Radial floating spindle carrier

Abstract

The present application belongs to the technical field of machine tool accessories, and in particular to a radial floating spindle support, which solves the technical problem of low tool end pose stiffness or complex structure of the existing floating spindle device when realizing radial floating. The radial floating spindle support comprises an inner ring, an outer ring and an actuating assembly. An electric spindle is arranged in the inner ring. A plurality of first parallel linear grooves are formed on the outer side wall of the inner ring in the circumferential direction. The bottom end of the outer ring extends an installation ring plate, which is provided with an installation site. The actuating assembly comprises a cam, a damper, three cable joints and a plurality of cables. The transmission shaft of the damper passes through the avoidance through hole of the installation ring plate upward and is fixedly connected with the cam. A second parallel linear groove is formed on the side wall of the cam. Two parts of the cables are arranged in a cross manner. The cables, as flexible constraint belts, constrain the inner ring and the cam to form a rolling contact pair. The resultant force of the three sets of actuating assemblies is balanced with the radial external force, so that the actual radial force borne by the tool is maintained within a preset value range, thereby realizing the radial floating function and preventing the workpiece from being damaged due to overcutting.

Description

Technical Field

[0001] This invention relates to the field of machine tool accessories, and more particularly to a radial floating spindle support. Background Technology

[0002] In the field of workpiece surface finishing, to adapt to the machining conditions of various parts with complex surface features, the cutting tool needs to have conformal motion capability to adapt to changes in surface morphology while maintaining stable contact force to ensure machining quality. Traditional rigid spindles cannot adaptively adjust to the undulations of casting surfaces, easily leading to overcutting or undercutting, affecting workpiece surface machining quality and efficiency. To achieve conformal tool motion, existing technologies mainly employ two floating spindle solutions. The first is the oscillating floating spindle, which adapts to workpiece surface changes through spindle oscillation. However, this solution causes tool posture to oscillate during floating, resulting in changes in the contact point between the tool and the workpiece, thus affecting machining effect and efficiency, and failing to meet the requirements for tool posture stability in workpiece surface finishing. The second is the radial translation floating spindle, which achieves radial translation of the spindle through an XY guide mechanism. Although it can maintain tool posture stability, it suffers from drawbacks such as complex structure, large size, and poor adaptability to working conditions, making it difficult to meet the flexibility requirements of automated machining. Summary of the Invention

[0003] To overcome the technical defects of existing floating spindle devices, such as low tool end position stiffness or complex structure when achieving radial floating, this invention provides a radial floating spindle support.

[0004] This invention provides a radial floating spindle support, comprising: an inner ring with a flange extending horizontally outward along its top edge, through which an electric spindle passes, the flange being used to fix a mounting flange for the electric spindle; several first parallel grooves are formed circumferentially on the outer wall of the inner ring; an outer ring for connecting to a machine tool, with the inner ring located within the outer ring, and a mounting ring plate extending horizontally inward along its bottom edge, the mounting ring plate having several mounting positions evenly distributed for mounting actuating components; and actuating components, the number of which corresponds to the number of mounting positions, including a cam, a damper, three cable connectors, and several cables, the number of cables being equal to the number of the first parallel grooves, the damper being fixed to the mounting flange. At the bottom of the mounting ring plate corresponding to the mounting position, there is a clearance through hole. The drive shaft of the damper passes through the clearance through hole and is fixedly connected to the cam. The side wall of the cam has a second parallel groove with the same number of grooves as the first parallel groove along the circumferential direction. One cable connector is fixed to the cam, and the other two cable connectors are fixed to the inner ring side walls on both sides of the cam. The cables are divided into two groups. One end of each group of cables is connected to two cable connectors on the inner ring. The other ends of the two groups of cables cross and pass around the side wall of the cam, and are fixedly connected to the cable connectors on the cam. The cables are arranged along the first parallel groove and the second parallel groove. The cables act as a flexible constraint band to constrain the inner ring and the cam to form a rolling contact pair.

[0005] Under machining conditions, when the radial force on the tool exceeds a preset value, the electric spindle drives the inner ring to undergo passive radial displacement, thereby driving the cam to rotate. This rotational motion is transmitted to the damper, which generates a torque that resists the rotation. The three sets of actuators operate synchronously, generating a resultant force on the inner ring in the opposite direction to the displacement. This resultant force balances the radial force exceeding the preset value, ensuring that the actual radial force on the tool remains within the preset range, thus preventing workpiece damage due to overcutting.

[0006] The technical solution provided by this invention has the following technical effects compared with the prior art:

[0007] I. Based on the realization of the radial floating function of the electric spindle, the present invention can provide high positional stiffness for the tool end through the cooperation of the actuation component and the inner ring to form line contact, effectively ensuring machining accuracy and overcoming the defect of traditional floating spindle devices that cannot guarantee positional stiffness.

[0008] Second, the present invention has a compact overall structure and small size, and does not require a complex hydraulic or pneumatic system, which reduces system complexity and maintenance costs, making it suitable for space-constrained applications.

[0009] Third, the present invention employs a floating support device formed by at least three uniformly distributed actuating components, which enables the spindle device to achieve adaptive adjustment under complex working conditions. It features stable motion, rapid response, and strong adaptability. At the same time, the structure can be flexibly expanded according to the spindle size, further improving its applicability to working conditions.

[0010] Fourth, the present invention adopts a rolling contact pair structure, in which the cable rolls between the first parallel groove of the inner ring and the second parallel groove of the cam, resulting in low friction loss and high transmission efficiency. At the same time, the groove structure effectively restricts axial movement and ensures the stability of the system. Attached Figure Description

[0011] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0012] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0013] Figure 1 This is a schematic diagram of the overall structure of a radial floating spindle support according to a certain embodiment of the present invention;

[0014] Figure 2 This is a partial cross-sectional structural diagram of a radial floating spindle support according to a certain embodiment of the present invention;

[0015] Figure 3 This is a schematic diagram illustrating the cooperation between the inner ring and the actuating component in a certain embodiment of the present invention;

[0016] Figure 4 This is a schematic diagram of the connection structure between the cable connector and the cable in a certain embodiment of the present invention;

[0017] Figure 5 This is a schematic diagram of the outer ring structure in a certain embodiment of the present invention;

[0018] Figure 6 This is an assembly schematic diagram of the rolling contact pair between the inner ring and the cam in a certain embodiment of the present invention;

[0019] Figure 7 This is a schematic diagram of the operation of the cam when the electric spindle generates radial displacement in a certain embodiment of the present invention.

[0020] In the diagram: 1. Inner ring; 2. Flange ring; 3. Electric spindle; 4. First parallel groove; 5. Outer ring; 6. Mounting ring plate; 7. Cam; 8. Damper; 9. Cable connector; 10. Cable; 11. Second parallel groove; 12. Clearance groove; 13. Annular washer. Detailed Implementation

[0021] To better understand the above-mentioned objectives, features, and advantages of the present invention, the solutions of the present invention will be further described below. It should be noted that, unless otherwise specified, the embodiments of the present invention and the features thereof can be combined with each other.

[0022] In this description, it should be noted that the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance. It should also be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joint" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms according to the specific circumstances.

[0023] Many specific details are set forth in the following description in order to provide a full understanding of the invention, but the invention may also be practiced in other ways different from those described herein; obviously, the embodiments in the specification are only some embodiments of the invention, and not all embodiments.

[0024] The following is in conjunction with the appendix Figures 1 to 7 Specific embodiments of the present invention will be described in detail below.

[0025] In one embodiment, such as Figure 1As shown, a radial floating spindle support is disclosed, comprising: an inner ring 1, the top of which has a flange ring 2 extending horizontally outward along the circumference, through which an electric spindle 3 passes, the flange ring 2 being used to fix and connect the mounting flange of the electric spindle 3; several first parallel grooves 4 are formed circumferentially on the outer wall of the inner ring 1; an outer ring 5, which is used to connect to a machine tool, the inner ring 1 being located in the outer ring 5, the bottom end of the outer ring 5 having a mounting ring plate 6 extending horizontally inward along the circumference, the mounting ring plate 6 having several mounting positions evenly distributed for mounting actuating components; and actuating components, the number of which corresponds to the number of mounting positions, including a cam 7, a damper 8, three cable connectors 9, and several cables 10, the number of cables 10 being equal to the number of the first parallel grooves 4, the damper 8 being fixed to the mounting position corresponding to the mounting position. At the bottom of the mounting ring plate 6, there is a clearance through hole. The drive shaft of the damper 8 passes through the clearance through hole and is fixedly connected to the cam 7. The side wall of the cam 7 has a second parallel groove 11 with the same number as the first parallel groove 4 along the circumferential direction. One cable connector 9 is fixed to the cam 7, and the other two cable connectors 9 are fixed to the side walls of the inner ring 1 on both sides of the cam 7. The cable 10 is divided into two groups. One end of each group of cables 10 is connected to the two cable connectors 9 on the inner ring 1. The other ends of the two groups of cables 10 cross and pass around the side wall of the cam 7 and are fixedly connected to the cable connectors 9 on the cam 7. The cables 10 are arranged along the first parallel groove 4 and the second parallel groove 11. The cables 10 act as a flexible constraint band to constrain the inner ring 1 and the cam 7 to form a rolling contact pair.

[0026] The radial floating spindle support described in this invention supports an electric spindle 3, which is housed within an inner ring 1. The flange 2 of the inner ring 1 is bolted to the mounting flange of the electric spindle 3. The axes of the inner ring 1, outer ring 5, and electric spindle 3 are collinear. The outer surface of the cam 7 and the outer surface of the inner ring 1 form a contact surface, constituting a rolling contact pair. Pure rolling rather than sliding occurs between them. Cables 10 are intersected and pass through the first parallel groove 4 of the inner ring 1 and the second parallel groove 11 of the cam 7. Cables 10 act as flexible constraint bands, binding the inner ring 1 and each cam 7 together to form a rolling contact joint. A characteristic of rolling contact joints is that the contact point moves with the joint's movement, unlike the fixed rotation center of traditional rotary joints. When the rolling contact joint moves, cables 10 wind or unwind within the first and second parallel grooves 4 and 11, adapting to the relative movement between the two rolling contact surfaces. The function of cables 10 is to create the necessary constraint conditions, ensuring contact between the inner ring 1 and the cam 7 and forcing rolling motion.

[0027] Cam 7 is connected to the output shaft of damper 8 and rotates synchronously with damper 8. In this embodiment, there are three sets of actuating components, which are evenly distributed in an equilateral triangle pattern about the central axis of outer ring 5 on the mounting position of mounting ring plate 6 of outer ring 5. In other embodiments, the number of actuating components can be determined according to the size of inner ring 1, and can be four, five or more sets, all evenly distributed about the central axis of outer ring 5 to adapt to different working conditions.

[0028] The centers of the three sets of cams 7 are B1, B2, and B3, respectively. The center of the inner ring 1 is O, the outer diameter of the inner ring 1 is R1, and the inner diameter of the outer ring 5 is R2. The mounting positions of each cam 7 are located on the same cross-section perpendicular to the axis of the electric spindle 3, and each mounting position is equidistant from the central axis of the outer ring 5 and distributed at equal angles. When the electric spindle 3 experiences radial displacement *m* due to external load, the inner ring 1 moves accordingly. Pure rolling occurs between the contact surface of the inner ring 1 and the contact surfaces of each cam 7, and the contact points change continuously with the movement. Driven by the rolling contact, the cams 7 rotate. This rotational motion is transmitted to the damper 8, which generates a torque resisting the rotation. This torque is transmitted to the inner ring 1 through the cams 7 and the rolling contact surface, forming a restoring force opposite to the direction of displacement. The three sets of actuating components operate synchronously, bringing the electric spindle 31 to a new state of force equilibrium.

[0029] Based on the above embodiments, in a preferred embodiment, when the electric spindle 3 is subjected to an external load and undergoes radial displacement, the inner ring 1 moves accordingly, and the cam 7 rotates as the inner ring 1 moves. The inner sidewall of the outer ring 5 is provided with a relief groove 12 to avoid the rotation of the cam 7.

[0030] Based on the above embodiments, in a preferred embodiment, the number of mounting positions and actuating components are three, the number of first parallel grooves 4 and second parallel grooves 11 is four, the number of cables 10 is four, and the cables 10 are divided into two groups, with two cables in each group.

[0031] Based on the above embodiments, in a preferred embodiment, an annular washer 13 is provided between the lower surface of the flange ring 2 of the inner ring 1 and the top surface of the cam 7.

[0032] Based on the above embodiments, in a preferred embodiment, when the inner ring 1 is displaced by m in any direction, due to pure rolling constraints, the rotation angle θ of each cam 7 is... i The relationship with displacement m is:

[0033] ,

[0034] In the formula, m = R2 - R1, where R1 is the outer diameter of inner ring 1, R2 is the inner diameter of outer ring 5, and R2 is the maximum range of movement of inner ring 1. Let r be the angle between the radius of the contact point of cam 7 and its displacement direction. i Let be the contour radius of the i-th cam 7 at the contact point.

[0035] Based on the above embodiments, in a preferred embodiment, for each cam 7, the corresponding damper torque M of the damper 8 is transmitted through the cam 7, and this torque is transmitted to the inner ring 1 through rolling contact, generating a force at the contact point:

[0036] ,

[0037] In the formula, r i Let F be the radius of the i-th cam 7 at the contact point; since the pressure angle is 90°, the force F exerted by cam 7 on inner ring 1 is... i Always along the radial direction of the contact point location.

[0038] Based on the above embodiments, in a preferred embodiment, to ensure the force transmission efficiency and adaptability of the radial floating spindle, the profile curve of cam 7 must meet specific requirements. The contact radius r between cam 7 and inner ring 1... i The following relationship must be satisfied:

[0039] ,

[0040] In the formula, a is the initial distance from the center of cam 7 to the center of inner ring 1, satisfying a = r0 + R1, where r0 is the base circle radius of cam 7, R1 is the outer radius of inner ring 1, and θ i Let θ be the rotation angle of each cam 7, and θ0 be the initial installation angle. When the electric spindle 3 is subjected to an external force and produces radial displacement, the cam 7 rolls purely relative to the inner ring 1. To ensure stable force transmission, the force exerted by the cam 7 on the inner ring 1 is always along the radial direction of the contact point.

[0041] A mechanical model is established. In the mechanical system of the inner ring 1 and cam 7, the electric spindle 3 is subjected to an external force F in the radial plane, and the constraint reaction force transmitted by each cam 7 through the rolling contact surface. This manifests as the three cams 7 generating forces F1, F2, and F3 on the inner ring 1, respectively. By establishing the mechanical equilibrium equation of the electric spindle 3, the magnitude and direction of the force borne at each contact point of the cam 7 can be calculated. According to the principle of static equilibrium, the resultant force of these forces in the x and y directions should be zero, and their resultant torque about the center of the electric spindle 3 should also be zero. Let the direction parallel to the ground be the x-axis, and the direction perpendicular to the ground be the y-axis. Both axes pass through the center of the electric spindle 3, then:

[0042] ,

[0043] ,

[0044] In the formula, F is the external force, G is the weight of the electric spindle 3, θ is the angle between F and the x-axis, and i is the sequence number of the actuating component. It is the resultant force of the inner ring in the x-direction. It is the component of the force on the i-th cam in the x-direction. It is the resultant force of the inner ring in the y direction. It is the component of the force on the i-th cam in the y-direction.

[0045] Under pure rolling conditions, the arc length traveled by the surface of cam 7 is equal to the arc length traveled by the surface of inner ring 1, and the angular position γ of the contact point on inner ring 1 is... i for:

[0046] In the formula, The offset angle is the initial state of cam 7.

[0047] Based on the above embodiments, in a preferred embodiment, the torque M of the damper 8 is related to the design force F. d The relationship satisfies:

[0048] ,

[0049] In the formula, n is the number of actuators, and r i Let γ be the contour radius of the i-th cam 7 at the contact point. i The angular position of the contact point on inner ring 1; based on the design force F d The requirement is to control the torque M generated by damper 8, thereby achieving constant force radial floating. Design force F d This is a preset value for the radial force acting on the tool. When the radial force exceeds this value, the electric spindle 3 begins to float.

[0050] When the electric spindle 3 is subjected to a radial external force, the inner ring 1 undergoes radial displacement along with the electric spindle 3. Figure 7 The innermost dashed line represents the initial position of the inner ring 1, and the thickened solid line represents the position of the inner ring 1 after radial displacement. At this time, the three sets of cams 7 rotate to different degrees under the action of rolling contact, and each cam 7 forms a corresponding contact reaction force on the inner ring 1 through the rolling contact surface. Because rolling contact is used instead of sliding contact, friction loss is small and transmission efficiency is high. The resultant force of the three sets of actuating components is balanced with the radial external force, so that the actual radial force borne by the tool is maintained within the preset value, thereby realizing the radial floating function and preventing the workpiece from being damaged due to overcutting.

[0051] Furthermore, each cam 7 of the present invention not only enables radial floating and support of the electric spindle 3, but also forms a rigid constraint structure through its uniformly distributed arrangement. When the axis of the electric spindle 3 tilts, each cam 7 forms an asymmetric contact reaction force on the inner ring 1 through the rolling contact surface, generating a restoring torque on the electric spindle 3, thereby achieving dynamic constraint and stable control of the electric spindle 3's posture. The present invention maintains high tool end position stiffness while achieving radial floating through the rolling contact joint mechanism.

[0052] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the present invention. Although detailed descriptions have been provided with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments, and they should all be covered within the protection scope of the claims.

Claims

1. A radially floating spindle support, characterized in that, include: The inner ring (1) has a flange ring (2) extending horizontally outward along the circumference at its top end. The electric spindle (3) passes through the inner ring (1). The flange ring (2) is used to fix the mounting flange of the electric spindle (3). Several first parallel grooves (4) are opened along the circumference on the outer side wall of the inner ring (1). The outer ring (5) is used to connect the machine tool. The inner ring (1) is located in the outer ring (5). The bottom end of the outer ring (5) extends horizontally inward along the circumference with a mounting ring plate (6). The mounting ring plate (6) has several mounting positions for mounting the actuating components evenly distributed on it. The actuating components, the number of which corresponds to the number of mounting positions, include a cam (7), a damper (8), three cable connectors (9), and several cables (10). The number of cables (10) is equal to the number of the first parallel grooves (4). The damper (8) is fixed to the bottom of the mounting ring plate (6) corresponding to the mounting position. The mounting ring plate (6) has clearance holes. The drive shaft of the damper (8) passes through the clearance holes and is fixedly connected to the cam (7). The side wall of the cam (7) has second parallel grooves (11) with the same number as the first parallel grooves (4) along the circumferential direction. One cable connector (9) is fixed to the cam (7), and the other two cable connectors (9) are fixed to the side walls of the inner ring (1) on both sides of the cam (7). The cables (10) are divided into two groups, and one end of each group of cables (10) is connected to the inner ring (1). Two cable connectors (9), the other ends of two sets of cables (10) cross and pass around the side wall of the cam (7) and are fixedly connected to the cable connectors (9) on the cam (7). The cables (10) are arranged along the first parallel groove (4) and the second parallel groove (11). The cables (10) act as a flexible constraint band to constrain the inner ring (1) and the cam (7) to form a rolling contact pair. When the electric spindle (3) is subjected to external load and generates radial displacement, the inner ring (1) moves accordingly, and the cam (7) rotates with the movement of the inner ring (1). The inner side wall of the outer ring (5) is provided with a relief groove (12) to avoid the rotation of the cam (7). There are three mounting positions and three actuating components. There are four first parallel grooves (4) and four second parallel grooves (11). There are four cables (10). The cables (10) are divided into two groups, and each group has two cables.

2. The radial floating spindle support according to claim 1, characterized in that, An annular washer (13) is provided between the lower surface of the flange (2) of the inner ring (1) and the top surface of the cam (7).

3. The radial floating spindle support according to claim 2, characterized in that, When the inner ring (1) is displaced by m in any direction D, due to the pure rolling constraint, the rotation angle θ of each cam (7) will be... i The relationship with displacement m is: ， In the formula, m = R2 - R1, R1 is the outer diameter of the inner ring (1), R2 is the inner diameter of the outer ring (5), and R2 is the maximum range of movement of the inner ring (1). Let r be the angle between the radius of the contact point of the cam (7) and its displacement direction. i Let be the contour radius of the i-th cam (7) at the contact point.

4. The radial floating spindle support according to claim 1, characterized in that, For each cam (7), the corresponding damper (8) torque M is transmitted through the cam (7) and generates a force at the contact point: ， In the formula, r i Let F be the contour radius of the i-th cam (7) at the contact point; since the pressure angle is 90°, the force F exerted by the cam (7) on the inner ring (1) is... i Always along the radial direction of the contact point location.

5. A radial floating spindle support according to claim 1, characterized in that, The contact radius r between the cam (7) and the inner ring (1) i The following relationship must be satisfied: ， In the formula, a is the initial distance from the center of the cam (7) to the center of the inner ring (1), satisfying a=r0+R1, where r0 is the base circle radius of the cam (7), R1 is the outer diameter of the inner ring (1), and θ i Let θ be the rotation angle of each cam (7), and θ0 be the initial installation angle; the force exerted by the cam (7) on the inner ring (1) is always along the radial direction of the contact point; under the pure rolling condition, the arc length traveled by the surface of the cam (7) is equal to the arc length traveled by the surface of the inner ring (1), and the angular position of the contact point on the inner ring (1) is γ. i for: ， In the formula, The offset angle of the contact point of the cam (7) in the initial state.

6. A radial floating spindle support according to claim 1, characterized in that, The torque M of the damper (8) and the design force F d The relationship satisfies: ， In the formula, n is the number of actuators, and r i Let γ be the contour radius of the i-th cam (7) at the contact point. i The angular position of the contact point on the inner ring (1); based on the design force F d The requirement is to control the torque M generated by the damper (8) so as to achieve constant force radial floating.

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