CN2219396Y - Centrifugal shoe clutch with improved structure - Google Patents

Abstract

The utility model relates to a centrifugal shoe clutch with an improved structure. The centrifugal shoe clutch with an improved structure comprises a chuck body, three friction wafers for a brake, a wheel drum, a driving belt and a belt pulley. The friction wafers for a brake are arranged on the chuck body. The outer parts of the three friction wafers for a brake are sheathed on the wheel drum. The drive belt is positioned on the belt pulley. The utility model is characterized in that the joint surfaces of the wheel drum and the friction wafers for a brake are respectively provided with symmetrical circular arc-shaped wavy surfaces. By means of the circular arc-shaped wavy joint surface, when the wheel drum and the friction wafers for a brake are mutually jointed, the twisting force for bearing load can be enhanced, the slip can be reduced, the loss for the transmission of power can be lowered, and the service life can be extended.

Description

Structurally improved centrifugal shoe type clutch

The utility model relates to a kind of centrifugal shoe type clutch, refers to a kind of its bearing load torsion that increases especially, reduces sliding phenomenon and produces, and reduces the transmission of power loss, and the structurally improved centrifugal shoe type clutch that increases the service life.

At present general locomotive all adopt centrifugal shoe type clutch (CLUTCH) as the combination of transmission of power with separate, and the structure of this clutch (sees also Fig. 1,2) mainly be on a disk body A, to be provided with three brake bushs (BRAKELINING) B, and outside brake bush B, be nested with a wheel hub C, drivign belt is placed in the driving that is subjected to engine on the belt pulley E, and drivign belt D drives disk body A rotation, when the rotating speed of disk body A reaches a certain degree, this brake bush B is subjected to centrifugal action and expands outwardly contact wheel hub C inwall, and then drive wheel hub C rotation, drive wheel again.Though the structure of this clutch is simple, and using has considerable time, because it is to reach combining of driving force with brake bush B with the rubbing action of wheel hub C, though and the size of friction is relevant with the rotating speed of engine, but because the wheel hub C of present this clutch and the mating face C1 of brake bush B, B1 is tied to form even surface (seeing also Fig. 2), therefore when rotating speed deficiency or bearing load increase, promptly can produce slip, and cause the loss of torsion, the not good shortcomings such as efficient attenuating that cause of transmission of power, in addition, brake bush B often also can produce thermal effect under closed and the situation of separating and sliding, elevate the temperature, cause the friction factor between the junction plane C1 of brake bush B and wheel hub C to descend rapidly, this kind phenomenon and can reduce working life of brake bush B simultaneously except that meeting causes above-mentioned shortcoming.

The purpose of this utility model is to provide a kind of bearing load torsion that increases, and reduces sliding phenomenon and takes place, and reduces the transmission of power loss, and the structurally improved centrifugal shoe type clutch that can increase the service life.

Relevant the utility model is to reach to create technological means and the structure thereof that purpose is used, and cooperates embodiment now, is described in detail as follows:

Fig. 1 is the organigram of existing centrifugal shoe type clutch.

Fig. 2 is the tectonic maps that concerns of the wheel hub of existing centrifugal shoe type clutch and brake bush.

Fig. 3 is that the utility model wheel hub and brake bush concern tectonic maps.

Fig. 4 is the wheel hub of existing centrifugal shoe type clutch and the torsion of brake bush (T) analysis chart.

Fig. 5 is torsion (T) analysis chart of wheel hub of the present utility model and brake bush.

Fig. 6 is wheel hub of the present utility model and brake bush contact length theory analysis figure

As shown in Figure 3, the utility model is set as the wavy of circular arc on the mating face 11 of wheel hub 1, and also be designed to symmetrical circular arc on the mating face 21 of brake bush 2 wavy, and the circular arc wavy surface that is had by the mating face 21 of the mating face 11 of wheel hub 1 and brake bush 2, when being engaged with brake bush 2, wheel hub 1 can reach the purpose of this utility model, promptly increase its bearing load torsion, the sliding phenomenon that reduces 2 of wheel hub 1 and brake bushs takes place, reduce the transmission of power loss, and prolong the working life of brake bush 2.

Now, prove that further the utility model can reach it and create purpose by following theoretical calculation analysis:

As shown in Figure 4, it is the brake bush of general centrifugal shoe type clutch and the torsion of wheel hub (T) analysis chart;

For component wear, generally suppose that all its product with speed, pressure is directly proportional: δ n=K * Pn promptly weares and teares ... (a)

Wherein, K=constant, Pn represent that its direction is vertical with brake bush, and δ=r * m

So δ n=δ * sin θ=r * m * sin θ=r * r1 * sin θ ... (b)

(b) substitution (a) formula is K * Pn=r * r1 * sin θ then ... (C)

Again, pressure maximum Pmax betides (sin φ) maximum value between brake bush and wheel hub,

That is: Pn=Pmax * sin φ/(sin φ) max

So to ask torsion (T) be frictional force to the moment of the O of wheel hub central authorities then $T={\∫}_{{\mathrm{\φ}}_2}^{{\mathrm{\φ}}_1}\mathrm{\μ}\×\mathrm{Pn}\×b\×r\×r\×\mathrm{d\φ}$ $=\[\mathrm{\μ}\×b\×r\×r\×P\max /\left(\sin \mathrm{\φ}\right)\max {\∫}_{{\mathrm{\φ}}_2}^{{\mathrm{\φ}}_1}$

sinφ×dφ

＝μ×b×Pmax×r×r×(cosφ1-cosφ2)

/(sinφ)max

Please consult Fig. 5 again, be torsion of the present utility model (T) analysis chart;

Torsion then $\left(T\right)={\∫}_{{\mathrm{\φ}}_2}^{{\mathrm{\φ}}_1}\mathrm{\μ}\×\mathrm{Pn}\×b\×r\left(r^{\′}\right)\×\mathrm{d\φ}$

＝[μ×Pmax×b×r(r′)/(sinφ) $\max \]{\∫}_{{\mathrm{\φ}}_2}^{{\mathrm{\φ}}_1}\sin \mathrm{\φd\φ}$

＝μ×Pmax×b×r×r′×(cosφ1-

cosφ2)/(sinφ)max

Suppose the about 18-25 degree of the effective contact angle of brake bush and wheel hub, account for brake bush total length 26-36% (supposing to get 30%),

Suppose β=160 ° r2=2.00 again

Be △ r=0.28 L1 (improvement back contact length)=r2 * β

＝5.58

L2 (contact length before the improvement)=2 * r

×sinβ/2r×dφ

△L＝L1－L2＝1.65

See also Fig. 6:

Suppose brake bush mean radius rL=53.60

n＝(rL×2×π)/L2

＝(53.60×2×3.14)/3.94

＝85.5

S2＝3.94×85.5×0.3＝101.0

So S1=S2+1.65 * 85.5 * 0.3=143.2 S1/S2=r '/r=1.42

Therefore, from above-mentioned formula operation as can be known the utility model be 1.42 times of prior art bearing load torsion (T).

From the above mentioned, the utility model really can reach the creation purpose, and has creativeness and the practicability that improves using effect.

Claims (1)

1. A kind of structurally improved centrifugal shoe type clutch, comprise disk body, three brake bushs, a wheel hub, drivign belt and belt pulleys, described brake bush is located on the disk body, these three brake bushs are nested with outward on wheel hub, drivign belt is placed on the belt pulley, it is characterized in that respectively being provided with symmetrical circular arc wavy surface on the mating face of described wheel hub and brake bush.

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