Magnetic coupling feeding mechanism of main shaft

Abstract

The utility model discloses a magnetic coupling feeding mechanism of a main shaft, which comprises a motor main shaft and a feeding shaft which is coaxially arranged side by side with the motor main shaft, ball grooves are correspondingly arranged on the end faces of one ends of the motor main shaft and the feeding shaft which are close to each other, and balls are placed in the ball grooves; the outer walls of the ends, close to each other, of the motor spindle and the feed shaft are sleeved with glands, and the two glands are kept in a non-contact state. The gland is provided with a ball hole penetrating in the axial direction, the ball hole corresponds to the ball groove in position, the gland limits the balls in the area between the ball groove and the ball hole, and part of the outer walls of the two balls protrude out of the ball hole and make contact with each other. The ends, close to each other, of the two glands are respectively provided with a magnetic steel with opposite magnetic polarities, and the two magnetic steels are kept in a non-contact state. The device is short in length, small in size, simple and easy to manufacture.

Description

Technical Field

[0001] This utility model relates to the technical field of spindle feed mechanism, specifically to a magnetic coupling feed mechanism for a spindle. Background Technology

[0002] In the fields of machining and precision manufacturing, the axial feed mechanism of the spindle is a core module that determines the compactness, dynamic response, and cost-effectiveness of the equipment. Traditional mechanical or electric spindles primarily use slide screw mechanisms or bearing transition connections, such as the utility model patent with authorization number CN203236272U, entitled "Two-Axis Linkage Servo Drive Power Head." The inherent drawbacks of traditional feed modes include:

[0003] 1. Mechanical redundancy and space inefficiency: The slide screw requires multiple nested guide rails and support components, resulting in axial length redundancy (usually accounting for 30%-50% of the total spindle length), which leads to a bulky overall size; although the bearing transition structure can alleviate rigid impact, it requires additional couplings, flanges and other connecting parts, which further encroaches on mechanical space.

[0004] 2. Limited dynamic performance: The friction loss and backlash of the lead screw drive are significant, and it is prone to creep phenomenon at high speed (accuracy loss of ±5μm at critical speed). It is also highly dependent on lubrication and prone to jamming under high temperature conditions. The elastic deformation of the bearing transition mechanism will introduce phase delay, affecting the real-time performance of micron-level feed.

[0005] 3. Cost and adaptability conflict: The manufacturing cost of high-precision ball screws and customized bearing components accounts for up to 40%, but their drive source is only compatible with rotary motors or hydraulic motors, making it difficult to be compatible with new power forms such as pneumatic and linear motors, which restricts the modular expansion capability of the equipment. Utility Model Content

[0006] In order to overcome at least one of the technical problems existing in the prior art, this utility model provides a magnetic coupling feed mechanism for a spindle that is short in length, small in size, simple, and easy to manufacture.

[0007] A magnetic coupling feed mechanism for a spindle includes a motor spindle and a feed shaft coaxially arranged side-by-side with the motor spindle. Spherical grooves are correspondingly formed on the end faces of the motor spindle and the feed shaft that are close to each other, and spheres are placed in the grooves. A pressure cap is fitted onto the outer wall of the end faces of both the motor spindle and the feed shaft, and the two pressure caps remain in a non-contact state. A through-hole is formed on the pressure cap, and the position of the through-hole corresponds to the position of the spherical groove. The pressure cap confines the spheres in the area between the spherical groove and the through-hole, and portions of the outer walls of the two spheres protrude outside the through-holes and contact each other. A magnet with opposite magnetic polarity is installed at the end face of each of the two pressure caps that are close to each other, and the two magnets remain in a non-contact state.

[0008] In some embodiments, the outer walls of the motor spindle and the feed shaft near the end are provided with threads for threaded connection with the gland; at least one fastener is installed on the outer wall of the gland, and the fastener fixes the gland to the motor spindle and the feed shaft respectively in the radial direction.

[0009] In some embodiments, the magnet is in the shape of a ring, and the end faces of the two pressure caps are provided with axially protruding positioning shafts, and the magnet is sleeved on the positioning shafts; it also includes at least two regularly distributed locking members, which fix the magnet to the motor spindle and the feed shaft respectively along the axial direction.

[0010] In some embodiments, the ball groove is a circular cavity, the ball is made of quenched alloy steel, and the magnet is a neodymium iron boron permanent magnet.

[0011] Additional aspects and advantages of this invention will continue to be set forth in the description which follows, and in part will be obvious from the description or may be learned by practice of this invention. Attached Figure Description

[0012] The above and / or additional aspects and advantages of this utility model will become apparent and readily understood from the description of the embodiments taken in conjunction with the following drawings, in which:

[0013] Figure 1 This is a schematic diagram of the planar structure of this application;

[0014] Figure 2 This is a schematic diagram of the cross-sectional structure of this application;

[0015] Figure 3 This is a three-dimensional schematic diagram of the present application after removing the motor spindle and feed shaft;

[0016] Figure 4 This is a cross-sectional structural diagram of the application when it is installed on the spindle.

[0017] Figure label:

[0018] 1. Motor spindle, 2. Feed shaft, 3. Ball groove, 4. Ball, 5. Pressure cap, 6. Ball hole, 7. Magnet, 8. Thread, 9. Fastener, 10. Positioning shaft, 11. Locking part, 12. Cylinder. Detailed Implementation

[0019] The embodiments of this utility model are described in detail below. Examples of the embodiments are shown in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this utility model, and should not be construed as limiting this utility model.

[0020] In the description of this utility model, it should be understood that the directional descriptions, such as the terms "up," "down," "front," "back," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," indicate the directional or positional relationship based on the directional or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.

[0021] In the description of this utility model, "several" means one or more, "multiple" means two or more, "greater than," "less than," and "exceeding" are understood to exclude the stated number, while "above," "below," and "within" are understood to include the stated number. If "first" or "second" is used in the description, it is only for the purpose of distinguishing technical features and should not be construed as indicating or implying relative importance, or implicitly indicating the number of indicated technical features, or implicitly indicating the order of the indicated technical features.

[0022] In the description of this utility model, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0023] Reference Figures 1-4 A magnetic coupling feed mechanism for a spindle includes a motor spindle 1 and a feed shaft 2 coaxially arranged and parallel to the motor spindle 1. Ball grooves 3 are correspondingly formed on the end faces of the motor spindle 1 and the feed shaft 2 that are close to each other, and a ball 4 is placed in the ball groove 3. A pressure cap 5 is fitted onto the outer wall of the end faces of both the motor spindle 1 and the feed shaft 2, and the two pressure caps 5 are kept in a non-contact state. A ball hole 6 is formed on the pressure cap 5, which is axially penetrating and corresponds to the position of the ball groove 3. The pressure cap 5 restricts the ball 4 within the ball groove 3. The area between the two spheres 4 and the ball hole 6, with parts of the outer wall of the two spheres 4 protruding outside the ball hole 6 and contacting each other; the double ball contact forms a physical limit, suppressing the radial displacement of the magnet 7 caused by vibration, which can eliminate the response hysteresis of magnetic coupling, realize zero delay in power transmission, and the contact friction damping absorbs high-frequency vibration energy. Even if the magnet 7 is accidentally demagnetized, the power transmission can still be maintained through the ball contact; each of the two pressure caps 5 has a magnet 7 with opposite magnetic polarity installed at one end close to each other, and the two magnets 7 are kept in a non-contact state.

[0024] The feed shaft 2 can be driven by any mechanism capable of axial forward and backward movement, such as a cylinder 12, hydraulic cylinder, electric device, or lead screw, and can rotate or not. Two spheres 4 are installed at the center, and two pressure caps 5 fix the two spheres 4 to the motor spindle 1 and the feed shaft 2 respectively. Partial areas of the two spheres 4 abut each other, which can reduce the friction area and reduce the rotational resistance of the motor spindle 1. The magnets 7 have strong magnetic force. The end faces of the two magnets 7 do not contact, maintaining a small distance, and the magnetic polarities are opposite. This can ensure propulsion during the rotation of the motor spindle 1. When the feed shaft 2 moves forward, the motor spindle 1 moves forward synchronously. When the feed shaft 2 moves backward, the motor spindle 1 moves backward synchronously. The structural design of the two spheres 4 and the two magnets 7 with opposite polarities can ensure that the motor spindle 1 moves backward synchronously, and there is no seamless forward and backward movement during rotation.

[0025] This application optimizes the structure of the existing mechanical spindle technology framework, shortening the length of the feed mechanism. It is simple, easy to manufacture, operates at low temperature, and offers fast, sensitive, and backlash-free operation. It solves the shortcomings of existing methods that use slide screws or bearings as transitional connectors, such as complex structures, excessive length, heavy mechanisms, low space utilization, inability to compress machine dimensions, and high manufacturing costs.

[0026] In some embodiments, the outer walls of the motor spindle 1 and the feed shaft 2 near their ends are provided with threads 8 for threaded connection with the gland 5; at least one fastener 9 is installed on the outer wall of the gland 5, preferably two symmetrically distributed, and the fastener 9 radially fixes the gland 5 to the motor spindle 1 and the feed shaft 2 respectively. The threaded engagement between the gland 5 and the motor spindle 1 and the feed shaft 2 achieves axial preload control, eliminates assembly clearance, and ensures the rigidity of the force transmission path; the radial locking of the fastener 9, such as set screws or pins, further suppresses the circumferential micro-movement of the gland 5 and prevents the risk of loosening under high-speed rotation; the threaded connection allows the gland 5 to be disassembled independently, which is convenient for maintenance or replacement of the ball 4 and the magnet 7, and the assembly time is shortened compared with the traditional interference fit; the double-stage fixing (axial thread + radial set screw) effectively disperses the alternating load stress.

[0027] In some embodiments, the magnet 7 is in the shape of a ring, and the end faces of the two pressure caps 5 are provided with axially protruding positioning shafts 10, and the magnet 7 is sleeved on the positioning shafts 10; it also includes at least two symmetrically distributed locking members 11, preferably three evenly distributed, and the locking members 11 fix the magnet 7 to the motor spindle 1 and the feed shaft 2 respectively along the axial direction.

[0028] The concentricity of the magnet 7 and the pressure cap 5 is ensured by the socket installation, avoiding uneven magnetic force or axial displacement caused by assembly deviation of the opposite pole magnets, thus improving the uniformity of the magnetic field; the ring design increases the magnetic action area, increasing the magnetic flux in the same volume; at least two symmetrically distributed locking parts (such as M4 screws) press the magnet 7 against the end face of the positioning shaft 10 to prevent the magnet from loosening due to centrifugal force during high-speed rotation (≥10,000 rpm); the contact area between the ring magnet 7 and the metal positioning shaft 10 is increased, and eddy current heat can be conducted through the pressure cap 5.

[0029] In some embodiments, the ball groove 3 is a circular cavity shape, which facilitates mutual contact with the ball 4; the ball 4 is made of quenched alloy steel, which has high hardness, long wear resistance and long service life, and is suitable for high-speed heavy-load working conditions; the magnet 7 is a neodymium iron boron permanent magnet with nickel plating on the surface for corrosion resistance, which has strong magnetic force, can provide axial force of more than 200N, is resistant to high temperature, and has eddy current loss reduced by 70% compared with ferrite magnets; the fastener 9 and the locking part 11 are bolts, screws or screws, etc.

[0030] The technical features of the above embodiments can be combined arbitrarily. For the sake of brevity, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. Although embodiments of the present invention have been shown and described, those skilled in the art will understand that various changes, modifications, substitutions and variations can be made to these embodiments without departing from the principles and spirit of the present invention. The scope of the present invention is defined by the claims and their equivalents.

Claims

1. A magnetic coupling feed mechanism of a main shaft, comprising a motor main shaft (1) and a feed shaft (2) arranged coaxially and side by side with the motor main shaft (1), characterized in that: The motor spindle (1) and the feed shaft (2) are provided with ball grooves (3) on the end faces of the close ends, and balls (4) are placed in the ball grooves (3); the motor spindle (1) and the feed shaft (2) are provided with gland nuts (5) on the outer walls of the close ends, and the two gland nuts (5) are kept in a non-contact state; the gland nuts (5) are provided with ball holes (6) penetrating in the axial direction, the ball holes (6) correspond to the positions of the ball grooves (3), the gland nuts (5) limit the balls (4) in the areas between the ball grooves (3) and the ball holes (6), and the outer walls of the two balls (4) partially protrude out of the ball holes (6) and contact each other; the close ends of the two gland nuts (5) are respectively provided with magnetic steels (7) with opposite magnetic polarities, and the two magnetic steels (7) are kept in a non-contact state.

2. The magnetic coupling feed mechanism for a spindle as claimed in claim 1, characterized in that: The outer walls of the close ends of the motor spindle (1) and the feed shaft (2) are provided with screw threads (8) for threadedly connecting with the gland nuts (5); the outer walls of the gland nuts (5) are provided with at least one fastener (9), and the fastener (9) respectively fixes the gland nuts (5) to the motor spindle (1) and the feed shaft (2) in the radial direction.

3. A magnetic coupling feed mechanism for a spindle as claimed in claim 2, characterised in that: The magnetic steels (7) are in the shape of a circular ring, the end faces of the two gland nuts (5) are provided with axially protruding positioning shafts (10), and the magnetic steels (7) are sleeved on the positioning shafts (10); at least two regularly distributed locking members (11) are further included, and the locking members (11) respectively fix the magnetic steels (7) to the motor spindle (1) and the feed shaft (2) in the axial direction.

4. A magnetic coupling feed mechanism for a spindle as claimed in claim 3, characterised in that: The ball grooves (3) are in the shape of a circular nest, the balls (4) are made of quenched alloy steel, and the magnetic steels (7) are made of neodymium-iron-boron permanent magnets.

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