中英文中英文文献翻译-电梯曳引机

m/s

）

For

lift

with

geared

traction

machine,

if

worm

gear

is

Archimedes

type,

total

mechanical

efficiency

ranges

from

0.5

to

0.55;

for

lift

with

gearless

traction

machine,

total

mechanical

efficiency ranges from 0.75 to 0.8.

For example:

For

an

AC

two-speed

lift

whose

rated

load

is

2000kg

and

rated

speed

is

0.5m/s,

worm

gear

is

Archimedes type, rated speed of motor is 960r/min, what is hp of motor?

According to

G = 200

0kg, α= 0.5

，

v

= 0.5m/s

，

η= 0.5

, we can calculate by inputting given

values.

Geared

traction

machine

is

classified

into

AC

and

DC

types.

W191

traction

machine

is

AC

frequency- variable

motor.

Currently,

besides

worm

geared

machine,

bevel

and

star

geared

machines are also available.

Gearless traction machine

P

?

G(1

?

α)v

2000

?

(1

?

0.5)

?

0.5

?

?

9.8kw

102η

102

?

0.5

Gearless traction machine is used in lifts with speed of more than 2.0m/s. With traction sheave

fixed in motor shaft, this traction machine is simple in structure without any mechanical geared

machine.

Specially designed for manufactured for lift, traction motor is suitable for lift operation

and classified into speed- variable DC and frequency-variable AC motor.

In figure 2-2 is shown an AC frequency- variable gearless traction machine.

This

machine

needs

much

more

brake

torque

than

geared

machine

when

it

is

manufactured,

therefore, it needs a rather bigger brake. Gearless traction machine is more often than not used in

compound winding drive, therefore, force applied on traction sheave, compound winding sheave

and bear is much larger than that on traction machine; corresponding shaft is of longer diameter.

With no geared machine, it has longer usage life.

Permanent

–

magnet synchronous gearless traction machine

We

can’t

help

mentioning

the

application

of permanent

–

magnet

synchronous

gearless

traction

machine in lift.

With the rapid development of traction technology in lift, more and more lifts

without machine room are adopting permanent

–

magnet synchronous gearless trailing technology.

For

lifts

without

machine

room,

there

is

no

need

to

enlarge

well

dimensions,

simplifying

and

beautifying construction, saving cost, especially the application value of such lifts is enhanced by

Brake

Traction sheave

Motor

图

2 -2

无齿轮曳引机

DAF290

Figure 2-2 Gearless traction machine DAF

low noise, high efficiency and power economization, and what distinguishes lifts without machine

room from others lies in the permanent

–

magnet synchronous gearless traction machine.

In figure 2-3 is shown PMS425AL permanent

–

magnet synchronous gearless traction machine

used in Thyssen

’s lifts without machine room.

The traction machine is flat in structure, so only a

very small space is needed between well walls and car to complete installation.

With gearless

design , motor torque directly passes on to traction sheave, combined with static friction of

non-deceleration part, driving efficiency can exceed 90%; besides, due to low rotation speed,

traction machine runs with low noise and is free from vibration. The traction machine has two

mechano- electronic brakes, therefore, the other brake can provide sufficient jerk force to stop car

with 100% rated load if one brake fails to function.

Characteristics of permanent

–

magnet synchronous gearless traction machine:

●

Comfortable riding;

●

Low running noise;

●

High efficiency;

●

Low load of electrical devices;

●

Convenient and reliable maintenance, without

need to change oil, eliminating oil leakage;

●

Easy to replace assembly, with exterior brake;

●

Wide range of setting and installation in

traction machine.

Composed of springs, brake block with liner, brake

arm

and

magnet-iron,

magnetic

brake

is

most

frequently

used

in

traction

machine,

as

shown

in

figure

2-4

.

When

magnetic

coil

is

power

on,

brake will release; when magnetic coil is power off,

brake block will produce torque, relying on springs pressed tightly on brake gear.

Brake function

Brake has two functions:

In

case

of

power

cut-off,

brake

can

make

lift

stop

automatically.

When

brake

engages,

deceleration of lift should not exceed that produced by overspeed governor or needed to stop car

on buffer.

If

lift

is

in

normal

operation

with

speed

of

more

than

1m/s,

lift

is

usually

decelerated

through

electrical control before mechanical brake engages.

When lift stops moving, brake should guarantee that lift remains stationary under 125%~150%

rated load.

Brake does not release until lift starts moving.

Characteristic of brake

When lift runs, i.e. motor is power-on,

brake will release; when lift stops, i.e.

motor is power-off, brake will engage.

Mounting position

For geared lift, brake is mounted between

motor and geared machine (see figure2-5),

i.e. on high- speed shaft.

Small brake torque is needed by high-speed

shaft, so that brake dimensions can be

reduced.

Gearless

traction

machine

adopts

adapter,

i.e.

is

adaptor

disk

etween

motor

and

geared

machine,

as

shown in figure 2-6. Brake gear is arranged on worm

gear side instead of on motor side, to ensure that lift

can also stop in case of ruptured adapter.

Cast into one with traction rope, brake gear of gearless traction machine is directly mounted on

traction

machine

shaft.

As

a

main

safety

part

of

lift

system,

brake

has

an

direct

impact

on

comfortable

ride

and

accurate

leveling.

During

lift

operation,

to

achieve

comfortable

ride

and

accurate leveling, such factors can be adjusted as brake release time, brake release time and brake

torque size.

To

reduce

brake

engage,

release

time

and

noise,

it

is

required

the

gap between

two

magnets

in

coils be proper rather than too wide.

The smaller the gap between brake block and gear is, the

better.

Brake block should not touch rotating gear after brake releases.

Traction sheave

Traction sheave is shown in figure 2-7.

Geared traction sheave is located on side of

geared machine. Operators stand on the shaft

side of motor, facing motor. Left-placed traction machine is the

one with sheave on the left of geared machine; while

right-placed traction machine is the one with sheave on the

right of geared machine, as shown in figure 2-8.

Traction sheave of gearless traction is directly connected with

motor.

Traction machine suport

Soldered by cast iron or secion iron with steel board, traction machine support is a seat that

connects motor, brake and geared machine.

Parts of tractrion machine are mounted on the

support, facilating transportaion, installation and adjustment.

When lift is installed, the support

will be fastened on two parallel H-stell beams with designated specification that serve to bear

weight.

Main performance and application requirement of traction machine

Take geared traction for instance, we will give a briefing on typical requirement.

Traction sheave diameter D should be more than 40d (d is diameter of traction rope)

Traction sheave diameter

Where:

D

—

Traction sheave diameter in mm

v

s

—

Traction rope rated speed in m/s

i

—

Gear ratio

n

—

Motor rated speed in r/min

Fore

example:

Given

the

fact

that

traction

ratio

is

1:1,

rated

speed

is

1.75m/s,

I

=

25:1,

n=1326r/min, rope diameter is 13mm, what is diameter of traction sheave?

Given the fact that

i = 25

∶

1

，

n=1326 r/min,

Traction ratio is 1/1, therefore, lift rated speed is traction rope rated speed

v

s

= 1.75m/s,

Fill in the formula 2-3 with these values,

Traction rope diameter d = 13mm, so 40d = 13×

40=520mm

Obviously, 630>520mm

Since 630mm traction machine diameter meets D>40d, a conclusion can be drawn that traction

machine diameter can be 630mm.

Reliable traction brake

When lift is moving upwards, offsetting coefficient should be 40% of car weight plus 150% rated

load.

During 10-minute travel, no slipping should occur between brake gear and brake block.

Given the fact that conditions stated in 2-7-2 is met, the minimum engage voltage of brake and

6

?

10

4

?

v

s

i

60000< /p>

?

1

.

75

?

25

D

?

?

?

630mm

πn

3

.

14

?< /p>

1326

maximum release voltage should be 80% and 55% lower than rated voltage of magnet respectively;

time delay of brake engage should not exceed 0.8s.

Brake blocks should be mounted in two groups; if either of them does not work, brake can still

obtain sufficient brake force to make car with rated load decelerate.

When traction machine is running with empty load at high speed, dB(A) surface value measured

(mean

value

of

values

measured

1

meter

from

the

top,

front,

left

and

right

of

traction

machine

respectively) should not exceed 67db(A).

When traction machine is running with 20~40% of rated load, valid value of retortion shocking

speed of output shaft should be less than 1mm/s.

Traction machine should be inspected in factory prior to shipment.

Power-on continuity should

be 40% in inspection, clockwise and counter clockwise rotation with empty load should run well,

with cycling time not less than 3 min, travel lasting 2 hours.

Working conditions of traction machine:

Sea level should not exceed 1000 meters.

Temperature of machine room should remain at 5~40

℃

.

Monthly

ambient

relative

humidity

should

not

more

than

90%,

meanwhile

minimum

average

temperature should not exceed 25

℃

.

Deviation between voltage supply fluctuation and rated voltage should not exceed ±

7%.

Ambient air should not contain corrosive and inflammable air.

Neither lubricant nor other substances should be applied on traction rope.

Quality of car and counterweight as well as the angle of traction rope should meet formula 1-1 in

1-3-4-1.

For V groove,

For semicircular groove or groove with cut,

Where:

? —

Friction coefficient of traction rope in groove;

β—

Tangent angle of groove with cut or semi circular groove

，

β=0

(see figure 2-7).

γ—

Angle

of

V-groove

on

traction sheave (see figure 2-7).

μ—

Friction

μ= 0.09

coefficient

between traction rope and sheave

，