An axial full-process closed liquid dynamic and static pressure supporting spindle system of an inertia friction welding machine

Abstract

This invention relates to a closed-loop axial hydrostatic / hydrostatic bearing spindle system for an inertial friction welding machine. The invention aims to address the problem that in inertial friction welding machines, the system cannot adaptively adjust the oil film thickness of the hydrostatic / hydrostatic thrust bearing according to the magnitude of the axial upsetting force from start to finish, thus failing to form a fully closed-loop system. The spindle system is equipped with opposing double-sided hydrostatic / hydrostatic thrust bearings. One side is a load-bearing hydrostatic / hydrostatic thrust bearing (11), and the other side is a non-load-bearing hydrostatic / hydrostatic thrust bearing (12). The non-load-bearing hydrostatic / hydrostatic bearing (12) acts as a back pressure, improving the oil film stability and stiffness of the load-bearing hydrostatic / hydrostatic thrust bearing (11), increasing welding accuracy, facilitating control of axial shortening, and improving welding stability and efficiency. The specific structure is shown in Figure 1.

Description

Technical Field

[0001] This invention belongs to the technical field of friction welding equipment and relates to an axial closed-loop liquid dynamic and static pressure support spindle system for an inertial friction welding machine. Background Technology

[0002] Inertial friction welding technology utilizes an electric motor (20) to provide potential energy to an inertial energy storage disk (18), then turns off the motor (20), and applies a forging force to the moving side workpiece (22) to bring the two workpieces into contact. Due to the heat generated by friction on the surface, the surfaces of the two workpieces enter a high-temperature state. The forging force causes elastoplastic deformation at the contact point of the two workpieces, and the two workpieces on both sides interact with each other, that is, the two workpieces are welded together. However, the welding process requires ensuring that the oil film structure of the hydrostatic thrust bearing has a certain rigidity and that the oil film is stable during the welding process. Therefore, a hydrostatic thrust bearing is set up to provide back pressure on the non-load-bearing side. The cavity pressure of the hydrostatic thrust bearing on the non-load-bearing side is adjusted by adjusting the flow rate to a reasonable back pressure value. This allows the thrust bearing to adaptively adjust the oil film gap within a predetermined range according to the magnitude of the upsetting force when bearing axial top force. After the upsetting force is removed, it can automatically return to the initial oil film thickness. Throughout this process, the feedback effect is always reflected in the automatic adjustment of the oil film thickness by the spindle system. Therefore, this spindle system is called the axial full-process closed hydrostatic support spindle system of inertial friction welding machine, which ensures axial load bearing and improves the efficiency of welding processing. Summary of the Invention

[0003] The technical problem this invention aims to solve is to achieve full-process closed-loop control of the spindle system during inertial friction welding. This means that after the main machine starts working, feedback is achieved by adjusting the thickness of the oil film on the bearing side and the non-bearing side (back pressure side) according to the magnitude of the forging force, thus forming a full-process closed-loop system. This system greatly improves the flexibility of adjusting the oil film thickness. Within the working range of the inertial friction welding machine, the full-process closed-loop system significantly improves the efficiency of the machine, enabling rapid and efficient completion of tasks. The full-process closed-loop hydrostatic bearing, due to its constant flow oil supply system, allows for precise control of the bearing structure, achieving high-precision work requirements and facilitating control of the axial shortening of the welded workpiece. Due to its structural characteristics, the full-process closed-loop hydrostatic bearing effectively avoids oil film instability caused by changes in the external environment, thereby ensuring the stability and reliability of the bearing process. This invention proposes an axial full-process closed-loop hydrostatic bearing spindle system for an inertial friction welding machine.

[0004] The axial closed-loop hydrostatic and hydrodynamic bearing spindle system of the inertial friction welding machine is implemented according to the following structure:

[0005] An axial closed-loop liquid dynamic-static pressure supported spindle system for an inertial friction welding machine has the following closed-loop working process: During the friction welding process, the rotating spindle system is subjected to an upsetting force. The closed-loop spindle system bears the axial upsetting force by setting opposing liquid dynamic-static pressure thrust bearings. The oil film clearance of the thrust bearings takes into account the sum of dimensional tolerances, thermal deformation, and force deformation, and takes a safety margin of 4 times to set the initial distance between the load-bearing side liquid dynamic-static pressure thrust bearing (11) and the non-load-bearing side liquid dynamic-static pressure thrust bearing (12). The initial oil film thickness of the opposing load-bearing side hydrostatic thrust bearing (11) is 2 to 3 times that of the non-load-bearing side (back pressure side). When subjected to upsetting force, the oil film on the load-bearing side becomes the oil film thickness of the non-load-bearing side when not subjected to upsetting force. In short, the sum of the oil film thicknesses on both sides remains unchanged. Since the opposing thrust bearings of the system use constant flow oil supply, the closed system can automatically adjust the oil film thickness on the load-bearing side and the non-load-bearing side according to the different upsetting forces. After the inertial friction welding process ends, the oil films on both sides automatically return to their initial state.

[0006] When adjusting the oil film gap in the friction welding process, the dynamic and static pressure thrust bearings on both sides of the opposed structure adopt a constant flow oil supply method, that is, the oil supply flow rate remains constant during operation. However, since the oil film thickness on both sides is inconsistent, the flow rates on both sides are not necessarily equal. According to the structural size requirements, the total oil film thickness on both sides is consistent. In the initial state, that is, when no upsetting force is applied, the oil film thickness of the bearing side liquid dynamic and static pressure thrust bearing (11) is 2 to 3 times the oil film thickness on the non-bearing side. When upsetting force is applied, the oil film thickness on both sides changes, and the oil film thickness on the non-bearing side (back pressure side) becomes 2 to 3 times the oil film thickness on the bearing side. Since the system is a closed structure, it can be appropriately adjusted according to the magnitude of the upsetting force, that is, the oil film thickness can be adaptively adjusted according to the load. This process has extremely high flexibility and can improve the adaptability of the inertial friction welding machine to axial upsetting force.

[0007] The back pressure function in the friction welding is undertaken by the non-load-bearing side hydrodynamic and hydrostatic thrust bearing (12). Since the non-load-bearing side hydrodynamic and hydrostatic thrust bearing (12) has a back pressure function, the back pressure value is set by adjusting the oil flow rate of the non-load-bearing side hydrodynamic and hydrostatic thrust bearing (12). If the back pressure value is too large, the pressure of the main load-bearing side oil cavity will be too large when bearing the upsetting force, the oil film will heat up, the thermal deformation of the oil pad will increase, and the stability of the oil film will be reduced. If the back pressure value is too small, the stiffness of the oil film on both sides will decrease, reducing the ability of the oil film to resist changes in external force. Moreover, when the upsetting force is removed, if the back pressure value is too small, the pressure difference between the two sides of the load-bearing side hydrodynamic and hydrostatic thrust bearing (11) and the non-load-bearing side hydrodynamic and hydrostatic thrust bearing (12) will be too large, resulting in the loss of feedback function, collision or even damage, causing damage to the equipment.

[0008] The overall welding process of the friction welding workpiece is as follows: when the inertial friction welding machine is stopped, the moving side mechanism (25) is positioned behind the fixed end travel guide rail (28) to increase the intermediate space. The moving side workpiece (23) is installed on the clamp (24) of the moving side mechanism (25). When welding begins, the inertial friction welding machine uses the moving end travel guide rail (26) to bring the moving side workpiece (23) close to the rotating side workpiece (22) and lock it in position. The motor (20) is started, driving the rotating side spindle (19) to rotate. The inertial energy storage disk (18) is made to have the rotational inertia required for welding the workpiece. The moving side mechanism (25) makes the moving side weldment contact the rotating side weldment (22) through internal structural changes. During this period, there is a continuous upsetting force. The contact part of the moving side mechanism weldment (23) converts potential energy into heat energy through friction, so that the contact part area enters a high temperature state and undergoes elastic-plastic deformation. Until the rotating side workpiece (22) and the moving side workpiece (23) are welded together after cooling, the upsetting force is removed and the welding process is declared over.

[0009] In the aforementioned friction welding, the reason why it is called the axial full-process closed liquid dynamic and static pressure support spindle system is that the full-process closed nature of the spindle system is specifically manifested in the fact that when the inertial friction welding machine performs rotational energy storage in the early stage of operation, the constant flow oil supply makes the pressure of the oil chamber on the bearing side and the non-bearing side reach a force balance state under the set oil film thickness. When bearing the upsetting force, it will adaptively adjust the gap between the oil films on both sides according to the magnitude of the upsetting force. After the upsetting force is removed, it can return to the initial position, thus forming a feedback structure. That is, from the start of energy storage on the inertial energy storage disk (18) to the end of the welding of the two workpieces after the potential energy is exhausted, the full-process closed system is formed.

[0010] This invention designs a series of opposing hydrostatic and hydrodynamic thrust bearings, serving as the load-bearing side and the non-load-bearing side (back pressure side), respectively. This allows the oil film thickness to be adjusted continuously to adapt to axial loads under varying axial upsetting forces, and to return to the initial oil film position after the upsetting force is removed, achieving a fully closed-loop system before and after welding. This fully closed-loop axial system significantly improves welding efficiency, enabling the inertial friction welding machine to adaptively adjust the oil film thickness according to different axial upsetting forces, reducing the workload of the control system. The fully closed-loop axial system also improves the precision of the inertial friction welding machine. Because it provides constant feedback during welding, it makes it easier to control the axial shortening of the welded workpiece, ensuring the axial accuracy of the weldment. Furthermore, the fully closed-loop axial system reduces the difficulty of controlling the axial load of the inertial friction welding machine. Since both oil chambers use constant flow oil supply, the axial load capacity of the inertial friction welding machine can be adjusted simply by changing the flow rate on both sides. Attached Figure Description

[0011] Figure 1This is a schematic diagram of the closed-loop liquid hydrostatic support spindle system for the entire axial process of an inertial friction welding machine.

[0012] Figure 2 This is a schematic diagram of the overall structure of an inertial friction welding machine.

[0013] In the diagram: 1-Rolling ball bearing, 2-Reducer transmission gear, 3-Retaining ring, 4-Retaining ring, 5-Chassis support structure, 6-Retaining ring, 7-Double row cylindrical roller bearing, 8-Retaining ring, 9-Keyway, 10-Load-bearing side hydrodynamic / hydrostatic thrust bearing base, 11-Load-bearing side hydrodynamic / hydrostatic thrust bearing, 12-Non-load-bearing side (back pressure side) hydrodynamic / hydrostatic thrust bearing, 13-Non-load-bearing side (back pressure side) hydrodynamic / hydrostatic thrust bearing base, 14-... 15-Retaining ring, 16-Double row angular contact ball bearing, 17-End cover, 18-Retaining ring, 19-Inertia storage disk, 20-Rotating side spindle, 21-Motor, 22-Reducer, 23-Rotating side weldment, 24-Motating side weldment fixture, 25-Motating side mechanism, 26-Motating end travel guide rail, 27-Inertia friction welding machine base, 28-Fixed end travel guide rail, 29-Support structure in the chassis. Implementation

[0014] Referring to the attached diagram, during the installation of the workpiece for inertial friction welding, the moving side mechanism (25) is located at the rear end of the fixed end travel guide rail (28). At this time, the distance between the rotating side and the moving side of both mechanisms is the greatest, which facilitates the installation and removal of the workpiece at the moving side clamp (24). During welding preparation, the moving end travel guide rail (26) is slowly moved by the motor until the two workpieces are close together, with the positions of the workpieces to be welded on both sides being approximately a few millimeters. At this time, the moving end travel guide rail (26) is locked. The motor (20) is run, and the speed is transmitted to the rotating side spindle (19) through the reducer (21), so that the inertial energy storage disk (18) obtains potential energy and at the same time the rotating side workpiece (22) reaches the predetermined speed. Then the motor (20) is removed and the spindle continues to rotate the rotating side workpiece (22) at the original speed through inertia. At this time, the moving side mechanism (25) operates through the internal mechanism, so that the moving side workpiece (23) reaches the working state of small displacement and large top force. The two welded workpieces on both sides are in contact and continuously consume the potential energy in the inertial energy storage disk (18). The two workpieces generate heat due to friction. The potential energy is converted into heat energy, so that the interface is in a high temperature state. The moving side weld (23) and the rotating side weld (22) undergo elastoplastic deformation and the materials interact with each other until the potential energy is exhausted and the temperature drops to the point where the material structure does not change, and the welding is declared over. However, it is worth mentioning that when subjected to upsetting force, because the system adopts a constant flow oil supply method, even when the flow rates of the oil chamber on the bearing side and the oil chamber on the non-bearing side are not equal, the oil films on both sides can achieve a closed-loop axial bearing process. That is, the thickness of the oil film on the bearing side and the non-bearing side is adaptively adjusted according to the magnitude of the applied axial upsetting force. This allows for direct feedback of the magnitude of the axial upsetting force to adjust the thickness of the oil film on the bearing side and the non-bearing side, thereby improving the welding efficiency of the inertial friction welding machine and the adaptability of the thrust bearing oil film to different upsetting forces.

Claims

1. An axially closed-loop hydrostatic / hydraulic support spindle system for an inertial friction welding machine, characterized in that: The axial closed-loop liquid dynamic-static pressure supported spindle system of the inertial friction welding machine consists of rolling ball bearings (1), reducer transmission gears (2), retaining rings (3), first retaining rings (4), chassis support structure (5), second retaining rings (6), double-row cylindrical roller bearings (7), third retaining rings (8), keyway (9), load-bearing side liquid dynamic-static pressure thrust bearing base (10), load-bearing side liquid dynamic-static pressure thrust bearing (11), non-load-bearing side liquid dynamic-static pressure thrust bearing (12), non-load-bearing side liquid dynamic-static pressure thrust bearing base (13), fourth retaining ring (14), double-row angular contact ball bearings (15), end cover (16), fifth retaining ring (17), inertial energy storage disk (18), rotating side spindle (19), and electric motor (20). The system consists of a reducer (21), a rotating side weldment (22), a moving side weldment (23), a moving side weldment clamp (24), a moving side mechanism (25), a travel guide rail, and an inertial friction welding machine base (27). Due to the upsetting force, the closed-loop spindle system bears the axial upsetting force by setting opposing liquid dynamic and static pressure thrust bearings. The oil film clearance of the thrust bearing takes into account the sum of dimensional tolerances, thermal deformation, and force deformation, and takes a safety margin of 3 to 4 times to set the initial and working oil film thickness of the bearing side liquid dynamic and static pressure thrust bearing (11) and the non-bearing side liquid dynamic and static pressure thrust bearing (12). The initial oil film thickness of the opposing bearing side liquid dynamic and static pressure thrust bearing (11) is 2 to 3 times that of the non-bearing side. When subjected to upsetting force... Afterwards, the oil film on the bearing side becomes the oil film thickness on the non-bearing side when it is not subjected to upsetting force. In short, the sum of the oil film thicknesses on both sides remains unchanged. Since the thrust bearing of the opposed structure of the system adopts constant flow oil supply, the closed system allows the oil film on both sides to adjust the oil film thickness on the bearing side and the non-bearing side according to the different upsetting forces. When the inertial friction welding process ends, the oil films on both sides automatically return to the initial state. The non-bearing side liquid hydrostatic thrust bearing (12) has the function of back pressure. The back pressure value is set by adjusting the oil flow rate of the non-bearing side liquid hydrostatic thrust bearing (12). When the inertial friction welding machine stops, the moving side mechanism (25) is at the rear end of the stroke guide rail, which makes the intermediate space larger. The moving side welding part (23) is installed on the moving side welding part clamp (24) of the moving side mechanism (25). When welding begins, the inertial friction welding machine uses the travel guide rail to bring the moving side weldment (23) close to the rotating side weldment (22) and lock it in position. The motor (20) is started, which drives the rotating side spindle (19) to rotate and makes the inertial energy storage disk (18) have the rotational inertia required for welding the workpiece. Then the motor is removed, and the moving side mechanism (25) operates through the internal mechanism to make the moving side weldment (23) contact the rotating side weldment (22). During this period, there is a continuous upsetting force. The contact part of the moving side weldment (23) converts potential energy into heat energy through friction, so that the contact part area enters a high temperature state and undergoes elastic-plastic deformation. Until it cools down, the rotating side weldment (22) and the moving side weldment (23) are welded together. The upsetting force is removed, and the welding process ends.The closed-loop design of the spindle system is specifically manifested in the fact that during the initial rotational energy storage phase of the inertial friction welding machine, constant current oil supply ensures that the pressure in the oil chambers on the bearing and non-bearing sides reaches a force balance state at the set oil film thickness. When subjected to upsetting force, the gap between the oil films on both sides is adaptively adjusted according to the magnitude of the upsetting force. After the upsetting force is removed, the initial position is restored, thus forming a feedback structure. That is, the entire process from energy storage starting from the inertial energy storage disk (18) to the depletion of potential energy and the end of welding of the two workpieces constitutes a closed-loop system.

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