System configuration and setup is easily completed using software. The SPCS operates with either a 0-10 VDC or 4-20 mA analog command signal, providing closed loop pneumatic proportional control for all Bimba position feedback actuators, including the PFCN, PFCNL, PFCL, PTF and Ultran rodless cylinders with external transducers.

• Compact Design
• Operating Pressure: 0-150 psig (0-10 bar)
• Flow: Up to 46 SCFM @ 150 psig (820 SLPM @ 6 bar)
• Positioning accuracy up to 1% of full stroke
• Maximum Payloads: 450 lbs horizontally, 135 lbs vertically
• Recommended for use with Bimba PFC cylinders w/low friction seals (L option)

When working with harder or larger diameter tubing that requires stronger pinch forces, then our pneumatic product line delivers. Designed for biopharmaceutical processing, food and beverage, and industrial applications where sterility and wash down procedures are needed, these robust units offer reliability and performance. Each model is designed for disposable tubing and contains an easy snap-in tube slot for quick loading and unloading procedures. Panel or base mountable, units can also be configured with optional state sensors, controllers, or setup in normally-open or normally-closed default states. Optional safety caps on larger models are also available to address finger crushing hazards.

Features/Benefits

• Compact design with user selectable tubing (up to 75 Shore A)
• Base or Panel mount ready with snap in tubing slot
• Optional valve state detection sensors
• Optional 3 or 4-way controllers for pressure venting between states
• Panel splash seals for wash down procedures
• Manual overrides on model 932 & 933
• Offered in Black Anodized Aluminum or 316L stainless steel
• Industry best warranty for 2 years

Pneumatic Pinch Valve Requirements:

Note that all our pneumatic pinch valves require filtered, clean compressed air that depending on selected model require between 40-100 input psi with a maximum of 125 psi. In addition, units require a solenoid controller for controlling pressurization and ventilation of the chambers between opening and closing states. Customer may select from either 3-way or 4-way controller options offered by Acro that have been thoroughly tested and validated for use with our models.

Humphrey’s custom valve assembly enabled customer to create a ventilator that met the respiratory care needs of both adults, and infants and young children. No longer will hospitals need to purchase two separate ventilators.

Customer Requirements

• Design a 2-way high-flow pilot-operated poppet-valve assembly with an integral check valve to stop the high flow air/oxygen supply when poppet is closed.
• Valve must be capable of delivering air/oxygen volumes from 2 ml/min up to 2.5 L/min.
• Meet existing space limitations with provisions for easily mounting the valve assembly.
• Medical grade air/oxygen ports to be 3/8-18 NPT.

The Humphrey Engineered Solution

• Humphrey engineers designed a custom manifold to meet space, porting and mounting requirements, and included the customer’s specified check valve.
• The Humphrey proven, standard model Y500 insert valve was modified, using only the top portion with the piston redesigned to ensure correct poppet-to-seat orientation.
• The Humphrey Mini-Mizer poppet solenoid valve, used as a pilot valve, achieved the desired 0.5 Watt current consumption.
• The mounting adapter was designed to permit easy attachment to the unit inside the cramped space using a readily available 1/4” square drive socket.

The Solution and Process

The Humphrey Engineered Solutions team started with their Y500 insert valve, using only the top half containing the poppet. They extended the skirt on the poppet to act as a guide, ensuring the correct orientation of the poppet to the seat. They selected the low current consumption Mini-Mizer solenoid valve to control the pilot flow of high pressure oxygen that actuates the modified Y500 insert valve.

Next they designed a custom manifold incorporating the customer’s qualified check valve and provided 3/8-18 NPT inlet and outlet connections. The manifold was designed so that the valve was normally open, supplying the flow volume of air/oxygen required for adults. When the unit was switched to the lower flow volume mode, the air/oxygen was routed through the check valve and a subsequently smaller orifice to meet the reduced flow requirement for children and infants.

Then the Engineered Solutions team designed an adapter plate that could be screwed onto the  mounting bracket using a simple 1/4” square drive socket. This eliminated the need for special tools. With the adapter in place, the valve assembly could be aligned and attached to the adapter from the top.

After looking on Humphrey’s website for a high flow 2-way valve, the customer contacted Humphrey for assistance in developing a custom valve assembly that would meet the performance requirements and fit in the limited space available. 

Originally the customer had considered Humphrey’s Y500 cartridge insert valve. Employing the Humphrey Engineered Solutions team approach, a Humphrey engineer worked directly with the customer’s engineer to identify all the customer’s requirements and the opportunities to improve the customer’s concept. 

The Humphrey engineer determined that only the top half of the Y500 insert valve containing the poppet was needed. At that point Humphrey modified the poppet to ensure proper operation, and developed a custom manifold to provide for two different air/oxygen flows. The Humphrey Mini-Mizer Solenoid valve was selected as the pilot operator to control the flow of high-pressure oxygen that actuated the valve. 

Having determined the space limitations, Humphrey engineers designed a screw-in adapter plate that used a 1/4” square drive socket. After 100% testing, each valve assembly was shipped separately from the adapter plate, enabling rapid assembly at thecustomer’s facility.

Challenge:

A manufacturer of medical equipment contacted Pneumadyne engineers to design a system that would combine the functions of several individual operatory devices into one convenient package. Our customer had already established the application requirements and overall package size but needed help with the pneumatic circuitry.

Requirements:

• Condense three circuits into one component
• Meet specific flow and pressure requirements
• Reduce the size of the circuit to fit the space constraints of the operatory equipment that the customer had already designed
• Pneumadyne Engineers had to work within an extremely tight time line which required weekly web-based meetings with several domestic and international offices
• Several components within the device had to be able to withstand an autoclave

Solution:

Pneumadyne engineers were able to meet the customer’s strict time line and develop an integrated manifold block that contains three separate circuits and fits the space allowed in the customer’s equipment. This multi-function assembly allowed the customer to replace several devices within an operatory.

• A regulator pre-set at 7.5 psi supplies pressure to a water chamber
• A separate valve within a plastic cap shuts the flow of water off between uses
• Four pressure transducers provide an electronic interface for the measurement of system flow and pressure
• All five solenoid valves are oxygen cleaned
• Special tests were developed and performed to ensure that the device met the customer’s flow and pressure specifications

This post is brought to you by Bimba Technical Tips.

Steppers and servos can be used with Bimba OLE actuators. They are the best motor technologies for position control. The choice of which to use is dependent on speed, torque, price, and often lead time. The following discussion explains the differences between the two technologies.

Step motor design

Step motors are called “digital motors” because they move in steps, like the hands on a clock. When the first coil is energized, the rotor teeth align with the teeth in the first stator winding and hold position. When the second winding is energized, the teeth in the rotor move slightly and align with the second stator winding and hold position. The total movement in this example is one full step.

There are usually 200 steps per revolution, each step being 1.8°. The step motor was made possible by the development of electronic step motor controllers. Electronics are required to energize the windings with proper voltage and current, with the proper phase, in the right sequence, at the right time. Controllers have evolved to be able to move step motors in as many as 20,000 steps per revolution, providing 100 times finer movement (0.018° per step).

Step motor system components

In order to understand step motor performance it is helpful to understand the components of a step motor based system.

Motor and actuator:Consider the motor and actuator together to be equivalent to an arm. It will not move without power.

• Output: Thrust and speed to move the load.
• Input: Power from the stepper drive.

Drive: The device that provides muscle to move the arm is called the drive.

• Output: Provides power to the motor windings in the right amount and in the right sequence to make the actuator “arm” move in the desired direction. A drive requires a source of electric power, such as a DC power supply. The voltage output of the DC power supply is transferred through the drive directly to the motor windings. The current and voltage on the motor windings are proportional to motor torque output and therefore to actuator thrust output. In general, the higher the voltage and current, the more thrust. Above a point, an increase in current only raises motor winding temperature instead of torque output.
• Input: Accepts step pulses and a direction command from the controller. Each electronic step pulse produces a change in the way the motor windings are energized which in turn causes the motor to turn one step which in turn makes the actuator move. 

Controller: Think of the controller as the brain that commands the muscle.

• Output: Provides step and direction pulses to the driver. Also provides various outputs to the PLC, including communications via a bus (RS232, RS485, Ethernet IP, Profibus, el. al.), in-position signal, alarm and fault outputs, and others.
• Inputs: Inputs are managed intelligently and systematically from a variety of sources. 
• Magnetic switches
• Sensors elsewhere on the machine
• PLC outputs
• Bus communications from a PLC
• Encoder signal from the motor

Encoder: The encoder is the “eye” of the system. It tells the controller whether its command has been followed. The controller compares the step pulses it has sent to the driver to pulses it receives from the encoder. If the pulses it sends are equal to the pulses it receives, the controller knows its command has been followed. If they are not equal, the controller makes an adjustment to the motor until it receives the correct number of encoder pulses.

The system block diagram conveniently separates all functional components for the purposes of discussion. It is common for manufacturers to combine functions. For example, controllers often have built in drives, and some have built in power supplies. Some motors have built in encoders, and some have built in drives and controllers as well. Some PLC’s have built in controllers.

Step motor performance

Step motors have inherent advantages:

• Step motors are the least expensive position control motor technology.
• Step motors can be used open loop, without an encoder. 
• Step motors provide very high torque at low speeds.
• Available in NEMA frame sizes which standardize mounting and shaft diameters. 

Step motors have inherent drawbacks:  

• Although step motors provide high torque at low speeds, torque output drops off rapidly as speed increases.
• Step motors can lose sync; that is, lose synchronization with the step pulses from the controller. In other words, step pulses from the controller are converted into power to the windings of the motor, but the motor does not rotate. This will happen when the torque required to move the load exceeds the torque capability of the motor at the desired speed. To avoid this issue:
• Increase the motor size. Size the motor to provide double the maximum required torque.
• Reduce speed to the point where motor torque is sufficient.
• Increase voltage to the motor windings (large power supply).
• Increase current to the motor windings (large power supply).
• Use an encoder to monitor position and correct for missed steps.
• Difficult to synchronize because error correction is made at the end of stroke, not continuously in real time.

Servo motor design

A servo by definition is any device with feedback. Servo motors have coils on their stator which are energized in sequence by a servo drive or amplifier, causing rotation (spinning) of the magnetic rotor. In order for the controller to determine what winding to energize next, it must know the current position of the rotor. This sensing is done using either hall sensors or a dual-function encoder.

Servo motor system components

The block diagram of a servo system is identical to the block diagram of a step motor system, although the technology of the components is different. The servo amplifier is the functional equivalent of the step motor drive. As with step motors, functions are often combined by manufacturers.

Servo motor performance

Servos have inherent advantages:

• High speed 
• High acceleration 
• High precision 
• More torque at higher speeds 
• Can readily synchronize multiple motors (real time error correction)

Servos have inherent disadvantages:

• More complex system than step motors
• Motors must be tuned for optimal performance
• More costly system than step motors
• Less torque at lowest speeds compared to step motors
• Non-standard mounting geometries (vary by manufacturer) and shaft diameters
• Less torque than comparably sized step motors at low speeds

Implications for use with electric actuators

Whichever technology is used, it must be matched to the actuator design.

• A servo at low speeds may not achieve the same low speed actuator performance as a step motor.
• Replacing a step motor with a servo on the same actuator will not necessarily result in more thrust at higher speeds because other actuator components may limit performance. 

Depending on the application, there are advantages to both motor technologies. The table below may be used as a guide.

Steppers and servos can be used with Bimba OLE actuators. They are the best motor technologies for position control. The choice of which to use is dependent on speed, torque, price, and often lead time. The following discussion explains the differences between the two technologies.

Step motor design

Step motors are called “digital motors” because they move in steps, like the hands on a clock. When the first coil is energized, the rotor teeth align with the teeth in the first stator winding and hold position. When the second winding is energized, the teeth in the rotor move slightly and align with the second stator winding and hold position. The total movement in this example is one full step.

There are usually 200 steps per revolution, each step being 1.8°. The step motor was made possible by the development of electronic step motor controllers. Electronics are required to energize the windings with proper voltage and current, with the proper phase, in the right sequence, at the right time. Controllers have evolved to be able to move step motors in as many as 20,000 steps per revolution, providing 100 times finer movement (0.018° per step).

Step motor system components

In order to understand step motor performance it is helpful to understand the components of a step motor based system.

Motor and actuator:Consider the motor and actuator together to be equivalent to an arm. It will not move without power.

• Output: Thrust and speed to move the load.
• Input: Power from the stepper drive.

Drive: The device that provides muscle to move the arm is called the drive.

• Output: Provides power to the motor windings in the right amount and in the right sequence to make the actuator “arm” move in the desired direction. A drive requires a source of electric power, such as a DC power supply. The voltage output of the DC power supply is transferred through the drive directly to the motor windings. The current and voltage on the motor windings are proportional to motor torque output and therefore to actuator thrust output. In general, the higher the voltage and current, the more thrust. Above a point, an increase in current only raises motor winding temperature instead of torque output.
• Input: Accepts step pulses and a direction command from the controller. Each electronic step pulse produces a change in the way the motor windings are energized which in turn causes the motor to turn one step which in turn makes the actuator move. 

Controller: Think of the controller as the brain that commands the muscle.

• Output: Provides step and direction pulses to the driver. Also provides various outputs to the PLC, including communications via a bus (RS232, RS485, Ethernet IP, Profibus, el. al.), in-position signal, alarm and fault outputs, and others.
• Inputs: Inputs are managed intelligently and systematically from a variety of sources. 
• Magnetic switches
• Sensors elsewhere on the machine
• PLC outputs
• Bus communications from a PLC
• Encoder signal from the motor

Encoder: The encoder is the “eye” of the system. It tells the controller whether its command has been followed. The controller compares the step pulses it has sent to the driver to pulses it receives from the encoder. If the pulses it sends are equal to the pulses it receives, the controller knows its command has been followed. If they are not equal, the controller makes an adjustment to the motor until it receives the correct number of encoder pulses.

The system block diagram conveniently separates all functional components for the purposes of discussion. It is common for manufacturers to combine functions. For example, controllers often have built in drives, and some have built in power supplies. Some motors have built in encoders, and some have built in drives and controllers as well. Some PLC’s have built in controllers.

Step motor performance

Step motors have inherent advantages:

• Step motors are the least expensive position control motor technology.
• Step motors can be used open loop, without an encoder. 
• Step motors provide very high torque at low speeds.
• Available in NEMA frame sizes which standardize mounting and shaft diameters. 

Step motors have inherent drawbacks:  

• Although step motors provide high torque at low speeds, torque output drops off rapidly as speed increases.
• Step motors can lose sync; that is, lose synchronization with the step pulses from the controller. In other words, step pulses from the controller are converted into power to the windings of the motor, but the motor does not rotate. This will happen when the torque required to move the load exceeds the torque capability of the motor at the desired speed. To avoid this issue:
• Increase the motor size. Size the motor to provide double the maximum required torque.
• Reduce speed to the point where motor torque is sufficient.
• Increase voltage to the motor windings (large power supply).
• Increase current to the motor windings (large power supply).
• Use an encoder to monitor position and correct for missed steps.
• Difficult to synchronize because error correction is made at the end of stroke, not continuously in real time.

Servo motor design

A servo by definition is any device with feedback. Servo motors have coils on their stator which are energized in sequence by a servo drive or amplifier, causing rotation (spinning) of the magnetic rotor. In order for the controller to determine what winding to energize next, it must know the current position of the rotor. This sensing is done using either hall sensors or a dual-function encoder.

Servo motor system components

The block diagram of a servo system is identical to the block diagram of a step motor system, although the technology of the components is different. The servo amplifier is the functional equivalent of the step motor drive. As with step motors, functions are often combined by manufacturers.

Servo motor performance

Servos have inherent advantages:

• High speed 
• High acceleration 
• High precision 
• More torque at higher speeds 
• Can readily synchronize multiple motors (real time error correction)

Servos have inherent disadvantages:

• More complex system than step motors
• Motors must be tuned for optimal performance
• More costly system than step motors
• Less torque at lowest speeds compared to step motors
• Non-standard mounting geometries (vary by manufacturer) and shaft diameters
• Less torque than comparably sized step motors at low speeds

Implications for use with electric actuators

Whichever technology is used, it must be matched to the actuator design.

• A servo at low speeds may not achieve the same low speed actuator performance as a step motor.
• Replacing a step motor with a servo on the same actuator will not necessarily result in more thrust at higher speeds because other actuator components may limit performance. 

Depending on the application, there are advantages to both motor technologies. The table below may be used as a guide.

The key to reducing production costs is found in CT effects. You may be able to further reduce the costs if you look closely at the CT effects.

So what exactly are CT effects?

Watch the video from Intelligent Actuators to learn more about how the CT Effect can save your business significant time and money.

This post is brought to you by Bimba Technical Tips.

How you mount your cylinder affects both cylinder performance and cylinder life expectancy. That’s because the wrong mounting or incorrect installation can result in side load. Side load occurs when a load is placed on the piston rod without guidance or support, or when the mounting and piston rod connection are misaligned. Side load creates excessive wear on the piston, piston rod, rod bearing and seals. Excessive wear leads to leakage and ultimately cylinder failure.

By selecting the right cylinder mounting, you optimize cylinder strength, efficiency and alignment. Let’s look at the two major types of mounts -- pivot and rigid -- and how they help avoid side load problems.

Pivot type mountings eliminate side loads when properly installed

There are several types of pivot mountings including clevis, pivot and trunnion. To realize the benefit of a pivot type mounting, it’s essential that a rod eye or rod clevis be used on the piston rod. Otherwise, it becomes a “rigid” mount cylinder, negating the benefit of the pivot. It’s also important that the axis of all the pivot pins in a set are parallel, or binding and side loading will occur. Long stroke pivot mount cylinders require stop tubes and dual pistons to spread out the distance between the rod bearing and piston to reduce the load at these two points. Trunnion mounted cylinders require that pillow blocks or mated bearings be fitted as close to the head of the cylinder as possible to minimize bending stresses in the head.

Get maximum cylinder life with proper rigid mount cylinders

There are a number of rigid mounts available: side-mounted, nose-mounted, flange-mounted and face-mounted cylinders. Each must be carefully aligned with the direction of the load travel to avoid side loads. If, for some reason, proper alignment cannot be achieved, a rod end connection that allows for some lateral misalignment should be used.

Proper mounting is just one factor to consider when specifying and installing a cylinder.

When specifying cylinders, it’s important to consider the operating environment. That’s because temperature, air quality and radiation can have a direct, negative effect on your cylinder’s performance. By taking the time to factor in the operating environment, you’ll be better prepared to select a cylinder with the right type of seals, materials and finishes for long life and optimum performance. Let’s look at a few environmental factors.

Temperature affects cylinder’s seals and lubrication

If your application involves temperature extremes -- below -20°F (-25°C) or over 200°F (95°C) -- you can expect shorter cylinder life span. At these temperature extremes, seals become damaged or brittle, metal becomes overstressed, and lubrication turns too thick or too thin. If the cylinders are operating below 0°F (-18°C) or up to 400°F (204°C) for extended periods of time, you can specify special seal modifications. The best way to avoid any temperature-related problems is to specify the temperature of the operating environment if either high or low temperatures are involved.

Radiation and caustic washdowns attack cylinder material

Radiation causes a change in almost all materials and, in some cases, causes materials to disintegrate. It’s important to know the type and intensity of radiation so you can accurately estimate the expected life of your cylinder. Regular cleaning of cylinder exteriors with a caustic washdown can cause corrosion, shortening cylinder life. Special finishes and materials are available to reduce the corrosive effect on the cylinders and special designs can help keep washdown fluid out of the cylinder’s interior.

Poor air quality can accelerate corrosion and shorten seal life

Indoor and outdoor air quality can affect your cylinder. Cylinders exposed to a factory’s toxic gases, dust and ozone may experience shortened seal life through friction or corrosion. Salt can be very corrosive to the piston rod, and the cylinder head and body. Food processing, in particular meat processing, often coats the cylinder with grease, affecting the rod and other cylinder components.

Cylinders operating outdoors are subject to rain, sun, wind, dust and, in some areas, snow and freezing. In addition, certain outdoor applications expose the cylinder to harmful substances. For example, cylinders used on road machinery with moist concrete dust or tarry substances require extra protection. Special finishes and/or materials are typically required for cylinders in farm machinery equipment since dust, fertilizers and animal wastes are extremely corrosive to many metals.

This post is brought to you by Bimba Technical Tips.

When specifying cylinders, it’s important to consider the operating environment. That’s because temperature, air quality and radiation can have a direct, negative effect on your cylinder’s performance. By taking the time to factor in the operating environment, you’ll be better prepared to select a cylinder with the right type of seals, materials and finishes for long life and optimum performance. Let’s look at a few environmental factors.

Temperature affects cylinder’s seals and lubrication

If your application involves temperature extremes -- below -20°F (-25°C) or over 200°F (95°C) -- you can expect shorter cylinder life span. At these temperature extremes, seals become damaged or brittle, metal becomes overstressed, and lubrication turns too thick or too thin. If the cylinders are operating below 0°F (-18°C) or up to 400°F (204°C) for extended periods of time, you can specify special seal modifications. The best way to avoid any temperature-related problems is to specify the temperature of the operating environment if either high or low temperatures are involved.

Radiation and caustic washdowns attack cylinder material

Radiation causes a change in almost all materials and, in some cases, causes materials to disintegrate. It’s important to know the type and intensity of radiation so you can accurately estimate the expected life of your cylinder. Regular cleaning of cylinder exteriors with a caustic washdown can cause corrosion, shortening cylinder life. Special finishes and materials are available to reduce the corrosive effect on the cylinders and special designs can help keep washdown fluid out of the cylinder’s interior.

Poor air quality can accelerate corrosion and shorten seal life

Indoor and outdoor air quality can affect your cylinder. Cylinders exposed to a factory’s toxic gases, dust and ozone may experience shortened seal life through friction or corrosion. Salt can be very corrosive to the piston rod, and the cylinder head and body. Food processing, in particular meat processing, often coats the cylinder with grease, affecting the rod and other cylinder components.

Cylinders operating outdoors are subject to rain, sun, wind, dust and, in some areas, snow and freezing. In addition, certain outdoor applications expose the cylinder to harmful substances. For example, cylinders used on road machinery with moist concrete dust or tarry substances require extra protection. Special finishes and/or materials are typically required for cylinders in farm machinery equipment since dust, fertilizers and animal wastes are extremely corrosive to many metals.