What are the factors affecting the specific surface area? Factors affecting the surface area include particle size (particle size) and particle shape (grain shape) as well as pore content. Imagine a real cube that is one meter long and is cut into small cubes of one micron (10-6 μm). This will produce 1018 particles. The area exposed by each particle is 6x10-12 square meters (m2), and the total area contributed by all particles is 6x106?m2. A million-fold increase in this exposed area compared to uncut materials is typical of ultra-fine powders having a large surface area. In addition to the particle size, the particle shape also contributes to the surface area of ​​the powder. In all geometries, the sphere has the smallest area/volume ratio, but a string of atoms will have the largest area/volume ratio if only bonded along the chain axis. All particulate matter has a geometric shape and thus has a surface area between the two extremes. The effect of particle shape on surface area is readily seen by comparing two surface areas of particles having the same composition and the same mass, but spherical and cubic, respectively. It is calculated that the cube area is larger than the sphere area with the same particle weight. Because of the difference in particle size, grain shape, and porosity, the range of specific surface area can vary greatly, but the effect of pores tends to completely obliterate the effects of particle size and external shape factors. A powder consisting of 0.1 micron radius spherical particles with a density of about 3 g/cm3? has a specific surface area of ​​about 10 m2/g, while a similar particle with a radius of 1.0 μm is 10 times smaller than the surface; however, if the same 1.0 micron radius particles contain a large amount The pores may have a specific surface area exceeding 1000 m2/g. This clearly indicates the important contribution of the pore to the surface area. ?
A DC motor is any of a class of rotary electrical
machines that converts direct current electrical energy into mechanical energy.
The most common types rely on the forces produced by magnetic fields. Nearly
all types of DC motors have some internal mechanism, either electromechanical
or electronic, to periodically change the direction of current flow in part of
the motor.
DC motors were the first type widely used, since they
could be powered from existing direct-current lighting power distribution
systems. A DC motor's speed can be controlled over a wide range, using either a
variable supply voltage or by changing the strength of current in its field
windings. Small DC motors are used in tools, toys, and appliances. The
universal motor can operate on direct current but is a lightweight motor used
for portable power tools and appliances. Larger DC motors are used in
propulsion of electric vehicles, elevator and hoists, or in drives for steel
rolling mills.
Dc motor areas of application: smart home field, robotics, precision medical equipment industry, automotive drive field, electronic products and personal care equipment
Application of the product:
Features: high torque, low noise, small volume, light weight, easy to use, running
constant speed, etc., can also be matched with various gearboxes to change the
output speed and torque.
Features: small volume, fast speed, stable performance, low price, good speed regulation.
Method
of use: the best stable in horizontal plane, installed on the dc motor output
shaft parts, cannot use a hammer to knock, knock prone to press into the dc
motor drive, may cause damage to internal components, and cannot be used in the
case of blocked.
Operating temperature range:
DC motor should be used at a temperature of -10~60℃.
The figures stated in the catalog specifications are based on use at
ordinary room temperature catalog specifications re based on use at
ordinary room temperature
(approximately20~25℃.
If a geared motor is used outside the prescribed temperature range,the
grease on the gearhead area will become unable to function normally and the
motor will become unable to start.Depending on the temperature conditions ,it
may be possible to deal with them by changing the grease of the motor's parts.Please feel free to consult
with us about this.
Storage temperature range:
DC motor should be stored ta a temperature of -15~65℃.
In case of storage outside this range,the grease on the gearhead area
will become unable to function normally and the motor will become unable to
start.
Service life:
â—Use with a
load that exceeds the rated torque
â—Frequent
starting
â—Momentary
reversals of turning direction
â—Impact
loads
â—Long-term
continuous operation
â—Forced
turning using the output shaft
â—Use in
which the permitted overhang load or the permitted thrust load is exceeded
â—A pulse
drive ,e.g.,a short break,counter electromotive force,PWM control
â—Use of a
voltage that is nonstandard as regards the rated voltage
â—Use
outside the prescribed temperature or relative-humidity range,or in a special
environment.
â—Please
consult with us about these or any other conditions of use that may apply,so
that we can be sure that you select the most appropriate model.
when it come to volume production,we're a
major player as well .each month,we rurn out
600000 units,all of which are compliant with the rohs directive.Have any
questions or special needed, please contact us, we have the engineer group and
best sales department to service to you Looking forward to your inquiry. Welcome to
our factory.
Dc Motor,Small Dc Motor,Mini Dc Motor,Robot Dc Motor,Dc Motor With Gearbox Shenzhen Shunchang Motor Co., LTD. , https://www.scgearmotor.com
