Machine tool spindle

Abstract

The utility model discloses a machine tool spindle to solve the technical problems that after the matching face of a convex shoulder on the rear portion of a pull rod and the inner side wall of a shaft core is filled with glue with the lubricating and wear-resisting protection functions, when the machine tool spindle is heated, the viscosity of the glue is increased, and then tool changing fails or the pull rod cannot be reset. A pull rod rear protruding shoulder is arranged at the position, close to the rear end of the shaft core, of the pull rod, and the peripheral face of the pull rod rear protruding shoulder is in sliding fit with the inner wall of the shaft core through a sliding fit structure. The sliding fit structure comprises a wear-resistant ring sleeved on a convex shoulder at the rear part of the pull rod; and the outer peripheral surface of the wear-resistant ring is in sliding fit with the inner wall of the shaft core. According to the structure, the mode that the matching face of the convex shoulder on the rear portion of the pull rod and the inner side wall of the shaft core is filled with glue with the lubricating and wear-resisting protection functions in the past is replaced, and the technical problem that after the machine tool spindle is heated, the viscosity of the glue is increased, and the axial movement resistance of the pull rod is further increased is thoroughly solved.

Description

Technical Field

[0001] The present disclosure relates to a spindle for a machine tool. The machine tool may typically be a numerically controlled (CNC) machine tool, and in particular, may be a machine tool (such as various machining centers, including engraving machines) in which the spindle is driven by a servo mechanism and can feed at least along the X, Y, and Z axes in three dimensions. Background Art

[0002] A machine tool spindle designed and manufactured by the applicant mainly includes seven parts, namely a spindle body, a spindle motor, a shaft core, a front bearing system, a rear bearing system, a tool holder locking and releasing mechanism and a spindle cooling system. Specifically: 1) The spindle body is the core supporting component of the machine tool spindle, and is used to be assembled with the other parts of the machine tool spindle to form a machine tool spindle; 2) The spindle motor includes a motor stator and a motor rotor, and the motor stator is fixed in the spindle body, and the motor rotor is adapted to the motor stator; 3) The shaft core is rotatably mounted in the spindle body through the front bearing system and the rear bearing system and rotates with the motor rotor, and a tool holder assembly structure is provided at the front end of the shaft core; 4) The front bearing system includes a front bearing seat and a front bearing, and the front bearing seat is arranged at the front end of the spindle body, and the front bearing is installed in the front bearing seat and rotatably supports the front part of the shaft core; 5) The rear bearing system includes a rear bearing seat and a rear bearing, and the rear bearing seat is arranged at the rear end of the spindle body, and the rear bearing is installed in the rear bearing seat and rotatably supports the front part of the shaft core. Rotating support for the rear part of the shaft core; 6) the tool holder locking and releasing mechanism includes an actuator and a driving mechanism, when the driving mechanism operates in a first driving mode, the actuator can lock the tool holder so that the tool holder and the tool holder assembly structure are tightly matched (in this way, torque can be transmitted between the tool holder and the tool holder assembly structure, so that the spindle motor can drive the tool holder to rotate at high speed through the motor rotor, the shaft core and the tool holder assembly structure), when the driving mechanism operates in a second driving mode, the actuator releases the tool holder so that the tool holder can be detached from the tool holder assembly structure; 7) the spindle cooling system includes a coolant channel network, the coolant channels in the coolant channel network are distributed in the shells of the spindle body, the front bearing seat and the rear bearing seat and are respectively connected to the machine tool coolant input interface and the machine tool coolant return interface.

[0003] Generally speaking, in the tool handle locking and releasing mechanism, the actuator includes a pull rod and a tool handle clamping tensioning and closing component, the tool handle clamping tensioning and closing component is installed at the front end of the pull rod to form a tool handle clamping mechanism, the tool handle clamping mechanism is sleeved in the shaft core and can move axially back and forth as a whole under the drive of the pull rod, and the channel in the shaft core for accommodating the tool handle clamping tensioning and closing component has a front end expansion part and a rear end contraction part, when the tool handle clamping mechanism moves axially from front to back as a whole under the drive of the pull rod, the tool handle clamping mechanism is clamped. When the tensioning and closing component moves from the front end expansion portion to the rear end contraction portion, the tool handle clamping tensioning and closing component is squeezed by the rear end contraction portion and closed inwardly, thereby clamping the tool handle head and driving the tool handle to fit tightly with the tool handle assembly structure. When the tool handle clamping mechanism moves axially from back to front as a whole under the drive of the pull rod and the tool handle clamping tensioning and closing component moves from the rear end contraction portion to the front end expansion portion, the tool handle clamping tensioning and closing component gradually releases the tool handle head, allowing the tool handle to detach from the tool handle assembly structure. The driving mechanism includes a pull rod forward pushing mechanism and a pull rod backward reset mechanism. The pull rod forward pushing mechanism is installed at the rear end of the main shaft body (behind the rear bearing seat) and has a pushing component corresponding to the rear end of the pull rod and a pushing drive device (usually a cylinder) for driving the pushing component to move forward. The pull rod backward reset mechanism has an elastic component installed between the core shaft and the pull rod and continuously applies an elastic force to the pull rod to move backward. When the driving mechanism operates in the second driving mode, the pushing component moves forward and pushes the pull rod forward, and the pull rod overcomes the elastic force of the elastic component to make the tool holder clamping mechanism move axially from back to front as a whole. When the driving mechanism operates in the first driving mode, the pushing component moves backward and disengages from the pull rod, and the pull rod uses the elastic force of the elastic component to make the tool holder clamping mechanism move axially from front to back as a whole.

[0004] The applicant submitted multiple patent applications on November 30, 2022 (publication numbers are CN115740518A, CN115740517A, CN115722690A, CN115971519A, CN115815644A, and CN115722689A), involving multiple improvements to the above-mentioned machine tool spindle. In the patent documents with publication numbers CN115722690A and CN 115971519A, the tool holder locking and releasing mechanism is described in detail and the tool changing dust blowing mechanism in the tool holder locking and releasing mechanism is improved, which can better clean the chips on the tool holder assembly structure during the tool changing process and ensure the installation and positioning accuracy of the tool holder; however, the tool holder clamping and closing component of the tool holder clamping mechanism in the existing tool holder locking and releasing mechanism needs to rely on the elastic force of the torsion spring to drive the tool holder clamping and closing component to open when releasing the tool holder head. In practice, the tool holder clamping and closing component is prone to failure to open, resulting in the inability to release the tool holder. Similarly, in the patent documents with publication numbers CN115722690A and CN115971519A, improvements to the spindle cooling system are mentioned in Figures 12 and 13 and related descriptions, involving a specific structure of setting a coolant channel in the shell of the spindle body, thereby improving the cooling effect of the spindle body; however, the cooling effect of the above structure on the motor stator, which is the main heat source when the machine tool spindle is running, needs to be further improved.

[0005] In the patent document with publication number CN115740518A, the anti-rotation structure arranged between the tool handle locking and releasing mechanism and the shaft core for preventing the pull rod and the shaft core from rotating relative to each other is improved, and the rear end cover of the shaft core and the anti-rotation head arranged on the rear section of the pull rod and inserted into the rear end cover of the shaft core are used to prevent the pull rod and the shaft core from rotating relative to each other; however, since the rear end cover of the shaft core and the anti-rotation head have high matching precision, and at the same time, the rear end cover of the shaft core needs to be installed on the rear end face of the shaft core, and the machine tool spindle inevitably has assembly errors, this may result in the rear end cover of the shaft core being unable to match both the anti-rotation head with high precision and the connecting structure on the rear end face of the shaft core, causing assembly difficulties. Similarly, in the patent document with publication number CN115740518A, it can be seen that: the pull rod is also provided with a pull rod rear boss at a position near the rear end of the shaft core (specifically before the anti-rotation head), and the rear end of the elastic component acts on the front end surface of the pull rod rear boss to continuously apply elastic force to the pull rod to move backward. At present, the mating surface between the pull rod rear boss and the inner wall of the shaft core is usually filled with glue (such as POM resin, i.e. polyoxymethylene resin) for lubrication and wear protection. The inventor found that when the machine tool spindle heats up, the viscosity of the glue increases. At this time, the axial movement resistance of the pull rod increases, which can easily lead to malfunctions such as tool change failure or the inability to reset the pull rod.

[0006] In addition, the aforementioned patent documents with publication numbers CN115740518A, CN115740517A, CN115722690A, CN115971519A, CN115815644A, and CN115722689A provide two types of tool handle assembly structures. One tool handle assembly structure includes a tapered inner hole wall of the shaft core, which, when the tool handle assembly structure is tightly fitted with the tool handle, tightly fits the tapered inner hole wall of the shaft core with a corresponding mating surface on the tool handle. The other tool handle assembly structure includes at least the tapered inner hole wall of the shaft core, a front end surface of the shaft core, and a tapered inner hole wall of the shaft core, which, when the tool handle assembly structure is tightly fitted with the tool handle, tightly fits the front end surface of the shaft core and the tapered inner hole wall of the shaft core with corresponding mating surfaces on the tool handle. The inventors discovered that since the torque transmission between the tool holder and the machine tool spindle is mainly achieved by the close fit between the tapered inner hole wall of the shaft core and the corresponding mating surface on the tool holder, when the tool encounters large cutting resistance during special processing (for example, large cutting loads, high material hardness, etc.), the tool holder may rotate relative to the shaft core due to insufficient torque transmitted between the tool holder and the machine tool spindle. Utility Model Content

[0007] The purpose of the embodiments disclosed herein is to provide a machine tool spindle to solve the technical problem that after the mating surface of the rear boss of the pull rod and the inner wall of the shaft core is filled with glue for lubrication and wear protection, when the machine tool spindle heats up, the viscosity of the glue increases, which in turn leads to failure in tool changing or inability to reset the pull rod.

[0008] A machine tool spindle, comprising:

[0009] Spindle body;

[0010] A spindle motor, comprising a motor stator and a motor rotor, wherein the motor stator is fixed in the spindle body, and the motor rotor is adapted to the motor stator;

[0011] A shaft core, the shaft core is rotatably mounted in the spindle body through a front bearing system and a rear bearing system and rotates with the motor rotor, and a tool handle assembly structure is provided at the front end of the shaft core;

[0012] A front bearing system, comprising a front bearing seat and a front bearing, wherein the front bearing seat is disposed at the front end of the spindle body, and the front bearing is mounted in the front bearing seat and rotatably supports the front portion of the shaft core;

[0013] A rear bearing system, comprising a rear bearing seat and a rear bearing, wherein the rear bearing seat is disposed at the rear end of the spindle body, and the rear bearing is mounted in the rear bearing seat and rotatably supports the rear portion of the shaft core;

[0014] a knife handle locking and releasing mechanism, the knife handle locking and releasing mechanism comprising an actuator and a drive mechanism, wherein when the drive mechanism operates in a first driving mode, the actuator can lock the knife handle so that the knife handle and the knife handle assembly structure are tightly fitted, and when the drive mechanism operates in a second driving mode, the actuator can release the knife handle so that the knife handle can be detached from the knife handle assembly structure;

[0015] The tool holder locking and releasing mechanism, the actuator comprises a pull rod and a tool holder clamping tensioning and closing component, the tool holder clamping tensioning and closing component is installed at the front end of the pull rod to form a tool holder clamping mechanism, the tool holder clamping mechanism is sleeved in the shaft core, and the driving mechanism comprises a pull rod forward pushing mechanism and a pull rod backward resetting mechanism, the pull rod forward pushing mechanism is installed at the rear end of the spindle body and has a pushing component corresponding to the rear end of the pull rod and a pushing driving device for driving the pushing component to move forward, the pull rod backward resetting mechanism has an elastic component installed between the shaft core and the pull rod and continuously applying an elastic force to the pull rod to move backward, when the driving mechanism operates in a first driving mode, the pushing component moves backward and disengages from the pull rod and the pull rod moves axially from front to back due to the elastic force of the elastic component, when the driving mechanism operates in a second driving mode, the pushing component moves forward and pushes the pull rod forward and the pull rod overcomes the elastic force of the elastic component and moves axially from back to front;

[0016] The pull rod is provided with a pull rod rear boss at a position near the rear end of the shaft core, and the outer peripheral surface of the pull rod rear boss is slidably fitted with the inner wall of the shaft core through a sliding fit structure; the sliding fit structure includes a wear-resistant ring mounted on the pull rod rear boss, and the outer peripheral surface of the wear-resistant ring is slidably fitted with the inner wall of the shaft core.

[0017] The above structure replaces the previous method of filling the mating surface between the rear boss of the pull rod and the inner wall of the shaft core with glue for lubrication and wear protection, and completely solves the technical problem that the viscosity of the glue increases when the machine tool spindle heats up, which further increases the axial movement resistance of the pull rod.

[0018] The following further describes the embodiments of the present disclosure in conjunction with the accompanying drawings and specific embodiments. Additional aspects and advantages of the embodiments of the present disclosure will be partially given in the following description, partially become obvious from the following description, or be learned through practice. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The drawings that constitute part of this specification are used to assist in understanding the embodiments of the present disclosure. The contents provided in the drawings and the related descriptions in this specification can be used to explain the embodiments of the present disclosure, but do not constitute improper limitations on the embodiments of the present disclosure.

[0020] Figure 1 This is a full cross-sectional view of a machine tool spindle according to an embodiment of the present disclosure.

[0021] Figure 2 for Figure 1 A partial enlarged view of point A in the middle.

[0022] Figure 3 for Figure 1 A three-dimensional view of the tool holder clamping component in the machine tool spindle from one direction.

[0023] Figure 4 for Figure 1 A three-dimensional view of the tool holder clamping component in the machine tool spindle from another direction.

[0024] Figure 5 for Figure 1 The diagram shows a three-dimensional diagram of the matching relationship between the locating ring and the shaft core in the machine tool spindle.

[0025] Figure 6 for Figure 1 Partial schematic diagram of point B in the middle.

[0026] Figure 7 for Figure 1 A sectional view of the machine tool spindle shown in another section plane.

[0027] Figure 8 for Figure 1 A three-dimensional view of the intermediate sleeve in the machine tool spindle is shown.

[0028] Figure 9 This is a three-dimensional schematic diagram of the matching relationship between the shaft core and the tool handle of a machine tool spindle according to an embodiment of the present disclosure.

[0029] : The markings in the figure are: spindle body 1, spindle motor 2, motor stator 21, motor rotor 22, shaft core 3, tool holder assembly structure 31, shaft core front end face 311, shaft core tapered inner hole wall 312, positioning key 313, shaft core rear end cover 32, outer ring 321, inner ring 322, bolt 323, shaft core inner blowing channel 33, front bearing system 4, front bearing seat 41, front bearing 42, rear bearing system 5, rear bearing seat 51, rear bearing 52, tool holder locking and release mechanism 6, actuator 61, pull rod 611, anti-rotation head 6111, pull rod rear shoulder 6112, wear-resistant ring 6112a, movable expansion sleeve 6113, first reducing section 6113a, second reducing section 6113b, positioning ring 6114, claw support surface 6114a, front positioning ring 6114b, rear positioning ring 6114c, carrying groove 61 14d, axial positioning washer 6115, axial preload structure 6116, compression spring 6116a, fixed sleeve 6116b, spring cylinder 6116c, intermediate air channel 6116d, fixed sleeve side ring groove 6116e, fixed sleeve side vent 6116f, insert 6116g, main air blowing channel 6117, pull rod side ring groove 6118, pull rod side vent 6119, sealing ring 6120, tool holder clamp The holding and closing component 612, the pulling claw 6121, the hook portion 6121a, the neck 6121b, the head 6121c, the radial groove 6121d, the driving mechanism 62, the cylinder 621, the pushing component 6211, the elastic component 622, the spindle cooling system 7, the intermediate sleeve 71, the coolant tank 711, the convex ring 712, the sealing element 72, the tool handle 8, the inner hole flange 81 of the tool handle head, and the keyway 82. DETAILED DESCRIPTION

[0030] The following is a clear and complete description of the embodiments of the present disclosure in conjunction with the accompanying drawings. A person of ordinary skill in the art will be able to implement the embodiments of the present disclosure based on these descriptions. Before describing the embodiments of the present disclosure in conjunction with the accompanying drawings, it should be noted that:

[0031] The technical solutions and technical features provided in each section, including the following description, may be combined with each other unless they conflict. In addition, where possible, these technical solutions, technical features, and related combinations may be assigned specific technical themes and protected by relevant patents.

[0032] The embodiments of the present disclosure involved in the following description are generally only a part of the embodiments rather than all the embodiments. Based on these embodiments, all other embodiments obtained by ordinary technicians in this field without making any creative work should fall within the scope of patent protection.

[0033] Regarding the terms and units in this specification: The terms "include", "comprise", "have" and any variations thereof in this specification and the corresponding claims and related parts are intended to cover non-exclusive inclusions. The terms "before" and "after" in this specification and the corresponding claims and related parts refer to the following: Figure 1 The relative position relationship of the central axis of the machine tool spindle in the axial direction is shown, where the axial direction of the central axis of the tool holder is "front". In addition, other related terms and units can be reasonably interpreted based on the relevant content provided in this specification.

[0034] Figure 1 This is a full cross-sectional view of a machine tool spindle according to an embodiment of the present disclosure. Figure 1 The existing machine tool spindle includes a spindle body 1, a spindle motor 2, a shaft core 3, a front bearing system 4, a rear bearing system 5, a tool holder locking and releasing mechanism 6, and a spindle cooling system 7. The spindle body 1 is the core supporting component of the machine tool spindle and is used to be assembled with the other parts of the machine tool spindle to form the machine tool spindle. The spindle motor 2 includes a motor stator 21 and a motor rotor 22. The motor stator 21 is fixed in the spindle body 1, and the motor rotor 22 is adapted to the motor stator 21. The shaft core 3 is rotatably mounted in the spindle body 1 through the front bearing system 4 and the rear bearing system 5 and rotates with the motor rotor 22. A tool holder assembly structure 31 is provided at the front end of the shaft core 3. The front bearing system 4 includes a front bearing seat 41 and a front bearing 42. The front bearing seat 41 is arranged at the front end of the spindle body 1. The front bearing 42 is installed in the front bearing seat 41 and rotatably supports the front part of the shaft core 3. The rear bearing system 5 includes a rear bearing seat 51 and a rear bearing 52. The rear bearing seat 51 is disposed at the rear end of the spindle body 1. The rear bearing 52 is mounted in the rear bearing seat 51 and rotatably supports the rear portion of the shaft core 3. The tool holder locking and releasing mechanism 6 includes an actuator 61 and a drive mechanism 62. When the drive mechanism 62 operates in a first driving mode, the actuator 61 can lock the tool holder 8 so that the tool holder 8 is tightly fitted with the tool holder assembly structure 31. When the drive mechanism 62 operates in a second driving mode, the actuator 61 releases the tool holder 8 so that the tool holder 8 can be detached from the tool holder assembly structure 31. The spindle cooling system 7 includes a coolant channel network. The coolant channels in the coolant channel network are distributed within the shells of the spindle body 1, the front bearing seat 41, and the rear bearing seat 51, and are respectively connected to the machine tool coolant input interface and the machine tool coolant return interface.

[0035] Generally speaking, in the tool handle locking and releasing mechanism 6, the actuator 61 includes a pull rod 611 and a tool handle clamping tensioning and closing component 612, and the tool handle clamping tensioning and closing component 612 is installed at the front end of the pull rod 611 to form a tool handle clamping mechanism. The tool handle clamping mechanism is sleeved in the shaft core 3 and can move axially back and forth as a whole under the drive of the pull rod 611. The channel in the shaft core 3 for accommodating the tool handle clamping tensioning and closing component has a front end expansion part and a rear end contraction part. When the tool handle clamping mechanism moves axially from front to back as a whole under the drive of the pull rod 611 and the tool handle clamping tensioning and closing component 612 moves from the front end expansion part to the rear end contraction part, the tool handle clamping tensioning and closing component 612 is squeezed by the rear end contraction part and closed inward, thereby clamping the head of the tool handle 8 and driving the tool handle 8 to fit tightly with the tool handle assembly structure 31 (i.e. Figure 1 (as shown in the state), when the tool holder clamping mechanism moves axially from back to front as a whole under the drive of the pull rod 611 and the tool holder clamping tensioning and closing component 612 moves from the rear end contraction portion to the front end expansion portion, the tool holder clamping tensioning and closing component 612 gradually releases the head of the tool holder 8 so that the tool holder 8 can be detached from the tool holder assembly structure 31. The driving mechanism 62 includes a pull rod forward pushing mechanism and a pull rod backward reset mechanism. The pull rod forward pushing mechanism is installed at the rear end of the spindle body 1 (behind the rear bearing seat 51) and has a pushing component 6211 corresponding to the rear end of the pull rod 611 and a pushing drive device for driving the pushing component 6211 to move forward. The pull rod backward reset mechanism has an elastic component 622 (which can be sleeved behind the pull rod 611) installed between the core shaft 3 and the pull rod 611 and continuously applies elastic force to the pull rod 611 to move backward. When the drive mechanism 62 operates in the second driving mode, the pushing component 6211 moves forward and pushes the pull rod 611 forward. When the pull rod 611 overcomes the elastic force of the elastic component 622, the tool holder clamping mechanism as a whole moves axially from back to front. When the drive mechanism 62 operates in the first driving mode, the pushing component 6211 moves backward and disengages from the pull rod 611. The pull rod 611, through the elastic force of the elastic component 622, moves the tool holder clamping mechanism as a whole axially from front to back. The pushing drive device generally uses a plurality of cylinders 621, the pistons of these cylinders 621 are connected together and move synchronously and in the same direction. The pushing component 6211 is located at the front end of the foremost cylinder 621. When the pistons of the plurality of cylinders 621 move forward synchronously, the pushing component 6211 can be guaranteed to have a large thrust.

[0036] In the existing machine tool spindle, a step that matches the outer surface shape of the tool shank clamping and closing component 612 is provided in the channel of the shaft core 3 for accommodating the tool shank clamping and closing component 612 at the transition position from the front end expansion portion to the rear end contraction portion. The front end of the tool shank clamping and closing component 612 has an inward clamping claw, and the rear end of the tool shank clamping and closing component 612 is hinged to the pull rod 611. At the same time, a torsion spring for driving the tool shank clamping and closing component 612 to open outward is installed at the hinge between the tool shank clamping and closing component 612 and the pull rod 611. When the tool handle clamping mechanism is driven by the pull rod 611 and the tool handle clamping and closing member 612 moves axially from the rear to the front, the step presses the tool handle clamping and closing member 612 inward to rotate the tool handle clamping and closing member 612, so that the claw at the front end of the tool handle clamping and closing member 612 is engaged with the front end of the head of the tool handle 8. When the tool handle clamping mechanism is driven by the pull rod 611 and the tool handle clamping and closing member 612 moves axially from the rear to the front, the torsion spring drives the tool handle clamping and closing member 612 to open outward, and the tool handle clamping and closing member 612 gradually releases the head of the tool handle 8. However, since the tool handle clamping tensioning and closing components (claws) need to be driven to open by the elastic force of the torsion spring, in practice, the tool handle clamping tensioning and closing components may fail to open, resulting in the inability to release the tool handle.

[0037] In the existing machine tool spindle, the coolant channel network distributed in the shell of the spindle body 1 can include a plurality of axial channels opened along the axial direction of the spindle body 1, and these axial channels are arranged at circumferential intervals along the circumference of the spindle body 1. The front ends of these axial channels are mostly connected in pairs (the front ends of these axial channels 71 can be mostly connected in pairs by respectively opening elliptical grooves that can be connected to the corresponding two adjacent axial channels on the front end face of the spindle body 1 and / or the rear end face of the front bearing seat 41) and the rear ends of these axial channels are mostly connected in pairs. The axial channels are connected in pairs (most of the rear ends of the axial channels can be connected in pairs by respectively opening elliptical grooves on the front end surface of the rear bearing seat 51 that can be connected to the corresponding two adjacent axial channels at the same time) so that the axial channels are connected in series in sequence, the rear end of one of the axial channels is connected to the machine tool coolant input interface and the front end is connected to the coolant input channel in the front bearing seat, the front end of one of the axial channels is connected to the coolant output channel in the front bearing seat, and the rear end of one of the axial channels is connected to the machine tool coolant return interface. Thus, the spindle cooling system 7 of the machine tool spindle will operate as follows: the coolant first flows from the back to the front through an axial channel and enters the coolant channel distributed in the shell layer of the front bearing seat 41 in the coolant channel network through the coolant input channel in the front bearing seat, thereby fully cooling the front bearing seat 41. Then, the coolant enters another axial channel through the coolant output channel in the front bearing seat, and then flows through the axial channels connected in series, thereby cooling the entire spindle body 1 and the rear bearing seat 51. Finally, it flows out of the machine tool spindle through an axial channel and the machine tool coolant return interface. However, the cooling effect of the coolant channel distributed in the shell layer of the spindle body 1 in the coolant channel network on the motor stator 21, the main heat source during the operation of the machine tool spindle, needs to be further improved.

[0038] In the existing machine tool spindle, a rotation-stopping structure for preventing relative rotation between the pull rod 611 and the shaft core 3 is further provided between the tool holder locking and releasing mechanism 6 and the shaft core 3. The rotation-stopping structure includes a shaft core rear end cover 32 installed at the rear end of the shaft core 3 and a rotation-stopping head 6111 provided on the rear section of the pull rod 611 and inserted into the shaft core rear end cover 32. The shape of the outer peripheral wall of the rotation-stopping head 6111 is adapted to the shape of the inner peripheral wall of the shaft core rear end cover 32 and circumferentially fixed therebetween. Generally speaking, a rotation-stopping head outer peripheral wall rotation-stopping plane is provided on the outer peripheral wall of the rotation-stopping head 6111, and an end cover inner peripheral wall rotation-stopping plane is provided on the inner peripheral wall of the shaft core rear end cover 32. The rotation-stopping head outer peripheral wall rotation-stopping plane matches the corresponding end cover inner peripheral wall rotation-stopping plane. For example, the rotation-stopping head outer peripheral wall rotation-stopping plane can make the rotation-stopping head 6111 form a hexagonal structure similar to the head of a bolt. In this way, the aforementioned anti-rotation structure has the ability to withstand greater torque. However, due to the high precision of the fit between the shaft core rear end cover 32 and the anti-rotation head 6111, and the fact that the shaft core rear end cover 32 needs to be installed on the rear end face of the shaft core 3, and the inevitable assembly error of the machine tool spindle, the shaft core rear end cover 32 may not be able to fit both with the anti-rotation head 6111 with high precision and with the connection structure on the rear end face of the shaft core 3 (usually bolted), causing assembly difficulties.

[0039] In the existing machine tool spindle, the pull rod 611 is further provided with a pull rod rear boss 6112 at a position near the rear end of the shaft core 3 (specifically, before the stop 6111). The rear end of the elastic component 622 acts on the front end surface of the pull rod rear boss 6112 to continuously apply elastic force to the pull rod 611 to move backward. At present, the mating surface between the pull rod rear boss 6112 and the inner wall of the shaft core 3 usually needs to be filled with glue (such as POM resin, i.e., polyoxymethylene resin) for lubrication and wear protection. The inventors have found that when the machine tool spindle heats up, the viscosity of the glue increases. At this time, the axial movement resistance of the pull rod 611 increases, which can easily lead to failures such as tool change failure or the inability to reset the pull rod 611.

[0040] In existing machine tool spindles, two types of toolholder assembly structures 31 are provided. One toolholder assembly structure includes a tapered inner bore wall 312 of the shaft core. When the toolholder assembly structure 31 is tightly fitted with the toolholder 8, the tapered inner bore wall 312 of the shaft core tightly fits with the corresponding mating surface on the toolholder 8. The other toolholder assembly structure includes a front end face 311 of the shaft core and a tapered inner bore wall 312 of the shaft core. When the toolholder assembly structure 31 is tightly fitted with the toolholder 8, the front end face 311 of the shaft core and the tapered inner bore wall 312 of the shaft core respectively tightly fit with the corresponding mating surfaces on the toolholder. The inventors have discovered that because the torque transmission between the toolholder 8 and the machine tool spindle is mainly achieved by the tight fit between the tapered inner bore wall 312 of the shaft core and the corresponding mating surfaces on the toolholder 8, when the tool encounters large cutting resistance during special processing (for example, in high-load situations such as heavy cutting rain or high material hardness), the toolholder 8 may rotate relative to the shaft core 3 due to insufficient torque transmitted between the toolholder 8 and the machine tool spindle.

[0041] The above description of existing machine tool spindles can be further understood from patent documents with publication numbers CN115740518A, CN115740517A, CN115722690A, CN115971519A, CN115815644A, and CN115722689A. The contents of these patent documents may also be incorporated into the embodiments of the present disclosure. The following describes the embodiments of the present disclosure, which address the technical issues existing in existing machine tool spindles.

[0042] Figure 2 for Figure 1 A partial enlarged view of point A in the middle. Figure 3 for Figure 1 A three-dimensional view of the tool holder clamping component in the machine tool spindle from one direction. Figure 4 for Figure 1 A three-dimensional view of the tool holder clamping component in the machine tool spindle from another direction. Figure 5 for Figure 1 The figure shows the three-dimensional diagram of the matching relationship between the locating ring and the shaft core in the machine tool spindle. Figure 1-Figure 5As shown in the improved tool handle locking and releasing mechanism, the front end of the pull rod 611 is installed with a movable expansion sleeve 6113, and the cylindrical surface of the movable expansion sleeve 6113 near the front end and the rear end of the movable expansion sleeve 6113 respectively has a first diameter-reducing section 6113a and a second diameter-reducing section 6113b; the tool handle clamping and closing component 612 includes a pull claw 6121 installed on the outside of the movable expansion sleeve 6113 and arranged at intervals along the movable expansion sleeve 6113, and the pull claw 6121 has a hook portion 6121a, a neck portion 6121b and a head portion arranged in sequence from front to back. 6121c, the front end surface of the outer side surface of the head 6121c is a conical surface or a spherical surface; the outer side of the pull claw claw 6121 in the shaft core 3 is detachably fixedly installed with a positioning ring 6114, and the outer ring surface of the positioning ring 6114 is provided with a positioning step, and the positioning step is adapted to the corresponding step hole of the shaft core 3, and an axial positioning washer 6115 is installed between the end faces of the positioning step and the step hole that cooperate with each other, and the rear end face of the positioning ring 6114 forms a pull claw support surface 6114a, and the pull claw support surface 6114a is movable with the conical surface or the spherical surface The pull rod 611 is provided with an axial pre-tightening structure 6116 which is axially movable with the pull rod 611, and the axial pre-tightening structure 6116 comprises a fixed portion which is axially fixed with the shaft core 3, a movable portion which is axially movable with the shaft core 3, and a compression spring 6116a which is compressed between the fixed portion and the movable portion. The compression spring 6116a continuously applies a forward force to the head 6121c of the pull claw 6121 through the movable portion. When the driving mechanism 62 runs the first driving direction In this mode, the movable expansion sleeve 6113 moves axially from front to back following the pull rod 611, and when the first reducing section 6113a and the second reducing section 6113b are movably engaged with the inner side surface of the hook portion 6121a and the inner side surface of the head 6121c respectively, and the pulling claw support surface 6114a is movably engaged with the conical surface or the spherical surface, the hook portion 6121a of the pulling claw claw 6121 opens outward, so that the outer part of the hook portion 6121a can clamp the inner hole flange 81 of the tool handle head, and drive the tool handle 8 to closely engage with the tool handle assembly structure 31.

[0043] Therefore, the tool handle locking and releasing mechanism does not rely on the elastic force of the torsion spring to drive the claw to release the tool handle 8, and has high working stability. In addition, since a positioning ring 6114 is detachably fixedly installed on the outer side of the claw 6121 in the shaft core 3, a positioning step is provided on the outer ring surface of the positioning ring 6114, and the positioning step is adapted to the corresponding step hole of the shaft core 3. An axial positioning washer 6115 is installed between the end faces of the positioning step and the step hole that cooperate with each other. The rear end face of the positioning ring 6114 forms a claw support surface 6114a, and the claw support surface 6114a is movably matched with the conical surface or the spherical surface. Therefore, the position of the claw support surface 6114a can be adjusted by adjusting the thickness of the axial positioning washer 6115, ensuring that the claw 6121 is opened and closed as required, which facilitates the debugging and maintenance of the tool handle clamping opening and closing component 612.

[0044] like Figure 1-Figure 5 As shown, the improved tool holder locking and releasing mechanism also includes a first tool changing dust blowing mechanism and a second tool changing dust blowing mechanism. Wherein, the first tool changing dust blowing mechanism (for details, please refer to the relevant records in the patent documents such as publication number CN 115740518A) includes an air intake side mechanism and an air blowing side mechanism, the air intake side mechanism is installed at the rear end of the spindle body 1 and has an external air intake structure of the pushing component arranged outside the pushing component 6211 and an internal air intake structure of the pushing component arranged inside the pushing component 6211, the external air intake structure of the pushing component has a matching part that is matched with the guide of the pushing component 6211 and an external air intake channel located in the matching part, the external air intake channel is connected to the tool changing dust blowing air intake interface of the machine tool, and the internal air intake structure of the pushing component has an internal air intake channel, The blowing side mechanism has a main blowing channel 6117 arranged in the pull rod 611, the front end of the main blowing channel 6117 extends to the external space at the front end of the movable expansion sleeve 6113, and the rear end of the main blowing channel 6117 extends to the rear end of the pull rod 611 and forms an air inlet. When the pushing component 6211 moves forward and pushes the pull rod 611 to move forward, the external air inlet channel is connected to the main blowing channel 6117 through the internal air inlet channel. When the pushing component 6211 moves backward and disengages from the pull rod 611, the external air inlet channel is disconnected from the main blowing channel. Among them, the second tool-changing dust-blowing mechanism includes an internal blowing channel 33 in the shaft core, and the outlet of the internal blowing channel 33 in the shaft core is arranged between the tool handle assembly structure 31 (specifically, the conical inner hole wall 312 of the shaft core) and the positioning ring 6114 (see Figure 5As shown), the inlet of the blowing channel 33 in the shaft core is arranged on the inner wall of the shaft core 3, and the blowing side mechanism also has an auxiliary blowing channel arranged in the pull rod 611, one end of the auxiliary blowing channel is connected to the main blowing channel 6117 and the other end extends to the outer wall of the pull rod 611, when the pushing component 6211 moves forward and pushes the pull rod 611 to move forward, the auxiliary blowing channel is connected to the inlet of the blowing channel 33 in the shaft core.

[0045] Of course, the air blowing channel 33 in the shaft core may also include other outlets, such as Figure 5 The outlet is arranged on the front end face 311 of the shaft core (see Figure 5 shown).

[0046] Obviously, by arranging part of the outlet of the blowing channel 33 in the shaft core between the conical inner hole wall 312 of the shaft core and the positioning ring 6114, and at the same time, arranging part of the outlet of the blowing channel 33 in the shaft core on the front end face 311 of the shaft core, the conical inner hole wall 312 of the shaft core and the front end face 311 of the shaft core can be blown when changing the tool, thereby avoiding impurities such as iron pins attached to the conical inner hole wall 312 of the shaft core and the front end face 311 of the shaft core affecting the installation and positioning accuracy of the tool handle 8.

[0047] like Figures 1-4 As shown, the fixing portion includes a fixing sleeve 6116b that is interference fit with the inner wall of the shaft core 3, and an intermediate air channel 6116d is provided in the fixing sleeve 6116b. When the pushing component 6211 moves forward and pushes the pull rod 611 to move forward, the auxiliary blowing channel and the inlet of the blowing channel 33 in the shaft core are connected through the intermediate air channel 6116d.

[0048] Therefore, the fixing sleeve 6116b fixes the axial pre-tightening structure 6116 on the one hand, and connects the auxiliary blowing channel with the inlet of the blowing channel 33 in the shaft core through the intermediate air channel 6116d on the other hand.

[0049] In a preferred embodiment, the auxiliary blowing channel includes a pull rod side annular groove 6118 provided on the outer wall of the pull rod 611 and a pull rod side vent hole 6119 for connecting the pull rod side annular groove 6118 with the main blowing channel 6117; the intermediate air channel 6116d includes a fixed sleeve side annular groove 6116e provided on the outer wall of the fixed sleeve 6116b and a fixed sleeve side vent hole 6116f for connecting the fixed sleeve side annular groove 6116e with the pull rod side annular groove 6118. The groove 6116e is connected to the inlet of the air blowing channel 33 in the shaft core; sealing rings 6120 are respectively provided at the front and rear ends of the pull rod side ring groove 6118 between the outer wall of the pull rod 611 and the inner wall of the fixed sleeve 6116b, so that when the driving mechanism 62 operates in the first driving mode, the pull rod side ring groove 6118 and the fixed sleeve side air vent 6116d are cut off, and when the driving mechanism 62 operates in the second driving mode, the pull rod side ring groove 6118 and the fixed sleeve side air vent 6116d are connected.

[0050] After the auxiliary blowing channel is designed to include a pull rod side annular groove 6118 opened on the outer wall of the pull rod 611 and a pull rod side air vent 6119 connecting the pull rod side annular groove 6118 with the main blowing channel 6117, and the intermediate air channel 6116d is designed to include a fixed sleeve side annular groove 6116e opened on the outer wall of the fixed sleeve 6116b and a fixed sleeve side air vent 6116f for connecting the fixed sleeve side annular groove 6116e with the pull rod side annular groove 6118, the gas used for blowing dust can be evenly distributed in the pull rod side annular groove 6118 and the fixed sleeve side annular groove 6116e, so that the gas pressure on the pull rod 611 and the fixed sleeve 6116b is evenly distributed in the circumferential direction.

[0051] In an optional embodiment, the movable part includes a spring cylinder 6116c sleeved on the pull rod 611, the compression spring 6116a is installed in the spring cylinder 6116c and is compressed by the end covers at both ends of the spring cylinder 6116c, the end covers at both ends of the spring cylinder 6116c can move axially relative to each other and the rear end cover of the spring cylinder 6116c is axially matched with the fixed part (specifically the fixed sleeve 6116b).

[0052] The spring cylinder 6116c can enclose the compression spring 6116a in the spring cylinder 6116c, ensuring that the compression spring 6116a does not come into contact with impurities such as iron filings, so the operation is stable and reliable.

[0053] In an optional embodiment, the outer peripheral surface of the positioning ring 6114 is provided with an external thread, and the inner hole in the shaft core 3 for installing the positioning ring 6114 is provided with an internal thread, and the external thread is adapted to the internal thread so that the positioning ring 6114 can be detachably fixedly installed in the shaft core. Further, the positioning ring 6114 is divided into a front positioning ring 6114b and a rear positioning ring 6114c, and the rear end face of the front positioning ring 6114b contacts and cooperates with the front end face of the rear positioning ring 6114c. The front positioning ring 6114b and the rear positioning ring 6114c are respectively detachably fixedly installed in the shaft core 3 through the corresponding external thread and the corresponding internal thread in the shaft core 3, and the inner periphery of the positioning ring 6114 (which may include the front positioning ring 6114b and the rear positioning ring 6114c) is provided with a rotation groove 6114d.

[0054] The front positioning ring 6114b and the rear positioning ring 6114c can be conveniently rotated and fastened in the shaft core 3 through the rotation groove 6114d. The front positioning ring 6114b and the rear positioning ring 6114c are axially pre-tightened to ensure the installation stability of the positioning ring 6114.

[0055] Typically, the rear end of the outer side of the barb 6121a and the front end of the inner hole flange 81 of the handle head are tapered surfaces for mutual adaptation. This ensures a tight fit between the barb 6121a and the inner hole flange 81 of the handle head, while also facilitating the removal of the barb 6121a from the inner hole flange 81 of the handle head.

[0056] In a preferred embodiment, a radial groove 6121d is provided on the rear end surface of the head of the pulling claw 6121, and the front end surface of the radial groove 6121d is a slope and the normal direction of the slope gradually moves away from the central axis of the machine tool spindle from front to back (see Figure 2-Figure 4 ); the movable portion continuously applies a forward force to the head of the pulling claw 6121 by inserting the plug 6116g corresponding to the radial groove 6121d, and the front end face of the plug 6116g is axially matched with the front end face of the radial groove 6121d.

[0057] In this way, it can be ensured that the same forward force is applied to each pulling claw and flap claw 6121. In addition, since the front end face of the radial groove 6121d is a slope and the normal direction of the slope gradually moves away from the central axis of the machine tool spindle from front to back, the forward force continuously applied to the head of the pulling claw and flap claw 6121 by the insert block 6116g inserted into the corresponding radial groove 6121d actually has a component that can drive the hook portion 6121a of the pulling claw and flap claw 6121 to contract inward. When the driving mechanism 62 operates the second driving mode to make the movable expansion sleeve 6113 follow the pull rod 611 to move axially from back to front, it can better promote the hook portion 6121a of the pulling claw and flap claw 6121 to contract inward, so that the hook portion 6121a can more easily release the inner hole flange 81 of the tool handle head.

[0058] Figure 6 for Figure 1 The local schematic diagram of point B in the figure. Figure 6 As shown, the improved anti-rotation structure includes a shaft core rear end end cover 32 installed at the rear end of the shaft core 3 and a anti-rotation head 6111 arranged on the rear section of the pull rod 611 and inserted into the shaft core rear end end cover 32. The shape of the outer circumferential wall of the anti-rotation head 6111 is adapted to the shape of the inner circumferential wall of the shaft core rear end end cover 32 so that they are circumferentially fixed. The shaft core rear end end cover 32 is composed of an outer ring part 321 and an inner ring part 322 that are detachably connected together. The inner circumferential wall of the shaft core rear end end cover 32 is composed of the inner hole of the inner ring part 322.

[0059] Since the rear end cover 32 of the shaft core is divided into an outer ring part 321 and an inner ring part 322 that are detachably connected together, the outer ring part 321 can be preferentially matched with the connection structure on the rear end surface of the shaft core 3, and the inner ring part 322 can be preferentially matched with the anti-rotation head 6111. On this basis, the outer ring part 321 and the inner ring part 322 are assembled again (generally speaking, the outer ring part 321 and the inner ring part 322 are detachably connected by bolts 323, and the bolts 323 pass axially through the outer ring part 321 and the inner ring part 322 The outer ring part and the inner ring part are detachably connected together), and when the outer ring part 321 and the inner ring part 322 are assembled, the matching adjustment gap and / or bench adjustment between the outer ring part 321 and the inner ring part 322 can be utilized to realize the detachable connection between the outer ring part 321 and the inner ring part 322. In this way, it is possible to effectively avoid the overall assembly error of the machine tool spindle, which causes the integrated shaft core rear end cover 32 to be unable to match with the anti-rotation head 6111 with high precision and to match with the connection structure on the rear end face of the shaft core 3 (usually bolted connection), causing assembly difficulties.

[0060] Typically, the outer circumferential wall of the stopper 6111 is provided with a stopper surface, and the inner circumferential wall of the end cap is provided with a stopper surface on the inner circumferential wall of the inner annular member 322. The stopper surface mates with the corresponding stopper surface on the inner circumferential wall of the end cap. For example, the stopper surface can form a hexagonal structure similar to the head of a bolt.

[0061] In an optional embodiment, a shaft core rotation displacement detection mechanism for detecting the rotation angle of the shaft core is installed at the rear end of the shaft core, and the shaft core rotation displacement detection mechanism includes a measuring gear installed on the shaft core and rotating synchronously with the shaft core, and a sensor for detecting the teeth of the measuring gear to obtain the rotation displacement information of the shaft core; the outer ring member 321 also serves as the measuring gear.

[0062] Likewise Figure 6 As shown, the pull rod 611 is provided with a pull rod rear boss 6112 near the rear end of the shaft core 3. The outer circumference of the pull rod rear boss 6112 slides with the inner wall of the shaft core 3 via a sliding fit structure. The sliding fit structure includes a wear-resistant ring 6112a sleeved on the pull rod rear boss 6112. The outer circumference of the wear-resistant ring 6112a slides with the inner wall of the shaft core 3. The rear end of the elastic component 622 of the machine tool spindle acts on the front end surface of the pull rod rear boss 6112, thereby continuously applying elastic force to the pull rod 611 to move backward.

[0063] More specifically, a first annular groove is defined on the outer circumference of the rear boss 6112 of the pull rod, and at least two second annular grooves are defined at intervals at the bottom of the first annular groove. Washers 6112b made of elastic material are respectively installed in the at least two second annular grooves. The wear-resistant ring 6112a is installed in the first annular groove and is elastically squeezed by the washers 6112b in the radial direction, thereby clinging to the inner wall of the shaft core 3. The washers 6112b can be elastic sealing rings or made of rubber.

[0064] The above structure replaces the previous method of filling the mating surface between the rear boss 6112 of the pull rod and the inner wall of the shaft core 3 with glue for lubrication and wear protection, and completely solves the technical problem that the viscosity of the glue increases when the machine tool spindle heats up, which further increases the axial movement resistance of the pull rod 611.

[0065] Figure 7 for Figure 1 A sectional view of the machine tool spindle shown in another section plane. Figure 8 for Figure 1 The three-dimensional diagram of the intermediate sleeve in the machine tool spindle is shown in FIG. Figure 1 、 Figure 7-Figure 8As shown, the improved spindle cooling system 7 includes an intermediate sleeve 71 which is sleeved between the inner wall of the spindle body 1 and the outer wall of the motor stator 21. A cooling liquid groove 711 is provided on the inner wall of the spindle body 1 and / or the outer wall of the intermediate sleeve 71. The cooling liquid groove 711 forms a cooling liquid flow path wrapped around the outer side of the motor stator 21. The input end and the output end of the cooling liquid flow path are respectively connected to the cooling liquid channel network through holes provided in the shell of the spindle body 1. Sealing elements 72 are provided on the mating surfaces of the two ends of the intermediate sleeve 71 and the spindle body 1 (usually, sealing elements 72 are provided on the mating surfaces of the outer side surfaces at both ends of the intermediate sleeve 71 and the spindle body 1).

[0066] By adding an intermediate sleeve 71 between the inner wall of the spindle body 1 and the outer wall of the motor stator 21 , a coolant flow path covering the outer side of the motor stator 21 is formed, which can cool the motor stator 21 more effectively.

[0067] In an optional embodiment, Figure 7 As shown, the input end of the coolant flow path is connected to the output end of the coolant channel distributed in the shell of the rear bearing seat 51 in the coolant channel network through a hole opened in the shell of the spindle body 1; the output end of the coolant flow path is connected to the input end of the coolant channel distributed in the shell of the front bearing seat 41 in the coolant channel network through a hole opened in the shell of the spindle body 1.

[0068] In an optional embodiment, Figure 7-Figure 8As shown, the inner wall of the spindle body 1 does not have the coolant groove, and the outer wall of the intermediate sleeve 71 has the coolant groove 711 (which is convenient for processing); the outer wall of the intermediate sleeve 71 is provided with a plurality of convex rings 712 evenly spaced along the axial direction so that an annular groove serving as the coolant groove 711 is formed between any two adjacent convex rings 712, and each of the plurality of convex rings 712 is provided with a concave portion 7121, and the concave portions 7121 of any two adjacent convex rings 712 differ by 180° in the circumferential direction, and the plurality of convex rings 712 are respectively disposed on the inner wall of the spindle body 1. The intermediate sleeve 71 is adapted to fit the wall. A recess 7121 formed on each of the multiple protruding rings 712 allows any two adjacent annular grooves 711 in the coolant flow path to communicate through the corresponding recess 7121. The input end of the coolant flow path communicates with the annular groove at the rear end of the intermediate sleeve 71 and is 180° circumferentially offset from the recess 7121 on the protruding ring 712 at the rear end of the intermediate sleeve 71. The output end of the coolant flow path communicates with the annular groove at the front end of the intermediate sleeve 71 and is 180° circumferentially offset from the recess 7121 on the protruding ring 712 at the front end of the intermediate sleeve 71. For ease of machining, the protruding ring 712 is formed by grinding the annular groove into the outer wall of the intermediate sleeve 71. The recess 7121 is formed by grinding a reduced surface on the protruding ring 712.

[0069] like Figure 8 As shown, when the surface of the intermediate sleeve 71 adopts the above structure, the coolant will be divided into two paths at the input end of the coolant flow path, one of which is Figure 8 The flow is shown in the dotted arrow, and the other is the same as Figure 8 The dotted arrows indicate a bilaterally symmetrical flow pattern, whereby the coolant entering each annular groove 711 is split into two paths, each flowing half a circle before converging at the lower recess 7121 and flowing into the next annular groove 711, ultimately exiting at the output end of the coolant flow path. This coolant flow pattern not only improves cooling efficiency but also provides greater uniformity across the entire intermediate sleeve 71.

[0070] Figure 9 This is a three-dimensional schematic diagram of the matching relationship between the spindle core and the tool handle of a machine tool according to an embodiment of the present disclosure. Figure 9 As shown, the improved tool handle assembly structure 31 also includes a positioning key 313 arranged on the front end surface of the shaft core and protruding from the front end surface of the shaft core. When the tool handle assembly structure 31 is tightly fitted with the tool handle 8, the positioning key 313 is adapted to the corresponding keyway 82 on the tool handle 8.

[0071] In an optional embodiment, a positioning key installation groove 313 is provided on the front end surface of the shaft core, and the positioning key 313 is assembled in the corresponding positioning key installation groove and fastened in the corresponding positioning key installation groove by a bolt 3131. In this way, the installation and fixation of the positioning key 313 can be facilitated.

[0072] Typically, at least two positioning keys 313 are circumferentially spaced apart on the front end surface of the shaft core. Typically, when the positioning key 313 is matched with the corresponding key slot 82 on the handle 8, the left and right side walls and the inner side wall of the positioning key 313 are tightly matched with the corresponding matching surfaces in the corresponding key slot 82 respectively.

[0073] Since a positioning key 313 protruding from the front end surface of the shaft core is provided on the front end surface of the shaft core, when the tool handle assembly structure 31 is tightly fitted with the tool handle 8, the positioning key 313 is adapted to the corresponding keyway 82 on the tool handle 8. Therefore, the positioning key 313 can increase the torque transmission between the tool handle 8 and the machine tool spindle, and prevent the tool handle 8 and the shaft core 3 from rotating relative to each other.

[0074] The above describes the relevant contents of the embodiments of the present disclosure. Based on these descriptions, a person of ordinary skill in the art will be able to implement the embodiments of the present disclosure. Based on the above contents of this specification, all other embodiments obtained by a person of ordinary skill in the art without making any creative efforts should fall within the scope of patent protection.

Claims

1. A machine tool spindle, comprising: Spindle body; A spindle motor, comprising a motor stator and a motor rotor, wherein the motor stator is fixed in the spindle body, and the motor rotor is adapted to the motor stator; A shaft core, the shaft core is rotatably mounted in the spindle body through a front bearing system and a rear bearing system and rotates with the motor rotor, and a tool handle assembly structure is provided at the front end of the shaft core; A front bearing system, comprising a front bearing seat and a front bearing, wherein the front bearing seat is disposed at the front end of the spindle body, and the front bearing is mounted in the front bearing seat and rotatably supports the front portion of the shaft core; A rear bearing system, comprising a rear bearing seat and a rear bearing, wherein the rear bearing seat is disposed at the rear end of the spindle body, and the rear bearing is mounted in the rear bearing seat and rotatably supports the rear portion of the shaft core; a knife handle locking and releasing mechanism, the knife handle locking and releasing mechanism comprising an actuator and a drive mechanism, wherein when the drive mechanism operates in a first driving mode, the actuator can lock the knife handle so that the knife handle and the knife handle assembly structure are tightly fitted, and when the drive mechanism operates in a second driving mode, the actuator can release the knife handle so that the knife handle can be detached from the knife handle assembly structure; The tool holder locking and releasing mechanism, the actuator comprises a pull rod and a tool holder clamping tensioning and closing component, the tool holder clamping tensioning and closing component is installed at the front end of the pull rod to form a tool holder clamping mechanism, the tool holder clamping mechanism is sleeved in the shaft core, and the driving mechanism comprises a pull rod forward pushing mechanism and a pull rod backward resetting mechanism, the pull rod forward pushing mechanism is installed at the rear end of the spindle body and has a pushing component corresponding to the rear end of the pull rod and a pushing driving device for driving the pushing component to move forward, the pull rod backward resetting mechanism has an elastic component installed between the shaft core and the pull rod and continuously applying an elastic force to the pull rod to move backward, when the driving mechanism operates in a first driving mode, the pushing component moves backward and disengages from the pull rod and the pull rod moves axially from front to back due to the elastic force of the elastic component, when the driving mechanism operates in a second driving mode, the pushing component moves forward and pushes the pull rod forward and the pull rod overcomes the elastic force of the elastic component and moves axially from back to front; Its characteristics are: The pull rod is provided with a pull rod rear boss at a position near the rear end of the shaft core, and the outer peripheral surface of the pull rod rear boss is slidably fitted with the inner wall of the shaft core through a sliding fit structure; the sliding fit structure includes a wear-resistant ring mounted on the pull rod rear boss, and the outer peripheral surface of the wear-resistant ring is slidably fitted with the inner wall of the shaft core.

2. A machine tool spindle according to claim 1, characterized in that: A first annular groove is provided on the outer peripheral surface of the rear boss of the pull rod, and at least two second annular grooves are provided at intervals at the bottom of the first annular groove. Washers made of elastic material are respectively installed in the at least two second annular grooves. The wear-resistant ring is installed in the first annular groove and is elastically squeezed by the washers in the radial direction to fit tightly against the inner wall of the shaft core.

3. A machine tool spindle according to claim 2, characterized in that: The gasket is an elastic sealing ring or is made of rubber material.

4. A machine tool spindle according to claim 1, characterized in that: The rear end of the elastic component acts on the front end surface of the rear shoulder of the pull rod to continuously apply elastic force to the pull rod to move backward.

5. The machine tool spindle according to claim 1, wherein: A rotation-stop structure for preventing relative rotation between the pull rod and the shaft core is provided between the tool handle locking and releasing mechanism and the shaft core, the rotation-stop structure comprises a shaft core rear end cover installed at the rear end of the shaft core and a rotation-stop head provided on the rear section of the pull rod and inserted into the shaft core rear end cover, the shape of the outer circumferential wall of the rotation-stop head is adapted to the shape of the inner circumferential wall of the shaft core rear end cover and circumferentially fixed therebetween, the rear boss of the pull rod is located in front of the shaft core rear end cover and is separated from the shaft core rear end cover by a certain distance.

6. A machine tool spindle according to claim 5, characterized in that: The rear end cover of the shaft core is composed of an outer ring part and an inner ring part that are detachably connected together, and the inner peripheral wall of the rear end cover of the shaft core is formed by the inner hole of the inner ring part.

7. A machine tool spindle according to claim 6, characterized in that: The rear end of the shaft core is equipped with a shaft core rotation displacement detection mechanism for detecting the rotation angle of the shaft core. The shaft core rotation displacement detection mechanism includes a measuring gear installed on the shaft core and rotating synchronously with the shaft core, and a sensor for detecting the teeth of the measuring gear to obtain the rotation displacement information of the shaft core; the outer ring member also serves as the measuring gear.

8. A machine tool spindle according to claim 6, characterized in that: The outer ring member and the inner ring member are detachably connected via bolts.

9. A machine tool spindle according to claim 8, characterized in that: The bolts pass through the outer ring member and the inner ring member in the axial direction to detachably connect the outer ring member and the inner ring member.

10. The machine tool spindle according to claim 5, characterized in that: The outer peripheral wall of the stop head is provided with a stop plane of the outer peripheral wall of the stop head, and the inner peripheral wall of the end cover at the rear end of the shaft core is provided with a stop plane of the inner peripheral wall of the end cover. The stop plane of the outer peripheral wall of the stop head matches the corresponding stop plane of the inner peripheral wall of the end cover.

Images