Rear motor spindle of numerically controlled lathe

Abstract

The utility model discloses a rear motor main shaft of a numerical control lathe, which relates to the technical field of processing machine tools and comprises a rotor component, a machine body component, a front bearing component, a rear bearing component, a front end cover, a rear end cover, a motor shell component, an encoder component and an oil cylinder flange. The rigidity, machining precision and efficiency of the spindle are improved, and the high-precision and high-rotating-speed requirements are met. And the oil cylinder flange and the rotor seat are designed in a split manner, so that the mounting and dismounting convenience and the customizable degree are improved. The stator assembly is made of high-quality magnetic materials, the magnetic circuit design is optimized, and heating is reduced. The motor shell assembly is made of efficient heat dissipation materials and designed, and effective heat dissipation is ensured. A traditional motor stator assembly is difficult to maintain through integrated glue pouring, the stator assembly and the motor shell are detachable in a split mode, the problems of complex installation and later maintenance are solved, and environmental pollution and harm to human bodies are reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of machining machine tools, in particular to a rear-mounted motor spindle for a numerically controlled lathe. Background Art

[0002] Lathes, as an important type of machine tool, are widely used to machine a wide variety of parts. As a core component of a lathe, the performance of the electric spindle is crucial to its machining accuracy, speed, and stability. Traditional lathe spindles utilize mechanical transmissions such as belts or gears. This method is not only inefficient but also prone to errors and vibration, compromising the precision and quality of machined parts. Traditional spindles, which rely primarily on gears or belts for connection, present unavoidable structural design issues. For example, gear transmission on the spindle can achieve very precise transmission ratios, high speeds, and high rigidity. However, this design also results in a large spindle structure, which occupies a significant amount of machine tool space. Furthermore, over time, gear transmissions can develop a range of issues, including gear wear due to fatigue failure, pitting corrosion on the gear surfaces caused by prolonged exposure to oil and high temperatures, and surface wear that creates gaps between the gears.

[0003] The existing rear-mounted motor manufacturing process is relatively complex. The motor housing is cast from molten aluminum, the stator assembly is embedded within it, and then the mold is filled with glue. After the glue is poured, the stator assembly becomes completely integrated with the motor housing and cannot be separated normally. After years of use, if an internal abnormality occurs in the motor and requires maintenance, it will be extremely difficult and significantly increase the cost of use. Furthermore, the glue filling wraps the entire stator assembly, occupying a large internal volume of the motor, reducing the motor's heat dissipation efficiency and increasing the load on the motor.

[0004] The existing rotor assembly and cylinder flange of the motor's rear spindle are an integrated design. The magnetic ring must be assembled before the stator assembly. Because the rotor assembly contains powerful permanent magnets, installation and removal are difficult and prone to contamination during assembly. After the rotor and stator assemblies are assembled, the magnetic ring cannot be removed, making it impossible to adjust the coaxiality of the magnetic ring with the shaft core, and the degree of customization is low. Utility Model Content

[0005] The technical problem to be solved by the utility model is to provide a lathe spindle with a motor at the rear, in view of the above-mentioned deficiencies in the prior art, and in particular to a lathe spindle with a motor at the rear, which has strong radial bearing capacity, high precision and high torque.

[0006] To achieve the above objectives, the present invention is implemented through the following technical solutions: A CNC lathe rear motor spindle, comprising:

[0007] A rotor assembly is rotatably disposed in the machine body along its central axis;

[0008] The body component is a hollow structure used to support and accommodate other components;

[0009] The front bearing assembly and the rear bearing assembly are respectively arranged at the front and rear parts of the machine body and are used to support the rotor assembly;

[0010] The front cover and the rear cover are respectively arranged at the front and rear ends of the machine body and are used to close the machine body;

[0011] The motor housing assembly is installed at the rear end of the machine body and is used to accommodate the stator assembly;

[0012] The stator assembly cooperates with the rotor assembly to generate electromagnetic force;

[0013] an encoder assembly for detecting the rotational position and speed of the rotor assembly;

[0014] The oil cylinder flange is provided at one end of the rotor assembly and is used for connecting the oil cylinder.

[0015] Furthermore, the rotor assembly includes a shaft core, a rotor seat locking nut, a rotor seat and a rotor magnetic part. One end of the shaft core passes through the front bearing assembly, the rear bearing assembly and the motor housing assembly and extends into the cylinder flange, and the other end extends out to be connected to the machine tool chuck for transmission. The rotor magnetic part is installed on the rotor seat, and the rotor seat is arranged at the rear end of the shaft core. The rotor seat and the shaft core are both provided with symmetrical flat keyways. The shaft core is connected to the rotor seat by embedding a flat key. The rotor seat locking nut is fitted with the end face of the rotor seat and is tightened through the external thread at the rear end of the shaft core to achieve the purpose of tightening the rotor seat.

[0016] Furthermore, the body assembly includes a body, and a front bearing assembly and a rear bearing assembly are provided in the through holes on the upper and lower parts of the body, a stator assembly is provided in the through hole in the middle part of the motor housing assembly, and the rotor assembly is axially inserted into the inner cavity of the stator assembly and supported by the front bearing assembly and the rear bearing assembly. The front end cover is provided under the body and fixed by screws, the rear end cover is installed on the rear end mounting cavity of the body, the motor housing assembly is installed on the rear end flange of the body, and the fastening ring is fastened to the front end of the body by screws. When the spindle is installed in the spindle box of the machine tool, the rear end uses screws to pass through the through holes of the body flange to lock the body, and the front end is fixed by the fastening ring to ensure the stability of the spindle during use.

[0017] Furthermore, the stator assembly includes a stator outer shell for circulating coolant, a ring-shaped stator core and a stator winding group respectively arranged at both ends of the stator core. The stator core is arranged on the outside of the rotor magnetic part. The stator core is formed by stacking and pressing a plurality of silicon steel sheets of equal height. The stator winding group is wound by a plurality of enameled wires of equal diameter. A thermistor is arranged in the stator winding group. The stator winding group is electrically connected to a three-phase AC power supply through a power cord. The rotor magnetic part is evenly inlaid with permanent magnets. The stator outer shell is arranged on the outside of the stator core. The outer circle of the stator outer shell is provided with a coolant water channel groove, which can quickly cool the temperature of the stator during operation.

[0018] Furthermore, a cooling water connector is provided on one side of the motor housing assembly, and a power line plug and an encoding line connector are provided on the other side.

[0019] Furthermore, the front bearing assembly includes a plurality of first and second front high-speed angular contact bearings stacked in a vertical direction and sleeved on the front end of the shaft core, as well as a front double-row cylindrical roller bearing, a front bearing spacer ring A and a front bearing spacer ring B, and is pre-tightened by a front bearing locking nut;

[0020] The rear bearing assembly includes a rear bearing spacer ring C, a rear double-row roller bearing, a rear bearing spacer ring D and a rear bearing locking nut, which are installed respectively. The front bearing locking nut and the rear bearing locking nut are both provided with a number of threaded holes, and a number of threaded holes are provided with organic screwdrivers for tightening and preventing loosening. The front double-row cylindrical roller bearing and the rear double-row roller bearing are slightly adjusted in clearance through the tapered inner hole. The taper of the spindle inner hole is 1:12. The inner ring is moved axially to cause it to expand and deform radially, so as to adjust the radial rigidity and preload. The front bearing spacer ring A, the front bearing spacer ring B, the rear bearing spacer ring C and the rear bearing spacer ring D are all designed with water retaining rings and labyrinth dustproof structures to prevent the dust and cutting particles generated during the turning process from damaging and polluting the inside of the spindle.

[0021] Furthermore, the front end cover and the rear end cover are provided with a labyrinth groove, which cooperates with the labyrinth grooves of the front bearing spacer ring A and the rear bearing spacer ring D to form a labyrinth structure. The rear end cover is installed on the rear end mounting cavity of the body assembly, and the front end cover is provided with an annular confluence groove and several discharge holes.

[0022] Furthermore, the motor housing assembly can be detachably mounted on the mounting cavity at the rear end of the body assembly and fastened by screws. The motor housing assembly includes a motor housing and several cooling medium connectors. The motor housing is cast as one piece and has a cooling medium flow channel designed inside. After being assembled with the stator assembly, a complete circulating water cooling system is formed. Several cooling medium connector screw holes, power cord interfaces, encoder line interfaces and encoder mounting positions are set on the outside of the motor housing.

[0023] Furthermore, the encoder assembly includes a hollow magnetic ring arranged on the outer circle of the rotor seat, an encoder reader arranged on the motor housing, and an encoder reader bracket. The hollow magnetic ring is provided with a number of countersunk holes for fixation and the outer circle of the hollow magnetic ring is provided with a zero point. The cylinder flange at the rear end of the hollow magnetic ring is a detachable design. After the cylinder flange is removed, the hollow magnetic ring can be debugged at any time according to different client needs, which also facilitates subsequent maintenance work. The encoder reader is fastened to the encoder reader bracket by screws. The encoder reader bracket is provided with a number of waist-shaped holes for adjusting the sensing distance between the encoder reader and the hollow magnetic ring during assembly.

[0024] Furthermore, the cylinder flange is provided with a threaded hole for connecting to the cylinder, the shaft core is provided with a shaft core inner hole through which a connecting rod can pass, and the cylinder flange is locked to the rear end of the shaft core by a locking nut, and the rotor seat is locked at the same time.

[0025] The utility model provides a rear-mounted motor spindle for a CNC lathe. Compared with the prior art, it has the following beneficial effects:

[0026] 1. The front bearing assembly adopts a new arrangement structure and uses large-size grease-lubricated angular contact bearings and double-row cylindrical roller bearings, which improves the axial and radial rigidity of the spindle, as well as the processing accuracy and efficiency, and meets the current market demand for high-precision and high-speed spindle applications;

[0027] 2. The cylinder flange and rotor seat are designed to be split. After removing the cylinder flange, the encoder assembly can be debugged and replaced according to the requirements of different machine tools. This greatly improves the convenience of installation and disassembly and increases the degree of customization, solving the problem of low versatility in the spindle market.

[0028] 3. When the motor is working, the high-speed rotation of the main shaft will generate a large amount of heat energy. Therefore, this utility model has very strict requirements on the structural design of the stator component cooling system and thermal stability. By using high-quality magnetic materials with high magnetic permeability and low remanence ratio, hysteresis and eddy current losses are reduced. Electromagnetic field simulation software is used to analyze the motor magnetic circuit and optimize the geometric dimensions of the magnetic circuit and the layout of the magnetic materials. Silicon steel sheets of appropriate thickness and material are selected and coated to reduce contact resistance.

[0029] 4. The rational design of the magnetic circuit of the rotor assembly makes it generate very low heat. The motor housing assembly adopts high-efficiency heat dissipation materials and design, and the outer shell is made of aluminum heat dissipation plate to improve heat exchange efficiency;

[0030] 5. The cooling system is designed with a reasonable circulation path to ensure that the cooling medium effectively absorbs and removes heat. The stator assembly of a traditional motor is embedded in the motor housing and then molded and glued together. If the coil or other components subsequently malfunction, they need to be destroyed and glued, making maintenance difficult or even directly discarding the motor.

[0031] 6. The stator assembly and the motor housing are designed as a split and detachable structure. The coil and the water channel jacket of the stator assembly are designed as one. Sealing rings are provided at the front and back, and a positioning mechanism is designed on the motor housing. This not only solves the problems of cumbersome early installation and difficult later maintenance caused by the integrated design, but also reduces environmental pollution and harm to the human body caused by casting glue. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is a cross-sectional view of the overall internal structure of the main shaft of a lathe with a rear motor according to the present invention.

[0033] Figure 2 This is a structural schematic diagram of the spindle pre-tightening structure of a lathe with a rear motor according to the present invention.

[0034] Figure 3 This is a schematic structural diagram of the motor-rear-mounted lathe spindle rotor assembly of the utility model.

[0035] Figure 4 This is a schematic diagram of the structure of the exterior of the main shaft of a lathe with a rear-mounted motor according to the present invention.

[0036] Figure 5 This is a schematic diagram of the structure of the motor-rear-mounted lathe spindle motor of the utility model.

[0037] In the figure: 1. Rotor assembly; 2. Body assembly; 3. Front bearing assembly; 4. Rear bearing assembly; 5. Front end cover; 6. Rear end cover; 7. Motor housing assembly; 8. Stator assembly; 9. Encoder assembly; 10. Cylinder flange; 11. Shaft core; 12. Rotor seat locking nut; 13. Rotor seat; 14. Rotor magnetic parts; 15. Body; 16. Fastening ring; 17. Front bearing locking nut; 18. Front bearing spacer ring B; 19. First front high-speed angular contact bearing; 20. Second front high-speed Angular contact bearing; 21. Front double-row cylindrical roller bearing; 22. Front bearing spacer A; 23. Rear bearing locking nut; 24. Rear bearing spacer D; 25. Rear double-row roller bearing; 26. Rear bearing spacer C; 27. Cooling medium connector; 28. Motor housing; 29. ​​Stator winding assembly; 30. Stator core; 31. Stator jacket; 32. Magnetic ring; 33. Encoder reader; 34. Encoder reader bracket; 35. Flat key; 36. Power cord connector; 37. Encoder line interface. DETAILED DESCRIPTION

[0038] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0039] See also Figure 1-5 The utility model provides a technical solution: a rear-mounted motor spindle of a CNC lathe, comprising a cylinder flange 10, a body assembly 2, a front bearing assembly 3, a rear bearing assembly 4, a front end cover 5, a rear end cover 6 and a motor housing assembly 7, a stator assembly 8, and an encoder assembly 9, which are respectively installed on a rotor assembly 1. The cylinder flange 10, the motor housing assembly 7 and the encoder assembly 9 are sequentially installed on one side of the body assembly 2, and the front end cover 5 and the fastening ring 16 are sequentially installed on the other side of the body assembly 2. The rotor assembly 1, the front bearing assembly 3, and the rear bearing assembly 4 are respectively installed in the body 15. The bearing assembly consists of a front bearing assembly 3 and a rear bearing assembly 4, which are respectively arranged at both ends of the shaft core 11. The stator assembly 8 is sleeved on the outside of the rotor assembly 1. One end of the rotor assembly 1 is passed through the motor housing assembly 7 and is drivably connected to the cylinder flange 10. The other end is a tapered inner hole and a threaded hole designed for connecting the chuck.

[0040] Among them, the rotor assembly 1 includes a shaft core 11, a rotor magnetic part 14, a rotor seat locking nut 12 and a rotor seat 13. The rotor assembly 1 can be rotatably arranged in the body 15 around the central axis. One end of the shaft core 11 passes through the rear bearing assembly 4 and the motor housing assembly 7 and extends into the cylinder flange 10, and the other end passes through the front bearing assembly 3. The rotor seat 13 is installed at the rear position of the shaft core 11. The rotor magnetic part 14 is arranged on the outer circle of the rotor seat 13. The rotor magnetic part 14 is evenly provided with a number of inlay grooves and is evenly inlaid with a number of permanent magnets. The rotor seat 13 is locked to the rear end of the shaft core 11 through the rotor seat locking nut 12, and the rotor assembly is locked.

[0041] Among them, the stator assembly 8 includes a stator jacket 31 provided with a circulating cooling water tank, a ring-shaped stator core 30 and a stator winding group 29 respectively arranged at the upper and lower ends of the stator core 30. The stator core 30 is arranged on the outside of the rotor magnetic part 14. The stator core 30 is formed by stacking and pressing a plurality of silicon steel sheets of equal height. The stator winding group 29 is wound by a plurality of enameled wires of equal diameter. A thermistor is provided in the stator winding group 29. The stator winding group 29 is electrically connected to the three-phase AC power supply through a power cord. The stator jacket 31 is sleeved on the outside of the stator core 30. The outer circle of the stator jacket 31 is provided with a coolant water channel groove, which can quickly cool the temperature of the stator during operation. The upper and lower ends of the stator jacket are provided with a plurality of sealing ring grooves to prevent the loss of coolant.

[0042] Among them, the front bearing assembly 3 is composed of a plurality of first front high-speed angular contact bearings 19, second front high-speed angular contact bearings 20, front double-row cylindrical roller bearings 21, front bearing spacer rings A22 and front bearing spacer rings B18 stacked in the vertical direction and sleeved on the front end of the shaft core 11, and pre-tightened by the front bearing locking nut 17. The front end cover 5 is close to the outer ring end face of the front double-row cylindrical roller bearing 21, the front bearing spacer ring A22 is supported on the flange end face of the shaft core 11 and supports the inner ring of the front double-row cylindrical roller bearing 21, and the front bearing spacer ring B18 is close to the inner ring end face of the first front high-speed angular contact bearing 19 and then pre-tightened by the front bearing locking nut 17. The rear bearing assembly 4 includes a rear bearing spacer C26, a rear double-row roller bearing 25, a rear bearing spacer D24 and a rear bearing locking nut 23, which are installed respectively. The rear bearing spacer C is sleeved on the rear end shoulder of the shaft core 11 and supports the inner ring of the rear double-row roller bearing 25. The outer ring of the rear double-row roller bearing 25 is supported on the inner end face of the rear end cavity of the body. The rear end cover is installed in the installation cavity of the body and presses the outer ring of the rear double-row roller bearing 25. The rear bearing spacer D24 is stacked on the inner ring of the rear double-row roller bearing 25 and is pre-tightened by the rear bearing locking nut 23. The front bearing locking nut 17 and the rear bearing locking nut 23 are both provided with a number of threaded holes, and the several threaded holes are provided with machine screws for tightening and preventing loosening. The dynamic balance of the main shaft can also be adjusted by the machine screws. The front double-row cylindrical roller bearing 21 and the rear double-row roller bearing 25 feature a tapered inner bore for fine-tuning of clearance. The spindle bore taper is 1:12. Axial movement of the inner ring causes radial expansion and deformation, adjusting radial rigidity and preload. The front and rear bearing spacers A22 and B18, as well as C26 and D24, feature water retaining rings and a labyrinth dustproof structure to prevent dust and cutting particles generated during turning from damaging and contaminating the spindle interior.

[0043] Among them, the front end cover 5 is provided with a receiving groove and a leakage liquid discharge hole, the receiving groove is connected to the shaft core drainage groove, and the rear end cover 6 is installed on the rear end installation cavity of the body 15. The front end cover 5 and the rear end cover 6 are both provided with a number of sealing ring grooves and maze grooves and cooperate with the front bearing spacer ring A22 and the rear bearing spacer ring D24 to form a complete maze structure.

[0044] The motor housing assembly 7 is mounted in the mounting cavity at the rear end of the machine body 15 and secured with screws. The motor housing assembly comprises the motor housing 28 and several cooling medium connectors 27, which include several O-rings and set screws. The motor housing 28 is a one-piece casting with internal cooling medium flow channels. When assembled with the stator housing 31, it forms a complete circulating water cooling system. The exterior of the housing is equipped with several cooling medium connector threads, a power cord connector 36, an encoder line interface 37, and an encoder mounting area. The stator assembly power cord and thermistor signal lines are connected to an external drive or machine tool through the line interface provided in the motor housing 28.

[0045] Among them, the cylinder flange 10 is provided with a threaded hole for connecting the driving cylinder, the shaft core 11 is provided with an inner hole of the shaft core through which the pull rod can pass, the cylinder flange 10 is sleeved on the boss of the rotor seat 13 and locked by several screws, and the rotor seat 13 is locked by the rotor seat locking nut 12.

[0046] Among them, the encoder assembly 9 includes a hollow magnetic ring 32 and an encoder head bracket 34 and an encoder head 33 arranged on the motor housing 28. The hollow magnetic ring 32 is sleeved on the boss of the rotor seat 13, and the screws lock the magnetic ring on the rotor seat 13 through several countersunk holes on the end face. The encoder head 33 is tightly locked on the encoder head bracket 34. The sensing distance between the encoder head 33 and the hollow magnetic ring 32 is adjusted by several waist-shaped grooves set on the encoder head bracket 34.

[0047] The present invention relates to a lathe spindle with a rear motor having a strong radial load-bearing capacity and high precision and high torque. The front end cover 5 is mounted on the front end of the machine body 15. The front bearing spacer A22 is mounted on the rear end face of the flying disc of the shaft core 11 by being sleeved. The front bearing spacer A22 and the front bearing spacer B18 form a structure with multiple bends and interlocking rings, but do not contact each other with a certain amount of gap. At the same time, water chutes are provided on the inner side of the front bearing spacer A22 and the outer side of the flying disc of the shaft core 11. During operation, foreign matter such as debris and cutting chips from the machine body will be blocked by the water chutes of the shaft core 11 under the high-speed rotation of the rotor assembly. A small amount of cutting fluid or sewage will be blocked by the labyrinth groove formed by the front bearing spacer A22 and the front bearing spacer B18 and the water chutes inside the front bearing spacer A22. Finally, it will flow along the annular confluence groove provided on the front bearing spacer A22 and be sprayed out through the plurality of drainage holes on the lower side of the front bearing spacer A22 to protect the normal operation of the spindle.

[0048] Next, coolant is connected to the cooling medium connector 27 and enters the coolant circulation channel that interconnects the motor housing 28 and stator jacket 31. Multiple sealing rings are installed at the upper and lower ends of the stator jacket 31 to form a closed cooling loop. After circulating once within the cooling water channel, the coolant flows through the coolant outlet connector and into the refrigerator. Because the coolant repeatedly circulates around the outer wall of the stator jacket 31, its reciprocating motion effectively removes most of the heat generated by the stator and coils, ensuring stable and continuous operation of the spindle motor at low temperatures.

[0049] During operation, the actual temperature of the spindle can be monitored in real time through the temperature sensor installed in the stator, thereby effectively protecting the normal operation of the electric spindle. The entire electric spindle adopts an adjustable dynamic balance design. In addition to adjusting the balance amount during assembly by the adjusting nuts 17 and 23 at the front and rear ends, the dynamic balance amount can also be adjusted after the spindle is assembled through the multiple balance holes set in the cylinder flange 10 and the front end of the shaft core 11.

[0050] The present invention replaces the pulley at the rear end of the spindle of a traditional mechanical lathe with a motor assembly of a more compact design. The motor assembly includes a motor housing assembly 7, a stator assembly 8, and a rotor assembly 1. The rotor assembly 1 is installed at the rear end of the shaft core 11. The stator assembly 8 is installed at the rear end of the machine body 15 corresponding to the rotor assembly 1. The shaft core 11 rotates at high speed under the drive of the rotor assembly 1, thereby forming a spindle structure with the motor at the rear. Designing the motor at the rear end of the spindle can not only provide torque for the spindle, but also solve the problem of uneven force on the rear end of the spindle due to belt pulling, which affects the spindle rotation accuracy. At the same time, the versatility of the spindle is maintained. On the basis of the main body assembly 2, the front bearing assembly 3, the rear bearing assembly 4, the front cover 5, and the rear cover 6 at the front end of the spindle remaining unchanged, it can be directly installed in the spindle of an existing mechanical spindle. It can be directly replaced without unnecessary operating steps, which greatly solves the problem of low versatility in the spindle market. On this basis, the motor assembly was further optimized, with the rotor assembly 1 and cylinder flange 10 designed as separate components. Cylinder flange 10 is positioned via a boss on rotor base 13, avoiding the effects of coaxiality differences caused by the split structure. Several countersunk holes are provided on the flange end face to secure it to the rotor base. Below cylinder flange 10 is a hollow magnetic ring 32. To remove or replace the magnetic ring, simply loosen the cylinder flange screws. This results in a simpler rear-end rotor structure and more convenient and efficient commissioning.

[0051] The present invention eliminates the traditional motor mold filling method of glue pouring, thereby designing a new type of combined fixing structure. Several sealing structures and positioning structures are set on the stator shell 31 in the stator assembly 8, wherein the stator core 30 and the stator shell 31 are designed to be assembled into one and then installed in the motor housing 28. The sealing ring on the stator shell 31 can prevent coolant leakage and prevent foreign matter or sewage from entering the motor coolant flow channel. It also has a certain degree of centering effect. The positioning structure set in the motor housing 28 locks the position so that the stator assembly will not move. Designing the motor housing 28 and the stator assembly 8 to be detachable greatly reduces the complexity of motor production, facilitates the maintenance of the spindle in the later stage, and saves spindle repair costs.

[0052] During operation, the present invention activates the motor via an external driver. The motor rotor uses permanent magnets to generate a fixed magnetic field. When the stator current generates a rotating magnetic field, it interacts with the magnetic field of the permanent magnets to produce torque. Based on the instructions from the machine tool system, a frequency converter controls the motor's start / stop, acceleration / deceleration, and direction of rotation. The spindle speed is monitored via an encoder, which feeds information back to the frequency converter. Cutting can begin when the spindle reaches the set speed. During machining, the machine tool system can also adjust the spindle speed according to processing requirements. Driving the spindle directly from the motor provides improved rigidity, higher precision, and smoother machining performance, while reducing kinetic energy loss and errors caused by vibration due to belt drives.

[0053] Those skilled in the art should understand that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, 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.

[0054] The above embodiments merely illustrate several implementations of the present invention. While the descriptions are relatively specific and detailed, they should not be construed as limiting the scope of the utility model patent. It should be noted that a person skilled in the art would be able to make numerous variations and improvements without departing from the concept of the present invention, and these variations and improvements fall within the scope of protection of the present invention. Therefore, the scope of protection of the present utility model patent shall be determined by the appended claims.

Claims

1. A CNC lathe rear motor spindle, characterized in that: include: A rotor assembly (1) is rotatably arranged in the machine body with respect to a central axis; The body component (2) is a hollow structure used to support and accommodate other components; A front bearing assembly (3) and a rear bearing assembly (4) are respectively arranged at the front and rear parts of the machine body and are used to support the rotor assembly (1); A front cover (5) and a rear cover (6) are respectively provided at the front and rear ends of the machine body and are used to close the machine body; A motor housing assembly (7) is mounted at the rear end of the machine body and is used to accommodate the stator assembly (8); The stator assembly (8) cooperates with the rotor assembly (1) to generate electromagnetic force; An encoder assembly (9) for detecting the rotational position and speed of the rotor assembly (1); The oil cylinder flange (10) is provided at one end of the rotor assembly (1) and is used for connecting to the oil cylinder.

2. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The rotor assembly (1) includes a shaft core (11), a rotor seat locking nut (12), a rotor seat (13) and a rotor magnetic member (14). One end of the shaft core (11) passes through the front bearing assembly (3), the rear bearing assembly (4) and the motor housing assembly (7) and extends into the cylinder flange (10), while the other end extends out to be connected to the machine tool chuck transmission. The rotor magnetic member (14) is mounted on the rotor seat (13). The rotor seat (13) is arranged at the rear end of the shaft core (11). The rotor seat (13) and the shaft core (11) are both provided with symmetrical flat keyways. The shaft core (11) is connected to the rotor seat (13) by embedding a flat key (35). The rotor seat locking nut (12) is fitted with the end face of the rotor seat (13) and is tightened through the outer thread at the rear end of the shaft core (11) to achieve the purpose of fastening the rotor seat.

3. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The machine body assembly (2) includes a machine body (15), wherein a front bearing assembly (3) and a rear bearing assembly (4) are provided in the through holes at the upper and lower parts of the machine body (15), a stator assembly (8) is provided in the through hole at the middle part of the motor housing assembly (7), a rotor assembly (1) is axially arranged in the inner cavity of the stator assembly (8), and is supported by the front bearing assembly (3) and the rear bearing assembly (4), a front end cover (5) is arranged below the machine body (15) and fixed by screws, a rear end cover (6) is mounted on the rear end mounting cavity of the machine body (15), the motor housing assembly (7) is mounted on the rear end flange of the machine body (15), a fastening ring (16) is fastened to the front end of the machine body by screws, and when the spindle is mounted on the spindle box of the machine tool, the rear end uses screws to pass through the through holes of the flange of the machine body (15) to lock the machine body (15), and at the same time, the front end is fixed by the fastening ring (16) to ensure the stability of the spindle when in use.

4. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The stator assembly (8) includes a stator jacket (31) for circulating coolant, a stator core (30) in an annular shape, and stator winding groups (29) respectively arranged at both ends of the stator core (30), the stator core (30) is arranged on the outside of the rotor magnetic part (14), the stator core (30) is formed by stacking and pressing a plurality of silicon steel sheets of equal height, the stator winding group (29) is formed by winding a plurality of enameled wires of equal diameter, a thermistor is arranged in the stator winding group (29), the stator winding group (29) is electrically connected to a three-phase AC power supply through a power line, the rotor magnetic part (14) is uniformly inlaid with permanent magnets, the stator jacket (31) is sleeved on the outside of the stator core (30), and the outer circle of the stator jacket (31) is provided with a coolant water channel groove, which can quickly cool the temperature of the stator when it is working.

5. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The motor housing assembly (7) is provided with a cooling water connector on one side, and a power line plug and a coding line connector on the other side.

6. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The front bearing assembly (3) includes a plurality of first front high-speed angular contact bearings (19) and second front high-speed angular contact bearings (20) stacked in a vertical direction and sleeved on the front end of the shaft core (11), as well as a front double-row cylindrical roller bearing (21), a front bearing spacer ring A (22) and a front bearing spacer ring B (18), and is pre-tightened by a front bearing locking nut (17); The rear bearing assembly (4) includes a rear bearing spacer ring C (26), a rear double-row roller bearing (25), a rear bearing spacer ring D (24) and a rear bearing locking nut (23) which are respectively installed. The front bearing locking nut (17) and the rear bearing locking nut (23) are both provided with a plurality of threaded holes, and a plurality of threaded holes are provided with organic screws for tightening and preventing loosening. The front double-row cylindrical roller bearing (21) and the rear double-row roller bearing (25) are slightly adjusted in clearance through the conical inner hole. The taper of the spindle inner hole is 1:

12. The inner ring is moved axially to cause it to expand and deform radially, thereby adjusting the radial rigidity and preload. The front bearing spacer ring A (22), the front bearing spacer ring B (18), the rear bearing spacer ring C (26) and the rear bearing spacer ring D (24) are all designed with a water retaining ring position and a labyrinth dustproof structure to prevent the dust and cutting particles generated during the turning process from damaging and polluting the inside of the spindle.

7. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The front end cover (5) and the rear end cover (6) are provided with a labyrinth groove, and the labyrinth groove cooperates with the labyrinth grooves of the front bearing spacer ring A (22) and the rear bearing spacer ring D (24) to form a labyrinth structure. The rear end cover (6) is installed on the rear end mounting cavity of the body assembly (2). The front end cover (5) is provided with an annular confluence groove and a plurality of discharge holes.

8. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The motor housing assembly (7) is detachably mounted on the mounting cavity at the rear end of the body assembly (2) and is fastened by screws. The motor housing assembly (7) includes a motor housing (28) and a plurality of cooling medium connectors (27). The motor housing (28) is integrally cast and has a cooling medium flow channel designed therein. After being assembled with the stator assembly (8), a complete circulating water cooling system is formed. The outside of the motor housing (28) is provided with a plurality of cooling medium connector screws, a power line interface, an encoder line interface, and an encoder mounting position.

9. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The encoder assembly (9) includes a hollow magnetic ring (32) arranged on the outer circle of the rotor seat, an encoder reader (33) arranged on the motor housing (28), and an encoder reader bracket (34). The hollow magnetic ring (32) is provided with a plurality of sink holes for fixing and the outer circle of the hollow magnetic ring (32) is provided with a zero point. The rear end cylinder flange (10) of the hollow magnetic ring (32) is a detachable design. After the cylinder flange is removed, the hollow magnetic ring (32) can be debugged at any time according to different client requirements, which also facilitates subsequent maintenance work. The encoder reader (33) is fastened to the encoder reader bracket (34) by screws. The encoder reader bracket (34) is provided with a plurality of waist-shaped holes for adjusting the sensing distance between the encoder reader (33) and the hollow magnetic ring (32) during assembly.

10. The rear motor spindle of a CNC lathe according to claim 1, characterized in that: The oil cylinder flange (10) is provided with a threaded hole for connecting to the oil cylinder, and the shaft core (11) is provided with a shaft core inner hole through which a connecting rod can pass, and the oil cylinder flange (10) is locked to the rear end of the shaft core by a locking nut, and the rotor seat (13) is locked at the same time.

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