Bosch Rexroth Introduces New Products at IFPE
Rexroth AV24 Pump
Bosch Rexroth’s AVBCN-R series boom-lock valves give machine builders the opportunity to refine control systems with the combination of two functions in one valve. The load-lowering and hose-burst safety compliance demanded by ISO-8643 / EN-474 regulations can be supplemented with full-range lowering speed control in the AVBCN-R valves.
The new Rexroth AVBCN-R series is intended to eliminate the need for highly synchronized opening of the two valves through its combination of low-hysteresis speed control, load-limiting overpressure protection and hose-burst safety in one single valve. This combination potentially reduces directional valve spool cost, and energy savings may be achieved through the low-side oil reclamation system. Rexroth’s AVBCN-R family of valves are designed for flow rates to 700 liters per minute (185 gallons per minute) 420 bar (6,000 pounds per square inch).
Rexroth also introduces its ML-18 load-sensing control valves, designed to focus on reducing power consumption on new TIER 4 applications such as skid steers, small wheel loaders and material handlers. The ML-18 features a monoblock design designed to reduce the interface restrictions between sections, along with a dedicated tank coring for the highest flow section and the use of back-pressure valving for forced flow regenerating. In tests by the company, the ML-18 reduces pressure drops by as much as 50 percent when compared to competitors in applications requiring up to 40 gallons per minute (gpm) (151 liters per minute) at 4,000 pounds per square inch (276 bar).
The new Bosch Rexroth Safety Integrity Level (SIL) 2-certified 4THEC5 joystick offers “plug and play” options with no additional external supervision for joystick functions. It is intended to help OEMs achieve certification for safety functions based on IEC 62061 and performance Level d capability based on ISO 13849. The joystick is targeted to machine manufacturers facing the assessment of the safety level of their products to achieve a certificate of European conformity. This safety level applies to all controls operated using the joystick (shaft and handle functions).
A compact design, the 4THEC5 SIL2 joystick has been validated for five million cycles. It is suitable for a variety of applications, particularly in construction and material handling machines. It is compatible with BODAS, CANOpen and J1939 protocols and can be used alongside the existing Rexroth range of multi-function handgrips to achieve any human machine interface configuration an OEM may require.
Rexroth introduces a new hydraulic load-holding valve – the AVBC-14 Control Plus valve intended to help improve fuel conservation while enhancing control precision. Engineered to replace traditional counterbalance valves, the patent-pending design allows the use of gravity to help lower a loaded or unloaded structure, while at the same time providing increased stability and smoother start and stop of motion. Control Plus valve technology is intended to reduce pump flow to the boom when lowering, making more flow available for faster execution of simultaneous movements and reducing machine cycle times for better overall performance.
The control piston design yields a “flow-compensation” effect where lowering speeds remain relatively constant regardless of the load. This is achieved without the energy use of a traditional pressure-compensated flow control. The same control piston provides millimeter-level precision in load positioning.
Rexroth expands its line of RS series counterbalance cartridges. Available in industry standard cavities such as T11A, T2A, T17A and T19A, the cartridges provide solutions to flows of 105 gpm at working pressures up to 6,000 psi. In order to minimize OEM engineering and retrofit obstacles for competitive replacement, the RS series valves feature an adjustment mechanism with clockwise rotation for decrease of the pressure setting.
The new Bosch Rexroth BODAS 32-bit compact RC4-5 controller offers a balance of power and flexibility designed to maximize both hydraulic component and overall system performance. The RC4-5 offers four Pulse Width Modulated (PWM) driver outputs with closed-loop current control. Closed-loop current control compensates for the real world changes in voltage and resistance to provide repeatable performance from machine to machine, day-in and day-out. Adjustable parameters for solenoid current, linearization and PWM frequency adapts the RC4-5 to a wide variety of 12- and 24-volt electro-proportional components.
The RC4-5 also provides a flexible set of inputs and outputs to support a wide variety of work, travel, auxiliary and operator functions for system integration. Many common sensors for force, speed, pressure, position and temperature measurement may be directly connected to the controller while two CAN bus channels offer communication gateways to a wider array of devices including joysticks, displays and engines. The RC4-5 lists a compact size of approximately 5”x6”x2” and has an 80 MHz, high-performance 32-bit processor that can handle multiple simultaneous complex control tasks.
The Hägglunds CBM hydraulic motor from Bosch Rexroth offers 50 percent more torque into a motor that is smaller and up to 50 percent lighter than its predecessor, offering the highest torque-to weight ratio. The Hägglunds CBM not only handles heavier workloads, but also takes up less space and places less weight on the drive shaft. The motor’s reduced installation requirements can result in lower overall investments and increased long-term revenue. The advantages of a hydraulic direct drive include full torque from zero speed, protection from shock loads and four-quadrant operation. The Hägglunds CBM has internal advances that allow it to supply 6000 Nm/bar of specific torque.
Bosch Rexroth introduces its A24VG double variable pump that offers increased power and fuel efficiency for mobile excavators. It features two axial piston rotary groups with a swashplate design for hydrostatic drives in a closed circuit. The A24VG is designed to deliver high power density and good efficiency, and is targeted for use in equipment such as mobile excavators, where the pump can provide the flow for the travel and swing drive. Located directly on the double pump, the onboard electronics control the travel and slew drive, both of which are operated in a closed circuit. In the A24VG, the oil flows directly from the pump to the motor without a control block, as it would in an open circuit, which avoids the possibility of throttling losses.
Using software-based controls, the A24VG can help increase the travel drive’s effectiveness by at least 10 percent, and the effectiveness of the swing drive can be improved. This allows for new sources of performance potential that can be used to downsize the diesel and reduce emissions, while also making the machine easier to operate.
Bosch Rexroth introduces the new size A1VO18 variable axial piston pump. It is designed to fit in the same volume as a comparable constant displacement pump due to its integrated cartridge valve, but also offers the ability to go off stroke when demand is reduced, thus decreasing the energy needed to run the system while still maintaining constant load pressure.
With the A1VO8 axial variable displacement pump the size is comparable to that of gear pumps, which makes is intended to make switching technologies for manufacturers easy. The A1VO8 has a displacement of 18 cc and is designed for speeds up to 3,300 rpm. The variable displacement pump is rated at a working pressure of 3,600 psi and a peak pressure of up to 4,000 psi, and has a flow capacity of up to 15.6 gal/min. The overall efficiency is nearly 90 percent. The Rexroth A1VO is also available in a 35 cc displacement size.
Rexroth also integrates its M4 series sectional valves in a single assembly with its modular ED family of compact directional valves. The new hybrid technology allows for any given machine function to be perfectly matched to each valve section’s performance and price. The M4 addresses machine functions requiring high precision with high-flow output, as well as low-flow or low-precision functions such as stabilizers, counterweight lifts and locking pins.
While mobile applications require diverse flow rates for varying functions, the M4 series match the right valve to the required flow. This means the hydraulic system can be optimized, potentially reducing the size and cost of components and helping to satisfy increasing requests from manufacturers for total machine weight reduction. At the same time, this assures overall cost effectiveness because valve sections are sized for a specific functional requirement.
Visit Bosch Rexroth in Booth 80216 at IFPE