Flexible universal joint.

Abstract

The invention relates to a constant velocity universal joint, suitable for production from a single piece, using flexible and body-integrated limbs to transmit power and motion between non-coaxial shafts.

Description

TARIFF FLEXIBLE UNIVERSAL JOINT The technical field to which the invention relates: The invention relates to a constant velocity universal joint, suitable for production from a single piece, using flexible and body-integrated limbs to transmit power and motion between non-coaxial shafts. State of the art: Universal joints are mechanical structures that allow two moving parts to be connected without losing their ability to move. They are also used to transmit rotational motion between non-coaxial shafts and to transmit angular motion from rotating shafts. In the automotive industry, shafts used to connect the transmission and differential are joined using universal joints. Universal joints compensate for the angular difference between the gearbox output shaft and the rear axle caused by varying road conditions. Universal joints are not only used in automotive applications but are also frequently used in construction and agricultural machinery. They are also used in shafts that transmit rotational movement from the PTO shafts of tractors to agricultural machinery. In short, universal joints are widely used in almost every application where shafts with axial displacement or those transmitting movement or torque at different angles need to be connected. Many different designs and inventions (cardan joint, Rzeppa joint, flexible shaft, flexible cardan joint, etc.) that solve this problem exist in the literature. To ensure the proper functioning of the joints, excessive and shock loads should be avoided. The cross journals of rigid joints can wear and develop play due to load and impact. If the joint malfunctions, it will start making noise. Furthermore, regular lubrication is necessary for the joints to have a long service life. The universal joints used in the current system are of an interlocking design. Therefore, play problems due to wear can occur. The invention described in patent number US 2004224778 ΑΓ, which is in the state of the art, relates to a rigid universal joint developed for use in the drivetrain of a motor vehicle. Universal joints are used in motor vehicle drive systems to connect pairs of rotating shafts and allow for angular variations between them. The universal joint has a torsional conformal structure that provides vibration damping properties. The universal joint includes a first bearing cup assembly and a second bearing cup assembly adapted for mounting in holes. The structure contains two first trunnion posts and two second trunnion posts. The invention described in patent number US 2014147193 ΑΓ, in the state of the art, describes a flexible universal joint. This universal joint comprises a hollow central longitudinal axis and two hollow shafts mounted orthogonally to each other and capable of rotating around a rotational axis. The three axes are mutually orthogonal and intersect at a pivot point located at the center of the universal joint. A flexible universal joint consisting of four simple flexible pivots mounted in pairs on two different bearings is described. According to one arrangement of the invention, the universal joint may include two cross-linked connecting parts. The two first arms of each cross are diametrically opposed to each other and are fixed to the intermediate frame of the first shaft. The invention described in patent number “US 1665280 A”, which is in the state of the art, describes a universal joint. The ball cage element described in the invention contains a removable integrated inner ball bearing. This cage element also describes a universal joint element equipped with numerous balls. The universal joint has grooves for inner and outer bearing elements that connect for rotation. In combination with a shaft pair, it has independently removable connections. The structure developed with this invention generally comprises a universal joint consisting of a single outer ball bearing, a removable integrated ball cage, an integrated ball bearing element positioned removablely within the cage, and curved ball bearings in which the aforementioned ball bearing elements are appropriately positioned. The universal joints used in the current system have an interlocking structure. Therefore, issues such as play due to wear, noise problems, and the need for lubrication of the joints are common. Universal joints in the current state of the art consist of rigid links containing six rotating pairs (joints), and therefore have longer production steps. In the transmission of low and medium torques, classic rigid-mechanism cardan joints are disadvantageous in terms of cost and labor due to their large number of parts. In the current system, universal joint bearings, which are manufactured to operate on universal joint arms, are subjected to irregular extra loads due to axial stresses, and over time, wear and deformation occur in the areas where the bearing rollers operate. This wear and deformation significantly reduces the service life of the universal joint. Consequently, due to the aforementioned drawbacks and the inadequacy of existing solutions, an improvement in the relevant technical field has become necessary. Brief Description and Objectives of the Invention The invention relates to a constant velocity joint suitable for one-piece production, which meets the aforementioned requirements, eliminates all disadvantages, provides additional advantages, and utilizes flexible and body-integrated limbs. The primary goal of this invention is to provide a universal joint free from wear, gaps in interlocking structures, and noise problems arising from joint failure. The universal joint developed for this purpose utilizes a flexible structure with integrated limbs. It produces no noises such as bearing noise in the working environment. Another aim of the invention is to provide a universal joint that can operate for a long time without requiring regular lubrication, ensuring a long service life for the joints. The universal joint developed for this purpose is completely flexible and consists of a single piece. This significantly reduces costs and assembly time due to the low number of parts and joints, and eliminates the need for lubrication. In other words, it requires no maintenance in the operating environment. Another objective of the invention is to produce a universal joint that can be manufactured from micro-sized to meter-sized dimensions according to the application requirements. The invention is suitable for strengthening flexible links using sheet metal made of spring steel and equivalent materials, and for increasing their torque capacity. For this purpose, the flexible mechanisms have the feature of being proportionally resized. Another objective of the invention is to provide a universal joint that can be manufactured practically. The universal joint developed with this invention is a monolithic structure and does not require any assembly process or time. The universal joint can also be produced by plastic injection molding. Therefore, it is suitable for mass production. Another objective of the invention is to provide a universal joint capable of delivering a constant speed output. The universal joint developed with this invention provides a constant speed output thanks to its flexible structure, without the need for any new additions. Explanation of the Figures: FIGURE-1; Drawing showing the isometric view of the universal joint, which is the subject of the invention. FIGURE-2; This is a drawing showing the front view of the universal joint, which is the subject of the invention. FIGURE-3; This is a drawing showing the side view of the universal joint, which is the subject of the invention. Descriptions of the Elements / Components Constituting the Invention To better illustrate the one-piece universal joint developed with this invention, the parts and elements shown in the figures are numbered, and the corresponding numbers are given below: 1. Flexible connecting arm 2. Transmitting shaft connection housing 3. Transmitting shaft 4. Transmitted shaft connection housing 5. Transmitted shaft Detailed Description of the Invention The invention relates to a one-piece, monolithic, constant-velocity universal joint suitable for production, utilizing flexible and body-integrated limbs to transmit power and motion between non-coaxial shafts. The universal joint developed with this invention can be manufactured from thermoplastic materials that are suitable for heat forming and provide high strength and flexibility. Furthermore, the production of the universal joint is also suitable for polypropylene, a thermoplastic polymer that is fatigue-resistant and increases strength. In addition, flexible connecting arms (1) can be produced using sheet metal made of spring steel or by using a combination of thermoplastic and spring steel. While the working method of the model produced with spring steel or the model produced with a combination of spring steel and thermoplastic is the same as the developed universal joint, it is possible to achieve a higher torque carrying capacity. Furthermore, the production method can also be varied. Mechanisms that can perform part or all of their movement thanks to flexible parts are defined as flexible mechanisms. These types of mechanisms have significant advantages such as low cost, fewer parts, light weight, no need for lubrication during or after use, and absence of wear, play, and noise problems. The universal joint developed with the invention is manufactured as a single piece, using integrated limbs with a single-piece body, as shown in Figure T. Manufactured as a single piece using thermoplastic materials, the universal joint includes a flexible connecting arm (1), a transmitting shaft connecting body (2), a transmitting shaft (3), a transmitted shaft connecting body (4), and a transmitted shaft (5). The transmitted shaft (5) and the transmitting shaft (3) are cylindrical in shape to be compatible with the part to which they will be connected. The transmitted shaft connecting body (4) and the transmitting shaft connecting body (2) are generally square in shape with truncated corners. A flexible connecting arm (1) extends from one edge of the transmitted shaft connecting body (4) to the corresponding edge of the transmitting shaft connecting body (2). The number of flexible connecting arms (1) in the universal joint subject to the invention can be varied according to the need. The flexible connecting arm (1) is essentially the connecting element that transmits the desired power and / or motion. It also tolerates axial angle differences resulting from different shaft angles by flexing, as required by the universal joint. The flexibility of the developed universal joint is a function of the elastic modulus and yield strength, which are fundamental material properties, as well as being related to the geometry and cross-section of the material. As flexible links become thinner in the bending direction, their flexibility increases while their load-carrying capacity decreases. Using these functions, an optimization calculation is applied according to the axial deflection angle between shafts and the torque carrying capacity requirement. The bodies to which the transmitting shaft (3) and the transmitted shaft (5) are connected, and the flexible connecting arm (1) are integrated with each other. The flexible universal joint can be inserted between all shafts with a difference in axis. The universal joint developed with this invention is suitable for use in relatively low torque applications, such as robotics, small unmanned land, air, and water vehicles, the toy industry, micro-machines (MEMS), and nano-micro vehicles. It is a joint that is cheaper, lighter, longer-lasting, and provides a constant speed output compared to rigid universal joints. Fluctuations in shaft speeds occurring in commonly used universal joints are eliminated with the flexible connecting arm (1) and thus a constant speed universal joint is obtained. Flexible mechanism theories are used for sizing the flexible links of flexible universal joints. Since the flexible links flex along their entire length, they are dimensioned in three stages using large displacement fixed support theories. In the first stage, the stresses generated in the flexible links due to the change in the angle between the shafts are determined based on the strength limit of the material used. In this calculation, the thickness of the flexible link is the most fundamental determinant of the stress-strain function. Reducing the material thickness also reduces the stresses caused by displacement. As a result, while allowing for larger differences in the angle between the shafts, the torque carrying capacity of the joint also decreases. The second stage of the calculations involves determining the torque carrying capacity. The material's resistance to applied torque is determined based on its shear strength. The width of the flexible links is crucial in this calculation. As the width increases, the torque capacity increases, and the resistance to increasing the angle between the shafts also increases. In the third stage of the calculations, stresses caused by displacements and stresses caused by torque are combined to determine the stresses that the flexible joints will be subjected to under real operating conditions. At this stage, a design table and graph are created to determine how much torque the joint can carry at what angle between which shafts. The universal joint developed with this invention was designed through calculations completed in three stages using analytical methods. This design was verified using computer-aided strength analysis programs, and subsequently, a prototype was produced. The prototype was then tested in a laboratory environment simulating a real working setting, demonstrating the functionality of the invention. In the universal joint, the number of flexible connecting arms (1) can be increased or decreased according to different torque requirements (capabilities). A four-arm design is shown as an example in Figure-T. If a higher value is desired in the torque carrying capacity of the proposed joint, it is possible to produce it with any number of flexible connecting arms (1) more than two, and the torque capacity increases linearly with the number of arms. The invention can be manufactured to different torque capacities simply by changing the number of flexible links, without requiring new design processes, and can be reproduced proportionally by sizing without requiring new design processes. Thanks to its flexible mechanisms that can be proportionally resized, the developed universal joint can be produced in a wide variety of sizes, from micro-sized to meter-sized, to meet specific needs. The flexible universal joint can be manufactured using additive manufacturing, a method that enables the production of flexible parts made from multiple materials. For mass production, it can also be produced in a single pass using plastic injection molding. Plastic injection molding allows for the easy production of structures with different geometries, as is the case with the universal joint in question. Its flexible structure makes it suitable for high-speed mass production.

Claims

REQUIREMENTS 1. It is a universal joint used to transmit power and motion between non-coaxial shafts, and its feature is that it includes at least two flexible connecting arms (1) that extend from one edge of the transmitted shaft connection body (4) to the edge parallel to the transmitting shaft connection body (2); positioned between the transmitting shaft connection body (2) connected to the transmitting shaft (3) and the transmitted shaft connection body (4) connected to the transmitted shaft (5), transmitting the desired power and motion, being flexible in structure, tolerating axial angle differences resulting from different shaft angles, not requiring lubrication during or after use, having a constant speed ratio and manufactured in one piece with the transmitting shaft (3), the transmitting shaft connection body (2), the transmitted shaft (5) and the transmitted shaft connection body (4).

2. It is a universal joint as in Claim 1, the feature of which is that the flexible connecting arm (1) is made of thermoplastic material or spring steel or a material in which thermoplastic and spring steel are used together.

3. The universal joint in question, as described in Claim T, is characterized by its suitability for thermoforming, high strength, and flexibility, and is manufactured from thermoplastic material.

4. It is a universal joint as in Claim 1, and its characteristic feature is that it is made of polypropylene material in order to provide fatigue resistance and increase its strength.

5. It is a universal joint as in Claim 1, and its feature is that it contains a flexible connecting arm (1) whose number can be increased or decreased according to different torque capacities.

6. The component in question is a universal joint like the one in T, whose characteristic feature is its suitability for mass production speeds thanks to its flexible structure.

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