Dynamic measures rotating shaft system and the method and apparatus thereof of running torque
The present invention relates to a kind of structure needing dynamic measurement output shaft torque, especially relate to a kind of electric booster bicycle axis and produce torque signals, according to the rotary shaft mechanism that torque signals control motor is exerted oneself, and relate to a kind of system need carrying out control inputs level of torque according to the moment of output shaft, be specifically related to rotating shaft system and method and apparatus thereof that a kind of dynamic measures running torque.
Traditional dynamic force moment sensor is that a kind of employing pastes foil gauge on axle, and axle in use produces strain, and foil gauge changes, and foil gauge is connected with inductance coil simultaneously, and this inductance coil is moving winding.Outside moving winding, there is dead line circle, by dead line circle input alternation electricity, make moving winding produce alternation inductance, the moving winding acting in conjunction generation current inductance changed with foil gauge, then by the receiving coil of dead line circle, the change of foil gauge is read.Indirectly data that what this method read is, the signal taked can be torsional deformation and the radial deformation of axle, can not accurately reflect moment size.And the method manufacturing process is complicated, cost intensive, take up room large problem.
Another kind of traditional mode is similar as above, and difference is to apply magnetic material on axle, and the changes of magnetic field of magnetic material produces signal and received by external coil, reaches the object detecting moment.This coating material technique is wayward, there is cost intensive equally and to take up room large problem.
Also have a kind of traditional mode to utilize Hall element to detect amount of deformation to have come.The method Applicable scope is narrower, truly can not reflect the size of power.
Summary of the invention
For defect of the prior art, the object of this invention is to provide one true reflection moment size under multiple service condition, not by electromagnetic interference, with low cost, manufacturing process simply measures moment rotary shaft mechanism.
Measure the rotating shaft system of running torque according to a kind of dynamic provided by the invention, comprising: input shaft, output shaft, rotating ring, stationary ring, elastic element, elastic element retaining ring, input shaft end bearing chamber;
Adopt between input shaft with output shaft and can transmitting torque and the mode that moment of torsion can produce axial force while transmitting torque be connected, make input shaft or the axial force that sliding helical gear hub splines of joining produces according to moment of torsion with input shaft is moved in the axial direction; Rotating ring rotates with input shaft and moves axially; In the axial direction, elastic element is between stationary ring and elastic element retaining ring;
The input shaft moved axially by axial force transmission to rotating ring, rotating ring again by axial force transmission to stationary ring;
Stationary ring does not rotate and moves axially under responsive to axial force, jointly orders about deformation of elastic element with the elastic element retaining ring being arranged on input shaft end bearing chamber;
Further, the rotating shaft system of dynamic measurement running torque also has any one technical characteristics following:
-between elastic element and elastic element retaining ring, be provided with piezoresistance;
-elastic element bilateral is provided with elastic element retaining ring, side is provided with Hall element, and opposite side is provided with magnetic material.
Preferably, input shaft is provided with helical gear spline, and output shaft is provided with helical gear internal spline input shaft and drives helical gear internal spline that output shaft synchronous is rotated by helical gear spline.
Preferably, input shaft and output shaft are coaxially arranged.
Preferably, after disappearing without the moment of torsion between input shaft and output shaft, elastic element makes the distress resolves in piezoresistance after recovering distortion.
Preferably, rotating ring adopts plain thrust bearing rotating ring, and stationary ring adopts plain thrust bearing stationary ring;
Preferably, rotating ring is fixed on input shaft, also can be fixed on helical gear hub splines.
Preferably, rotating ring is fixed on input shaft, then remaining parts all with one heart cunning be assigned in input shaft, rotating ring is fixed on helical gear hub splines, then helical gear hub splines is axially sliding is assigned on input shaft.
Preferably, in the axial direction, the maximum amount of movement of input shaft equals the maximum variable shape amount of elastic element.
Measure the method for running torque according to a kind of dynamic provided by the invention, it utilizes above-mentioned dynamic to measure the rotating shaft system of running torque:
-utilize piezoresistance to obtain moment according to the change of piezoresistance resistance; Or
-utilize Hall element according to Hall displacement and magnetic material detection displacement, transfer electronic signal to and read moment or axial displacement.
According to a kind of device with the rotating shaft system of dynamic measurement running torque provided by the invention, comprise the rotating shaft system that above-mentioned dynamic measures running torque.
Compared with prior art, the present invention has following beneficial effect:
The signal that the present invention obtains can complete reaction moment size, does not limit by direction, has nothing to do to being out of shape with each of axle, actual response moment, structure is simple, makes simple, with low cost, applied range, various motor can be applied to, automatic equipment, the devices such as robot, as the strength size of motor shaft class that uses when: (1) robot captures object can direct reaction controlling, make strength just right; (2) when bicycle middle shaft is ridden, the output torque of sprocket wheel directly controls motor, and bicycle and bicycler people's car are unified, perfect trip; (3) automobile and other machinery are in the situation that automatically need regulate input torque according to load; (4) mounted in medium of bicycle motor torque transducer; (5) testing installation that is dynamic or Static Detection moment of torsion is needed.
Accompanying drawing explanation
By reading the detailed description done non-limiting example with reference to the following drawings, other features, objects and advantages of the present invention will become more obvious:
Fig. 1 is the present invention for the axis of torque form structure of bicycle middle shaft and A thereof to sectional view.
The Impact direction that Fig. 2 is system provided by the present invention when axis of torque is subject to resisting moment acting and gear spline thereof accept situation, figure cathetus arrow represents stressed.
Fig. 3 is the perspective view of output shaft of the present invention.
Fig. 4 is the perspective view of input shaft of the present invention.
Fig. 5 is the exploded isometric structural representation that the present invention is applied to bicycle axis of torque.
Fig. 6 is elastic element schematic configuration diagram of the present invention.
1, input shaft
101, helical gear hub splines
102, first shaft shoulder
2, clutch shaft bearing
301, rotating ring
302, stationary ring
501, elastic element retaining ring
502, elastic element
6, output shaft
601, helical gear internal spline
602, second shaft shoulder
7, input shaft end bearing chamber
8, output shaft end bearing chamber
9, jump ring
10, needle roller
12, bearing steel bowl
Below in conjunction with specific embodiment, the present invention is described in detail.Following examples will contribute to those skilled in the art and understand the present invention further, but not limit the present invention in any form.It should be pointed out that to those skilled in the art, without departing from the inventive concept of the premise, some distortion and improvement can also be made.These all belong to protection scope of the present invention.
In the present invention, this axis of torque is twin shaft, namely by input shaft by transmission of torque to output shaft, described input shaft is concentric with output shaft, and input shaft is by helical spline and the concentric transmitting torque of output shaft helical teeth internal spline.(in change case, the modes such as spiral sheave mechanism, spring mechanism, cam mechanism can also be adopted to replace helical spline and helical teeth internal spline) is assigned in output shaft by helical spline input shaft is sliding, and output shaft is arranged in bearing chamber by bearing.When output shaft has resisting moment, input shaft is subject to reaction force, has mobile trend.Have elastic component after thrust-bearing stationary ring, stationary ring can not infinitely be passed by the axial force that thrust-bearing can be made to produce at rotational resistance square, stops the mobile trend of input shaft, and makes after rotational resistance square disappears, elasticity is recovered, and this amount of movement can only be the maximum deformation quantity of this elastic element.Stationary ring does not rotate, but can move axially under responsive to axial force, makes deformation of elastic element, produces active force, compressing piezoresistance, makes it to produce resistance variations, thus obtains torque signals.Or adopt Hall and magnet steel element testing displacement amount to obtain torque signal.On the responsive to axial force rotating ring that transmitting torque produces simultaneously, rotating ring and stationary ring transmit axial force in rotation, and axial force makes input shaft and the rotating ring be fixed on input shaft move, then measures its displacement by electronic component or measure its locomotivity.At stationary ring, elastic element is installed, for stoping the effect of displacement and transmitting force.Element for each displacement restores to the original state after resisting moment disappears.
The present invention adopts piezoresistance to be arranged between elastic element and stationary ring, and at the resistance that responsive to axial force makes piezoresistance change according to different resisting moment outputs, namely the resistance of this change reacted the resisting moment of output shaft.When impelling the restorable elastic element of piezoresistance without stationary ring when moment of torsion has.Piezoresistance detects moment of torsion, and after moment of torsion disappears, axial force disappears, and has elastic component between piezoresistance and stationary ring, and elastic element recovers the distress resolves in distortion piezoresistance.The present invention also can adopt Hall element to be arranged on the elastic element retaining ring of elastic element side, and stationary ring side elastic element retaining ring installs magnetic material, by Hall displacement and magnetic material detection displacement, transfers electronic signal to and reads moment; Also Hall element can be adopted to be measure displacement.
The present invention is applicable to the torgue measurement of foot-operated electric booster bicycle axis, after dimension modifying design, be applicable to any rotating shaft need measuring dynamic rotary moment.The present invention utilizes synchronized disalignment to export the object reaching and measure moment.In helical teeth in the present invention's rotating shaft and output shaft, helical spline reaches disalignment and exports synchronized, when simultaneously having a resisting moment Ft according to the principle (as shown in Figure 2) of helical teeth on output shaft 6, this resisting moment Ft inherently makes rotating shaft produce the power Fa moved axially under the effect of helical teeth, Fa applies power to plain thrust bearing rotating ring 301, this power passes to plain thrust bearing stationary ring 302 by ball, the stressed elastic element retaining ring 501 that makes of plain thrust bearing stationary ring 302 is out of shape, this deformation force is pressed in the piezoresistance 11 that is arranged between elastic element retaining ring 501 and elastic element 502, piezoresistance 11 is produced according to different resisting moment change and the resistance value of change.After resisting moment disappears, elastic element 502 recovers shape, and the power acted in piezoresistance 11 disappears immediately.The invention solves the difficult problem that running shaft measures torque, make measurement more directly accurately, cost significantly reduces, and measured value is not subject to electromagnetic interference, longer service life.
The present invention is provided with jump ring at input shaft upper spline place, moving, being positioned this for limiting with spacing output shaft 6 in the direction that axial force is identical.Bearing steel bowl 12 is arranged in output shaft end bearing chamber 8, plays the effect of bearing with ball 13.Needle roller 10 is arranged between output shaft and input shaft, plays circumference centering and makes output shaft 1 and the concentric effect of input shaft 6.
Particularly, as shown in Figure 1, be the product structure schematic diagram that the present invention is applied to bicycle middle shaft,
The invention provides a kind of structure can measuring the rotational resistance square of axle, comprising: input shaft 1, clutch shaft bearing 2, ball 13, bearing steel bowl 12 plain thrust bearing rotating ring 301, plain thrust bearing stationary ring 302, elastic element retaining ring 501, elastic element 502, output shaft 6, piezoresistance 11, needle roller 10, jump ring 9, input shaft end bearing chamber 7, output shaft end bearing chamber 8.
In Fig. 1, input shaft 1 is the input shaft of bicycle, input shaft 1 is connected with the helical gear internal spline 601 of output shaft 6 by the helical gear hub splines 101 respectively on input shaft 1 and output shaft 6, helical gear internal spline 601 is driven to make output shaft 6 synchronous axial system when input shaft 1 rotates by helical gear hub splines 101, if now output shaft 1 does not have resisting moment, ideally, axial force can not be produced between helical gear hub splines 101 and helical gear internal spline 601, about between helical gear hub splines 101 and helical gear internal spline 601 produce resolution of forces figure as shown in Figure 2.
In Fig. 2, Ft represents tangential force, and Fa represents axial force, and Fn represents normal force, and Fr represents radial force.When output shaft 6 has had certain resisting moment, input shaft 1 will produce the tangential force Ft shown in Fig. 2 and axial force F a, this power of axial force F a is that output shaft 6 is under resisting moment effect, the active force that input shaft 1 produces, the axial force equal and opposite in direction that this axial force F a and resisting moment produce at the helical gear internal spline 601 of output shaft 6, direction is contrary, and therefore axial force F a directly can reflect the size of resisting moment.
When input shaft 1 in Fig. 1 drives the output shaft 6 with resisting moment to rotate, clutch shaft bearing 2 sliding joining is arranged on input shaft 1, and clutch shaft bearing 2 is arranged in input shaft end bearing chamber 7, when input shaft 1 drives the output shaft 6 with resisting moment, output shaft 6 there is second shaft shoulder 602, what be installed in that the ball 13 of output shaft end bearing chamber 8 and bearing steel bowl 12 acting in conjunction block that resisting moment produces moves axially, and reaction force makes input shaft 1 move in the axial direction, pass to the plain thrust bearing rotating ring 301 at the first shaft shoulder 102 place being fixed on input shaft 1, plain thrust bearing stationary ring 302 is passed to again by ball, plain thrust bearing stationary ring 302 is again by elastic element 502, reaction force is passed to piezoresistance 11, make piezoresistance 11 pressurized, produce the resistance change according to power change, thus obtain electrical signal.
Elastic element 502 is connected on elastic element retaining ring 501, elastic element retaining ring 501 is arranged on input shaft end bearing chamber 7, can only move in the deformation band of elastic element 502 at the input shaft 1 of the movement by axial force, after resisting moment disappears, axial force disappears immediately, elastic element 502 recoverable force, piezoresistance 11 resistance recovers initial value.
When Figure 2 shows that axis of torque rotates, power transmits schematic diagram.The axial reaction force that the resisting moment of doing work is produced by helical gear, force input shaft 1 to move down, the shaft shoulder 102 on input shaft 1 presses down plain thrust bearing rotating ring 301, is delivered to elastic element 502 always, elastic element 502 is out of shape, oppresses piezoresistance 11 thus obtain electrical signal.
Above specific embodiments of the invention are described.It is to be appreciated that the present invention is not limited to above-mentioned particular implementation, those skilled in the art can make various distortion or amendment within the scope of the claims, and this does not affect flesh and blood of the present invention.