Method and system for constant temperature control of electric spindle

Abstract

To provide a device configured to carefully control a load (i.e., motor speed and a motor load) so that motor loss becomes approximately the same as heat dissipation as one method to control an operating temperature of an electric spindle.SOLUTION: A method and a system are provided for controlling a temperature of an electric motor by adjusting electrical loss of the motor. In one embodiment, a required load for the motor is determined and a first motor voltage is supplied to meet the required load. A predetermined temperature set point for the motor is compared with the temperature of the motor to determine a second motor voltage based on the temperature of the motor and the predetermined temperature set point. A motor voltage is adjusted based on the calculated voltage and motor load measurement that is adjusted based on the measured motor speed and an actual motor voltage.SELECTED DRAWING: Figure 1a

Description

[Technical field]

[0001] The present invention relates to a system, method and apparatus for constant temperature control of a motorized spindle. [Background technology]

[0002] Motorized spindles are driven by electric motors whose stator and rotor are integral parts of the spindle. Typically, spindles are used in environments with unpredictable speeds and torque loads, which cause varying losses in the motor and, as a result, temperature changes. As a result, motorized spindles experience dimensional variations that alter the dimensions of the workpiece. When precision is required at high tolerance levels (i.e., micron and sub-micron levels), even very small dimensional changes due to temperature can affect the production of precisely machined parts. Such thermal effects in motorized spindles are an unsolved problem.

[0003] One existing approach to mitigating the impact of thermal effects is to "warm up" the motorized spindle to an operating temperature before the machining operation begins and then maintain this operating temperature.

[0004] One way to control operating temperature is to carefully control the load (ie, motor speed and motor load) so that the motor losses are approximately equal to the heat dissipation.

[0005] Another way to maintain operating temperature is to actively control the temperature of the coolant. This typically requires a temperature control system that can measure the temperature of the coolant and heat and / or cool the coolant so that dimensional changes (due to temperature) occur before machining takes place. However, the problem with this procedure is that it increases setup / down times, which is undesirable and problematic when there are additional temperature changes and therefore additional dimensional changes during machining.

[0006] It would therefore be desirable to provide a system, method and apparatus that ameliorate or at least mitigate one or more of the problems set forth above.

[0007] Before moving to a summary of the invention, it will be understood that the discussion of the background of the invention is included to explain the context of the invention and is not an admission that any of the referenced material is publicly available, known, or part of the common general knowledge. Summary of the Invention

[0008] The present invention provides a method to utilize motor capabilities to actively control motor temperature with a temperature controller integrated into the motor drive. The method is applicable to embedded axis drives and various motor types, including but not limited to rotary motors, linear motors, motorized spindles, synchronous motors including permanent magnet spindle motors, and asynchronous motors including induction motors. In applications where the motor is an integral part of a larger component such as a spindle, heat losses can be transferred to other components of the spindle causing proportional dimensional changes. Even small dimensional changes can have a significant impact on the production of a precisely machined workpiece. Heat can also dissipate from the motor to other machine parts in the vicinity of the motor. This is particularly problematic in high precision machines with heat sensitive components in the vicinity of the motor. In high precision machines, the effects of heat on the accuracy and repeatability of the machine can be significant. The present invention can be applied to reduce the effects of heat in these components or to affect the components in a more predictable way.

[0009] The term "load" refers to the load on the motor as well as the speed of the motor, so the required load may include both the required load on the motor and the required speed of the motor, which may be, for example, rotary or linear depending on the type of motor.

[0010] In a first aspect, the present invention provides a method for producing a composition comprising the steps of: Induction Motor Spindle By adjusting the electrical losses of Induction Motor SpindleHow to control the temperature 16. A method for producing a motorized spindle, comprising the steps of: (a) determining a required load for the induction motorized spindle and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the induction motorized spindle; (c) determining a temperature of the induction motorized spindle; (d) comparing the temperature of the induction motorized spindle to the predetermined temperature set point; (e) determining a second motor voltage based on the temperature of the induction motorized spindle and the predetermined temperature set point; and (f) adjusting a motor voltage based on the voltage calculated in steps (a) and (e). to provide.

[0011] The invention determines the load required by the motor and adjusts the first voltage to meet the required load. If the temperature falls below a threshold temperature, a second voltage can be applied to the motor to increase the temperature toward a predetermined temperature set point. Advantageously, although some motor efficiency is sacrificed, the motor operates at a constant temperature, reducing the possibility of temperature induced dimensional changes during machining in applications such as CNC systems.

[0012] Step (f) may include increasing the second motor voltage if the temperature is below a predetermined temperature. Alternatively, step (f) may include decreasing the second motor voltage if the temperature exceeds a predetermined temperature setpoint.

[0013] Alternatively, the motor may be an induction motor, in which case step (f) comprises varying the motor flux by varying the motor voltage.

[0014] The predetermined temperature may be a temperature range or may be a specific temperature. Preferably, in step (d), the temperature of the motor is compared to a predetermined temperature setpoint for a predetermined time. The predetermined time may be 120 ms.

[0015] In a second aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: Synchronous motorized spindles that compensate for varying losses by varying the flux generating current to meet load and speed requirements How to control the temperature (a) determining a required load for the synchronous motorized spindle and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the synchronous motorized spindle; (c) determining a temperature of the synchronous motorized spindle; (d) comparing the temperature of the synchronous motorized spindle to the predetermined temperature set point; and (e) adjusting the motor flux generating current to meet load and speed requirements. Provide do.

[0016] In a third aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: Induction Motor Spindle By adjusting the electrical losses of Induction motor spindle Control the temperature of 1. A system, the system including an interface for providing one or more parameters to a CNC component that controls one or more drive units and, in turn, one or more induction motorized spindles, the CNC component being programmed to: (a) determine a required load for the induction motorized spindle and provide a first motor voltage to meet the required load; (b) provide a predetermined temperature set point for the induction motorized spindle; (c) determine a temperature of the induction motorized spindle; (d) compare the temperature of the induction motorized spindle to the predetermined temperature set point; (e) determine a second motor voltage based on the temperature of the induction motorized spindle and the predetermined temperature set point; (f) adjust the motor voltage based on the voltage calculated in steps (a) and (e); and (g) adjust a motor load measurement based on a measured motor speed and an actual motor voltage. Provide a system.

[0017] Preferably, the predetermined temperature set point for the motor in step (b) is set by an operator depending on the desired load sequence.

[0018] Preferably, step (g) includes incorporating a motor data sheet associated with the motor when adjusting the motor load measurement. For example, a normal motor speed control may be applied using a normal V / F from the motor data sheet.

[0019] In a fourth aspect, the present invention provides a method for producing a pharmaceutical composition comprising the steps of: Synchronous Motorized Spindle Temperature control system and (e) adjusting the motor flux generating current to meet load and speed requirements. The system further includes an interface for providing one or more parameters to one or more drive units, which in turn controls one or more synchronous motorized spindles, the CNC component being programmed to: (a) determine a required load for the synchronous motorized spindle and provide a first motor voltage to meet the required load; (b) provide a predetermined temperature set point for the synchronous motorized spindle; (c) determine a temperature of the synchronous motorized spindle; (d) compare the temperature of the synchronous motorized spindle to the predetermined temperature set point; and (e) adjust the motor flux generating current to meet load and speed requirements. Provide do .

[0020] In a fifth aspect, the present invention includes an interface for providing one or more parameters to one or more drive units that regulate the temperature of one or more motors by adjusting the terminal voltage of the motors while maintaining a particular speed and torque. and the motor is mounted in a machine tool spindle. An electric motor control system is provided.

[0021] Preferably the motor is integrated into a machine tool spindle. It will be appreciated that the motor may be a synchronous or induction motor, the losses of which are modified by varying a voltage in phase with the motor flux.

[0022] In a sixth aspect, the present invention provides a method for controlling the temperature of an electric motor having a motorized spindle and a constant temperature controller, comprising the steps of: (a) providing a desired temperature set point for the motorized spindle; and (b) depending on the state of the constant temperature controller, selectively applying: (i) a constant voltage / frequency to control the speed of the motor if the constant temperature controller is disabled; otherwise, (ii) a controlled voltage to the motor such that there is sufficient power to rotate the motor at a given speed and load and regulate the temperature via the constant temperature controller.

[0023] Preferably, the method further includes determining a speed of the motorized spindle, and in response to the speed of the motorized spindle being equal to zero, (i) controlling the motorized spindle via a constant temperature control at zero speed, otherwise, if the speed is not zero, (ii) applying a controlled voltage to the motor such that there is sufficient power to rotate the motor at a predetermined speed and load and regulating the temperature via the constant temperature controller. [Brief description of the drawings]

[0024] [Figure 1a] FIG. 1a is a schematic diagram of typical elements in a CNC controlled motorized spindle system in which the present invention can operate. [Figure 1b] FIG. 1b is a schematic diagram of typical elements in a CNC controlled motorized spindle system including multiple axes driven by a motorized spindle. [Figure 2a] FIG. 2a is a flow chart illustrating the method of the present invention for controlling the temperature of an electric motor by regulating electrical losses. [Figure 2b] FIG. 2b is a flow chart illustrating the present invention method for controlling the temperature of a synchronous motor in which losses are modified by varying the synchronous voltage in phase with the motor flux. [Figure 2c] FIG. 2c is a flow chart illustrating the method of the present invention, including details of the steps for constant temperature control during operation. [Figure 3a] FIG. 3a is a schematic diagram illustrating the operation of a constant voltage / frequency speed control of an induction motor. [Figure 3b] FIG. 3b is a schematic diagram illustrating V / F control of an induction motor with constant temperature control. [Figure 4] FIG. 4 is a schematic diagram illustrating the operation of the constant temperature controller of FIG. 3b. [Diagram 5] FIG. 5 is a flow diagram illustrating a further embodiment of the method of the present invention, including details of the steps for constant temperature control. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] Figure 1a is a schematic diagram of standard elements in a CNC (Computer Numerical Control) system 100 used to control one or more motors and / or one or more motorized spindles. The present invention will be described with reference to a CNC environment and motors involving machine tools, but need not be so limited. The present invention may be applied to control different types of motors in any application where a constant temperature is required. In a preferred embodiment, the CNC system 100 is capable of machining complex parts to micron-level tolerances.

[0026] The term "motorized spindle" as used herein may refer to a motor, a spindle, or a motorized spindle. As will be appreciated, motor 135 need not be rotary or linear and may take any form including, for example, a permanent magnet spindle. In a first embodiment, motor 135 is an induction motor. In this embodiment, it will be appreciated that the magnetic flux generated by an induction motor is proportional to the voltage applied to the induction motor.

[0027] In this embodiment, the load on the motor (i.e. its speed and load) is the primary concern, and temperature is a secondary concern. Temperature changes are limited to a minimum range.

[0028] The CNC system 100 includes a user interface 105 through which various parameters for the CNC system 100 can be input. One of the parameters may be the desired set point temperature at which the motor is to be maintained. The user interface 105 may have several components such as a part program interpreter, a programmable logic controller, and a servo command interpreter, etc. (not shown). In a preferred embodiment, the CNC component 110 may send position and / or velocity commands to a drive unit 115 to control the motor or motorized spindle 135. It is noted that a thermistor 140 is embedded in the motor windings to measure the motor temperature and feed the temperature reading back to the drive, as shown in FIG. 1a.

[0029] Additionally, an encoder or proxy switch 130 is provided to obtain and receive position and velocity feedback from the motor to the drive 115. It will be appreciated that there may be one or more motors 135 controlled by the system 100.

[0030] The CNC system 100 may also include several movable axes, each associated with a separate motor 125 and its drive 112, as shown in Figure 1b. Each motor 135 is controlled by a voltage supplied by an associated drive 115. When a motor 135 is operating, it converts electrical energy into rotary or linear motion.

[0031] It will be appreciated that, as also shown in Figure lb, the CNC system 100 may include multiple motorized spindles 115, each of which may be controlled according to the methods of the present invention. For clarity, Figure lb shows only one motorized spindle 115. As the motor 135 operates to meet the changing speed and load requirements required, its temperature will rise and fall according to heat losses.

[0032] The present invention includes a method for exploring motor capabilities to actively maintain motor temperature without the need for an additional temperature controller. The temperature of the motor is controlled by software methods built into the drive that controls the motor. Advantageously, this does not require additional hardware.

[0033] Figure 3a is a diagram 300 illustrating a constant voltage / frequency approach, known as a V / F curve, for controlling the speed of a motor 135. Several components 305 common to Figures 3a and 3b are provided, including a V / F curve 320, a commutation component 325, a calculation component 330, an induction motor 335, and a spindle load update component 340.

[0034] FIG. 3b illustrates a constant voltage / frequency control of an induction motor according to the method of the present invention.

[0035] This example describes a control strategy for controlling the motor 335 in the form of scalar control (V / F) to achieve a constant temperature of the motor in a closed loop system, although it will be appreciated that other methods such as vector control and direct torque control may be provided.

[0036] As shown in FIG. 3b, voltage V2 is an adjustable parameter applied to the V / F curve.

[0037] As shown in FIG. 1a, this is accomplished by measuring the load required for motorized spindle 135 and adjusting the motor voltage via drive 115 to maintain a constant temperature and meet the required load / speed. If the temperature falls below a threshold temperature set point, the motor voltage is increased by a second voltage (V, further described with reference to FIG. 4) that may increase the temperature toward the predetermined temperature set point. 2b ) may be applied to increase the

[0038] Although some motor efficiency is sacrificed, the motor 135 operates at a constant temperature, which in applications such as the CNC system 100 advantageously allows for a reduction in the likelihood of dimensional changes due to temperature, with a consequent effect on the production of precisely machined workpieces in preferred embodiments of the machine tool.

[0039] 2a is a flow diagram illustrating a method 200a of the present invention for controlling the temperature of an electric motor by regulating electrical losses. The method may be implemented in software or firmware in hardware on the CNC system 100 or may reside on a computer associated with the system that controls the operation of the motorized spindle 135.

[0040] Method 200a begins at step 205a where a required load on the motor is determined and a first motor voltage is provided to meet the required load. Control then passes to step 210a where a predetermined temperature set point is applied to the motor. Control then passes to step 215a where the motor temperature is determined and then passes to step 220a where the motor temperature is compared to the predetermined temperature set point. Control then passes to step 225a where a second motor voltage is determined based on the motor temperature, the predetermined temperature set point, and then passes to step 230a where the motor voltage is adjusted based on the voltage calculated in steps 205a and 225a. Control then passes to step 235a where the motor load measurement is adjusted based on the measured motor speed and the actual motor voltage.

[0041] 2b is a flow diagram illustrating a method 200b of the present invention for controlling the temperature of a synchronous motor, where losses are corrected by varying a synchronous voltage in phase with the motor flux. The method may be implemented in software or firmware in hardware on the CNC system 100, or may reside in a computer associated with the system that controls the operation of the motorized spindle 135.

[0042] Method 200b begins at step 205b where a required load on the motor is determined and a first motor voltage is provided to meet the required load. Control then passes to step 210b where a predetermined temperature set point for the motor is provided. Control then passes to step 215c where the temperature of the motor is determined, after which control passes to step 220b where the motor temperature is compared to the predetermined temperature set point. Control then passes to step 225b where the motor synchronous voltage is adjusted in phase with the motor flux.

[0043] FIG. 2c is a flow diagram illustrating a method 200c of an embodiment of the present invention, which may be in software or firmware in hardware on the CNC system 100 or may be resident on a computer associated with the system that controls the operation of the motorized spindle 135.

[0044] The method 200c begins at step 205c, where a user may input a desired temperature set point for the motorized spindle 135 via the user interface 105 of FIG. 1a.

[0045] Control then passes to step 210c, where it is determined whether the motorized spindle has been activated (eg, by a user via user interface 105).

[0046] If the motorized spindle 135 is running, control passes to step 215c where it is determined whether the constant temperature controller 310 is enabled, otherwise, if the motorized spindle is not running in step 210c, control returns to step 205.

[0047] If step 215c determines that the constant temperature controller 310 is enabled, control passes to step 220c where the motorized spindle 135 is controlled via voltage provided by the motorized spindle drive 115 as in Figure 1a. The motorized spindle 135 includes an encoder / proxy switch 130 to provide feedback signals for the position or speed of the motorized spindle 135 and temperature via a thermistor 140 as in Figure 1a. As described above, the drive 115 controls the position and speed of the motorized spindle 135 and may store data generated while the motorized spindle 135 is operating.

[0048] Returning to FIG. 2c, control then passes to step 220c where the control voltage to the motor is adjusted so that there is enough power to turn the motor for a given speed and load, and the temperature is also regulated.

[0049] The constant temperature controller 310 is further described with reference to Figures 3b and 4. The calculations performed in step 220c are performed by the constant temperature controller 310 of Figure 3b.

[0050] The operation of the first embodiment of the constant temperature controller 310 is composed of processing components 1, 2, and 3, as shown in FIG.

[0051] The calculation of V2 used in step 225c of flowchart 200c is shown in FIG.

[0052] Voltage V2 is the sum of the outputs of processing components 1 and 2. The input of processing component 1 is the spindle load percentage L, which is the spindle load percentage supplied by the encoder. sd The output of processing component 1 is the voltage V 2a which is the minimum value of V2 on the V / F curve of FIG. 3a, for a given spindle load L sd Such that the motor provides sufficient power to rotate the spindle relative to the

[0053] Furthermore, the processing component 2 adjusts the voltage V2, allowing the temperature to be adjusted when the magnetic flux is adjusted.

[0054] As shown in FIG. 4, the processing component 2 receives as input T measured , and T, the desired motor temperature set by the operator in degrees. set The difference between these temperatures is input to processing component 2, which outputs an output voltage V 2b supplies.

[0055] Output V 2b ,V 2a are summed at the junction to provide V2, the voltage at breakpoint 2 (P2) measured in volts. V2 is then input to component 320 of Figure 3b. Component 320 outputs a voltage V, the magnitude of which is proportional to the spindle speed ω shown in Figure 3b. CMD is determined.

[0056] As shown in Figure 3b, the output of the constant temperature controller, V2, is applied to the V / F curve of the induction motor.

[0057] As shown in FIG. 4, in one embodiment, which will be further described with reference to FIG. 5, the processing component 3 receives as input T measured , and T, the desired motor temperature set by the operator in degrees. set The difference between these temperatures is the input of processing component 3. Processing component 3 provides the output voltage magnitude (V) for a zero speed spindle.

[0058] Returning to FIG. 2c, control then passes to step 225c where it is further determined whether the cycle has ended, if so, control passes to step 235c, otherwise control passes back to step 205c. If constant temperature control was not enabled in step 215c, control simply passes to step 230c, as shown in FIG. 2c. Note that the output of the V / F open loop curve block in FIG. 3b is only the magnitude of the voltage to the motor. This is converted to a three-phase voltage, taking into account the motor's electrical angle of rotation θ.

[0059] As shown in FIG. 3a, the operation component 320 generates a spindle speed command ω in RPM (revolutions per minute) in addition to the ω1 spindle speed at breakpoint 1 (P1) in RPM. CMD It will be appreciated that the input receives as inputs V1 the voltage at breakpoint 1 (P1) in volts (V), ω2 the spindle speed at breakpoint 2 (P2) in RPM, V2 the voltage at breakpoint 2 (P2) in volts (V), ω3 the spindle speed at breakpoint 3 (P3) in RPM, and V3 the voltage at breakpoint 3 (P3) in volts (V).

[0060] The V2 value (voltage at breakpoint 2 (P2)) shown in FIGS. 3a and 3b is determined by the sum of the outputs from the constant temperature controllers, as shown in FIG.

[0061] 5 is a flow diagram illustrating a further embodiment of a method 500 of the present invention, which may be in software or firmware in hardware on the CNC system 100 or may reside on a computer associated with the system that controls the operation of the motorized spindle 135. This embodiment of the present invention allows for the case where a constant temperature is maintained when the spindle speed is zero (i.e., when the spindle is stationary). This situation may occur when a workpiece is loaded into the machine and no grinding is occurring (for example). This embodiment, together with the processing component 3 (FIG. 4), reduces the need for warm-up between the loading and grinding stages.

[0062] Method 500 begins at step 505 where a user may input a desired temperature set point for motorized spindle 135 via user interface 105 of FIG. 1a.

[0063] Control then passes to step 510, where it is determined whether the motorized spindle has been activated (eg, by a user via user interface 105).

[0064] If the motorized spindle 135 is running, control passes to step 515 where it is determined whether the constant temperature controller 310 is enabled, and if not, control returns to step 505 .

[0065] If the constant temperature controller 310 is determined to be enabled in step 515, then control passes to step 520 where it is determined whether the spindle speed is equal to zero. If the spindle speed is not equal to zero, then control passes to step 525 where the motorized spindle 135 is controlled via voltage provided by the motorized spindle drive 115 as in FIG. 1a. The motorized spindle 135 includes an encoder / proxy switch 130 to provide feedback signals for the position or speed of the motorized spindle 135 and temperature via a thermistor 140 as in FIG. 1a. As described above, the drive 115 controls the position and speed of the motorized spindle 135 and may store data generated while the motorized spindle 135 is operating.

[0066] If the constant temperature controller 310 is determined to be enabled in step 515 and the spindle speed is determined to be zero in step 520, control passes to step 540 where the motorized spindle is controlled via constant temperature control at zero speed (V) as shown in FIG. 3a and processing component 3 of FIG. 4.

[0067] Steps 525 and 530 are performed in the same manner as corresponding steps 230c and 220c of FIG. 2c.

[0068] As shown in Figure 4, the processing component 3 receives as input T measured , and T, the desired motor temperature set by the operator in degrees. set The difference between these temperatures is the input of processing component 3. Processing component 3 provides an output voltage (V) to the spindle at zero speed.

[0069] Returning to Figure 5, control then passes to step 535 where it is determined if the cycle has ended, if so control passes to step 545, if not control passes back to step 505. If constant temperature control was not enabled in step 515 then control simply passes to step 530. Note that the output of the V / F open loop curve block in Figure 3b is just the magnitude of the voltage to the motor. This is converted to a three phase voltage taking into account the motor's electrical angle of rotation θ.

[0070] Please note that due to the simplification of the proposed method, the temperature of the motor may only be increased from its current value. The temperature controllability at light load is better than that at heavy load. If the motor is already running at full load, the temperature controllability of the proposed method is not applicable.

[0071] The invention as originally claimed in the present application is set forth below. [1] A method for controlling the temperature of an electric motor by regulating the electrical losses in the motor. [2] (a) determining a required load for the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the motor; (c) determining a temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) determining a second motor voltage based on the temperature of the motor and the predetermined temperature set point; (f) adjusting the motor voltage based on the voltage calculated in steps (a) and (e); and (g) adjusting the motor load measurement based on the measured motor speed and actual motor voltage; The method of [1] includes the steps of: [3] and step (f) includes increasing the second motor voltage if the temperature is below the predetermined temperature set point. Method [1] [4] and step (f) includes decreasing the second motor voltage if the temperature is above the predetermined temperature setpoint. Method [1] [5] the electric motor is an induction motor, and step (f) includes varying the motor voltage to thereby vary the magnetic flux of the motor; Method [1] [6] the predetermined temperature set point is a temperature range; Method [1] [7] In step (d), comparing the temperature of the motor to the predetermined temperature set point is determined over a predetermined period of time. Method [2] [8] A method for controlling the temperature of a synchronous motor, where losses are modified by varying a synchronous voltage in phase with the motor flux. [9] (a) determining a required load for the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the motor; (c) determining a temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) adjusting a motor synchronous voltage in phase with the motor flux; The method of [8] includes the steps of:

[10] A system for controlling the temperature of an electric motor by regulating the electrical losses in the motor.

[11] an interface for providing one or more parameters to a CNC component that controls one or more drive units, which in turn controls one or more motors, said CNC component comprising: (a) determining a required load for the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for said motor; (c) determining a temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) determining a second motor voltage based on the temperature of the motor and the predetermined temperature set point; (f) adjusting the motor voltage based on the voltage calculated in steps (a) and (e); (g) adjusting the motor load measurement based on the measured motor speed and the actual motor voltage;

[10] system.

[12] the predetermined temperature set point for the motor in step (b) is set by an operator according to a desired load sequence;

[11] system.

[13] and when adjusting the motor load measurement, step (g) incorporates a motor data sheet associated with the motor.

[11] system.

[14] A system for controlling the temperature of a synchronous motor, where losses are modified by varying the synchronous voltage in phase with the motor flux.

[15] and an interface for providing one or more parameters to a CNC component that controls one or more drive units and, in turn, one or more motors, the CNC component comprising: (a) determining a required load for the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for said motor; (c) determining a temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) adjusting a motor synchronous voltage in phase with the motor flux;

[14] system.

[16] 1. An electric motor control system comprising: an interface for providing one or more parameters to one or more drive units that regulate a temperature of one or more of said motors by adjusting a terminal voltage of the motor while maintaining a particular speed and torque.

[17] The motor is mounted in a machine tool spindle.

[16] Electric motor control system.

[18] The motor is an induction motor.

[17] Electric motor control system.

[19] A motor magnetic flux is provided, the motor magnetic flux being provided by a permanent magnet.

[17] Electric motor control system.

[20] The motor is a synchronous motor.

[11] Electric motor control system.

[21] Using the method of [9],

[11] Electric motor control system.

[22] 1. A method for controlling the temperature of an electric motor having a motorized spindle and a constant temperature controller, comprising: (a) providing a desired temperature set point for the motorized spindle; (b) depending on the state of the constant temperature controller, (i) if the constant temperature controller is disabled, a constant voltage / frequency for controlling the speed of the motor; otherwise; (ii) a controlled voltage to the motor such that there is sufficient power to rotate the motor at a given speed and load, and the temperature is regulated via the constant temperature controller; selectively applying The steps include:

[23] determining a speed of the motorized spindle; and in response to the speed of the motorized spindle being equal to zero, (i) controlling said motorized spindle via constant temperature control at zero speed, otherwise if said speed is non-zero; (ii) applying a controlled voltage to the motor such that there is sufficient power to rotate the motor at a predetermined speed and load and regulating the temperature via the constant temperature controller; The method of

[22] further includes:

Claims

1. A method for controlling the temperature of an electric motor by regulating the electrical losses in the motor.

2. (a) determining a required load on the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the motor; (c) determining a temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) determining a second motor voltage based on the temperature of the motor and the predetermined temperature set point; (f) adjusting the motor voltage based on the voltage calculated in steps (a) and (e); and (g) adjusting the motor load measurement based on the measured motor speed and actual motor voltage; The method of claim 1 comprising the steps of:

3. and step (f) includes increasing the second motor voltage if the temperature is below the predetermined temperature set point.

2. The method of claim 1.

4. and step (f) includes decreasing the second motor voltage if the temperature is above the predetermined temperature set point.

2. The method of claim 1.

5. the electric motor is an induction motor, and step (f) includes varying the motor voltage to thereby vary the magnetic flux of the motor.

2. The method of claim 1.

6. the predetermined temperature set point is a temperature range; 2. The method of claim 1.

7. In step (d), comparing the temperature of the motor to the predetermined temperature set point is determined over a predetermined period of time. The method of claim 2.

8. A method for controlling the temperature of a synchronous motor, where losses are modified by varying a synchronous voltage in phase with the motor flux.

9. (a) determining a required load for the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the motor; (c) determining a temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) adjusting a motor synchronous voltage in phase with the motor flux; The method of claim 8, comprising the steps of:

10. A system for controlling the temperature of an electric motor by regulating the electrical losses in the motor.

11. an interface for providing one or more parameters to a CNC component that controls one or more drive units and, in turn, one or more motors, said CNC component comprising: (a) determining a required load on the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the motor; (c) determining the temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) determining a second motor voltage based on the temperature of the motor and the predetermined temperature set point; (f) adjusting the motor voltage based on the voltage calculated in steps (a) and (e); (g) adjusting the motor load measurement based on the measured motor speed and the actual motor voltage; The system of claim 10.

12. the predetermined temperature set point for the motor in step (b) is set by an operator according to a desired load sequence; The system of claim 11.

13. and when adjusting the motor load measurement, step (g) incorporates a motor data sheet associated with the motor. The system of claim 11.

14. A system for controlling the temperature of a synchronous motor, where losses are modified by varying the synchronous voltage in phase with the motor flux.

15. The method further includes an interface for providing one or more parameters to a CNC component that controls one or more drive units and, in turn, one or more motors, the CNC component comprising: (a) determining a required load on the motor and providing a first motor voltage to meet the required load; (b) providing a predetermined temperature set point for the motor; (c) determining the temperature of the motor; (d) comparing the temperature of the motor to the predetermined temperature set point; (e) adjusting a motor synchronous voltage in phase with the motor flux; 15. The system of claim 14.

16. and an interface for providing one or more parameters to one or more drive units that regulate the temperature of one or more of said motors by adjusting terminal voltage of the motors while maintaining a particular speed and torque.

17. The motor is mounted in a machine tool spindle.

17. The electric motor control system of claim 16.

18. The motor is an induction motor.

20. The electric motor control system of claim 17.

19. A motor magnetic flux is provided, the motor magnetic flux being provided by a permanent magnet.

20. The electric motor control system of claim 17.

20. The motor is a synchronous motor.

12. The electric motor control system of claim 11.

21. Using the method of claim 9 12. The electric motor control system of claim 11.

22. 1. A method for controlling the temperature of an electric motor having a motorized spindle and a constant temperature controller, comprising: (a) providing a desired temperature set point for the motorized spindle; (b) in response to a state of the constant temperature controller, (i) if the constant temperature controller is disabled, a constant voltage / frequency to control the speed of the motor; otherwise, (ii) a controlled voltage to the motor such that there is sufficient power to rotate the motor at a given speed and load, and the temperature is regulated via the constant temperature controller; selectively applying The steps include:

23. determining a speed of the motorized spindle; and in response to the speed of the motorized spindle being equal to zero, (i) controlling the motorized spindle via constant temperature control at zero speed, otherwise if the speed is non-zero; (ii) applying a controlled voltage to the motor such that there is sufficient power to rotate the motor at a predetermined speed and load, and regulating the temperature via the constant temperature controller; 23. The method of claim 22, further comprising:

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