Nachi Hydraulic Parts & Services

Features

1. Excellent performance and quality guaranteed by strict material selection, improved heat treatment techniques and high precision machining technology.
   
   
2. Nachi hydraulic pumps have been designed to operate at the lowest noise level possible.

Installation and Maintenance

Note the following when Nachi hydraulic pumps are installed and at the time of maintenance.

1. The eccentricity between the motor drive shaft and pump shaft must be kept within 0.05mm ( 0.002 in ). The eccentric angle between them must be maintained within 1 degree. Be sure to use flexible coupling when linking a drive motor with a pump.
   
   
2. When a belt, gear, or chain is used to drive a hydraulic pump, care must be taken that the radial or the thrust load will not be applied to the pump shaft. If this type design is necessary, install a device to assure the pump shaft of no load ( bending force ) applied at right angles.
   
   
3. For safe installation, use a pump base which has sufficient rigidity.
   
   
4. Each Nachi hydraulic pump has its rotating direction fixed. Prior to the start of regular operation, check the rotating direction of the pump by referring to the model code on the nameplate or the arrow mark ( on the pump body ) showing proper rotating direction. The normal rotating direction of Nachi hydraulic pumps is clockwise as viewed from the shaft end.
   
   
5. Hydraulic pumps with an external drain should have the drain piping connected directly to the reservoir at a point below the oil level. The piping should be sized to keep the back pressure below 4.3 PSI.
   
   
6. When a steel pipe is used for the inlet and outlet piping of a hydraulic pump, be careful that an abnormally large force is not applied to the pump.
   
   
7. The length of the joint made with the use of key fitted in the keyway across the pump shaft should be over 2/3 the coupling width. For safe and positive connection, select a coupling having a size suitable to shaft diameter.
   
   
8. When each key is driven into the keyway, do not apply an excessively large force to the shaft. Be sure to use a coupling puller to remove the coupling. Otherwise, the inner parts may be damaged. Never strike the shafts of both the motor and pump when the coupling is removed.
   
   
9. Install each hydraulic pump in a manner so that the interior of the pump may be kept filled with oil even while the pump is not being operated.
   
   
10. An air bleed-off valve should be installed for an hydraulic circuit which does not require air bleeding at the time the pump is started.
    
    
11. Be sure to use bolts specified by this company for use with Nachi hydraulic pumps. We recommended the use of bolts with a torque rating of more than grade 12.9.

Hydraulic Oil Control

1. To keep the hydraulic oil clean, provide a suction filter with a mesh size of 100~150 at the inlet suction port of the pump.
2. To increase pump life, a 25u filter is recommended.
3. Please contact Nachi before using any fire resistant fluids.

Terms
The following technical terms used in this catalog have the meanings cited below.

• Rated Pressure:
  Refers to the pressure under which the hydraulic pump can be operated continuously.
  
  
• Maximum Operating Pressure:
  Refers to the pressure to which the pump can be operated within 1/10 of the cycle time or within 6 seconds at the longest.