Huayi Compressor

Industrial Oil Chillers / Oil Cooling Unit


  • CNC lathes, milling machines, grinding machines, broaching machines;
  • CNC integrated machining center;
  • Hydraulic presses, carved machines;
  • Small and medium mechanical hydraulic stations and lubrication systems;
  • All kinds of electric discharge machine

II.Functions & Features

  • To keep machining accuracy subject to the changing oil temperature;
  • Prevent oil from deteriorating due to high temperature, and protect the seal from aging due to high temperature.
  • Maintain the viscosity of the oil and keep the machine work stably;
  • The temperature can be set according to the machine body temperature to prevent thermal deformation of the mechanical structure;
  • The independent industrial oil cooler has a complete sucking oil system and a separate electrical control system, so long as the oil tank is connected, it can work online with the machine tool;
  • The unit is equipped with an automatic alarm function, which can prompt the user to repair the device in a specific way to avoid damage to the machine.

III.Technical Specifications


Cooling Capacity           (W)1000250035005000700010000
Rated Power                 (KW)0.851.62.12.845
Power Source380V/50HZ(Compressor 220V/50Hz)380V/50HZ
Current                   (A)4.27.8105.67.39.5
Temperature Regulating Range (°C)5°C~35°C
Working Temperature                               (°C)≦42°C
Weight                    (kg)5062.565687580
Dimension                    (mm)445 x 365 x 628600 x 460 x 950600 x 520 x 1000530x520x1345650x650x1375800x800x1650
Oil Pump VolumeL/min; adjustable)101025253232
Inlet /Outlet SizecustomizableG3/8″G3/8″-G3/4″G3/8″-G3/4″G3/8″-G3/4″G1″G1″
Machine ProtectionCompressor overheat protection; Short circuit protection, water temperature control, automatic monitoring and protection of oil pressure


  1. Cooling Capacity results subject to the ambience temperature at 35°C, inlet oil temp. at 25°C and inlet oil temp. at 20°C.
  2. The oil suction port of the oil chiller is fitted with filter;
  3. This industrial oil chiller / cooling unit machine should be used in well-ventilated places free of dust, corrosive gas or debris.
  4. Do not use corrosive liquid;
  5. The operating environment is 5-42°C. The external dimensions and related parameters will be changed subject to the final customer’s request.
  6. Other industrial oil chiller / cooling unit specifications and sizes can be customizable upon request.

III.Models Instruction


(1)          (2)     (3)

(1)Serial Number:

OLPR: Industrial oil chiller / cooling unit series;

O: Oil chiller

P: Oil tank with oil pump

R: with heating system

(2)Cooling Capacity(x100W)

XX indicate cooling capacity 100x(XX)=100XX (W)

e.g. XX is 25, it indicates cooling capacity at 100W x 25=2500W

(3) X stands for updated product

IV.Instruction on How to Choose Oil Chiller

1.Selection of Oil Chiller for Spindle Cooling:

(1) Oil temperature: spindle cooling oil temperature should be about 20 ~ 30 °C (close to the ambient temperature value);

(2) Oil pressure: the required oil supply pressure for spindle cooling is about 0.3 ~ 0.5 MPa;

(3) Calculation of spindle heating power:

P heat = P motor η

P heat – spindle heat kW

P motor – spindle motor power kW

η – spindle heat loss efficiency

For general mechanical spindles, heat loss η = 5-8% can be calculated;

For high-speed spindles, heat loss η = 20 to 30% can be calculated.

Example: The power of a machine tool spindle motor is 22kW, which is an ordinary mechanical spindle. Estimate the calorific value of the machine tool spindle:

P heat=22 x (5%~8%) =1.1~1.76kW

The refrigeration capacity of OLP-25 at an oil temperature of 30°C and an ambient temperature of 30°C is 2.5 kW, which is greater than the spindle heating power of 1.76 kW, which meets the requirements. When the oil supply pressure is 0.3 MPa, the flow rate is 10 L/min.

2.Selection of Oil Chiller for Hydraulic Station:

(1) Oil temperature: The oil temperature of the hydraulic station should be around 30-50°C (ambient temperature is about 30°C);

(2) Oil pressure: the pressure required by the hydraulic station cooling cycle is about 0.3 ~ 0.5MPa;

(3) Calculate the heating power according to the pump power of the hydraulic station:

P heat = P motor · η1 · η2 · η3

P Heat – Heat kW

P Motor – Hydraulic Station Total Motor Power kW

η1 – shaft efficiency, value 70% to 80%

η2 – Motor load ratio, value based on different operating conditions

η3 – heat loss efficiency, value 70% to 85%

For a hydraulic station where the hydraulic pump is continuously operating at a high pressure, the value of η is taken as the upper limit value.

Example: The pump power of a certain hydraulic station is 5 kW. After working for 20 minutes and stopping (or standby in low pressure) for 10 minutes, the heat output is:

P heat = P motor η1·η2·η3 =5×80 %×( 20/30) ×80%=2.13 Kw

The OLP-25 cooling capacity is 2.5kW, which is greater than the heating power 2.13kW, to meet the requirements;

(4) Calculate heat power based on the oil tank temperature rise rate

P heat = CP · ρ · Vs · ΔT/t

P thermal heating power kW

1kW=860kcal/h, 1 kcal/h=1.16×10-3 kW

CP: constant specific heat capacity kJ/kg·°C, constant specific heat capacity of hydraulic oil 1.9674 kJ/kg·°C

ρ: specific gravity (density) kg/L, the specific gravity of cooling oil is 0.876 kg/L

Vs: total oil L

ΔT:  temperature rise °C

T:  time S

Example: The total oil volume of a hydraulic station is 200L. In normal operation, the oil temperature rises from 25°C to 35°C in 10 minutes. The heat output of the hydraulic station is:

P heat = CP · ρ · Vs · ΔT/t = 1.9674 × 0.876 × 200 × (35-25) / (60 × 10) = 5.745 kW

According to the selection principle of the cooling machine: the cooling capacity of the oil cooler should be greater than 20% of the heat generation.

Therefore, the oil cooler OLP-70 with a cooling capacity of 7 kW can be used.