I. INTRODUCTION

Hybrid actuator “HySerpack” is a hydraulic servo control system which integrates a motor, a pump, an actuator and an oil tank into one compact unit.   It eliminates unnecessary piping which is the main source of oil leak as well as valves which results in complicated piping.   It requires only small amount of oil to operate due to its compact construction.　This makes it possible to use even flammable oil for the unit under any circumstances without being regulated by laws.

Because of its simple design and effective control technology, it reduces power consumption dramatically and eases the load on environment.

II. ADAVANTEGES

A few advantages HySerpack has over other hydraulic systems are:

  1. Because no oil compressor or control valves are required, no construction or piping work is required.
  2. The motor runs only when the unit is working. So the power consumption is equal to the amount of work to be done. Thus running cost is dramatically saved.
  3. Compact, versatile, high power, accurate, low noise and high efficient. Thanks to these merits, it has a tremendously large effect on energy saving.
  4. No cooling water is required. Oil has not to be replaced for the life of the unit because it does not deteriorate owing to a completely sealed system.  It eases the impact on environment.
  5. Because of the completely sealed and electro-driven unit, the performance is not affected at all by the angle of installation, altitude, ambient temperature or whatsoever which may disturb the operation of a traditional hydraulic unit.

Types of Controls

There are two types of control methods for HySerpack as below　-　The difference derived from the types of sensors used on units:

DHA Type Absolute linear scale is installed inside of cylinder to sense & control the rod position precisely.

Servo Control Manual

DHA model table
PTP Type The type of units which uses limit switches to regulate positions of cylinder rod. Economical model

Interface Instruction

PTP model table

 

Q&A

Why is no valve required for HySerpack?

The cylinder rod’s movement is regulated by the amount and direction of oil flow propelled by a gear pump.  The rotating direction of the pump is determined by the rotating direction of a servo motor which is controlled by input signals.  Once the pump comes to rest, then the rod stops.  When the pump speed is altered, the rod speed varies accordingly.  In sum, the change of pumping direction produces the change of direction of the rod movement, and the speed of pump dictates the amount of oil flowing between the oil reservoir and the cylinder, which results in the change of the speed of the cylinder rod movement.  Thus all valves can be eliminated from the unit.  The thrust of the rod is controlled by oil pressure in the cylinder. The oil pressure is regulated by the torque on the motor.

Why does HySerpack consume so little electricity?

HySerpack employs a direct drive method.

      The conventional hydraulic system keeps its motor and pump running in full even while the cylinder makes no movement.     It wastes a large amount of energy and consequently increases the temperature of oil in the cylinder.  The rise of oil temperature requires either an unnecessarily large oil tank for cooling oil down in due course or an enforced oil cooling system which has awfully poor energy efficiency.  As for HySerpack, the motor and pump stop when the actuator rests.  Therefore no energy is consumed even while it is pressurizing objects as long as it does not move.  Thus HySerpack is an extremely effective energy saving unit.

 

How can pipes be eliminated from HySerpack?

HySerpack controls the cylinder rod movement only by the direction, amount and pressure of fluid oil discharged from the pump.

Therefore no control valve is required at all.  Once all control valves are eliminated, no piping is required except for the very short ones which connect the pump and the cylinder.  HySerpack is a self-contained electro-driven actuator which can be incorporated into a complete system quickly and easily.

 

It is said that it is difficult to tune a servo.-control system for operation. 　Is this true？

HySerpack is a self-contained servo-driven hydraulic unit. A drive motor, pump, oil tank, cylinder and all other ancillary parts are assembled into one compact unit then oil is filled up before test runs in shop. A servo amp and operating software come with the unit. During the test both software and hardware are fine-tuned so they function as designed without any further adjustments.  Thus as soon as HySerpack is installed and incorporated into a machine on site, the machine start working as designed and desired.