a limiting bushing and a dustproof ring, wherein the inner surface of the limiting bushing is in close contact with the outer surface of the small end of the displacement rod, and the dustproof ring and the displacement rod are in an interference fit.

6. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 5, characterized in that, The limiting bushing is made of polyamide-imide material. The linear motion bearing and the large end of the displacement rod form a rolling friction pair, and the limiting bushing and the small end of the displacement rod form a sliding friction pair.

7. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 6, characterized in that, The support is made of titanium alloy, and the axial displacement of the linear motion bearing is limited by an elastic retaining ring through the hole.

8. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 7, characterized in that, The self-lubricating roller bearing has a molded gasket made of self-lubricating composite material between its inner and outer rings, and the outer ring is made of high-nitrogen stainless steel.

9. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 8, characterized in that, One end of the bearing joint is rotatably connected to the self-lubricating roller bearing via a bearing rod, and the other end is threadedly connected to the large end of the displacement rod.

10. The push rod mechanism for measuring the pitch of a variable-pitch propeller according to claim 9, characterized in that, The induction disk is made of strong magnetic steel, and the induction disk is connected to the small end of the displacement rod by an elastic cylindrical pin.

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