Direct-drive drilling and milling machine having outer rotor electric motor

Abstract

Disclosed in the present invention is a direct-drive drilling and milling machine having an outer rotor electric motor, which uses an outer rotor brushless electric motor or an outer rotor brushless electric motor assembly as a driving power source to directly drive spindle movement of the drilling and milling machine by means of a key connection with clearance fit, said two power sources both having stepless speed regulation and forward and reverse rotation setting functions. The present invention enables drilling, tapping and milling to be integrated together, so that the number of parts is significantly reduced; thus, while environmental protection, high efficiency and energy conservation are realized, the objectives of easy manufacturing, convenient operation, visualization, high precision, low usage cost, and a long service life are also achieved.

Description

A direct-drive drilling and milling machine with an outer rotor motor Technical Field

[0001] The invention belongs to the field of mechanical processing equipment, and in particular relates to an outer rotor motor direct-drive drilling and milling machine. Background Art

[0002] Traditional drilling, tapping, and milling machines utilize motor-driven pulleys to drive a spindle and chuck within a sleeve to perform drilling, tapping, and milling operations. Whether using V-belts or synchronous belts, these motors suffer from power loss (for example, a single V-belt has an efficiency of only 70%) and are prone to wear, necessitating frequent belt replacement. Common motors include induction motors, series motors, and inner-rotor brushless motors. Induction motors are large, heavy, and difficult to regulate. They are typically regulated using pyramidal or variable-diameter pulleys. Belt tension in both methods affects drilling quality and belt life. Using variable-frequency speed control is costly and inherently impedes belt drive losses. While series motors are inexpensive, their inherent efficiency is only around 60%. Their high speed requires gear shifting to drive the sleeve for various operations. Speed ​​changes can only be achieved by adjusting voltage or current, further reducing efficiency and increasing noise. While inner-rotor brushless motors drive belt drives, while simple to adjust, retain the inherent weaknesses of belt drives. In view of the fact that the above-mentioned various transmission modes and driving methods all have the common characteristics of low transmission efficiency, complex motor fixation, a large number of parts, high energy consumption, many wearing parts, high noise, and are not conducive to environmental protection.

[0003] Summary of the Invention

[0004] The present invention provides an outer rotor motor direct-drive drilling and milling machine, which utilizes an outer rotor brushless motor or an outer rotor brushless motor assembly to directly drive the movement of the drilling and milling machine spindle, eliminating belt transmission, and is used to solve the problems existing in the prior art; in addition, a device is added to the traditional sleeve assembly to connect it to a displacement sensor, and signal transmission is used to enable digital display and work setting of drilling or feeding processing, and a device is attached to the frame to guide or lock the sleeve assembly, so that it has the functions of drilling and milling.

[0005] To achieve the above objectives, the present invention employs the following technical solution: a direct-drive drilling and milling machine using an outer rotor brushless motor or outer rotor brushless motor assembly, comprising a frame and a chassis. The chassis comprises a power box assembly for driving and controlling, an upper cover assembly for air guidance and protection, and a front cover assembly for operation and function selection. The chassis is secured to the frame's columns via a chassis locking mechanism. The frame comprises a base, an intermediate worktable assembly, column assemblies, and any other mechanical structure capable of supporting the chassis for drilling operations.

[0006] Outer rotor brushless motors and outer rotor brushless motor assemblies are two types of power devices that drive the spindle of a drilling machine, used in high-speed drilling machines or low-speed drilling machines respectively. Their common feature is that they both directly drive the machine tool spindle by cooperating with the machine tool spindle key to achieve operations such as drilling, tapping, and milling. 1. The method of directly driving the machine tool spindle with an outer rotor brushless motor is that the output shaft of the outer rotor motor is a hollow shaft with a keyway, which cooperates with the key on the drilling machine spindle to drive the spindle rotation. This motor structure is referred to as M1. 2. The motor shaft of the outer rotor brushless motor assembly is a hollow shaft, and a gear is installed at the end of the shaft as a sun gear to drive the planetary gear to rotate. Under the action of the internal gear, the planetary carrier is driven to rotate. The keyway hole in the middle of the planetary carrier cooperates with the drilling machine spindle to drive the spindle rotation to achieve related operations. Obviously, the required transmission ratio can be selected according to different needs. This structure is referred to as M2. The outer rotor brushless motor and outer rotor brushless motor assembly, under the action of the motor drive controller, realize forward and reverse rotation and stepless speed regulation. Through signal transmission, the speed can be directly displayed and the required speed can be selected.

[0007] The power box assembly includes a housing assembly, which houses the outer rotor motor, drill bushing assembly, guide locking mechanism, and controller. The outer rotor motor's keyed output shaft is coaxially keyed to the drill bushing assembly's main shaft. The main shaft and motor output shaft are keyed with clearance, allowing them to rotate with the motor output shaft and move axially along the output shaft.

[0008] As an optional implementation of the technical solution, an external rotor motor assembly can be selected, that is, the main shaft and the planetary carrier in the motor assembly have a keyway hole clearance fit, the planetary carrier drives the main shaft to rotate, and the main shaft can move axially in the hollow shaft of the motor and the keyway hole of the planetary carrier.

[0009] The drill sleeve assembly is fitted with a clearance between the housing assembly and is perpendicular to the work surface. The gear of the lift drive assembly and the rack on the sleeve surface form a gear-and-rack pair, which can move axially within the housing assembly hole to achieve the purpose of drilling. The outer surface of the sleeve has a rack, a limit plane, and a guide groove. The spindle is set within the sleeve of the drill sleeve assembly. One end is equipped with a drill chuck (or drill bit), which is equipped with a protective cover assembly. The other end is equipped with a wave washer, a lever, and a hole retaining ring. The lever is connected to the displacement sensor. As the drill sleeve assembly moves axially, the displacement signal of the displacement sensor is processed and displayed digitally on the screen.

[0010] A displacement sensor is a sensing device that transmits position signals. To prevent chip vibration from affecting sensor accuracy, the sensor is mounted on a transparent bracket with vibration-damping features and screwed to the machine frame. A lever on the drill sleeve assembly drives the sensor's moving mechanism, outputting a displacement signal. After processing, the displacement data is obtained and displayed.

[0011] The lifting drive assembly consists of a gear shaft, a shaft retaining ring, a spring box, a scroll spring and a handle. The gear shaft step and the shaft retaining ring fix the assembly in the box assembly, and form a gear rack pair with the rack on the sleeve surface in the drill sleeve assembly. Under the action of the handle and the scroll spring, the drill sleeve assembly is driven to axially reciprocate.

[0012] The guide locking mechanism consists of a locking screw, a tightening nut, a retaining ring, and a handle. The locking screw is threaded into the housing. A boss is located on the front of the locking screw, which, when assembled, extends into the guide groove of the drill sleeve assembly. A gap a is left between the retaining ring and the housing assembly. When the locking screw reaches the retaining ring's limit, the tightening nut is tightened, providing a guide function that stabilizes the axial movement of the drill sleeve assembly. Loosening the retaining nut and tightening the screw locks the drill sleeve assembly, securing it in place. Milling operations can now be performed with the assistance of auxiliary devices.

[0013] As an optional implementation of the above technical solution, the rotor of the outer rotor brushless motor is equipped with heat dissipation blades. After the upper cover assembly and the front cover assembly are assembled, a centrifugal cooling system is formed to cool the motor and other heat-generating components.

[0014] The upper cover assembly consists of an upper cover, an air guide cover, and fixing screws. Its function is to form a centrifugal air duct in combination with the power box assembly and has a protective function.

[0015] The front cover functions as an operational control, consisting of an emergency stop switch and related operating buttons, including a start / stop button, acceleration button, deceleration button, reset button, set and release buttons, lighting button, tapping mode button, and reverse button. These buttons enable functions such as starting, speed regulation, drilling settings, tapping mode selection, inching reverse, and emergency stop. When assembled with the power box assembly and upper cover assembly, they form a complete box and complete the cooling system.

[0016] The beneficial effects of the present invention are:

[0017] 1. The present invention uses an external rotor motor to directly drive the spindle or an external rotor motor assembly to directly drive the spindle, and uses a brushless motor to drive and control the processing functions of drilling, tapping and milling, and can adjust the speed steplessly according to needs;

[0018] 2. The present invention eliminates the power loss caused by the belt, greatly reduces the use of spare parts and wearing parts, and the spindle has no belt tensioning and radial force caused by key connection, which greatly reduces the wear of the drill sleeve assembly and the box assembly, extending the service life of the drilling machine while also improving the processing accuracy;

[0019] 3. The present invention uses a novel digital acquisition system and drive control system to achieve high efficiency, energy saving and visual operation. The motor has overload protection, overheat protection, current protection, etc. The motor works stably and is not easily damaged, reducing maintenance costs;

[0020] 4. The present invention integrates drilling, tapping and milling together, realizing multi-purpose use of one machine, greatly reducing the use cost, and achieving the purpose of energy saving and environmental protection;

[0021] 5. The present invention uses advanced motor drive and control technology to achieve wide voltage drive. It can still work stably under the condition of voltage fluctuation of ±10%, and the motor life is not affected. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] FIG1 is a schematic structural diagram of a drilling and milling device in one embodiment of the present invention from a viewing angle;

[0023] FIG2 is a schematic structural diagram of various components of a chassis in one embodiment of the present invention;

[0024] FIG3 is a schematic diagram of the structure of an M1 type motor in one embodiment of the present invention;

[0025] FIG4 is a schematic structural diagram of an M2 type motor assembly in one embodiment of the present invention;

[0026] FIG5 is a schematic structural diagram of a power box assembly using an M1 type motor in one embodiment of the present invention;

[0027] FIG6 is a schematic structural diagram of a power box assembly using an M2 type motor assembly in one embodiment of the present invention;

[0028] 7 is a cross-sectional view and a schematic perspective view of the structure of a drill sleeve assembly according to an embodiment of the present invention;

[0029] FIG8 is a schematic diagram of a sensor assembly according to an embodiment of the present invention;

[0030] FIG9 is a cross-sectional view taken along line FF of FIG5 , which is a schematic structural diagram of a lifting drive assembly in one embodiment of the present invention;

[0031] FIG10 is a cross-sectional view taken along line EE of FIG5 , which is a schematic structural diagram of a guide locking mechanism in one embodiment of the present invention;

[0032] FIG11 is a schematic structural diagram of an upper cover assembly in one embodiment of the present invention;

[0033] FIG12 is a schematic structural diagram of a front cover assembly in one embodiment of the present invention;

[0034] FIG13 is a schematic diagram of the wind flow direction of a cooling system according to an embodiment of the present invention;

[0035] FIG14 is an external structural diagram of the present invention.

[0036] In the figure: 1-chassis; 2-frame; 3-power box assembly; 4-upper cover assembly; 5-front cover assembly; 6-outer rotor motor rotor assembly; 7-outer rotor motor stator assembly; 8-internal gear; 9-sun gear; 10-planet carrier assembly; 101-planet gear; 102-planet gear shaft; 103-planet carrier; 11-bracket; 12-bearing 1; 13-screw hole retaining ring; 14-shaft retaining ring 1; 15-frame locking handle assembly; 16-box assembly; 17-tapping signal output port; 18-controller; 19-lifting drive assembly; 191-gear shaft; 192-shaft retaining ring 2; 193-spring box; 194-volute spring; 195-handle 1; 20-drill sleeve assembly; 201-spindle; 202-waterproof disk; 203-Bearing 2; 204-Sleeve; 205-Bearing 3; 206-Shaft retaining ring 3; 207-Wave washer; 208-Lever; 209-Hole retaining ring; 21-Displacement sensor assembly; 211-Displacement sensor; 212-Sensor bracket; 213-Screw 1; 22-Protective cover assembly; 23-Drill chuck (or drill bit); 24-Guide locking mechanism; 241-Handle 2; 242-Screw; 243-Tightening nut; 244-Shaft retaining ring 4; 25-Lighting assembly; 26-Electromagnetic switch; 27-Power cord assembly; 401-Top cover; 402-Screw 2; 403-Air guide cover; 501-Emergency stop switch; 502-Control panel label; 503-Screw protection plate; 504-Front cover; 505-Display and signal processing assembly; 506-Screw 3. DETAILED DESCRIPTION

[0037] As shown in FIG. 1 to FIG. 14 , the drilling and milling machine of the present invention is specifically implemented in a component integration manner, where the entire machine is divided into two major components: a chassis 1 and a frame 2 (see FIG. 1 ).

[0038] The chassis 1 is divided into three major components: a power box component 3, an upper cover component 4 and a front cover component 5 (see Figure 2). The three major components are integrated into the chassis 1 by screw connections (Figure 2 left).

[0039] The power box assembly 3 is also mainly composed of component assembly and integration, and its power sources are two kinds: outer rotor brushless motor M1 (see Figure 3) and outer rotor brushless motor assembly M2 (see Figure 4), which can be selected and used according to needs. Their common feature is that they directly drive the machine tool spindle 201.

[0040] The outer rotor brushless motor M1 mainly consists of an outer rotor motor rotor assembly 6 and an outer rotor motor stator assembly 7. The output shaft of the outer rotor brushless motor assembly M2 is a hollow shaft, which passes through the main shaft 201 and has a clearance fit with it. The main shaft 201 can move up and down and rotate inside the hollow shaft. The outer rotor brushless motor assembly M2 includes an outer rotor motor rotor assembly 6, an outer rotor motor stator assembly 7, an internal gear 8, a sun gear 9, a planetary carrier assembly 10, a planetary gear 101, a planetary gear shaft 102, a planetary carrier 103, a bracket 11, a bearing 12, a spiral hole retaining ring 13 and a shaft retaining ring 14. The power of the planetary carrier assembly 10 is output by the planetary carrier 103. The planetary gear 101 is installed on the planetary carrier 103 through the planetary gear shaft 102. There is a keyway hole in the middle of the planetary carrier 103. This keyway hole forms a key connection with the main shaft 201 with a clearance fit; the power source directly transmits power to the main shaft 201, and the main shaft 201 moves up and down with the drill sleeve assembly 20 of the drilling and milling machine. The main shaft 201 can move up and down in the keyway hole and rotate accordingly.

[0041] The mating surface between housing assembly 16 and sleeve 204 of drill sleeve assembly 20 (Figure 7) is constructed from a wear-resistant material insert and other metal materials. It is coaxial with the mounting surface of outer rotor brushless motor M1 or outer rotor brushless motor assembly M2. Using the assembly tooling, first assemble guide locking mechanism 24, including handle 241, tightening nut 243, and shaft retaining ring 4 244. Adjust the limit distance a to 0 (see Figure 10).

[0042] Drill sleeve assembly 20 includes sleeve 204, which is equipped with a waterproof disc 202, a second bearing 203, a third bearing 205, a third shaft retaining ring 206, a wave washer 207, a shift lever 208, and a hole retaining ring 209. Drill sleeve assembly 20 (see Figure 7) is assembled in two steps. First, without assembling the wave washer 207, shift lever 208, and hole retaining ring 209, the semi-finished drill sleeve assembly 20 is assembled from the bottom up, aligning the guide groove on the outer surface of sleeve 204 with the boss on the front of the screw 242 in the guide locking mechanism 24.

[0043] At this time, assemble the lifting drive assembly 19 (see Figure 9), drive the gear shaft 191 through the handle 195, and when the gear of the gear shaft 191 is reliably engaged with the rack on the outer surface of the sleeve 204 of the drill sleeve assembly 20, tighten the spiral spring 194 and position the spring box 193, assemble the shaft retaining ring 292, fix the lifting drive assembly 19, and at this time, the semi-finished drill sleeve assembly 20 is at the top dead center.

[0044] Tighten screw 242 of guide locking mechanism 24 to complete assembly of drill sleeve assembly 20. This involves sequentially assembling wave washer 207, lever 208, and retaining ring 209. Once assembly is complete, loosen screw 242, adjust a to 0 (Figure 10), tighten nut 243, and after verifying that drill sleeve assembly 20 is correctly moving up and down, assemble displacement sensor assembly 21 (see Figure 8).

[0045] Install the displacement sensor 211 into the transparent sensor bracket 212 using screws 213 to complete the displacement sensor assembly 21. Align the slider boss on the displacement sensor 211 with the lever slot on the drill collar assembly 20 and secure the sensor assembly with screws to complete the assembly. As the drill collar assembly 20 moves up and down, the sensor outputs a displacement signal, which is then connected to the display screen and signal processing component 505 to display the displacement.

[0046] The drill sleeve assembly 20 is loosely fitted with the housing assembly 16 and is perpendicular to the work surface. The gear of the lift drive assembly 19 and the rack on the surface of the sleeve 204 form a gear and rack pair, which allows axial movement within the hole of the housing assembly 16 to achieve the purpose of drilling. The outer surface of the sleeve 204 is provided with a rack, a limiting surface, and a guide groove. The spindle 201 is disposed within the sleeve 204 of the drill sleeve assembly 20. A drill chuck (or drill bit) 23 is assembled at one end, and the drill chuck (or drill bit) 23 is equipped with a protective cover assembly 22. The other end is equipped with a wave washer 207, a lever 208, and a hole retaining ring 209. The lever 208 is connected to a displacement sensor 211. As the drill sleeve assembly 20 moves axially, the displacement signal from the displacement sensor 211 is processed and digitally displayed on the screen.

[0047] After the above assembly is completed and checked to be correct, the outer rotor motor or outer rotor motor assembly can be assembled. Since it is coaxial with the drill sleeve assembly 20, it is only necessary to align the key on the main shaft 201 with the keyway hole in the output shaft of the outer rotor motor or the keyway hole of the planetary carrier 103 of the outer rotor motor assembly to complete the assembly and tighten the bolts.

[0048] At this point, the rack locking handle assembly 15, tapping signal output port 17, controller 18, lighting assembly 25, electromagnetic switch 26, and power cord assembly 27 can be assembled in sequence according to the diagram, and then the circuits can be connected according to the electrical diagram to complete the assembly of the power box assembly 3.

[0049] Assemble the upper cover 401 and the air guide cover 403 together with screws 402 as shown in the figure to form the upper cover assembly 4.

[0050] Assemble the display screen and signal processing component 505 on the front cover 504 with screw 3 506 according to the diagram, place the screen protection plate 503, affix the control panel label 502, and finally assemble the emergency stop switch 501 to complete the assembly of the front cover assembly 5.

[0051] Assemble the front cover assembly 5 and the power box assembly 3 and connect the wires according to the electrical diagram. The control panel features functions such as motor start, emergency stop, stepless motor speed regulation, tapping (with forward and reverse signal control and speed limit), lighting, depth setting, and reverse rotation. Then, install the top cover assembly 4 and securely screw it to the front cover assembly 5 and power box assembly 3 to complete the assembly of the chassis 1. The assembled state is shown in the left image of Figure 2. Once the chassis 1 is assembled, a cooling duct is formed for the entire unit, with the air flow shown in Figure 13.

[0052] After the chassis is assembled, the frame locking handle assembly 15 is locked to complete the assembly of the entire machine. The visual effect of the entire machine is shown in Figure 14.

[0053] After the whole machine is assembled, a cross workbench is added to the work surface of the frame 2, and the drill sleeve assembly 20 is locked by utilizing the locking function of the guide locking mechanism to realize the milling function.

[0054] The protection scope of the present invention is not limited to the above-mentioned specific embodiments. Based on the basic technical concept of the present invention, any implementation methods that can be thought of by ordinary technicians in this field without any creative work shall fall within the protection scope of the present invention.

Claims

1. An outer rotor motor direct drive drilling and milling machine, characterized in that: An outer rotor brushless motor or an outer rotor brushless motor assembly is used as the driving power source, and the spindle movement of the drilling and milling machine is directly driven by a key connection with a clearance fit. Both power sources have stepless speed regulation and forward and reverse setting functions.

2. The outer rotor motor direct-drive drilling and milling machine according to claim 1, characterized in that: The output shaft of the outer rotor brushless motor is a hollow shaft with a keyway, and the hollow shaft with the keyway forms a key connection with the main shaft with a clearance fit; the outer rotor brushless motor assembly is integrated with the outer rotor brushless motor and the planetary speed change mechanism, and the output shaft of the outer rotor brushless motor is a hollow shaft, which passes through the main shaft and has a clearance fit therewith, and the main shaft can move up and down and rotate inside the hollow shaft; the power of the planetary speed change mechanism is output by the planetary carrier, and there is a keyway hole in the middle of the planetary carrier, and this keyway hole forms a key connection with the main shaft with a clearance fit; both power sources directly transmit power to the main shaft, and the main shaft moves up and down with the drill sleeve assembly of the drilling and milling machine, and the main shaft can move up and down in the keyway hole and rotate accordingly.

3. The outer rotor motor direct drive drilling and milling machine according to claim 2, characterized in that: The upper part of the drill sleeve assembly is provided with a corrugated washer, a lever and a retaining ring for a hole. There is a notch on the sleeve of the drill sleeve assembly which acts together to position the lever. The front part of the lever is connected to the displacement sensor so that the slider of the displacement sensor moves with the drill sleeve assembly, thereby outputting a displacement signal, which is processed and displayed in digital form as the displacement of the drill sleeve assembly.

4. The outer rotor motor direct drive drilling and milling machine according to claim 2, characterized in that: It also includes a guide locking mechanism, which has the dual functions of locking and guiding. The boss at the front of the screw of the guide locking mechanism is inserted into the guide groove on the outer surface of the sleeve in the drill sleeve assembly. There is a shaft retaining ring four at the front of the screw, and there is a limit distance a with the adjacent surface of the box assembly. The handle is rotated. When the limit distance a is equal to 0, the nut is locked, and the guiding function is realized at this time; the nut is loosened and the screw is tightened. At this time, the drill sleeve assembly is fixed, and a cross workbench is installed on the frame workbench to complete the milling operation.

5. The outer rotor motor direct drive drilling and milling machine according to claim 1, characterized in that: The rotor housing of the outer rotor motor is provided with fan blades, which together with the upper cover assembly, the front cover assembly and the power box assembly form a centrifugal cooling system. Wind is sucked in from the upper air inlet, passes through the motor surface, and is discharged from the lower part of the power box assembly.

6. The outer rotor motor direct drive drilling and milling machine according to claim 5, characterized in that: The control panel of the front cover assembly is provided with a start / stop button, an acceleration button, a deceleration button, a reset button, a setting and release button, a lighting button, a tapping mode button and a reverse button. The state is selected and adjusted according to operational needs. When entering the tapping mode, the machine tool automatically limits the speed range according to the tapping range to ensure safety.

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