Gearbox Types

 

Planetary gearbox

Planetary gear

The planetary gearbox got its name because it resembles the solar system. The components of the planetary gearbox include the sun gear, the ring gear, and the planetary gear. The sun gear is a center gear fixed in the center, a ring gear (ring wheel), which is an outer ring with inward-facing teeth, and a planetary gear that rotates around the sun gear and meshes with the sun and the crown. serrated.

Physical properties

The sun, rings, and planetary gears in a planetary gearbox are made of aluminum, stainless steel, or brass. The material used depends on the manufacturer.

Note: Gears made of steel material are prone to noise and wear when they come into contact with other gears.

Planetary Gearbox Applications

Planetary gearboxes are used in applications that require low backlash, compact size, high efficiency, impact resistance, and high torque-to-weight ratio.

•        rotary drive

•        lift up

•        crane

•        Machine tool

•        car

Advantages of planetary gears

•        High power density

•        Compact

•        High energy transmission efficiency

•        Greater stability

•        Load distribution between planetary gears

Disadvantages of planetary gears.

•        High rolling load

•        Complex design

•        Accessibility

 

 

Gearmotor type

As the name suggests, the gearmotor consists of an electric motor (brush, brush, AC, servo) and a gear reducer, also known as a gearbox, integrated into a simple package. Gear motor combinations reduce complexity and costs in designs that require high-speed, low-torque output. The gearmotors can be manufactured as one piece or combined as separate components. A gear motor in which the motor and the gear reducer share the same axis means one part. Anaheim Automation offers a wide variety of stepper gear motors, brushless gear motors, DC gear motors, and integrated AC gear motors with spur gears, planetary gears, or worm gears.

Gear motors are used in many applications in everyday household appliances, as well as in industrial applications. Industrial applications include cranes, elevators, jacks, and conveyor machines. Hand tools like washers, mixers, watches, drills, and dryers have appliance geared motors used every day.

How does the gearbox work?

All gearboxes work in a similar way. The direction the gear rotates depends on the input direction and the gear direction. For example, when the initial gear turns clockwise, the combined gear turns counterclockwise. This continues for multiple gears. The combination of gears of different sizes and the number of teeth in each gear plays an important role in the output torque and speed of the shaft. The high gear ratio allows for more output torque and lower speed, and a lower gear ratio allows for higher output speed and less output torque.

Planetary gearboxes work relatively the same. The planetary gearbox system consists of three main components: a center sun gear, a planet carrier (carrying one or more planetary gears), and a ring (outer ring). The center sun gear is orbited by a planetary gear (of the same size) mounted on a planetary carrier. The planet gear meshes with the sun gear, while the teeth on the outer ring mesh with the planet gear. There are several configurations of the gearbox system. A typical configuration consists of three components: input, output, and fixed components.

For example, one of the possible configurations is a planetary as input, a ring as output, and a fixed planetary carrier. In this configuration, the input shaft rotates the sun gear, the planet gear rotates on its own axis, and torque is applied to the output shaft (in this case, the ring) applying torque to the rotating planet carrier at the same time. The speed at which the gears turn (gear ratio) is determined by the number of teeth on each gear. The torque (power output) is determined by the number of teeth and which components of the planetary system are fixed.

How is the gearbox controlled?

The output of the motor (for example, stepper, brushless, AC and brushed motors) is used as input to the gearbox and controls the speed at which the gearbox rotates. The following configuration shows the controller that controls the external motor connected to the input shaft of the gearbox. As a result, when power is applied to the motor, the motor shaft rotates inside the gearbox, causing the gearbox output shaft to rotate. The output speed and torque depend on the internal configuration of the gearbox.

How to choose a suitable gearbox

When considering a gearbox, several factors must be considered to meet the specific application requirements.

Gear ratio

The gear ratio is defined as the correlation between the number of teeth of two different gears. In general, the number of teeth on a gear is proportional to its circumference. This means that a gear with a larger circumference will have more gear teeth. Therefore, the ratio between the circumferences of the two gears can also provide an accurate gear ratio. For example, if one gear has 36 teeth and another gear has 12 teeth, the gear ratio will be 3: 1.

Output torque

The output torque depends on the gear ratio used. A large gear ratio is chosen to obtain high output torque. Using a higher gear ratio will reduce the speed of the motor's output shaft. Conversely, using a lower gear ratio results in a lower output torque value and faster engine speed being transmitted to the output shaft. This statement shows the relationship between torque and speed are inversely proportional to each other.

Speed ​​(rpm)

Speed ​​is proportional to the gear ratio of the system. For example, if the input gear has more teeth than the output gear, the output shaft speed increases as a result. On the other hand, using a reverse scenario where there are more gear teeth at the output compared to the input, the speed decreases at the output shaft. In general, the output speed can be determined by dividing the input speed by the gear ratio. The higher the ratio, the lower the muzzle velocity and vice versa.

Gear arrangement

The gear arrangement is a unique engineering design that offers a number of advantages over conventional fixed shaft gear system designs. The unique combination of power transmission efficiency and compact size can reduce efficiency loss. The more efficient the arrangement of gears (eg, spurs, helixes, planets, and worms), the more energy is transferred and converted to torque than is lost as heat.

Backlash

Backlash is the angle at which the gearbox output shaft can rotate without moving the input shaft or the gap between the teeth of two adjacent gears. For applications that do not involve charge reversal, there is no need to consider play. However, in load reversing precision applications such as robotics, automation, CNC machines, etc., play is important for accuracy and positioning.

Gearbox Advantage

     • Low noise

     • High efficiency

     • High reduction rate

     • Increase the output torque

     • Reduced print speed

     • Durability

Disadvantages of the gearbox

     • More expensive than other transmission systems.

     • Adequate lubrication is required for smooth operation.

     • Improperly cut teeth can cause excessive vibration and noise during operation.

     • Quality matters and costs rise