CN102501726A - Omnidirectional wheel applicable to high precision and heavy duty - Google Patents

Abstract

An omnidirectional wheel applicable to high precision and heavy duty mainly comprises a hub, an axle sleeve, rollers, fasteners and the like, and the projection of the profile of each roller on the axial direction of the hub is a round. Each roller mainly comprises a roller core, a roller sleeve, a roller shaft, bearings, roller-positing end covers, roller clearance-eliminating end covers, roller looseness-preventing parts and other parts. Each roller is mounted as a module on the hub, and can be freely rotated around the roller shaft, so that the roller and the hub can be precisely positioned and rapidly disassembled and assembled. The outline of each roller is designed into an elliptic curve, and can strictly ensure that the profile of the roller is projected on a round, moreover, the elliptic curve can be directly machined under numerical control, the jump of the moving omnidirectional wheel in the height direction can be reduced, and thereby the stability and precision of the moving process are guaranteed. In addition, the rollers and the hub are axially and circumferentially positioned, the positioning link adopts an integrated structure, and therefore does not have extra mounting errors, the transition between the rollers is smooth, the connecting links between the rollers and the hub are less, and the reliability of the omnidirectional wheel is high.

Description

A kind of directional wheel that is applicable to the big carrying of high precision

Technical field

The present invention relates to a kind of directional wheel that can realize that any direction moves in the plane.

Background technology

At present, the directional wheel mechanism kind of research is a lot of both at home and abroad, is a kind of that comparison is successful and technology is comparatively ripe with the Mecanum wheel and the wheel of deriving thereof wherein, also can be omnidirectional's wheel, cardan wheel.This directional wheel is made up of driving wheel and passive roller usually, and the latter can passive rotation in the time of the former active movement.

The roller profilograph of Mecanum wheel is designed to space constant speed helix line; And the constant speed helix line belongs to space curve; Need be plane curve with curve approximation in the design process, and this curve can't parametrization, can only be with series of points coordinate representation; Therefore in machine up or other forming technologies, adopt the plurality of sections circular arc approximate.These links can be introduced error unavoidably, cause roller outline projection curve and theoretical circle little deviation to occur, in the especially quick rolling process, can produce periodically minor fluctuations in the wheel rolling process.

American National patent of invention US 6; 394,203 B1 disclose a kind of directional wheel that is used for universal mobile fork truck, and this directional wheel has a built-in wheel hub of rigidity; Supporting 6 rollers on the circumference of hub; Roller can freely rotate around self axis, and roller becomes to be similar to 45 ° of angles with wheel axis, and roller and wheel hub adopt central supported, two ends cantilever design; Roller is split into two halves with the plane symmetry perpendicular to axis, and on roller axle, the bearing utilization is screwed onto nut on the roller axle crack that disappears to per half roller through 2 angular contact bearing strings; This structure has big gap in the middle of causing the two halves roller, and corresponding roller and ground-surface contact wire are discontinuous, can produce periodic vibration in the wheel rolling process; Roller carries out axis hole through roller axle and wheel hub and is connected, and for reducing the transition gap between the two halves roller, the axis hole fitting surface of roller axle and wheel hub requires shorter, concerning the structure of this central supported two ends cantilever, its strength and stiffness relatively a little less than; In the wheel rolling process, roller axle and disappear and produce very larger axial force between the nut of crack, the equivalent diameter of the two matching thread little (ridge is thin), the double thread Joint strenght proposes very high request; In addition, roller itself and roller and wheel hub are installed bad, the structure relative complex of conformability, and the dismounting maintenance difficulty is big.

Summary of the invention

Technology of the present invention is dealt with problems and is: overcome the deficiency of prior art, provide that a kind of roller two end supports, profilograph are interrupted, roller and wheel hub can accurately be located and the directional wheel structure of fast assembling-disassembling.

Technical solution of the present invention is: a kind of directional wheel that is applicable to the big carrying of high precision comprises wheel hub, axle sleeve, roller, central fastener, circumference fastener; The center of wheel hub is provided with axle sleeve, and roller is fixedly mounted on the wheel hub through the circumference fastener, and the projection on the axis direction of wheel hub of the outline of all rollers forms a full circle; Roller can freely rotate along the axis of himself, when the outer surface of roller rolls as directional wheel and ground-surface contact surface; Described roller comprises roller core, roller shell, roller axle, bearing, roller location end cap, roller disappear crack end cap, anti-release member; Roller axle is the axis of symmetry of roller; Roller core and roller shell are spindle, the intercepting from the elliptic curve of plane of described spindle, and roller axle is passed along the axis of roller core; Roller shell is bonded in the outside of roller core; Bearing is positioned at said fusiform end pair of rollers axle and supports the location, the bearing of said fusiform left end outside fixed installation roller location end cap, the bearing outside fixed installation roller of the said fusiform right-hand end crack end cap that disappears; Anti-release member is positioned at roller location end cap and roller core, and roller disappears between crack end cap and the roller core; The draw-in groove end face boss location of the shaft shoulder of roller axle and wheel hub.

Described roller quantity is 6～9, and roller becomes 30 ° of-60 ° of angles with wheel axis, roller and wheel hub two end supports, and the roller outer contour is uninterrupted continuously.

Described roller core has contained the cavity of loss of weight effect, and the roller core two ends are provided with bearing hole and the internal thread hole that bearing and roller location end cap are installed.

The material of described roller shell is polyurethane or rubber.

The present invention's advantage compared with prior art is:

(1) directional wheel of the present invention adopts roller two end supports mode, and roller axle directly is fixed on the wheel hub, has simplified middle power transmission link; The roller profilograph is that roller and ground-surface contact wire are continuous, uninterrupted, can not produce vibration in the wheel rolling process.Roller two end supports mode is with respect to central supported two ends cantilevered fashion, and structural strength and rigidity are better, load-carrying capacity is higher.Roller core adopts the equal strength cavity design, and is in light weight, structural rigidity good; Roller axle is convenient with respect to the roll assembly installation, accuracy of positioning is high, roller assembling high conformity; Bearing adopts face-to-face mounting means, and bearing inner ring utilizes roller shaft shoulder location, and the outer ring utilizes end cap to compress the location; End cap is fixed through outside thread and roller core; Cooresponding equivalent diameter of thread big (ridge is thick) therefore bears under the same axial load situation, and this structural strength is higher;

(2) roller and wheel hub have very high accuracy of positioning, and the transition of directional wheel rolling process middle roller steadily, does not produce axially or the play of circumferencial direction, can strict guarantee roller outline projection be a full circle.And each roller all can independently be changed, and easy disassembling, maintainability are good;

(3) roller profilograph of the present invention adopts elliptic curve, and elliptic curve belongs to plane curve, the starting point of given elliptic arc, terminal point and major and minor axis size; But direct numerical control processing; And strict guarantee roller outline projection is on a circle, and this process adopts parametrization design, does not have the curve approximation problem; Directional wheel in the motion process be can reduce greatly the beating of short transverse, motion process stationarity and precision guaranteed.

Description of drawings

Fig. 1 is a directional wheel constructional drawing of the present invention;

Fig. 2 is a directional wheel roller profilograph multiview drawing of the present invention;

Fig. 3 is 7 roller combinations of directional wheel of the present invention profile diagram;

Fig. 4 is roller structure figure of the present invention and roller and wheel hub installation graph of a relation;

Fig. 5 is roller end face of the present invention location, axial gap-eliminating structure figure;

Fig. 6 is the wheel hub of directional wheel of the present invention and the location assembly drawing of axle sleeve;

Fig. 7 is roller mounting means figure of the present invention.

The specific embodiment

As shown in Figure 1, directional wheel of the present invention mainly comprises wheel hub 1, axle sleeve 2, roller 3, central fastener 4, circumference fastener 5.The center of wheel hub 1 is provided with axle sleeve 2, and the two connects through central fastener 4, and roller 3 is fixedly mounted on the wheel hub 1 through circumference fastener 5, and the projection on the axis direction of wheel hub 1 of the outline of all rollers 3 forms a full circle.The quantity of roller 3 is according to the diameter of the diameter of wheel hub 1, wheel width, roller 3, and roller 3 confirms that with the space angle of wheel axis the quantity of embodiment of the invention middle roller 3 is 7, and the axis of roller 3 becomes the angle of α=45 ° with the axis of wheel hub 1.Roller 3 is installed on the wheel hub 1 as an assembly, and roller 3 can freely rotate along the axis of himself, when the outer surface of roller 3 rolls as directional wheel and ground-surface contact surface.In the wheel rolling process, the roller that contacts with ground is around roller self rotational.

As shown in Figure 2, curve a is positioned at the roller axle plane, and curve c is positioned at axletree to the projecting plane; Two plane included angles are α; Curve a is the profilograph intrinsic curve of roller 3, and curve b is the projection of curve a in α angle plane, is represented by dotted lines here; Curve c is the envelope circle that roller 3 forms to the projecting plane at axletree, and curve b, c overlap fully in theory.As previously mentioned, curve a is an elliptic curve, and oval semi-minor axis n is identical with the radius r of curve c, according to radius r and angle, can calculate oval major semiaxis m, on the profilograph of roller arbitrarily point coordinate with (x, y) expression, satisfied following equation:

$\left\{\begin{array}{c}\frac{x^2}{m^2}+\frac{y^2}{{\mathrm{<figure-callout\; id="2"\; label="n"\; filenames="HSA00000636280500011.png,HSA00000636280500012.png"\; state="\{\{state\}\}">n</figure-callout>}}^2}=1\\ m=n/\sin \mathrm{\&alpha;},n=r\end{array}\right.---(1$

As shown in Figure 3,7 rollers 3 of directional wheel circumference are hidden other framing members here; Roller is arranged in the wheel available space; When guaranteeing that adjacent rollers 3 contacts with ground, profilograph c transition steadily, uninterrupted, it is free to rotate to leave slight gap between each roller., quantity, roller and the wheel axis space angle of roller wide according to the hub diameter of directional wheel, wheel, the diameter of roller carry out the roller parameter designing.In addition; In order to ensure directional wheel motion steadily, reduce the roller transition application force of moment, prolong roller service life; Need to guarantee continuous movement coefficient of ratio ε＞1 of roller; The contact wire length overall of the whole rollers that promptly contact and ratio＞1 of circumference of the wheel with ground, in other words, coincidence angle beta＞0 of the projection of corresponding adjacent rollers on wheel axis.

Like Fig. 4, shown in Figure 7; Directional wheel roller 3 concerns with the relative installation of wheel hub 1; Roller 3 is after independently assembled is accomplished as one, utilizes the U-shaped draw-in groove of roller axle 34 and wheel hub to carry out the circumferencial direction location, utilizes the roller axle shaft shoulder and wheel hub draw-in groove end face boss to carry out axial location.Be designed with connecting bore on the wheel hub draw-in groove end face, it is fixing with roller axle and wheel hub 1 that circumference fastener 5 passes this hole.

Like Fig. 4, shown in Figure 5, roller 3 comprises roller core 33, roller shell 32, roller axle 34, bearing 31, roller location end cap 35, roller disappear crack end cap 37, anti-release member 36.Roller axle 34 is the axis of symmetry of roller 3; Roller core 33 is spindle with roller shell 32; Roller axle 34 is passed along the axis of roller core 33, and roller shell 32 is bonded in the outside of roller core 33, and bearing 31 is positioned at said fusiform end pair of rollers axle 34 and supports the location; Bearing adopts face-to-face and installs, and two ends are symmetry basically.Fixed installation roller location, bearing 31 outsides of fusiform left end end cap 35, bearing 31 outsides fixed installation roller of the fusiform right-hand end crack end cap 37 that disappears, anti-release member 36 disappears between crack end cap 37 and the roller core 33 at roller.Shown in Fig. 5 a, roller location end cap 35 is tightened aft end face and is fitted on the roller core 33, the outer ring of bearing 31 is carried out spacing, and inner ring utilizes the shaft shoulder location of roller axle 34.Shown in Fig. 5 b; The roller of tightening the other end disappears behind the crack end cap 37; Utilize the disappear slit of 33 of crack end cap 37 and roller cores of roller to carry out the bearing crack that disappears and handle; It is locking to utilize anti-release member 36 (holding screw) to hold out against afterwards, and holding screw must not be given prominence to the roller crack end cap 37 that disappears, and influences the rotation of roller 3 with respect to wheel hub 1.

Roller shell 32 adopts non-metal elastic abrasion-proof materials such as polyurethane or rubber, and roller shell 32 is bonded in one with roller core 33.Roller core 33 inside are provided with and alleviate the chamber, and two ends are designed with bearing hole and tapped bore, are respectively applied for bearing 31 and roller location end cap 35, the roller crack end cap 37 that disappears is installed.

Roller axle 34 is designed to stepped shaft; Utilize the roller axle 34 and the axis hole transition fit of wheel hub 1 to carry out the circumferencial direction location of roller 3; The roller axle 34 terminal shaft shoulder and wheel hub 1 boss carry out axial location; Utilize circumference fastener 5 that the two is fixed, other parts in the roll assembly are freely rotated around roller axle 34 like this.

Like Fig. 6, shown in Figure 7, comprehensive roller 3 concerns that with the relative installation of wheel hub 1 at first two independent hubs 1 utilize quadrant locating dowel pin 6 to carry out the circumferencial direction location with axle sleeve 2, and utilize central fastener 4 to be combined into one.By diagram vertical arrows direction, roller 3 is installed in the U-shaped draw-in groove of wheel hub 1 afterwards, adjustment roller 3 is free to rotate, and play must not take place.Roller 3 is installed one by one, and the directional wheel after the combination is as shown in Figure 1.Adopt this connection mode, do not have other changeover mechanisms between roller 3 and the wheel hub 1, simplified middle power transmission link, roller structure good rigidly, load-carrying capacity are high, and can change single roller separately, and easy disassembling, maintainability are good.

The content of not doing to describe in detail in the specification sheets of the present invention belongs to those skilled in the art's known technology.

Claims (4)

1. a directional wheel that is applicable to the big carrying of high precision is characterized in that comprising: wheel hub (1), axle sleeve (2), roller (3), central fastener (4), circumference fastener (5); The center of wheel hub (1) is provided with axle sleeve (2), and roller (3) is fixedly mounted on the wheel hub (1) through circumference fastener (5), and the projection on the axis direction of wheel hub (1) of the outline of all rollers (3) forms a full circle; Roller (3) can freely rotate along the axis of himself, when the outer surface of roller (3) rolls as directional wheel and ground-surface contact surface; Described roller (3) comprises roller core (33), roller shell (32), roller axle (34), bearing (31), roller location end cap (35), roller disappear crack end cap (37), anti-release member (36); Roller axle (34) is the axis of symmetry of roller (3); Roller core (33) and roller shell (32) are spindle, the intercepting from the elliptic curve of plane of described spindle, and roller axle (34) is passed along the axis of roller core (33); Roller shell (32) is bonded in the outside of roller core (33); Bearing (31) is positioned at said fusiform end pair of rollers axle (34) and supports the location, the bearing of said fusiform left end (31) outside fixed installation roller location end cap (35), the bearing of said fusiform right-hand end (31) outside fixed installation roller crack end cap (37) that disappears; Anti-release member (36) is positioned at roller location end cap (35) and roller core (33), and roller disappears between crack end cap (37) and the roller core (33); The draw-in groove end face boss location of the shaft shoulder of roller axle (34) and wheel hub (1).

2. a kind of directional wheel that is applicable to the big carrying of high precision according to claim 1; It is characterized in that: the quantity of described roller (3) is 6～9; Roller becomes 30 ° of-60 ° of angles with wheel axis, roller and wheel hub two end supports, and the roller outer contour is uninterrupted continuously.

3. a kind of directional wheel that is applicable to the big carrying of high precision according to claim 1 and 2; It is characterized in that: described roller core (33) has contained the cavity of loss of weight effect, and roller core (33) two ends are provided with bearing hole and the internal thread hole that bearing (31) and roller location end cap (35) are installed.

4. a kind of directional wheel that is applicable to the big carrying of high precision according to claim 1 and 2 is characterized in that: the material of described roller shell (32) is polyurethane or rubber.

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