The method of output torque accurate measuring systems and torque measurement thereof
technical field:
the present invention relates to a kind of method of output torque accurate measuring systems and torque measurement thereof.
background technology:
the metering system that is applied at present motor reducer array output moment of torsion mainly contains two kinds: a kind of is traditional mechanical lever-type metering system; Another kind is to adopt torque sensor directly to measure moment of torsion.
the measurement of mechanical lever is that tested moment of torsion is converted to pressure by lever, measures the amount of this pressure by pull pressure sensor, then calculates torque value size by following formula.
in above formula :-tested moment of torsion
the acting force that-pull pressure sensor is measured
the arm of force of-the acting force that records
this measuring system is made up of rotor, reel cage (stator), base etc., and rotor, stator are installed on base by bearing, and freely swing by pendulum bearing.One power transmission arm is housed on the outer ring of stator, is delivered on tension-compression sensor by this power transmission arm retarding torque, and connecting piece on connecting piece and base on power transmission arm makes tension-compression sensor in two power bar states.By measuring the size of tension-compression sensor, can calculate measuring system torque value size.Manufacture machining precision and the two power bar positioning precisioies of this kind of metering system and mechanical lever and the edge of a knife have much relations.For improving the measuring accuracy of system, just need to improve the manufacture machining precision of mechanical lever and the edge of a knife, certainly will increase like this manufacture processing cost of equipment.
torque sensor can be divided into horizontal and two kinds of forms of disc type according to profile, for obtaining higher measuring accuracy, requires the installation accuracy of this kind of sensor high, because manufacturing cost is high, bringing a high price of torque sensor, and along with the raising of measuring accuracy, price increases a lot.Wherein horizontal sensor needs larger axial installation dimension, and the price of disc type sensor will be far above the horizontal sensor of identical measuring accuracy.Compared with pull pressure sensor, the in the situation that of equal measuring accuracy, the price of torque sensor will be far above the precision of pull pressure sensor.
existing application pull pressure sensor torque-measuring apparatus. measuring accuracy is high, and the radial force producing in energy offset measurement, but has applied flexible piece in this system, can produce relaxation, can not measure reactive torque, and structure is more complicated.
thickener Torque Measuring Device, can carry out moment of torsion demonstration in time according to the conversion of load, and effectively controls the running that turns rake, but this device should not be used for high-precision torque measurement, compared with the torque measuring method of mechanical lever-type, and complex structure.
summary of the invention:
the object of this invention is to provide a kind of method of output torque accurate measuring systems and torque measurement thereof.
above-mentioned object realizes by following technical scheme:
a kind of output torque accurate measuring systems, its composition comprises: the inner stator coil of installing of stator casing of motor, described stator casing and the shell of speed reduction unit are fixed, rotor is connected with described reducer input shaft by shaft coupling, described reducer output shaft is circumferentially fixing with output shaft coupling, the shell of described stator casing and described speed reduction unit is respectively by rear bearing and front bearing and base formation revolute pair, the shell both sides of described speed reduction unit have lever and weight linear meter, described lever is connected with pull pressure sensor by ball pivot A, described pull pressure sensor is connected with base by ball pivot B, described weight linear meter is installed counterweight, code-disc is installed in the rear end of described motor.
utilize above-mentioned output torque accurate measuring systems to carry out a method for torque measurement,
the first step, after described stator coil energising, described rotor produces and rotatablely moves and output torque;
second step, the rotation of described rotor, after described speed reduction unit speed change, is exported by described reducer output shaft, and described motor and described speed reduction unit rotate freely around axis;
the 3rd step after the moment of torsion that described motor produces increases by described speed reduction unit, forms drive source after the output of output shaft coupling;
the 4th step, record the line of described ball pivot A and described ball pivot B and described motor and described speed reduction unit be combined into revolving shaft between distance, the pulling force signal that pull pressure sensor described in gathering is born is also converted into after power, in conjunction with described distance, the output torque T after the motor described in obtaining and the combination of described speed reduction unit is:
(1)；
in formula:
active line be positioned on the line of centres of ball pivot A and described ball pivot B;
for the moment of the axis of rotation generation of described counterweight to described speed reduction unit;
for the moment of torsion sum that in mechanism, each kinematic pair produces;
, and actual value determine by calibration system;
the 5th step, described calibration system is after torch measuring system assembles, described output shaft coupling is replaced to the scaling board with circular arc, standard test weight 2 is mounted on described scaling board by standard test weight 1, mounts the tensile relationship that various criterion counterweight weight and described pull pressure sensor bear to be:
in formula: the pulling force that the pull pressure sensor described in when only mounting counterweight 1 is born;
for the pulling force that mounts accurate counterweight 1 and pull pressure sensor is born during by standard test weight 2 simultaneously;
for the radius of circular arc, the axis of rotation that is centered close to speed reduction unit of circular arc;
for the gravity of standard test weight, its value is the quality of counterweight and the product of acceleration of gravity;
through type 2 and 3, can obtain:
the 6th step, from formula 4, the above the manufacturing accuracy, assembly precision of circular arc and the measuring accuracy of described pull pressure sensor of precision and described scaling board relevant, and it is irrelevant with processing and the assembly precision of other parts with this Size dependence, after the actual value of measuring, can be by this parameter read-in dynamometry software;
the computing formula that simultaneous formula 1 and formula 2 can obtain the output torque T after motor reducer combination is:
finally, after demarcation, formula 5 is write to Survey Software, hardware and software syndeton combines and forms the accurate measuring systems of output torque.
the method of described torque measurement, described scaling board is symmetrical structure, the center of circle of described circular arc is positioned at the symcenter of described scaling board, on the centre of gyration line that the motor described in described symcenter is positioned at and described speed reduction unit combine.
the method of described torque measurement, circular arc on the vertical line that the total centre of gravity of described standard test weight 1 and described standard test weight 2 passes through and described scaling board is tangent, and the position that described standard test weight 1 and described standard test weight 2 mount is on described motor axis of rotation and with respect to the opposite side of described pull pressure sensor.
beneficial effect:
the present invention will have the stator casing of motor and the motor of its inner stator coil of installing and speed reduction unit combination, again by realizing rotary pair between self-aligning bearing and base, tension-compression sensor adopts ball pivot to be connected with base and lever, there is installation accuracy and require lowly, install simple and convenient and do not affect measurement result advantage accurately; Recycle the function of whole hardware configuration in conjunction with software, less demanding to part and the assembly precision of composition lever, measuring accuracy depends on the precision of pull pressure sensor; Simple in structure, overall cost is low; Pull pressure sensor can be measured pressure and pressure, and this system can adapt to the torque measurement of forward and reverse direction; There is measuring system versatility high.
brief description of the drawings:
accompanying drawing 1: torch measuring system schematic diagram of mechanism.
accompanying drawing 2: the schematic diagram of mechanism of demarcation.
accompanying drawing 3: the schematic diagram of mechanism of demarcating when processing and assembly precision are low.
accompanying drawing 4: extension spring pre-pressing structure sketch.
accompanying drawing 5: stage clip pre-pressing structure sketch.
accompanying drawing 6: the structure diagram of motor reducer combination cantilever.
1. output shaft couplings in figure; 2. front bearing; 3. counterweight; 4. weight linear meter; 5. speed reduction unit; 6. reducer input shaft; 7. shaft coupling; 8. stator coil; 9. rotor; 10. code-disc; 11. rear bearings; 12. stator casings; 13. levers; 14. ball pivot A; 15. pull pressure sensor; 16. ball pivot B; 17. bases; 18. reducer output shafts; 19. scaling boards; 20. circular arcs; 21. standard test weights 1; 22. standard test weights 2; 23. bearings 1; 24. bearings 2; 25. extension springs; 26. stage clips.
embodiment:
embodiment 1:
a kind of output torque accurate measuring systems, its composition comprises: the inner stator coil (8) of installing of stator casing (12) of motor, the shell of described stator casing and speed reduction unit (5) is fixed, rotor (9) is connected with described reducer input shaft (6) by shaft coupling (7), described reducer output shaft (18) is circumferentially fixing with output shaft coupling (1), in the time that stator coil (8) is switched on, rotor (9) produces and rotatablely moves and output torque, the rotation of rotor is after the speed change of speed reduction unit (5), exported by described reducer output shaft (18), the shell of described stator casing (12) and described speed reduction unit (5) forms revolute pair by rear bearing (self-aligning bearing) (11) and front bearing (self-aligning bearing) (2) with base (17) respectively, the combination that realizes motor and speed reduction unit (5) can rotate freely around axis, the shell both sides of described speed reduction unit have lever (13) and weight linear meter (4), described lever is by ball pivot A(14) be connected with pull pressure sensor (15), described pull pressure sensor is by ball pivot B(16) be connected with base (17), the combination free that this structure can hinder motor and speed reduction unit (5) rotates, described weight linear meter is installed counterweight (3), and described counterweight (3) applies pretightning force to described pull pressure sensor (15), to eliminate the fit-up gap between part, after the moment of torsion that motor produces increases by speed reduction unit (5), via output shaft coupling (1) output, as the drive source of other function topworkies, code-disc (10) is installed in the rear end of described motor, can measure the real-time rotate speed of rotor with respect to stator by code-disc (10).
embodiment 2:
ask the output torque accurate measuring systems described in 1 according to embodiment, as shown in Figure 4, be with the difference of embodiment 1, realize the elimination of two ball pivot fit-up gaps that described pull pressure sensor (15) is formed by the pre-pressure of extension spring (25); Described extension spring (25) is fixed by described weight linear meter (4) and the shell of described speed reduction unit (5), the both sides of the speed reduction unit (5) described in described weight linear meter (4) lays respectively at described lever (13), after described pull pressure sensor (15) assembles, described extension spring (25) length that is stretched, the size of the pulling force that produces should make described ball pivot A(14) and described ball pivot B(16) the elimination of the fit-up gap at draw direction.
embodiment 3
ask the output torque accurate measuring systems described in 1 or 2 according to embodiment, as shown in Figure 5, be with the difference of embodiment 1 or 2, realize the elimination of two ball pivot fit-up gaps that described pull pressure sensor (15) is formed by the precompression of stage clip (26); Described stage clip (26) is positioned at the same side with described pull pressure sensor (15), after assembling, compressed and two ends are fixed with described lever (13) and described base (17) respectively, described stage clip (26) produces a pre-thrust to described lever (13), and the size of this power should make described ball pivot A(14) and described ball pivot B(16) the elimination of the fit-up gap at draw direction.
embodiment 4
ask the output torque accurate measuring systems described in 1 or 2 according to embodiment, as shown in Figure 6, be with the difference of embodiment 1, motor described in embodiment 1 and described speed reduction unit combine the frame mode that adopts free beam between rear and base as shown in Figure 1, be that motor reducer combination is positioned between rear bearing (11) and front bearing (2), and the combination of motor and speed reduction unit and the assembling between base adopt the frame mode of semi-girder in embodiment 4, i.e. bearing 1(23 as shown in Figure 6) and bearing 2(24) be positioned at the same side of motor reducer combination, this kind of frame mode makes described bearing 1(23) and described bearing 2(24) at a distance of nearer, can form two coaxial rotation pairs (23) and (24) by a part and speed reducer housing, have advantages of that workpiece accuracy is high, measured value is accurate.
embodiment 5:
utilize above-mentioned output torque accurate measuring systems to carry out a method for torque measurement,
the first step, after described stator coil (8) energising, described rotor (9) produces and rotatablely moves and output torque;
second step, the rotation of described rotor is after described speed reduction unit (5) speed change, and by described reducer output shaft (18) output, described motor and described speed reduction unit (5) rotate freely around axis;
the 3rd step, the moment of torsion that described motor produces forms drive source after increasing by described speed reduction unit (5) after output shaft coupling (1) output;
the 4th step, record described ball pivot A(14) and described ball pivot B(16) line and described motor and described speed reduction unit be combined into revolving shaft between distance, the pulling force signal that pull pressure sensor (15) described in gathering is born is also converted into after power, in conjunction with described distance, the output torque T after the motor described in obtaining and the combination of described speed reduction unit is:
in formula:
active line be positioned at ball pivot A(14) and described ball pivot B(16) line of centres on;
for the moment of the axis of rotation generation of described counterweight (3) to described speed reduction unit (5);
for the moment of torsion sum that in mechanism, each kinematic pair produces;
, actual value can not calculate acquisition by theory, because of processing and assembling there is error, and actual value and theoretical value also there is error, be reduction measuring error, above-mentioned three parameters should be determined by calibration system;
the 5th step, described calibration system is after torch measuring system assembles, described output shaft coupling (1) is replaced to the have circular arc scaling board (19) of (20), standard test weight 2(22) by standard test weight 1(21) to be mounted on described scaling board (19) upper, mount the tensile relationship that various criterion counterweight weight and described pull pressure sensor (15) bear to be:
in formula: the pulling force that the pull pressure sensor described in when only mounting counterweight 1 is born;
for the pulling force that mounts accurate counterweight 1 and pull pressure sensor is born during by standard test weight 2 simultaneously;
for the radius of circular arc, the axis of rotation that is centered close to speed reduction unit (5) of circular arc;
for the gravity of standard test weight, its value is the quality of counterweight and the product of acceleration of gravity;
through type 2 and 3, can obtain:
the 6th step, from formula 4, the above the manufacturing accuracy, assembly precision of circular arc (20) and the measuring accuracy of described pull pressure sensor (15) of precision and described scaling board (19) relevant, and it is irrelevant with processing and the assembly precision of other parts with this Size dependence, after the actual value of measuring, can be by this parameter read-in dynamometry software;
the computing formula that simultaneous formula 1 and formula 2 can obtain the output torque T after motor reducer combination is:
（5）；
from this formula, the precision of this systematic survey gained moment of torsion is only relevant with the manufacturing accuracy of scaling board circular arc and the measuring accuracy of assembly precision and pull pressure sensor, even if occur that processing as shown in Figure 3 and the very large situation of rigging error also can not affect the measuring accuracy of this system, when occur along motor and speed reduction unit built-up shaft to rigging error time, what adopt because of the two ends of pull pressure sensor is the ball pivot of Three Degree Of Freedom, therefore this error can not exert an influence to the measurement result of pull pressure sensor, and calibrated value also can not be subject to the impact of this error;
finally, after demarcation, formula 5 is write to Survey Software, hardware and software syndeton combines and forms the accurate measuring systems of output torque.In the time bumping in transportation or measurement environment changes greatly, actual value likely change, can pass through said process calibration value again, then just relevant parameter writes Survey Software replacement raw parameter, to revise the measuring accuracy to output torque.
embodiment 6:
ask the method for the torque measurement described in 5 according to embodiment, described scaling board is symmetrical structure, the center of circle of described circular arc is positioned at the symcenter of described scaling board, on the centre of gyration line that the motor described in described symcenter is positioned at and described speed reduction unit combine.
embodiment 7:
according to the method for the torque measurement described in embodiment 5 or 6, circular arc (20) on the vertical line that the total centre of gravity of described standard test weight 1 and described standard test weight 2 passes through and described scaling board is tangent, and the position that described standard test weight 1 and described standard test weight 2 mount is on described motor axis of rotation and with respect to the opposite side of described pull pressure sensor.