supply ac brushless servo motor, dc

The Introduction of Planetary Gearbox

Planetary gears are very popular due to their advantages such as high power density, companctness, and multiple and large compact gear ratios and load sharing among planets. Gearing arrangement is comrised of four different elements that produce a wide range of speed ratios in compact layout. These elecments are, Sun gear, an extenally toothed ring gear co-axial with the gear train Annulus, an internally toothed ring gear coaxial with ghe gear train Planets, externally toothed gears with mesh with the sun and anulus, and Planet Carrier, a support structure for planets, co-axial with the train. Planetary gear reducer motor system as shown in Figure 1 is typically used to perform speed reduction due to serveral advantages over conventional parallel shaft gear systems.

Planetary gears are also used to advantages over conventional parallel shaft gear systems. Planetary gears are also used to obtain high power density, large reduction in small volume, pure torsional reactions and multiple shafting. Another advantage of the planetary gearbox arrangement is load distribution. If the number of planets in the system are more the ability of load shearing is greater and the higher the torque density. The planetary gear box arrangment also creats greater and the higher the torque density. The planetary gearbox arrangment also creates greater stability due to the even distribution of mass and increased rotational stiffiness.

In recent years, enhancement of interior quietness in passenger cars. Automobiles is an important factor for influencing occupant comfort. Planetary gear sets are essential components of automatic transmissions because of their compact size and wide gear ratio range. They produce high speed reductions in compact spaces, greater load sharing, higher torque to weight ratio, diminished bearing loads and reduced noise and vibration. A Despite their advantage, the noise induced by the vibration of planetary gear systems remains a key concern. Planetary gears have receive considerably less research attention than single mesh gear paris. This paper focus on the study o two PGTs with different phasing (angular positions) while keeping every individual set unchanged.

This figure shows that the basic layout planetary gear train in which there is one Sun gear. Three Planet gear and one ring gear. They can produce the high speed reduction in compact space and having greater load shearing capacity & high torque to weight ratio.

Planetary basics — ratios, helix angles, axial loads, crowning

A planetary gearhead takes a high-speed, low-torque input, say from an electric motor, then increases torque and reduces speed at the output by the gearhead ratio. This lets motors run at higher, more-efficient rpms in equipment that operates at low speeds. It also reduces inertia reflected back to the motor, increasing stability. And using a planetary gearhead often lets machine builders reduce the size and cost of motion-control hardware.

Planetary units with helical gears, rather than spur gears, have a larger contact ratio. The contact ratio is the number of teeth in mesh at any given moment. While typical spur gearing has a 1.5 contact ratio, helical gearing more than doubles it to 3.3. Benefits of higher contact ratios include:

• 30 to 50% more torque capacity than equivalent spur-type planetary gearing.
• Better load sharing, which increases life.
• Smoother and quieter operation.
• Backlash reduced by as much as 2 arc-min.

The gearhead’s helix angle also has a significant impact on performance because the greater the angle, the more teeth in the mesh at any one time. So increasing the helix angle from the typical 12° up to 15° raises torque capacity by 17 to 20%; and by as much as 40% over straight-cut spur gears. Gears with a 15° helix angle also emit less noise.


DC Brush Motor

Choosing the right DC Motor (or DC gear motor) for a specific application can be a daunting task and many manufacturers only provide basic motor specifications. These basic specifications might not be sufficient for your needs. Listed below are ideal motor specifications and whenever possible, ways to approximate values.

A truly quiet DC worm gear motor is often needed in medical applications not only to reinforce the quality of the deployed medical devices but also to not be a contributing source to ambient noise where concentration and communication are vital. While that is a driving factor in the development of the new DCmind line of DC brush motors from Crouzet Motors, what is even more important is the significant increase in both lifetime and efficiency that accompany that engineering development.

Typical Specifications

For DC electric motors in Minnesota and around the country, there are common specifications needed to design a motor.

Nominal Voltage – For DC electric motors, it is important to know the nominal voltage of the drive motor. The designer also needs to know if a motor is to be operated outside of the nominal voltage range for any period of time.

Horsepower Rating – This is the rating of the nominal work that the worm gear reducer is expected to perform. The power rating can be expressed in horsepower or watts. This requirement can also be stated as a combination of torque and speed. We will also need to know if the motor will run at different load points, as either under loading or overloading the motor are detrimental to its service life.

Rated speed – The motor designer needs to know how fast the motor is required to run in the application. We also need to know if there are times when this speed would change, either by using a speed control to vary the voltage supplied to the motor or by increasing or decreasing the load on the motor.

Duty cycle – As a Permanent Magnet DC Motor runs, the current passing through the windings causes heat to be generated, raising the temperature of the motor as time passes. As the motor reaches its continuous running load point, the temperature should stabilizes within an hour or so. If the temperature does not stabilize, you need a higher horsepower rated motor.

Stall Torque – The maximum amount of torque provided by a motor with the shaft not rotating is known as stall torque. Keep in mind that if a motor is subjected to stall conditions for more than a few seconds, it likely will sustain irreparable damage.
Inrush Current – This is the current that a motor draws upon start up, whether or not it is under load. This current drops immediately as the motor’s speed increases, but in some cases any attached electronics can become seriously damaged by the extremely high current. Sometimes motor components can be damaged also. In those cases a current limiter would be recommended.

My conclusion is that DC brushless drives will likely continue to dominate in the hybrid and coming plug-in hybrid markets, and that induction drives will likely maintain dominance for the high-performance pure electrics. The question is what will happen as hybrids become more electrically intensive and as their performance levels increase? The fact that so much of the hardware is common for both drives could mean that we will see induction and DC brushless live and work side by side during the coming golden era of hybrid and electric vehicles.

The Type of Gear Reducers

Gear drives are also known as gear reducers or gearboxes. These are rugged mechanical devices desined to transmit high power at high operating efficiencies and have a long service life. The worm gear motor is an important component of the mixer drive systems, providing speed reduction and increasing allowable torque. Moreover, in some cases it provides support to the mixer shaft.

Helical gears are used in parallel shaft gear reducers. In helical gears, gear teeth are machined along a helical path with respect to the axis of rotation. Helical gears are commonly used with two-, three-, and in some cases even four-, five-, and six-stage speed reductions. In-line helical reducers are a variation of parallel shaft speed reducers configured such that the output and input shafts are in-line.

Spiral bevel gears are used when the input and output shafts of the gear reducers are required to be at right angles. The curve shape of the spiral bevel teeth makes gradual contacts, resulting in less noise during operation. Helical, parallel shaft, and helical bevel gear units have high operating efficiency, approximately 98% for each gear stage reduction.

Worm gears, are the most economical speed reducers, capable of providing a sizable speed reduction with a single gear set. The input and output shaft of these gears are at right angles to each other. However, becasue of the sliding contact between the worm pinion and the gear, the worm gear reducer is less efficient. The efficiency decreases as the speed redcution ratio increases. For example, at a speed reduction ratio of 10:1, the efficiency of the worm gearbox may be approximately 90%. However, at a redution ratio of about 50:1, the efficiency of the worm reducer drops to about 70%. Gearbox manufactures offer gear reducers in helical bevel and helical worm design.

Helical, spiral bevel, and worm gears are external gears with the teeth on the outer periphery of the gears. In planetary gears the teeth profile is on the inside of a circular ring with meshing pinion. Planetary gears consist of an internal gear with a small pinion, known as a sun gear, surrounded by multiple planetary gears. These gears can provide high speed reduction ratios and are relatively compact in size. Gear reducer manufacturers also offer geared-motor, that consists of a factory assembled motor with the gear unit. Figure 12.34 shows a variety of gear reducer with motor configurations.

NMRV worm gear series also available as compact and flexibility. NMRV worm gear series also available as compact integral helical/worm option, has been designed with a view to modularity: low number of basic models can be applied to a wide range of power ratings guaranteeing top performance and reduction ratios from 5 to 1000.

Stepper Drive Modes

This chapter has explained how to operate steppers by energizing one or two winding pairs at a tiem, but tere are a number of different ways to drive a Nema 23 stepper motor, and this discussion touches on four of them:

* Full-step (one phase on) mode – Each control signal energizes on winding.

* Full-step (two phases on) mode – Each control signal energizes two windings.

* Half-step mode – Each control signal alternates between energizing one and two windings.

* Microstep mode – The controller delivers sinusoidal signals to the stepper’s windings.

Full-Step (One Phase On) Mode

The simplest way to control a stepper is to energize one winding at a time. This is the method discussed at the start of this chapter. Figure 4.15 shows what the signaling sequence looks lide when controlling a stepper motor drive in this mode.

With each control signal, the rotor truns to align itself with the energized winding. The rotor always turns through the stepper’s rated step angle. That is, if a PM motor is rated for 7.5, each control signal causes it to turn 7.5.

Full-Step (Two Phase On) Mode

In the full-step (two phase on) mode, the controller energizes two windings at once. This turns the rotor through the stepper’s rated angle, and the rotor always aligns itself between two windings. Figure 4.16 illustrates one rotation of a stepper motor driven in this mode.

Figure 4.17 shows what the corresponding drive sequence looks like.

The main advantage of this mode over full-step (one phase on) is that it improves the motor’s torque. Because two windings are always on, torque increases by approximately 30%-40%. The disadvantage is that the power supply has to provide twice as much current to turn the stepper.

Half-Step Mode

The half-step mode is like a combination of the two full-step modes. That is, the controller alternates between energizing one winding and two windings. Figure 4.18 depicts three rotations of a stepper in half-step mode.

Figure 4.19 illustrates a control signal for a stepper motor driven in half-step mode.

In this mode, the rotor aligns itself with windings (when one winding is energized) and between windings (when two windings are energized). This effectively reduces the motor’s step angle by half. That is, if the stepper’s step angle is 1.8, it will trun at 0.9 in half-step mode.

The disadvantage of this mode is that, when a single winding is energized, the rotor turns with approximately 20% less toruqe. This can be compenstated for by increasing the current.

Microstep Mode

The purpose of microstep mode is to have the stepper turn as smoothly as possible. This requires dividing the energizing pulse into potentially hundreds of control signals. Common numbers of division are 8,64,and 256. If the energizing pulse is divided into 256 signals, a 1.8 stepper will turn at 1.8/256=0.007 per control signal.

In this mode, the controller delivers current in a sinusoidal pattern. Successive windings receive a delayed version of this sinusoid. Figure 4.20 gives an idea of what this looks like.

Using this mode reduces torque by nearly 30%, but another disadvantage involes speed. As the width of a control signal decrease, the ability of the motor to respond also decrease. Therefore, if the controller delivers rapid pulses to the stepper in microstep mode, the motor may not turn in a reliable fashion.

Sychronous type AC Servo Motor

The stator consists of a cylindrical frame and a stator core. The stator core is located in the frame and an armature coil is wound around the stator core. The end of the coil is connected with a lead wire and current is provide from the lead wire. The rotor consists of a shaft and a permanent magnet and the permanent magnet is attached to the outside of the shaft. In a synchronous type AC Leadshine servo motor, the magnet is attached to a rotor and an armature coil is wound around the stator unlike the DC servo motor. Therefore, the supply of current is possible from the outside without a stator and a synchronous type AC servo motor is called a “brushless servo motor” because of this structural characteristic. Because this structure makes it possible to cool down a stator core directly from the outside, it is possible to resist an increase in temeprature. Also, because a synchronous type AC servo motor does not have the limitation of maximum velocity due to recification spark, a good characteristic of torque in the high-speed range can be obtained. In additon, because this type of motor has no brush, it can be operated for a long time without maintenace.

Like a DC servo motor, this type of AC servo motor drive uses an optical encoder or a resolver as a detector of rotation velocity. Also, a ferrite magnet or a rate earth magnet is used for the magnet which is built into the rotor and plays the role of a field system.

In this type of AC Servo Motor, because an armature contribution is linearly proportional to torque. Stop is easy and dynamic brake wordks during emergency stop. However, because a permanent magnet is use, the structure is very complex and the detection of position of the rotor is needed. The current from the armature includes high frequency current and the high frequecy current is the source of toruqe ripple and vibration.

The Input/Outpout System – Discrete Devices

In the first module, you learned about the basic architecture and operation of the Allen-Bradley Micrologix 1000, including a brief introduction to its I/O system. This second module goes into more detail about the I/O system of the Micrologix 1000 Omron PLC. It includes four sections:

1. Types of input/output devices
2. Input interfaces
3. Output interfaces
4. System and I/O power distribution wiring

Types of Input/Output Devices

A MicroLogix 1000 PLC uses its input and output interfaces to connect with field input/output devices. To review, all input devices provide a signal to the PLC, and all output devices receive a signal from the PLC. All I/O devices, however, do not send and receive the same type of signal. There are two different types of I/O signals and two types of I/O devices that use them. The two types of I/O devices are discrete devices and analog devices.

At the end of this section, you will know:

• the difference between the two types of I/O devices
• which type works with the MicroLogix 1000

Discrete Devices

Discrete devices are input or output devices that provide or receive discrete digital signals. A discrete digital signal is one that can report only two states, such as ON/OFF or open/closed.

A limit switch is an example of a discrete input device because,1at any given time, it is either open or closed. It sends a discretePLdigital signal to a PLC. This signal can have one of only two values, 0 or 1, indicating that the device is either OFF or ON, respectively (see Figure 2-1).

A pilot light is an example of a discrete output device (see Figure 2-2). It can only be ON or OFF. A discrete output deviceOFFDiscrete0receives a discrete digital signal from a PLC telling it to be in either one state or the other. A discrete output can never be in a state in between ON and OFF.Figure 2-2. A pilot light receives a discrete signal from a PLC.

Next article we will continue introducing Analog Devices. The following products are some hot sale OMRON PLC on our store.

cp1e e20sdr a OMRON PLC, CP1E CPU AC 100-240V input, 24DI 16DO Relay, USB port, Original brand new

OMRON PLCCP1E series offers all functionality you need to control relatively simple applications, including outstanding positioning capability. All CP1E CPUs offer high-speed USB for quick programming. The “Easy Input Editor” software feature allows faster programming by using an intuitive ladder editor to create an organized application program. The CP1E series comes in two different types: CP1E-E is the most economical, while the CP1E-N has a built-in real-time clock, motion control capabilities, and a serial port to connect an HMI, barcode reader, or other serial device. Several optional units are available to increase the functionality. As the CP1E series shares the same architecture as the CP1L, CP1H, CJ, and CS series, programs are compatible for memory allocations and instructions.


★ New CP1E CPU Units now available.
-Lineup including CPU Units with built-in three ports: USB, RS-232C, RS-485.
-The depth of CPU Units with RS-232C connectors is reduced by 20 mm. (N30/40/60S(1))
★ Easy connection with computers using commercially available USB cables.
★ With E30/40/60(S), N30/40/60 or NA20 CPU Units, Add I/O, Analog I/O or Temperature Inputs by Connecting Expansion Units or Expansion I/O Units.
★ Input interrupts
★ Complete High-speed Counter Functionality.
★ Versatile pulse control for Transistor Output for N14/20/30/40/60 or NA20 CPU Units.
★ PWM Outputs for Transistor Output for N14/20/30/40/60(S@) or NA20 CPU Units.
★ Mounting Serial Option Boards or Ethernet Option Board to N30/40/60 or NA20 CPU Units.
★ Built-in analog I/O, two inputs and one output, for NA-type CPU Units.

CP1H-XA40DT-D PLC OMRON, CPU 24VDC, input 24 point transistor output 16 point Original brand new


Pulse output for 4 axes. Advanced power for high-precision positioning control
High-speed counters. Differential phases for 4 axes
Easily handles multi-axis control with a single unit
Eight interrupt inputs are built in. Faster processing of approximately 500 instructions speeds up the entire system
Serial communications. Two ports. Select option boards for either RS-232C or RS-485 communications
EtherNet communications, enabled by using an option board, two ports can be used as an EtherNet port to perform, EtherNet communications between the CP1H and a host computer
USB peripheral port
The structured text (ST) language, makes math operations even easier
LCD displays and settings, enabled using option board
Transistor output (sinking)

CJ1W-ID211 PLC OMRON I/O 16 input point 24VDC Original brand new


High-speed input models are available, meeting versatile applications.
ON Response Time: 15μs, OFF Response Time: 90μs
Use 24-VDC, 100-VAC, and 200-VAC models to connect to devices with different types of outputs.
The 24-VDC models can be connected to devices with either NPN or PNP outputs. There is no need to select the polarity. *1
A digital filter in the Unit can be set from 0 to 32 ms to reduce the influence of external noise.
Either a Fujitsu or MIL connector interface can be used. *2
Several models of Terminal Block Conversion Units are available, making it easy to connect to external devices.

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