Rock drill bit sharpening system with outrunner motor and VESC controller

Abstract

A rock drill bit sharpening system is disclosed, designed to enhance torque and power efficiency for sharpening carbide button inserts, including those with polycrystalline diamond (PCD) enhancements. The system integrates an outrunner motor and a VESC motor controller to address the technical problem of maintaining performance in compact applications. The control system communicates with the VESC motor controller to adjust operational parameters, offering flexibility with power sources ranging from 24-48 VDC or 100-260 VAC. The system includes an RFID reader for precision control and Wi-Fi connectivity for remote monitoring. This system is particularly useful for mobile and compact sharpening applications, providing performance levels typically associated with larger machines. The resharpening machine features a modular design for easy component replacement, enhancing the system's adaptability and efficiency in various operational environments.

Description

ROCK DRILL BIT SHARPENING SYSTEM WITH OUTRUNNER MOTOR AND VESC CONTROLLER FIELD OF INVENTION

[0001] The present disclosure pertains to rock drill bit sharpening systems that utilize outrunner motors and VESC motor controllers to improve torque and power efficiency in compact applications.BACKGROUND

[0002] In drilling operations, the cutting teeth (buttons) on rock drill bits or cutters become flattened (worn) after continued use. A factor contributing to premature rock drill bit failure and poor drilling performance is operating beyond the reconditioning point. Failure to sharpen in time can prove costly. Regular maintenance of the rock drill bit or cutter by sharpening the buttons to restore them to substantially their original profile enhances the bit / cutter life, speeds up drilling and reduces drilling costs. Sharpening should be undertaken when the wear of the buttons is optimally one third to a maximum of one-half the button diameter.

[0003] Regular maintenance on rock drill bits is important to maintain maximum penetration rates and to avoid overheating the bit, as this can destroy its metallurgical properties. Re-profiling the carbide button and removing excess steel is important in order to optimize drill bit service life, enhance the performance of the entire drilling operation and keep down the drilling and grinding costs.

[0004] A range of different manual and semi-automatic sharpening apparatus have been developed including hand held grinders, single arm and double arm grinding machines and grinders designed specifically for mounting on drill rigs, service vehicles or set up in the shop.

[0005] These types of machines utilize a grinding machine having a spindle or rotor rotated at high speed. A sharpening tool or grinding cup, mounted on the end of the rotor or spindle, grinds the button and typically the face of the bit / cutter surrounding the baseof the button to restore the button to substantially its original profile for effective drilling. In addition to the rotation of the sharpening tool, these types of grinding machines may include features where the grinding machine is mounted at an angle to the longitudinal axis of the button and the grinding machine is rotated to provide orbital motion with the center of rotation lying in the center of the sharpening tool. When sharpening the buttons, the centering aspects of the grinding machine tend to center the grinding machine over the highest point on the button.

[0006] Existing solutions often struggle to provide the characteristics required for sharpening a diverse array of button sizes. Furthermore, the integration of advanced systems capable of real-time data monitoring and remote operation is limited, hindering the ability to optimize performance and ensure consistent quality. These limitations highlight the need for an innovative approach that addresses these challenges, offering a streamlined and efficient solution for modem resharpening needs.

[0007] In the field of resharpening, there is a growing demand for compact and mobile solutions that can deliver the performance levels typically associated with larger, stationary machines. Traditional systems often rely on bulky components, which limit their portability and efficiency. These systems may also lack the flexibility to operate across a wide range of power sources, making them less adaptable to various operational environments. Additionally, the need for increased automation and precision in the resharpening process is becoming increasingly important, especially as the industry moves towards more sophisticated and automated operations.SUMMARY

[0008] The present invention provides a rock drill bit sharpening system with integration of an outrunner motor with a motor controller in a compact button bit sharpening machine, which has not been previously applied in this context. This combination allows for enhanced torque and power characteristics suitable for sharpening a wide range of carbide button sizes, including those with polycrystalline diamond (PCD) enhancements. In a preferred embodiment the motor controller is a VESC motor controller.

[0009] The rock drill bit sharpening system further incorporates a control mechanism capable of communicating with the motor controller to adjust motor speed and torque based on operational data.

[0010] In a further embodiment the control system for the rock drill bit sharpening system includes RFID scanning for precision control and Wi-Fi connectivity for remote monitoring. This approach provides a distinct solution for mobile and compact sharpening applications, offering performance levels typically associated with larger, stationary machines.

[0011] One embodiment of the present disclosure provides a rock drill bit sharpening system for grinding working tips of hard metal inserts of rock drill bits, comprising: a sharpening / grinding machine, means for holding a rock drill bit to be ground and a support system. The sharpening machine is equipped with an outrunner motor configured to provide enhanced torque and power characteristics suitable for sharpening a wide range of carbide button insert sizes, including those with polycrystalline diamond (PCD) enhancements. The outrunner motor is connected to a spindle assembly having an output drive shaft having a longitudinal axis. One of a plurality of sharpening tools of different sizes and profiles may be detachably connected to the output drive shaft for sharpening different sizes and profiles of working tips. The rock drill bit sharpening system includes a control system capable of monitoring and collecting data on operation and use of the rock drill bit sharpening system. A VESC motor controller is operatively connected to the outrunner motor and the VESC motor controller is configured to control motor speed and torque, and capable of operating on a VDC or VAC power source The power source can range from 24-75 VDC or higher if utilizing higher voltage high capacity batteries or 100-260 VAC. The control system is configured to communicate with the VESC motor controller and is used to monitor and collect data and is capable of controlling one or more operational parameters in response to initial data inputted as well as data collected during the sharpening process. The outrunner motor includes a cooling system to maintain optimal operating temperatures during extended use. In one embodiment the outrunner motor is designed with a modular structure to allow easy replacement or upgrading of components.

[0012] The control system in the embodiment disclosed has a programmable operator control panel that enables the operator to input data and a programmable control card provided attached to the rear of the operator control panel having a circuit board containing a central processor (i.e. microprocessor or microcontroller) for the control system of the rock drill bit sharpening system. The central processor can be located anywhere suitable for the application and can be suitably interconnected with other subprocessors and / or sensors to monitor various functions as deemed necessary for proper operation and collect data from those functions. The overall control system includes systems and controls that together with a microprocessor or microcontroller can control all aspects of rock drill bit sharpening system including grinding time on each button, rotational speed of the sharpening tool / grinding cup, feed pressure, bit holder tilt function, operating lights and coolant flow. The microprocessor or microcontroller and the control system can be used to provide other functions either manual or automatic.

[0013] An RFID reader may be connected to the control system, the RFID reader having a proximity sensor configured to detect an RFID tag on a sharpening tool / grinding cup containing specific ID data including a size and profile of the sharpening tool / grinding cup and transmit the specific ID data to the control system to control the speed of rotation of the output drive shaft and feed pressure during grinding. When a sharpening tool / grinding cup equipped with an RFID tag in accordance with present invention is scanned by the RFID reader a proximity sensor detects the RFID tag and scans the data on the tag. The data preferably includes a specific ID identifier for the particular sharpening tool / grinding cup and the number of grinding cycles over which it has been used to date. The ID identifier data includes the sharpening tool / grinding cup size and grinding surface profile. Once the RFID tag has been scanned the data is transmitted to the programmable microprocessor. The control system comprises the microprocessor, a non-transitory memory storing executable instructions and a parameter database, and operator VO. The sharpening tool / grinding cup size and profile can be displayed on the touch screen. If the sharpening tool / grinding cup is not equipped with an RFID tag or other specific ID identifier the operator will need to manually enter the data into the control system through the operator control panel. In one embodiment the motor controller includes a user interface for manual adjustments of speed and torque settings.

[0014] In another embodiment, the disclosure includes a rock drill bit sharpening system comprising an outrunner motor configured to provide enhanced torque and power characteristics suitable for sharpening a wide range of carbide button insert sizes, including those with polycrystalline diamond (PCD) enhancements; a VESC motor controller operatively connected to the outrunner motor, the VESC motor controller configured to control motor speed and torque, and capable of operating on a power source ranging from 24-75 VDC or 100-260 VAC; a control system configured to communicate with the VESC motor controller to adjust operational parameters based on gathered operational data, the control system further comprising an RFID scanner for precision control of the sharpening process and a Wi-Fi module for remote monitoring and data gathering; wherein the control system is further configured to enable software updates of all components connected to the control system, including the VESC motor controller, thereby facilitating enhanced automation and performance monitoring of the resharpening machine.

[0015] In another embodiment the present disclosure provides a rock drill bit sharpening system comprising a spindle assembly having an output shaft to which a detachable sharpening tool is mountable; a brushless outrunner electric motor mechanically coupled to the spindle assembly, the outrunner electric motor comprising an internal stator and an external rotor configured to rotate about a longitudinal axis of the spindle assembly; a VESC motor controller operatively connected to the outrunner electric motor and configured to command motor phase currents to regulate torque and rotational speed; and a control system operatively connected to the VESC motor controller and configured to set operating parameters for sharpening, wherein the VESC motor controller is configured to execute field-oriented control to maintain a target rotational speed under load during sharpening of rock drill bit buttons.

[0016] In a further embodiment the disclosure provides a method for sharpening rock drill bits, comprising providing a sharpening system including an outrunner motor and a VESC motor controller; attaching a sharpening tool to the output drive shaft of a spindle assembly of the sharpening system; controlling the outrunner motor using the VESC motor controller to adjust torque and rotational speed; and sharpening the rockdrill bits by engaging the sharpening tool with the drill bit buttons, wherein the VESC motor controller enables precise adjustments to optimize sharpening efficiency and effectiveness.

[0017] In a further embodiment the present disclosure provides a motor drive for a rock drill bit sharpening machine, comprising a VESC motor controller configured to execute field-oriented control on a brushless outrunner electric motor that drives a spindle carrying a sharpening tool; and an interface configured to receive command inputs specifying at least a target rotational speed and to provide telemetry outputs comprising at least current, voltage, and temperature, wherein the motor drive maintains the target rotational speed within a predefined tolerance under material-removal load encountered during sharpening of rock drill bit buttons.

[0018] In a further embodiment the present disclosure provides a compact motor-spindle module for a rock drill bit sharpening machine, comprising a housing containing a brushless outrunner electric motor mechanically coupled to a spindle with a detachable sharpening tool mount; and a VESC motor controller integrated with or attached to the housing and electrically connected to the motor, wherein the VESC motor controller executes field-oriented control to regulate torque and rotational speed for sharpening rock drill bit buttons.

[0019] These and other features will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings and claims.

[0020] Further features of the invention will be described or will become apparent in the course of the following detailed description.BRIEF DESCRIPTION OF DRAWINGS

[0021] In order that the invention may be more clearly understood, an embodiment will now be described in detail by way of example, with reference to the accompanying drawings, in which:

[0022] FIG. 1 is perspective view from the front right side of one embodiment of a rock drill bit sharpening system with an outrunner motor and VESC controller according to the present invention.

[0023] FIG. 2 is perspective view from the front left side of the rock drill bit sharpening system of Fig. 1.

[0024] FIG. 3 is a rear perspective view of the rock drill bit sharpening system of Fig. 1.

[0025] FIG. 4 is a left side plan view of the rock drill bit sharpening system of Fig. 1.

[0026] FIG. 5 is a front plan view of the front of the rock drill bit sharpening system of Fig. 1.

[0027] FIG. 6 is a cross-section of the rock drill bit sharpening system of Fig. 5 thru line A-A.

[0028] FIG. 7 is an enlarged front perspective view of the control box of the rock drill bit sharpening system of Fig. 1.

[0029] FIG. 8 is a cross section of the control box of Fig. 7.

[0030] FIG. 9 is an enlarged view in cross-section of the rock drill bit sharpening machine in Fig 6.

[0031] FIG. 10 is an enlarged plan view of the sharpening system thru line F-F in Fig 5.

[0032] FIG. 11 is a side plan view of the motor housing of the resharpening machine of Fig 9.

[0033] FIG. 12 is a cross-section of motor housing of Fig. 11 thru line C-C.

[0034] Similar references are used in different figures to denote similar components.DETAILED DESCRIPTION

[0035] Referring to Figs 1 - 12, an embodiment of a compact rock drill bit sharpening system optionally suitable for mobile applications according to the present invention is illustrated. The rock drill bit sharpening system is generally indicated at 20. The sharpening system 20 includes a sharpening (grinding) machine 21, means for holding one or more bits to be sharpened generally indicated at 22 and a support system generally indicated at 23. The support system carrying the sharpening machine is movable toward and away from the rock drill bit along a feed direction substantially coincident with the longitudinal axis of the button; a linear actuator coupled between a frame and the support structure and configured to advance and retract the sharpening machine along the feed direction; a load cell mechanically in series with the linear actuator and the support structure and configured to measure a feed force applied by the sharpening tool to the buttonThe sharpening machine 21, means for holding the bits 22 and support system 23 are arranged to permit relative movement been the sharpening machine 21 and the bit to be ground to permit alignment of the sharpening machine 21 with the longitudinal axis of the buttons on the bit. The sharpening system 20 has a control system having a programmable operator control panel 24 that enables the operator to input data and a programmable control card provided attached to the rear of the operator control panel having a circuit board containing a central processor (i.e. microprocessor or microcontroller) for the control system of the rock drill bit sharpening system. In the embodiment illustrated the control system is located within control box 25 and is capable of directly or indirectly monitoring and adjusting one or more operational parameters. The operational parameters of most interest are selected from the group consisting of feed pressure, grinding cup RPM and grinding time.

[0036] In the embodiment of the sharpening system 20 shown in Figs. 1-12, the sharpening machine 21 is carried by support system 23 which includes an arm or lever system 26 attached to frame 27. The support system carrying the sharpening machine enables the sharpening machine to be movable toward and away from the rock drill bit along a feed direction substantially coincident with the longitudinal axis of the button. Frame 27, in the embodiment illustrated has an open front box configuration, having a left side panel 28, right side panel 29, top panel 30 and a back panel 31. A canopy 32 ispivotally connected at points 33,34 to the left side panel 28 and right side panel 29 adjacent the top panel 30.

[0037] In the embodiment shown in Fig. 1-6, the arm or lever system 26 for carrying and positioning the sharpening machine 21 as noted previously is attached to frame 27. Arm system 26 consists of a pair of parallel arms 35,36 with one end 37,38 of each arm 35,36 pivotally mounted to the frame 27. The other end 39,40 of each arm 35,36 is pivotally connected to the backside 41 of a control box 25. The arm system 26 controls the vertical movement of the sharpening machine 21 up and down.

[0038] Within frame 27, is means 42 to provide a balance pressure to the portion of the support system 23 that controls the movement of the grinding machine 21 in the direction of the longitudinal axis of the button or bit when not in use and feed pressure when in use. In the embodiment shown, the means 42 to provide feed pressure is an actuator, generally indicated at 43 pivotally connected to arm 35. In the embodiment illustrated the actuator 43 is an electro-mechanical linear actuator having a screw whose length and speed of travel is controlled by an electric motor 44. The linear actuator coupled between the frame and the support system is configured to advance and retract the sharpening machine along the feed direction. A load cell mechanically in series with the linear actuator and the support structure is configured to measure a feed force applied by the sharpening tool to the button

[0039] High feed forces in conventional self-centering sharpening machines could potentially cause the sharpening machine to fall off the button with great force. To produce the high feeds safely, and control the feed pressure, means is provided to monitor and control the feed pressure. In the embodiment illustrated the means to monitor the feed pressure is a load cell 45 provided between the end of the linear actuator 43 and the point of connection 46 to the arm 35. The load cell 45 measures the feed pressure of the sharpening machine 21 against the drill bit. An output signal from the load cell 45 is delivered to the control system. The control system controls the movement of the screw of the linear actuator 43 through the motor 44 and thereby controls the feed pressure. The combination of control system, linear actuator and load cell also allow for feed (grinding) pressure to start from zero. This differs significantly from conventional grindingmachines as the minimum feed pressure in conventional grinding machines is equal to the weight of the grinding machine and support system. Where the load cell signals an abrupt reduction in load, possibly due to the grinding cup moving off the button being ground, the control system may be programmed to shut down the grinding operation or other procedure to minimize danger to the operator.

[0040] The control system is configured to: (i) execute a zero force approach that compensates for gravitational and inertial effects of the sharpening machine and the support system such that initial contact force at the button is approximately zero, (ii) regulate the linear actuator during sharpening in closed loop to maintain a target feed force based on the load cell measurement, and (iii) detect an abrupt reduction in the measured feed force and, in response, inhibit spindle rotation and command retraction of the sharpening machine.

[0041] To accommodate the fact that the surface of the button to be ground may be worn unevenly, means are provided to enable the sharpening machine 21 to move slightly during grinding over the uneven button surface without adjustment by the linear actuator. In the embodiment illustrated the means to enable the grinding cup to move slightly is provided by is provided by the design of the arms 35, 36 together with the means for holding one or more bits to be sharpened 22 to provide some give or flex. Alternatively, a spring working together with the load cell 45 to maintain mean target feed value on the button.

[0042] Figs 1-12 shows the sharpening machine 21 attached to plates 47 below the control box 25. The sharpening machine 21 is locked in place by levers 48. A water-cooled electric outrunner motor, generally indicated at 49, has an exterior housing 50 defining a chamber in which the rotor 51 and stator 52 are located. A drive coupling 53 at the bottom of the housing 50 permits attachment of a spindle assembly 54. The drive coupling 53 is inserted into the mating drive coupling 55 on spindle assembly 54. The spindle assembly 54 has an output drive shaft 56 to which a grinding cup / sharpening tool 57 can be connected. Coolant water for delivery to the grinding cup / sharpening tool surface is provided though water pump 58 and connection 59.

[0043] The rock drill bit resharpening machine 21, shown in Figs. 6, 9-12, includes an outrunner motor 60 and a motor controller 61. The outrunner motor has more power / torque in relation to physical size than a typical electric, pneumatic or hydraulic motor. This enables the rock drill bit sharpening system of the present invention to have a much more powerful motor on a relatively compact sharpener, bringing performance in line with performance levels traditionally associated with much larger stationary production type sharpening machines. In Figs 6, 9-12 the motor controller is a VESC motor controller, The rock drill bit resharpening machine 21 is engineered to improve torque and power characteristics, making the machine appropriate for sharpening a diverse range of carbide button insert sizes, including inserts with polycrystalline diamond (PCD) enhancements. Figs 6, 9-12 demonstrate the integration of various components, including the control system, which is set up to communicate with the VESC motor controller for adjusting operational parameters based on collected data.

[0044] The outrunner motor 60 serves as an important component of the sharpening machine 21, providing the necessary torque and power for effective sharpening. This motor is configured to handle a variety of rock drill bit button sizes, ensuring versatility in the machine's application. The design of the motor allows for efficient operation, contributing to the machine's overall performance.

[0045] With reference to the Figs 6 and 9 one embodiment of a spindle assembly, generally indicated at 54, for a sharpening machine for grinding the hard metal inserts or working tips of rock drill bits (percussive or rotary), tunnel boring machine cutters (TBM) and raised bore machine cutters (RBM) and more specifically, having an outrunner motor 60 is illustrated.

[0046] The spindle assembly 54 is intended to be driveably connected to the outrunner motor 60 of the sharpening machine 21. The spindle assembly 54 is attached to the motor housing 51 by bolts. A drive coupling 53 at the bottom of the motor housing 51 permits attachment of a mating drive coupling 55 on the spindle assembly. The spindle assembly 54 has an output drive shaft 56 to which a sharpening tool / grinding cup 57 can be detachably connected. Coolant water for delivery to the sharpening tool / grinding cup surface is provided by tubing 62 from a water pump 58 and water source connection.

[0047] The electric motor 49, 60 in the embodiment illustrated is a brushless motor of the so-called outrunner type and comprises an internal stator 52 and rotor 51 located within a motor housing 50. The stator 52 is connected to or forms part of a static component of the electric motor 60. The electric motor 60 further comprises an external rotor 51. The rotor 51 rotates externally around the stator 52 about the longitudinal axis during operation of the electric motor 60. An industrial outrunner brushless motor typically consists of the following components: stator 52 (with windings), rotor 51 (with permanent magnets), motor shaft, bearings, position sensors (like Hall sensors), and an electronic controller. In the embodiment illustrated the electronic controller is a VESC controller 61. The VESC motor controller has a processor configured to implement field weakening at rotational speeds above a base speed of the outrunner electric motor. In the outrunner design the rotor, holding the magnets, is located on the outside of the stator, allowing it to rotate around the stationary stator windings. The position sensors are embedded within the stator and detect the rotor position by sensing the magnetic field from the permanent magnets. At least one position or speed sensor selected from the Hall effect sensors and encoders provide rotor position feedback to the VESC motor controller. Due to the larger diameter of the rotor, outrunner motors can generate high torque compared to other electric, pneumatic or hydraulic motors with similar size. The exposed rotor surface allows for better heat dissipation.

[0048] A VESC motor controller 61 as shown in Fig 10 is operatively connected to the outrunner motor 60, and the control system to control motor speed and torque. The controller can operate on a power source ranging from 24-75 VDC or 100-260 VAC, offering flexibility in different operational environments. Power input is located at connection 82. The advanced capabilities of the controller enable precise adjustments, enhancing the machine's efficiency and effectiveness. The VESC motor controller 60, which stands for "Vedder Electronic Speed Controller," works by receiving input signals from the control system, processing them with a microcontroller, and then precisely controlling the power delivered to the electric motor 60 through a complex algorithm, allowing for fine-tuned speed and direction adjustments based on the input, all while utilizing advanced control strategies like Field Oriented Control (FOC) for optimal efficiency and performance; essentially acting as an interface between the power sourceand the motor 60, regulating the current flow to achieve the desired motor behavior. The VESC motor controller takes input from the control system specifying desired motor speed and direction. A microcontroller within the VESC interprets the input signal and calculates the optimal control strategy for the motor. It uses advanced algorithms like FOC to precisely control the magnetic field within the motor, resulting in smooth and efficient operation. Utilizes Pulse Width Modulation (PWM) to regulate the voltage supplied to the motor 60, allowing for fine-tuned speed control. A feedback mechanism in the form of sensors like Hall effect sensors or encoders monitor motor performance and ensure accurate control. The control system may monitor motor temperature and controller temperature during sharpening and reduce at least one of torque and speed in response to a temperature exceeding a threshold.

[0049] VESC technology is open-source, allowing developers and enthusiasts to customize and modify the software to suit specific applications. It can implement complex motor control algorithms like field weakening for high-speed operation. The control system of the present invention is configured to receive operational data from the VESC motor controller comprising at least motor current, motor voltage, motor temperature, and controller temperature, and to adjust the operating parameters in response to the operational data. The VESC motor controller has a non-volatile memory, storing motor parameters including stator resistance, stator inductance, and back-EMF constant, and the control system may be configured to initiate an identification procedure to populate the motor parameters.

[0050] Figs 1-5 show different views of one embodiment of the rock drill bit sharpening system 20 of the present invention. They show the relative location of the sharpening (grinding) machine 21, means for holding one or more bits to be sharpened generally indicated at 22, a support system 26 attached to the frame 27. Location of main power in 64 is best shown in Fig 2 - 4 as well as water input 59 and water pump 58 and bit holder 22.

[0051] The compact VESC motor controller enables wider range of VDC operating voltages to perform meet the operational requirements. The sharpener illustrated is rated 24-48 VDC. Because the VESC motor controller with Outrunnermotor is VDC rated, the use of AC / DC converters allows for the 24-48 VDC sharpener with outrunner motor to be operated from a 100-260 VAC, 50 / 60Hz, 1 Ph power source using a appropriately sized AC / DC power supply that puts out 24-48 VDC, 48VDC being preferred due to the lower current during operation. The use of a three-phase power supply is also possible. VDC voltage range could be even higher up to 24-75V with the outrunner motor illustrated. If a fully battery operated motor is utilized it could utilize higher voltage high capacity batteries.

[0052] The control system is configured to communicate with the VESC motor controller to cause the motor to operate at preferred controlled variable speed and torque, while also gathering operational data during operation (such as motor voltage, motor current, motor temperature, motor controller temperature, etc. A Hall sensor is an integral part of monitoring and adjusting rpms under load.

[0053] The control system (with connected VESC motor controller) may have the capability to scan RFID tags on sharpening tools and operator ID cards. This allows for precision control of the VESC motor controller and the outrunner motor to match operational data specific to RFID data on individual sharpening tools.

[0054] The control system is also Wi-Fi enabled and may be connected to remote web sites to monitor and gather operational data for analytical and reporting purposes.

[0055] The operational and performance data of the VESC motor controller, as well as the outrunner motor, may be an integral part of remote online Wi-Fi based troubleshooting / monitoring of the button bit sharpening system. The motor controller maaysupport additional communication protocols, including Bluetooth or CAN bus, for enhanced connectivity.

[0056] The control system may also enable software updates for all components connected to the control system, including the VESC motor controller.

[0057] Fig 6 provides a cross-sectional view of the button bit sharpening machine 21, control box 25, arms 35,36 and linear actuator 37 thru line A-A in Fig 5, highlighting its compact design and the integration of the outrunner motor 60 and illustrates theexternal housing and the arrangement of key components, emphasizing the machine's portability and efficiency.

[0058] Fig 7 provides a perspective front view of the control box 25 for the sharpening system 20 showing an RFID reader 70, stop 71 start 72 buttons, display panel 85, WiFi antenna 73 visor 74 and left side joy stick 75. Handles 76 are provided for assisting with manual alignment of the sharpening machine 21 with the button to be ground. The WiFi antenna 73 can optionally be located internally in the control box 25.

[0059] FIG 8 is cross-sectional side view of the control box 25 showing the motor 60 and components including motor 77 for providing orbital rotation of the sharpening machine. It also shows the plates 37 and slots for attachment of the sharpening machine 21 to the control box 25.

[0060] FIG 9: This front cross-sectional view of the resharpening machine shows the positioning of the sharpening tool / grinding cup 57, servomotor 78 for the splash guard 79 and other operational parts.

[0061] FIG 10: This figure is an exploded plan view of the sharpening system thru line F-F in Fig 5. It shows the location of the VESC motor controller 61 and cooling fan 80.

[0062] FIG 11 : This figure provides a side plan view of the motor housing 50, illustrating the motor coupling 53, cooling flange 81 and water input 83. The water outlet 84 is show in Fig. 1. The coolant delivery system for the outrunner electric motor is arranged to deliver coolant proximate a grinding surface of the sharpening tool during operation. From water outlet 84 the cooling water is directed to the output spindle assembly for flushing and cooling the rock drill bit during sharpening. The water is then collected in the water recycling system. In the embodiment illustrated the motor is liquid-cooled but may be fan-cooled to maintain a motor temperature within a predefined range during sharpening.

[0063] FIG 12: This figure provides a cross section of the motor housing thru line C-C in Fig 11. It provides a detailed view of this component's integration into the overall system including VDC Input 86 from VESC motor controller 61.

[0064] As noted above, rock drill bit sharpening system has a control system, having a programmable operator control panel capable of directly or indirectly monitoring and adjusting one or more operational parameters. A programmable control card is provided attached to rear of operator control panel, having a circuit board containing the central processor (i.e. microprocessor or microcontroller) for the control system of rock drill bit sharpening system. The central processor can be located anywhere suitable for the application and can be suitably interconnected with other sub-processors to monitor various functions as deemed necessary for proper function. The overall control system includes systems and controls that together with a microprocessor or microcontroller can control all aspects of the rock drill bit sharpening system including grinding time on each button, rotational speed of the sharpening tool / grinding cup, grinding pressure, bit holder tilt function, operating lights and coolant flow. The microprocessor or microcontroller and the control system can be used to provide other functions either manual or automatic. The microprocessor or microcontroller and control system can also control the flow of coolant to the face of the button during sharpening / grinding. The control system may a touchscreen display for real-time monitoring and control of the sharpening process.

[0065] In addition, the control panel software can be configured to permit user input such as the user could select for example whether long grinding cup life or high material removal rate of the grinding cup is preferred.

[0066] When using a sharpening tool / grinding cup equipped with an RFID tag, an RFID reader 70 is provided connected to the control system. The control system in the embodiment illustrated further comprises a touch screen display 85. When a sharpening tool / grinding cup, equipped with an RFID tag, is positioned adjacent the RFID reader 70, a proximity sensor detects the RFID tag and scans the data on the tag. The data may include a specific ID identifier for the particular sharpening tool / grinding cup and / or the number of grinding cycles over which it has been used to date. The ID identifier dataincludes the sharpening tool / grinding cup size and grinding surface profile. Once the RFID tag has been scanned the data is transmitted to the programmable microprocessor and the grinder size and profile can be displayed on the touch screen or display.

[0067] The control system and the programmable control card provided attached to the rear of the operator control panel having a circuit board containing a central processor (i.e. microprocessor or microcontroller) for the control system of the rock drill bit sharpening system have circuit inputs for the outrunner motor, VESC controller, water pressure, orbital rotation of the sharpening machine, spindle tightening, and controlling linear actuator function providing feed pressure. The control panel is illustrated with joysticks 75 on both the left and right side of the control box. The joysticks 75 provide a means to achieve two-hand control when deemed necessary for reasons such as safety, etc. The joysticks 75 may be used to scroll down the menu as well as select various functions. Two-hand control may be achieved by requiring that the operator move both joysticks to activate the desired function.

[0068] The control system of rock drill bit sharpening system may be provided with a transmitter and a receiver configured to enable rock drill bit sharpening system to communicate over the internet to a server or virtual server located remotely from the rock drill bit sharpening system. The illustrated embodiment of the rock drill bit sharpening system shows a WiFi connection thru WiFi antenna 73 but other forms of connection such as cellular are possible.

[0069] In a preferred embodiment of rock drill bit sharpening system, each operator is required to login before using the rock drill bit sharpening system and log out after use. Login can be by way of the touch screen display on the rock drill bit sharpening system or a token containing operator ID data such as in the form of key fob, that can be scanned or connected when in proximity to the rock drill bit sharpening system.Requiring operator login insures only persons trained in the proper and safe operation of the rock drill bit sharpening system are utilizing same. A further benefit to management is that hard data can be communicated from the rock drill bit sharpening system on operator performance and efficiency.

[0070] After the operator has logged in and the rock drill bit sharpening system is ready for normal operation, the operator puts a bit into the means on the rock drill bit sharpening system for holding the bits to be ground. In the embodiment illustrated, the means 22 for holding the bits to be ground is a bit holder 90 having opposite peripheral side walls, a front side and a V-shaped rear side. The peripheral side walls, front side and V-shaped rear side define a pentagonal shaped aperture into which one or more bits to be ground are placed. In the embodiment illustrated the front side is adapted to support a manual locking means 93 having a macro adjustment means and a micro adjustment. The manual locking means has a modified macro adjustment to save space due to the water recycling system being installed under the bit holder 90. A lever 94 is for macro adjustment of an outer tube, the other lever 95 is for micro adjustment of an inner tube. There is a ratchet type action to control the tilt of the bit holder 90 with lever 96 controlling the ratchet type action where the detents and mating surfaces of the pawl being engaged and disengaged by handle 96 for fast adjustment.

[0071] Once the bit is secure the operator selects a sharpening tool / grinding cup having the proper size and profile of the buttons on the bit that are to be ground. When using a sharpening tool / grinding cup equipped with an RFID tag, when the sharpening tool / grinding cup is brought into proximity of the RFID reader 70, a proximity sensor detects the RFID tag and scans the data on the tag. The RFID reader can be configured to be capable of reading multiple types of RFID tags, enhancing compatibility with various sharpening tools. The data preferably includes a specific ID identifier for the particular grinding cup and may also indicate the number of grinding cycles over which it has been used to date. The ID identifier data includes the sharpening tool / grinding cup size and grinding surface profile. Once the RFID tag has been scanned the data is transmitted to the programmable microprocessor and the grinder size and profile can be displayed on the touch screen to confirm the operator has selected the correct size and profile of grinding cup. The control system may track the use of the particular sharpening tool / grinding cup and the grinding apparatus it is being used on and records the number of cycles it has been used.

[0072] The operator then detachably connects the sharpening tool / grinding cup to the free end of the output drive shaft of the sharpening machine and aligns the sharpening tool / grinding cup about the longitudinal axis of the first one of the working tips to be ground.

[0073] The control system of the grinding apparatus can be pre-programmed with recommended operational parameters for different sizes and profiles of grinding cups. On reading the RFID tag associated with a particular grinding cup, the control system can automatically set the grinding time and feed pressure for the grinding cup. The operator can be provided with an override ability to increase or decrease grinding time and or feed pressure where the button wear is more or less than normal. As an alternative, it is possible for the RFID tag on the sharpening tool to be provided with the desired rotational speed, feed pressure and grinding time for the size and profile of the working tip. When this data is received by the control system it instructs the appropriate components on the sharpening system accordingly.

[0074] Where the data on the RFID tag is the size and profile of the grinding cup / sharpening tool selected, the control system of the rock drill bit sharpening system sets a rotational speed of the output drive and a feed pressure based on the data scanned from the RFID tag and communicates that to the VESC Controller to control the rotational speed and torque of the outrunner motor and based on the connected power source ranging from 24-75 VDC or 100-260 VAC.

[0075] Sharpening a first working tip to be ground may then commence at the rotational speed, feed and grinding time determined by the central processor or as set out on the RFID tag where the RFID tag includes that information After grinding a first working tip to be ground, the operator then aligns the sharpening tool / grinding cup about the longitudinal axis of another one of the working tips to be ground having the same size and profile of the first working tip, then sharpening / grinding the second working tip to be ground at the rotational speed, feed and grinding time determined by the central processor;

[0076] These steps in para

[0074] are repeated until all of the working tips on the rock drill bit of the same size and profile have been ground. The control system may monitor and track the number of rotations the sharpening tool / grinding cup is used during grinding until the operator removes the sharpening tool / grinding cup from the output drive shaft of the sharpening machine.

[0077] When the operator has finished using a particular sharpening tool / grinding cup he disconnects it from the output drive shaft and the sharpening tool / grinding cup is brought into proximity to the RFID reader so that data on the number of cycles it has been used may be transcribed to the RFID tag as well as transmitted to a server. Scanning a different tool can transmit stored data on the number of cycles the previous tool has been used to a server.

[0078] The use of the control system of the present invention provides the management of the grinding facility with valuable data on the operation, performance and life of not only the grinding cups but the grinding apparatus and can compare performance of different grinding apparatus in the same or different facilities.

[0079] By connecting each grinding apparatus to a network and to the internet, the control system equipped with transmitter and receiver capability allows the equipment manufacturer to be advised of error messages during operation of the grinding apparatus and either fix the error and / or schedule maintenance on the grinding apparatus. It also provides a means for the manufacturer to quickly install software upgrades or fixes. Finally, the data received by the manufacturer assists in designing further improvements to the equipment. Where the control system is integrated with a cloudbased platform for data storage and analysis, it allows for predictive maintenance. The control system can be configured to transmit operational data comprising at least rotational speed, torque command, current, and temperatures to a remote server via a wireless interface during or after sharpening.

[0080] Having illustrated and described a preferred embodiment of the invention and certain possible modifications thereto, it should be apparent to those of ordinary skillin the art that the invention permits of further modification in arrangement and detail and is not restricted to the specific semi-automatic grinding apparatus illustrated.

[0081] It will be appreciated that the above description related to the preferred embodiment by way of example only. Many variations on the invention will be obvious to those knowledgeable in the field, and such obvious variations are within the scope of the invention as described and claimed, whether or not expressly described.

Claims

CLAIMS1. A rock drill bit resharpening system for sharpening carbide button inserts on rock drill bits comprising:a resharpening machine having an output drive shaft and an outrunner motor configured to provide enhanced torque and power suitable for sharpening a wide range of carbide button insert sizes, including those with polycrystalline diamond (PCD) enhancements;a motor controller operatively connected to the outrunner motor, the motor controller configured to control motor speed and torque, and capable of operating on a VDC or VAC power sourcea control system configured to communicate with the motor controller to adjust operational parameters.

2. A rock drill bit resharpening system according to claim 1 wherein the motor controller is a VESC motor controller.

3. A rock drill bit resharpening system according to claim 1 or 2 wherein the control system further comprises an RFID reader connected to the control system, the RFID reader having a proximity sensor configured to detect an RFID tag on a sharpening tool containing specific ID data including a size and profile of the sharpening tool, the RFID reader configured to transmit the specific ID data to the control system to control the speed of rotation of the output drive shaft and feed pressure during grinding.

4. A rock drill bit resharpening system according to any one of claims 1 to 3 wherein the control system further is equipped with a transmitter and a receiver to enable the resharpening system to communicate over the internet to a server or virtual server located remotely from the resharpening system.

5. A rock drill bit resharpening system according to claim 4 wherein the control system is further configured to enable software updates of all components connected to the control system, including the motor controller, thereby facilitating enhanced automation and performance monitoring of the resharpening machine.

6. A rock drill bit resharpening system according any one of claims 1 to 5, wherein the outrunner motor includes a cooling system to maintain optimal operating temperatures during extended use.

7. A rock drill bit resharpening system according any one of claims 1 to 6, wherein the outrunner motor is designed with a modular structure to allow easy replacement or upgrading of components.

8. A rock drill bit resharpening system according any one of claims 1 to 7, wherein the motor controller includes a user interface for manual adjustments of speed and torque settings.

9. A rock drill bit resharpening system according any one of claims 1 to 8, wherein the motor controller supports additional communication protocols, including Bluetooth or CAN bus, for enhanced connectivity.

10. A rock drill bit resharpening system according any one of claims 1 to 9, wherein the control system includes a touchscreen display for real-time monitoring and control of the sharpening process.

11. A rock drill bit resharpening system according any one of claims 1 to 10, wherein the control system is integrated with a cloud-based platform for data storage and analysis, allowing for predictive maintenance.

12. A rock drill bit resharpening system according any one of claims 1 to 11, wherein the RFID reader is capable of reading multiple types of RFID tags, enhancing compatibility with various sharpening tools.

13. A compact rock drill bit sharpening system for sharpening working tips on rock drill bits comprising: a spindle assembly having an output drive shaft to which a detachablesharpening tool is mountable; a brushless outrunner electric motor mechanically coupled to the spindle assembly, the outrunner electric motor comprising an internal stator and an external rotor configured to rotate about a longitudinal axis of the spindle assembly; a VESC motor controller operatively connected to the outrunner electric motor and configured to command motor phase currents to regulate torque and rotational speed; and a control system operatively connected to the VESC motor controller and configured to set operating parameters for sharpening, wherein the VESC motor controller is configured to maintain a target rotational speed under load during sharpening of the rock drill bit.

14. A method for sharpening working tips on a rock drill bit, comprising:a. providing a sharpening machine including a brushless outrunner electric motor driving a spindle assembly having an output drive shaft and a VESC motor controller operatively connected to the motor;b. attaching a sharpening tool to the output drive shaft;c. setting, via a control system, rotational speed of the output drive shaft and feed pressure; andd. sharpening the working tips by engaging the sharpening tool with the working tips while the VESC motor controller executes field-oriented control to regulate phase currents of the outrunner motor so as to maintain the rotational speed under load.

15. The system of claim 13, wherein the VESC motor controller is compatible with a DC input in a range of 24-75 V and with an AC input in a range of 100-260 VAC through an AC / DC power supply.

16. The system of claim 15, wherein the VESC motor controller comprises a processor configured to implement field weakening at rotational speeds above a base speed of the outrunner electric motor.

17. The system of any one of claims 13 or 15 to 16, further comprising at least one position or speed sensor selected from Hall effect sensors and encoders providing rotor position feedback to the VESC motor controller.

18. The system of any one of claims 13 or 15 to 17, wherein a control system may be configured to enable input if the working tip is a carbide working tip or a polycrystalline diamond (PCD)-enhanced working tip and then set different torque-speed profiles for sharpening carbide working tips or polycrystalline diamond (PCD)-enhanced working tips.

19. The system of claim 18, wherein a control system provided and is configured to receive operational data from the VESC motor controller comprising at least motor current, motor voltage, motor temperature, and controller temperature, and to adjust the operating parameters in response to the operational data.

20. The system of any one of claims 13 or 15 to 19, further comprising a coolant delivery system arranged to deliver coolant proximate a grinding surface of the sharpening tool during operation.

21. The system of any one of claims 13 or 15 to 20, further comprising an orbital motion drive configured to impart orbital motion to the sharpening tool about a center of the tool, the orbital motion drive being controlled independently of rotational speed control provided by the VESC motor controller.

22. The system of any one of claims 15 to 21, wherein the outrunner electric motor is liquid-cooled or fan-cooled to maintain a motor temperature within a predefined range during sharpening.

23. The system of any one of claims 15 to 22, wherein the control system is configured to communicate with the VESC motor controller to perform firmware updates.

24. The system of any one of claims 15 to 23, wherein the control system comprises a wireless communications interface configured to transmit operational data to a remote server for monitoring and diagnostics.

25. The system of claim 24, wherein the control system further comprises an operator interface configured to allow selection between a constant rotational speed mode and a constant surface speed mode, the latter mode maintaining a target surface speed at the sharpening tool based on tool diameter.

26. The system of any one of claims 13 or 15 to 25, wherein the VESC motor controller is configured to apply current limits and thermal derating based on sensed motor or controller temperature.

27. The system of any one of claims 15 to 26, wherein the control system is further configured to authenticate the VESC motor controller prior to enabling operation to ensure compatibility with predefined torque-speed profiles.

28. The system of any one of claims 13 or 15 to 27, wherein the VESC motor controller comprises a non-volatile memory storing motor parameters including stator resistance, stator inductance, and back-EMF constant, and the control system is configured to initiate an identification procedure to populate the motor parameters.

29. The system of any one of claims 15 to 28, wherein the control process further comprising means for measuring motor temperature and controller temperature during sharpening and reducing at least one of torque and speed in response to a temperature exceeding a threshold.

30. The system of claims 31, wherein maintaining the target rotational speed under load comprises estimating rotor position via Hall effect sensors and applying pulse-width modulation to regulate phase voltages responsive to a field-oriented control algorithm.

31. The system of any one of claims 15 to 30, wherein the control system is capable of transmitting operational data comprising at least rotational speed, torque command, current, and temperatures to a remote server via a wireless interface during or after sharpening.

32. A motor drive for a rock drill bit sharpening machine, comprising: a VESC motor controller configured to execute field-oriented control on a brushless outrunner electric motor that drives a spindle assembly having an output drive shaft carrying a sharpening tool; and an interface configured to receive command inputs specifying at least a target rotational speed and to provide telemetry outputs comprising at least current, voltage, and temperature, wherein the motor drive maintains the target rotational speed within a predefined tolerance under material-removal load encountered during sharpening of a rock drill bit.

33. A compact motor-spindle module for a rock drill bit sharpening machine, comprising: a housing containing a brushless outrunner electric motor mechanically coupled to a spindle assembly having an output drive shaft with a detachable sharpening tool mount; and a VESC motor controller integrated with or attached to the housing and electrically connected to the motor, wherein the VESC motor controller executes field-oriented control to regulate torque and rotational speed for sharpening rock drill bit buttons.

34. A rock drill bit sharpening system for sharpening working tips on rock drill bits comprising comprising:a. a resharpening machine having an output drive shaft and an outrunner motor configured to provide enhanced torque and power suitable for sharpening a wide range of working tip sizes and profiles, including those with polycrystalline diamond (PCD) enhancements;b. a VESC motor controller operatively connected to the outrunner motor, the VESC motor controller configured to control motor speed and torque, and capable of operating on a VDC or VAC power source;c. an RFID reader positioned to scan an RFID tag associated with the sharpening tool;d. a control system comprising a processor, a non-transitory memory storing executable instructions and a parameter database, and operator VO;e. a motor drive configured to receive command signals from the control system to set operating parameters comprising at least spindle rotational speed, feed pressure, and grinding time; wherein the RFID tag stores at least: (i) a unique tool identifier, (ii) a tool size and a tool profile identifier corresponding to a grinding surface geometry, and (iii) usage metrics including a cumulative grind-cycle count, and wherein the control system is configured to: (a) read the RFID tag to retrieve the tool size, tool profile identifier, and usage metrics, (b) automatically select a set of operating parameters from the parameter database based on the tool size and the tool profile identifier, (c) command the motor drive to execute the selected operating parameters during sharpening, (d) measure one or more operational values during sharpening comprising at least spindle speed and elapsed grind time, and determine updated usage metrics including an incremented grind-cycle count, and (e) the updated usage metrics for each RFID ID upon completion of sharpening of a rock drill bit working tip is uploaded by the control system and stored on a server .

35. A rock drill bit sharpening system for sharpening carbide button inserts on rock drill bits comprising comprising a sharpening machine having a spindle assembly having an output drive shaft with a detachable sharpening tool; wherein the sharpening machine has an outrunner motor configured to provide enhanced torque and power suitable for sharpening a wide range of carbide button insert sizes, including those with polycrystalline diamond (PCD) enhancements; a VESC motor controller operatively connected to the outrunner motor, the VESC motor controller configured to control motor speed and torque, the bit holder configured to hold a rock drill bit; a support structure carrying the sharpening machine and movable toward and away from the rock drill bitalong a feed direction substantially coincident with the longitudinal axis of the button; a linear actuator coupled between a frame and the support structure and configured to advance and retract the sharpening machine along the feed direction; a load cell mechanically in series with the linear actuator and the support structure and configured to measure a feed force applied by the sharpening tool to the button; and a control system operatively connected to the linear actuator and to the load cell, wherein the control system is configured to: (i) execute a zero force approach that compensates for gravitational and inertial effects of the sharpening machine and the support structure such that initial contact force at the button is approximately zero, (ii) regulate the linear actuator during sharpening in closed loop to maintain a target feed force based on the load cell measurement, and (iii) detect an abrupt reduction in the measured feed force and, in response, inhibit spindle rotation and command retraction of the sharpening machine.

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