CN101872371A - Design method of steel ball safety coupling - Google Patents

Abstract

The invention discloses a design method of a steel ball safety coupling which is used for connection between shafts of a mechanical transmission part and takes an effect on torque transfer, belonging to the manufacture field of calculating the contour dimension of a steel ball chamber of the coupling, the number of steel balls and the like. The method comprises the following steps of: firstly, determining the specification number of the safety coupling, determining the contour dimension and the dimension of a rotor chamber and estimating the effective inner diameters of the steel balls according to the power and the rotating speed of a motor; drafting a graph with AUTOCAD, and automatically calculating the sectional area and the centroid radius of the chamber; inputting each parameter into an MATHCAD program, and calculating through a series of formulae by the program to obtain transmitted power or protection torque; contrasting with input requirements, revising the effective inner diameters of the steel balls and recalculating the transmitted power; and repeatedly revising to finally obtain the weight of the steel balls required to be filled. By using an auxiliary program to which the invention relates, design calculation is fast and the accuracy is high, and the accurate control of the transmitted power and the protected torque of the safety coupling can be realized.

Description

Design method of steel ball safety coupling

Technical field

The present invention announces be a kind of mechanical drive department split axle that is used for industries such as metallurgy, mine, boats and ships, papermaking and heavy-duty machinery with spool between be connected, play the science design of the steel-ball type safety coupling product of transmission moment of torsion, belong to the manufacturing field of systems such as design steel-ball type safety coupling steel ball cavity volume, cross sectional shape, size, steel ball number.

Background technology

The centrifugal force that the steel-ball type safety coupling utilizes the steel ball of high speed rotating to produce, thereby and then the shaft coupling housing produced friction force transmit moment of torsion, the moment of torsion that is transmitted increases with the raising of rotating speed.So it has the advantages that to realize soft start, and can realize automatic overload protection, after load is recovered normally, recover transmission automatically.Because the starting characteristic of ball coupling and the geomery of each part, steel ball number etc. are closely bound up, it calculates principle higher complicacy.In the past; when product design is made; cavity volume, cross sectional shape, manufacturing dimension and steel ball number to steel ball can only pass through calculating such as craft, counter; computational accuracy is low; and efficient is low, makes produced steel-ball type safety coupling be difficult to satisfy performances such as the accurate transfer moment of torsion of product and protection moment of torsion.

Summary of the invention

Technical matters: the auxiliary design method that the purpose of this invention is to provide a kind of steel-ball type safety coupling; change because the setting of steel ball and relevant manufacturing dimension improper; make the transmission moment of torsion of shaft coupling; soft start and automatic overload protective effect can not get the effectively situation of performance; by by computer application; each Fabrication parameter of designing and calculating steel-ball type safety coupling rapidly and accurately reaches the optimum value of product performance index.

Technical scheme: the present invention is the methodology with the MATHCAD software design, and simultaneously by AUTOCAD graphics software Aided Design, concrete steps are as follows:

1.) design initial conditions:

A. power and the rotating speed that requires according to the design input determined gauge number and physical dimension,

B. design rotor cavity volume size,

C. estimate effective internal diameter of steel ball;

2.) draw drawing in proportion:

D. press 1: 1 scale figure by AUTOCAD,

E. calculate cavity volume sectional area and centroid radius with the AUTOCAD plug-in unit,

3.) calculate check with the MATHCAD program:

F. cavity volume sectional area and centroid radius are input to the MATHCAD program,

G. all the other each parameters are input to the MATHCAD program,

The h.MATHCAD Automatic Program is calculated transmitted power or protection moment of torsion and the steel ball weight under the existing parameter;

Computation process is as follows:

1. calculate centroidal line speed v=2 π * rotating speed * centroid radius/60, the m/s of unit;

2. calculate the single chamber sectional area * cavity volume length * 10 of single chamber volume Q= ^-9, the m of unit ³

3. calculating steel ball general assembly (TW) G=calculates volume Q* chamber, single chamber and counts * filling rate * 7.85*10 ³, units;

4. calculate centrifugal force F1=and calculate steel ball general assembly (TW) G* (centroidal line speed v) ²/ centroid radius, unit, N;

5. calculate friction force F2=centrifugal force F1* kinetic friction coefficient;

6. calculated torque T=friction force F2* inner chamber radius;

7. rated output P=torque T * rotating speed/9550.

I. contrast the transmitted power or the protection moment of torsion of customer requirements,, then finalize a text, finish design process by existing parameter if meet the demands;

J. if error greater than 1%, is then got back to step c, revise effective internal diameter of steel ball, revise the cavity volume size in case of necessity, calculate transmitted power or protection moment of torsion and steel ball weight once more;

4.) revise repeatedly, be slightly larger than the transmitted power of requirement or protect moment of torsion, draw the weight that to insert steel ball simultaneously until transmitted power that calculates or protection moment of torsion.

Beneficial effect: the present invention is by the auxiliary calculation procedure of MATHCAD; and with AUTOCAD software Aided Design; can design the geomery parameter of shaft coupling quickly and accurately; calculate safety coupling and need insert weight and the transmitted power or the protection moment of torsion of steel ball; give full play to the Aided Design function of computing machine; improve design efficiency and design accuracy, realize the accurate control of safety coupling transmitted power and protection moment of torsion.

Description of drawings

Fig. 1 is the sectional drawing that calculates cavity volume sectional area and centroid radius in the AUTOCAD interface.

Fig. 2 is whole designing and calculating checking procedure process flow diagram.

Embodiment

The present invention is for the auxiliary calculation procedure of a cover with the MATHCAD software design, simultaneously by AUTOCAD graphics software Aided Design.

1. design initial conditions:

1.1 according to power and the rotating speed that the design input requires, determine gauge number and physical dimension,

1.2 just establish rotor cavity volume size,

1.3 effective internal diameter of estimation steel ball;

2. draw drawing in proportion:

2.1 by the scale figure of AUTOCAD by 1: 1,

2.2 calculate cavity volume sectional area and centroid radius automatically with the AUTOCAD plug-in unit;

3. calculate transmitted power or protection moment of torsion and steel ball weight with the MATHCAD Automatic Program:

3.1 cavity volume sectional area and centroid radius input MATHCAD program,

3.2 all the other each parameters are input to the MATHCAD calculation procedure,

3.3MATHCAD Automatic Program is calculated transmitted power or protection moment of torsion and steel ball weight under the existing parameter,

3.4 the transmitted power of contrast customer requirements or protection moment of torsion if meet the demands, are then finalized a text by existing parameter, finish design process,

3.5, revise effective internal diameter of steel ball if error greater than 1%, is then got back to 1.3 of the technical program, revise the cavity volume size in case of necessity, calculate transmitted power or protection moment of torsion and steel ball weight once more;

4. revise repeatedly, be slightly larger than the transmitted power of requirement or protect moment of torsion, draw the weight that to insert steel ball simultaneously until transmitted power that calculates or protection moment of torsion.

With Aided Design program involved in the present invention, designing and calculating is quick, the degree of accuracy height.

Steel ball safety coupling with a kind of specification is an example below, and program, method and the step that the present invention relates to are described.

Example: requiring transmitted power is 4.5KW, and rotating speed is 1500r/min.

1. design initial conditions

1.1 look into " JB/T 5987-1992 steel-ball type power saving safety coupling ", determine that the shaft coupling gauge number is No. 4;

1.2 according to standard size design rotor cavity volume size, housing internal diameter 128mm, cavity volume length 112mm;

1.3 the about 55mm of the estimation effective internal diameter of steel ball.

2. draw drawing in proportion, see Fig. 1

2.1 by the scale figure of AUTOCAD by 1: 1;

2.2 learn cavity volume sectional area d=678.7mm with automatic calculating of AUTOCAD plug-in unit ²With centroid radius r=55.9mm.

3. calculate with the Aided Design Automatic Program, see Fig. 2

3.2 the cavity volume sectional area of step 2.2 gained and centroid radius input specific program;

3.3 parameters such as power, rotating speed, steel ball filling rate, friction factor are input to auxiliary calculation procedure, and the Aided Design Automatic Program is calculated;

Calculation procedure computation process is as follows:

1. calculate centroidal line speed v=2 π * rotating speed * centroid radius/60, the m/s of unit;

2. calculate the single chamber sectional area * cavity volume length * 10 of single chamber volume Q= ^-9, the m of unit ³

3. calculating steel ball general assembly (TW) G=calculates volume Q* chamber, single chamber and counts * filling rate * 7.85*10 ³, units;

4. calculate centrifugal force F1=and calculate steel ball general assembly (TW) G* (centroidal line speed v) ²/ centroid radius, unit, N;

5. calculate friction force F2=centrifugal force F1* kinetic friction coefficient;

6. calculated torque T=friction force F2* inner chamber radius;

7. rated output P=torque T * rotating speed/9550.

3.4 the transmitted power that the Aided Design Automatic Program is calculated under the existing parameter is 4.542KW and steel ball weight 2.184kg;

3.5 the transmitted power 4.5KW of contrast customer requirements, error rate is 0.94%, meets the demands, and finishes design process.

4. if error greater than 1%, is then got back to 1.3 of the technical program, revise effective internal diameter of steel ball, revise the cavity volume size in case of necessity, utilize the Aided Design program once more, calculate transmitted power or protection moment of torsion and steel ball weight automatically, revise repeatedly, until meeting the demands.

Require power P s:=4.5KW

Centroid radius r:=0.0559m

Single chamber sectional area d:=678.7mm2

Inner chamber radius W:=0.064m

Rotation speed n :=1500rpm

Centroidal line speed $v:=n\·2\·\mathrm{\π}\·\frac{r}{60}=8.781m/s$

A:=6 is counted in the chamber

Cavity volume length b:=112mm

Filling rate f:=0.61

Single chamber volume $Q:=d\·\frac{b}{1000000000}=7.601\×{10}^{-5}m3$

Steel ball general assembly (TW) I:=7.85Qaf1000=2.184kg

Centrifugal force $F1:=I\·\frac{v\·v}{r}=3.012\×{10}^{3}N$

Friction force F2:=F10.15=451.845N

Torque T T:=F2W=28.918Nm

Power $P:=\mathrm{TT}\·\frac{n}{9550}=4.542\mathrm{KW}$

Error rate $\mathrm{\ξ}:=\frac{(P-\mathrm{Ps})}{\mathrm{Ps}}=0.0094$

Claims (1)

1. the auxiliary design method of a steel ball safety coupling is characterized in that this method calculates the power of transmission, moment of torsion and steel ball weight automatically, and concrete grammar is:

1.) design initial conditions:

A. power and the rotating speed that requires according to the design input determined gauge number and physical dimension,

B. design rotor cavity volume size,

C. estimate effective internal diameter of steel ball;

2.) draw drawing in proportion:

D. press 1: 1 scale figure by AUTOCAD,

E. calculate cavity volume sectional area and centroid radius with the AUTOCAD plug-in unit,

3.) calculate check with the MATHCAD program:

F. cavity volume sectional area and centroid radius are input to the MATHCAD program,

G. all the other each parameters are input to the MATHCAD program,

The h.MATHCAD Automatic Program is calculated transmitted power or protection moment of torsion and the steel ball weight under the existing parameter;

Computation process is as follows:

1. calculate centroidal line speed v=2 π * rotating speed * centroid radius/60, the m/s of unit;

2. calculate the single chamber sectional area * cavity volume length * 10 of single chamber volume Q= ^-9, the m of unit ³

3. calculating steel ball general assembly (TW) G=calculates volume Q* chamber, single chamber and counts * filling rate * 7.85*10 ³, units;

4. calculate centrifugal force F1=and calculate steel ball general assembly (TW) G* (centroidal line speed v) ²/ centroid radius, unit, N;

5. calculate friction force F2=centrifugal force F1* kinetic friction coefficient;

6. calculated torque T=friction force F2* inner chamber radius;

7. rated output P=torque T * rotating speed/9550.

I. contrast the transmitted power or the protection moment of torsion of customer requirements,, then finalize a text, finish design process by existing parameter if meet the demands;

J. if error greater than 1%, is then got back to step c, revise effective internal diameter of steel ball, revise the cavity volume size in case of necessity, calculate transmitted power or protection moment of torsion and steel ball weight once more;

4.) revise repeatedly, be slightly larger than the transmitted power of requirement or protect moment of torsion, draw the weight that to insert steel ball simultaneously until transmitted power that calculates or protection moment of torsion.