High-strength off-axis sliding block type universal transmission shaft

Abstract

The utility model discloses a high-strength off-axis sliding block type universal transmission shaft which structurally comprises an end shaft sleeve, an orthogonal shaft body and a sliding rod. The sliding rod is a component with two ends provided with shafts or shaft holes or arc-shaped sliding strips and arc-shaped sliding grooves, and the shafts or the shaft holes at the two ends are perpendicular to each other. According to the assembly relation, the orthogonal shaft body serving as the connecting body is formed by hinging the shaft or the shaft hole of the orthogonal shaft body with the shaft holes or the shafts of the end shaft sleeves and the sliding rods respectively; or the arc-shaped sliding strip structure and the arc-shaped sliding groove structure of the orthogonal shaft body are in sliding connection with the arc-shaped sliding groove structure and the arc-shaped sliding strip structure of the end shaft sleeve and the sliding rod respectively; the sliding rod has an omnidirectional pointing function, so that the two rotating shafts which are not parallel in direction have a rotating transmission function; the structure at least comprises a paired structure in which a group of arc-shaped sliding strips are matched with arc-shaped sliding grooves, or a structure in which the arc-shaped sliding strips are matched with the arc-shaped sliding grooves at all sliding fit positions; and the method can be widely applied to the field with precise high-torque requirements.

Description

[Technical Field]

[0001] This invention belongs to the field of mechanical technology. More precisely, it is an improved universal cross-shaft transmission mechanism with a new structure that improves rigidity, reduces size, and increases service life. [Background Technology]

[0002] Universal couplings come in various structural types, such as: cross shaft type, ball cage type, ball fork type, cam type, ball pin type, ball hinge type, ball hinge plunger type, three-pin type, three-fork type, three-ball pin type, and hinge rod type. The most commonly used is the cross shaft type, followed by the ball cage type. In practical applications, they are classified into heavy-duty, medium-duty, light-duty, and small types based on the magnitude of the transmitted torque. They are mechanical parts used to connect two shafts (driving shaft and driven shaft) in different mechanisms, enabling them to rotate together and transmit torque. In high-speed, heavy-load power transmission, some couplings also serve to buffer, dampen vibrations, and improve the dynamic performance of the shaft system. A coupling consists of two halves, connected to the driving shaft and driven shaft respectively. Generally, power machines are mostly connected to working machines using couplings. National standard specifications include: the cross shaft type universal coupling is the most widely used universal coupling, and bearings are the vulnerable parts of the cross shaft type universal coupling. The main differences among several large cross-shaped universal couplings lie in the variations of the bearing housing and the crosshead, resulting in different structural forms. To ensure the synchronization of the driving and driven shafts, double couplings are used in practical applications. The connection methods for double couplings are nothing more than welding or flange bolt connection, and the length of the middle section can vary in various ways. The crosshead components of cross-type universal couplings come in the following forms: SWC type integral fork-head cross-type universal coupling (JB / T 5513-2006), SWP type partial bearing housing cross-type universal coupling (JB / T3241-2005), SWZ type integral bearing housing cross-type universal coupling (JB / T3242-1993), WS type small double cross-type universal coupling (JB / T 5901-1991), WSD type small single cross-type universal coupling (JB / T 5901-1991), cross-type coupling for SWP type cross-type universal coupling, and cross-type coupling for WGC type cross-type universal coupling (JB / T 7341.2-2006). The above-mentioned heavy-duty and small cross-type universal couplings are all general-purpose types. Different automotive models have their own dedicated cross-type universal couplings or other types of universal couplings. For example, passenger cars use ball-cage universal couplings. In addition, agricultural machinery, industrial machinery, and other moving machinery products also have dedicated universal couplings, and most lifting equipment uses cross-type universal couplings. There are many types of couplings. According to the relative position and positional changes of the two connected shafts, they can be divided into: ① Fixed couplings. Mainly used where the two shafts require strict alignment and no relative displacement during operation. They generally have a simpler structure, are easier to manufacture, and the two shafts rotate at the same instantaneous speed. These mainly include flange couplings, sleeve couplings, and clamp couplings. ② Movable couplings. Mainly used where the two shafts are misaligned or have relative displacement during operation. Based on the method of displacement compensation, they can be further divided into rigid movable couplings and flexible movable couplings.Rigid movable couplings compensate for misalignment and displacement by utilizing the dynamic connection between the working parts of the coupling, which allows for movement in one or more directions. Examples include jaw couplings (allowing axial displacement), cross-groove couplings (used to connect two shafts with small parallel or angular displacements), universal couplings (used where the two shafts have a large misalignment angle or significant angular displacement during operation), gear couplings (allowing combined displacement), and chain couplings (allowing radial displacement). Flexible movable couplings (also known as flexible couplings) compensate for misalignment and displacement of the two shafts by utilizing the elastic deformation of elastic elements. These elastic elements also provide buffering and vibration damping properties. Examples include serpentine spring couplings, radial multi-layer leaf spring couplings, elastic ring pin couplings, nylon pin couplings, and rubber sleeve couplings. Some couplings are standardized. When selecting a coupling, first choose the appropriate type based on the working requirements, then calculate the torque and speed according to the shaft diameter, then find the applicable model in the relevant manual, and finally perform necessary verification calculations for certain key components.

[0003] Functional Classification: Couplings are used to connect two shafts together. The two shafts cannot be separated while the machine is running; they can only be separated after the machine is stopped and the connection is disassembled. Due to manufacturing and installation errors, deformation under load, and temperature changes, the relative position of the two shafts connected by a coupling can change, often making perfect alignment impossible. Based on whether the coupling has elastic elements, its ability to compensate for various relative displacements (i.e., whether it can maintain its connection function under relative displacement conditions), and its intended use, couplings can be classified into rigid couplings, flexible couplings, and safety couplings. Main Types, Characteristics, and Functions of Couplings in Transmission Systems | Remarks | ... Flexible safety couplings also have different levels of compensation performance, including pin type, friction type, magnetic powder type, centrifugal type, hydraulic type and other safety couplings. The selection of coupling mainly considers the required shaft speed, the load, the installation accuracy of the two connected parts, the smoothness of rotation, price, etc., and refers to the characteristics of various couplings to select a suitable coupling type.

[0004] When making a specific selection, consider the following points: Most couplings are standardized or pre-defined. The designer's task is to select, not design. The basic steps for selecting a coupling are as follows: Choose the type of coupling based on the magnitude of the transmitted load, the shaft speed, the installation accuracy of the two connected components, etc., and refer to the characteristics of various couplings to select a suitable type. 1) The magnitude and nature of the torque to be transmitted and the requirements for buffering and vibration reduction. For example, for high-power, heavy-duty transmissions, gear couplings can be selected; for transmissions with severe impact loads or requiring the elimination of torsional vibration of the shaft system, highly elastic couplings such as tire couplings can be selected. 2) The operating speed of the coupling and the magnitude of the resulting centrifugal force. For high-speed drive shafts, couplings with high balance accuracy should be selected, such as diaphragm couplings, rather than sliding block couplings with eccentricity. 3) The magnitude and direction of the relative displacement of the two shafts. When it is difficult to maintain strict and precise alignment of the two shafts after installation and adjustment, or when the two shafts will generate a large additional relative displacement during operation, flexible couplings should be selected. For example, when the radial displacement is large, a sliding block coupling can be selected; when the angular displacement is large or the connection of two intersecting shafts is large, a universal coupling can be selected. 4) Reliability and working environment of couplings. Generally, couplings made of metal components that do not require lubrication are more reliable; couplings that require lubrication are easily affected by the degree of lubrication and may pollute the environment. Couplings containing non-metallic components such as rubber are more sensitive to temperature, corrosive media, and strong light, and are prone to aging. 5) Due to manufacturing, installation, load deformation, and temperature changes, it is difficult to maintain strict and precise alignment of the two shafts after installation and adjustment. There is a certain degree of displacement in the x and y directions and skew angle CI. When the radial displacement is large, a sliding block coupling can be selected; when the angular displacement is large or the connection of two intersecting shafts is large, a universal coupling can be selected. When the two shafts generate a large additional relative displacement during operation, a flexible coupling should be selected.

[0005] Universal couplings are widely used in various general-purpose machinery applications due to their large deviation angle and high torque transmission capabilities. Common types of universal couplings include: general-purpose, high-speed, miniature, telescopic, and high-torque universal couplings. The WS and WSD miniature cross-shaft universal couplings are suitable for connecting transmission shafts with an included angle β ≤ 45° between two shafts; single and double cross-shaft universal couplings transmit a nominal torque of 11.2–1120 N·m. Universal couplings are suitable for connecting transmission applications where the included angle β ≤ 45° between two shafts on the same spatial plane, transmitting a nominal torque of 11.2–1120 N·m. The WSD type is a single cross-shaft universal coupling, and the WS type is a double cross-shaft universal coupling. The maximum included angle between each shaft section is 45°. The finished bore is H7; keyways, hexagonal holes, and square holes can be added upon request. The included angle between the two shafts is allowed to change within a limited range according to operational needs.

[0006] Selection issues:

[0007] Before selecting a universal joint, the following prerequisites and conditions must be clearly defined: 1. Is there a transmission device between the prime mover and the universal joint? If so, what is the transmission ratio? How many shafts output power after the intermediate transmission device, i.e., is there power splitting? Consider the type, power, and speed of the prime mover. 2. Consider the type of prime mover and the type of load that the universal joint will transmit: unidirectional constant load, pulsating load, or bidirectional alternating load. What is the installation status of the universal joint? Horizontal, vertical, or inclined installation? The shaft angle should ideally be less than 3 degrees. If inclined installation is unavoidable, determine the horizontal and vertical angles. 3. Consider the working environment of the prime mover. Are there harsh environmental conditions such as high temperature, dust, water spray, or chemical corrosion? Select the appropriate type of universal joint based on the operating environment. 4. Know the required connection type and specific installation dimensions at both ends of the universal joint, and understand whether there are any special requirements such as mounting brackets. 5. What is the rotational speed of the universal joint itself? Is dynamic balancing required? 6. Is there any restriction on the installation location? What is the specific installation length? Is extension / retraction required? If extension / retraction is required, what is the outward extension of the universal coupling in its shortest state? For universal couplings that do not require extension / retraction, compensation for axial dimensional errors must be considered, and the location for compensation in the system should be determined. By understanding the above prerequisites, the specifications of the universal joint can be gradually determined, and finally, the structural form can be selected. Universal couplings come in various structural forms, including cross-shaft type, ball cage type, ball fork type, cam type, ball pin type, ball hinge type, ball hinge plunger type, three-pin type, three-fork type, three-ball pin type, and hinge rod type. The most commonly used is the cross-shaft type, followed by the ball cage type. In practical applications, they are classified into heavy-duty, medium-duty, light-duty, and small types based on the magnitude of the transmitted torque. To select a suitable universal coupling for a prime mover from such a wide range of options, a thorough understanding of the above prerequisites and external influencing factors is necessary. [Summary of the Invention]

[0008] The purpose of this invention is to overcome the shortcomings of existing technologies, mainly by improving the reduction of volume under high transmission torque, increasing service life, and maintaining the same accuracy.

[0009] The features of this invention are: compact structure, high transmission efficiency and accuracy, and long service life.

[0010] The key technology of this invention is the use of a special structure and layout for off-axis circular sliding, and the use of an off-axis slider mode (off-axis rotation means that the center of rotation of the slider is not on the center of symmetry of the rotating object, but outside the geometric center of the slider; for example, the center of rotation of a disk is on its geometric center, and the center of rotation of a circular arc is outside the geometric center of the arc), which takes into account various indicators.

[0011] Specific details of the invention:

[0012] The high-strength off-axis slider universal transmission shaft structure comprises an end bushing, an orthogonal shaft body, and a hinge rod. The end bushing is a connector rigidly connected to the transmission shaft and has a rotating shaft or shaft hole perpendicular to the transmission shaft. The orthogonal shaft body is a connector with a pair of rotating shafts, shaft holes, or arc-shaped slides / slide bars with orthogonal axes. The hinge rod is a component with shafts, shaft holes, or arc-shaped slide bars / slide grooves at both ends, and the shafts or shaft holes at both ends are perpendicular to each other. To ensure the balance of strength of each sliding connection structure, the arc-shaped slide bar matching arc-shaped slide groove structure is used, at least once, or all sliding fit positions are constructed using arc-shaped slide bars matching arc-shaped slide grooves. Because the fit between the slide bar and the slide groove is compact, it is easy to match high strength within a small scale, and the distributed strength is beneficial to increasing service life and ensuring long-term accuracy.

[0013] Assembly relationship of high-strength off-axis slider universal transmission shaft: The orthogonal shaft, as the connecting body, is hinged to the shaft or shaft hole of the orthogonal shaft and the shaft hole or shaft of the end bushing and the hinge rod respectively; or the arc-shaped slide bar and arc-shaped slide groove structure of the orthogonal shaft are slidably connected to the arc-shaped slide groove and arc-shaped slide bar structure of the end bushing and the hinge rod respectively.

[0014] Working principle of high-rigidity precision ball worm gear system:

[0015] When two non-parallel rotating shafts are rigidly connected by an end bushing, the orientation of the hinge depends on two orthogonal axes in each end region, which are exactly two degrees of freedom. Therefore, the hinge has omnidirectional pointing function, and the two non-parallel rotating shafts have rotational transmission function. Its characteristic lies in the fact that the structure includes at least one pair of arc-shaped sliders matching arc-shaped grooves, or all sliding fit positions use arc-shaped sliders matching arc-shaped grooves. The arc-shaped sliders and arc-shaped grooves are respectively machined on the connection points of the bushing, orthogonal shaft, and hinge, and the connection points must be mutually mating relationships between the arc-shaped grooves and arc-shaped sliders.

[0016] Furthermore: A hinge is a component that connects two orthogonal axes (or orthogonal axis components whose axes do not intersect) through a hinge axis or an off-axis hinge axis;

[0017] Furthermore, the characteristic of the above-mentioned orthogonal axis is that the axes of the two orthogonal axes of the orthogonal axis are intersecting orthogonal straight lines, or orthogonal skew straight lines. [Image Description]

[0018] The present invention will be further described below with reference to the accompanying drawings and preferred embodiments:

[0019] [ Figure 1Schematic diagram of a high-strength off-axis slider universal transmission shaft structure.

[0020] [ Figure 2 Schematic diagram of the exploded structure of a high-strength off-axis slider universal transmission shaft.

[0021] Explanation of the labels in the diagram:

[0022] 1 end bushing

[0023] 1-1 bushing hole

[0024] 1-2 vertical axes

[0025] 2 orthogonal axes

[0026] 2-1 Shaft Hole

[0027] 2-2 Arc-shaped slider

[0028] 3 hinges

[0029] 3-1 Arc-shaped groove

[0030] 3-2 rod

[0031] 4 transmission axis 1

[0032] 5 transmission axes 2

[0033] 6 orthogonal axes 1

[0034] 7 orthogonal axes 2

[0035] 8 transmission axes [Detailed Implementation]

[0036] like Figure 1 , Figure 2 As shown:

[0037] The high-strength off-axis slider universal transmission shaft is composed of an end bushing (1), an orthogonal shaft body (2) with off-axis and a hinge rod (3); the end bushing (1) is a connector that is rigidly connected to the transmission shaft 1 (4) and has a vertical shaft (1-2) structure that is perpendicular to the bushing hole (1-1); the orthogonal shaft body (2) is an intermediate body, which is an orthogonal shaft hole (2-1) with an axis of orthogonal axis 1 (6); and an arc-shaped slider (2-2) with a rotation center of orthogonal axis 2 (7), and the orthogonal axis 1 (6) and the orthogonal axis 2 (7) are orthogonal to each other.

[0038] That is, the orthogonal axis 1 (6) is perpendicular to the orthogonal axis 2 (7); the hinge (3) is generated by the arc-shaped sliding groove (3-1) at both ends of the rod (3-2) cooperating with the arc-shaped sliding bar (2-2) of the orthogonal axis (2), and the off-axis rotational motion is perpendicular to the vertical axis (1-2) and just passes through the intersection of the vertical axis (1-2) and the axis (6).

[0039] Working principle: Since both orthogonal axes have the pointing function of universal joints, any action of the two axes can be coordinated through the intermediate body, thus satisfying the function of universal joint coupling and enabling right-angle rotation transmission between transmission shaft 1 (4) and transmission shaft 2 (5).

Claims

1. A high-strength off-axis slider-type universal transmission shaft, its structure consists of an end bushing, an orthogonal shaft body, and a hinge rod. The end bushing is a connector rigidly connected to the transmission shaft and has a rotating shaft or shaft hole perpendicular to the transmission shaft. The orthogonal shaft body is a connector with a pair of rotating shafts, shaft holes, or arc-shaped grooves / slides with orthogonal axes. The hinge rod is a component with shafts, shaft holes, or arc-shaped slides / grooves at both ends, and the shafts or shaft holes at both ends are perpendicular to each other. The assembly relationship is as follows: the orthogonal shaft body, as the connecting body, is connected via... The orthogonal shaft or shaft hole is hinged to the shaft hole or shaft of the end bushing and the hinge rod respectively; or the arc-shaped slide bar or arc-shaped groove structure of the orthogonal shaft is slidably connected to the arc-shaped slide bar or arc-shaped slide bar structure of the end bushing and the hinge rod respectively; its working principle is as follows: when the end bushing rigidly connects two non-parallel rotating shafts, since the orientation of the hinge rod depends on the two orthogonal axes of each end region, which are exactly two degrees of freedom; therefore, the hinge rod has a pointing function in all directions, so the two non-parallel rotating shafts have a rotation transmission function; Its characteristics are: The structure includes at least one pair of curved slide bars matching curved slide grooves, or all sliding fit positions are made of curved slide bars matching curved slide grooves; the curved slide bars and curved slide grooves are respectively machined on the connection parts of the bushing, orthogonal shaft, and hinge rod, and the connection must be a mutual mating fit between the curved slide grooves and curved slide bars.

2. The high-strength off-axis slider universal transmission shaft according to claim 1, characterized in that: The axes of the two orthogonal axes of an orthogonal axis are either intersecting orthogonal straight lines or orthogonal skew straight lines.

Images