--- title: "Hydraulic Components" url: "https://www.imspares.com/categories/hydraulic/" --- # Hydraulic Components Complete range of hydraulic system components including pumps, valves, motors, and pressure controls for injection molding machines. ## Parts of the hydraulic system 1. **Oil tank**: Holds the hydraulic oil. Returning oil settles here and sheds heat and air before the pump draws it again. 2. **Suction filter**: Strainer on the pump’s suction line inside the tank. It keeps dirt and metal particles out of the pump. 3. **Electric motor**: Drives the pump. Newer machines use a servo motor that only runs as fast as the cycle needs, which saves energy. 4. **Coupling and bell housing**: The bell housing bolts the pump to the motor and keeps the shafts aligned. The flexible coupling inside carries the torque. Part numbers: HY-PW-05. 5. **Hydraulic pump**: Turns the motor’s rotation into oil flow. Fixed-speed machines mostly use vane or piston pumps; servo-hydraulic machines often use internal gear pumps. Part numbers: HY-PW-06, HY-PW-07, HY-PW-02. 6. **Pressure gauge**: Shows the system pressure, so the operator can check the settings and spot a pressure loss early. Part numbers: HY-MO-01. 7. **Valve manifold**: The valve block that sends oil to each movement. Solenoid valves on top and cartridge valves inside switch clamping, injection, ejection and nozzle movements. 8. **Relief valve**: Opens when the pressure goes above its setting and sends the oil back to the tank, protecting the pump, hoses and cylinders. Part numbers: HY-CV-06. 9. **Hydraulic cylinder**: Turns oil pressure into straight-line force: for clamping the mold, injecting, ejecting and moving the injection unit. 10. **Accumulator**: Stores oil under nitrogen pressure and releases it in a burst for fast injection, more flow than the pump alone delivers. Part numbers: HY-AU-02. 11. **Oil cooler**: Water-cooled heat exchanger on the return line. It keeps the oil from overheating, which would thin it and wear the seals and pumps. ## Accumulators Hydraulic accumulators and bladder assemblies - [HY-AU-02 Hydraulic Accumulator](https://www.imspares.com/parts/hy-au-02/): Bladder-type hydraulic accumulator for injection molding machine high-speed injection circuits. ### Parts of a bladder accumulator 1. **Gas valve**: Charging valve for the nitrogen. The pre-charge pressure is checked and topped up here with a charging kit. 2. **Shell**: Steel pressure vessel that holds the bladder and the oil, built for the accumulator’s rated pressure. Part numbers: HY-AU-02. 3. **Mounting clamp**: Clamp band and bracket that hold the accumulator to the machine frame so it cannot move with the pressure surges. 4. **Bladder**: Rubber bag filled with nitrogen. Oil pushed into the shell squeezes the gas; when the system needs oil, the gas expands and pushes it back out. 5. **Oil port**: Threaded or flanged connection at the bottom of the shell that joins the accumulator to the hydraulic circuit. 6. **Poppet valve**: Spring-loaded valve in the oil port. It closes when the shell runs empty, so the bladder cannot be pushed out through the port. 7. **Safety block**: Shut-off and relief block under the accumulator. It isolates the accumulator for service and lets the stored oil drain to the tank before anyone works on the circuit. ## Control Valves Directional control valves, proportional valves, and check valves - [HY-CV-02 Directional Control Valve](https://www.imspares.com/parts/hy-cv-02/): Solenoid-operated directional control valve for injection molding machine hydraulic circuits. - [HY-CV-04 Proportional Pressure/Flow Valve](https://www.imspares.com/parts/hy-cv-04/): Proportional solenoid valve for precise pressure and flow control in injection molding machines. - [HY-CV-05 Check Valve](https://www.imspares.com/parts/hy-cv-05/): Hydraulic check valve for injection molding machine circuits. - [HY-CV-06 Relief Valve / Safety Valve](https://www.imspares.com/parts/hy-cv-06/): Hydraulic relief and safety valve for injection molding machine system pressure protection. - [HY-CV-08 Cartridge Valve](https://www.imspares.com/parts/hy-cv-08/): Hydraulic cartridge valve for injection molding machine manifold blocks. - [HY-CV-15 Solenoid Operated Valve — High Flow](https://www.imspares.com/parts/hy-cv-15/): High-flow solenoid operated directional valve for large-tonnage injection molding machines. ### Parts of a hydraulic valve manifold 1. **Manifold block**: Steel block drilled with oil passages. The valves bolt onto it or screw into it, which replaces most of the piping between them. 2. **Directional valve**: Solenoid valve that switches oil between the two ports of a cylinder or motor, to start, stop and reverse a movement. Part numbers: HY-CV-02. 3. **High-flow solenoid valve**: Larger, pilot-operated directional valve: a small solenoid valve on top shifts the main spool. Used for clamping and injection on large machines. Part numbers: HY-CV-15. 4. **Proportional valve**: Sets pressure or flow in proportion to an electrical signal from the controller, so speeds and pressures follow the profile set on the screen. Part numbers: HY-CV-04. 5. **Relief valve**: Limits the system pressure. When the pressure goes above its setting it opens and sends oil to the tank. Part numbers: HY-CV-06. 6. **Cartridge valve**: Valve inserted into a bore in the block, shown here in section. A spring-loaded poppet opens or closes a large passage; used for high flows in clamping, injection and ejection circuits. Part numbers: HY-CV-08. 7. **Check valve**: Lets oil flow one way only, for example from the pump into the circuit, and blocks it from flowing back. Part numbers: HY-CV-05. ## Monitors & Gauges Pressure gauges, flow meters, and hydraulic monitoring instruments - [HY-MO-01 Hydraulic Pressure Gauge](https://www.imspares.com/parts/hy-mo-01/): Glycerin-filled hydraulic pressure gauge for injection molding machine system monitoring. ### Parts of a hydraulic pressure gauge 1. **Glycerin-filled case**: Sealed case filled with glycerin, which damps the needle against pump pulsation and vibration. The plug on top closes the filling hole. Part numbers: HY-MO-01. 2. **Dial**: The printed scale, usually in MPa or bar, read through the window. 3. **Needle**: Sits on the pinion shaft and turns with the movement to point at the pressure. 4. **Bourdon tube**: Curved, flattened tube closed at the tip. Oil pressure tries to straighten it, and the tip moves in proportion to the pressure. 5. **Movement**: Link, toothed sector and pinion that turn the small movement of the tube tip into the full sweep of the needle. 6. **Connection**: Threaded socket that screws into the gauge port. Inside the case it also anchors the Bourdon tube and carries the oil into it. ## Pumps & Motors Gear pumps, vane pumps, piston pumps, and hydraulic motors - [HY-PW-02 Gear Pump (Sumitomo QT32)](https://www.imspares.com/parts/hy-pw-02/): Sumitomo QT32 series internal gear pump for injection molding machine hydraulic systems. - [HY-PW-03 Hydraulic Power Unit / Oil Pump Assembly](https://www.imspares.com/parts/hy-pw-03/): Complete hydraulic pump motor assembly for injection molding machine power unit. - [HY-PW-05 Pump Coupling & Bell Housing](https://www.imspares.com/parts/hy-pw-05/): Pump coupling and bell housing adapter for injection molding machine hydraulic pump drives. - [HY-PW-06 Hydraulic Vane Pump](https://www.imspares.com/parts/hy-pw-06/): High-performance hydraulic vane pump for injection molding machine hydraulic power units. - [HY-PW-07 Hydraulic Piston Pump](https://www.imspares.com/parts/hy-pw-07/): Variable displacement hydraulic piston pump for high-pressure injection molding machine applications. - [HY-PW-08 Hydraulic Plasticizing Motor (NHM Series)](https://www.imspares.com/parts/hy-pw-08/): NHM series radial piston hydraulic motor for injection molding machine screw pre-plasticizing drive. ### Parts of a hydraulic power unit 1. **Complete pump unit**: Motor, bell housing, coupling and pump supplied together on their bracket, ready to bolt onto the tank in one piece. Part numbers: HY-PW-03. 2. **Electric motor**: Drives the pump, either at constant speed (induction motor) or at the speed each phase of the cycle needs (servo motor). 3. **Coupling and bell housing**: The bell housing centres the pump on the motor flange; the jaw coupling inside joins the two shafts and absorbs vibration. Part numbers: HY-PW-05. 4. **Hydraulic pump**: Vane, piston or gear pump that turns the motor’s rotation into oil flow for every movement of the machine. Part numbers: HY-PW-06, HY-PW-07, HY-PW-02. 5. **Plasticizing motor**: Low-speed, high-torque radial piston motor at the back of the injection unit. It turns the screw that melts and meters the plastic. Part numbers: HY-PW-08. 6. **Oil tank**: Reservoir under the pump unit. The pump draws its oil from it, and all returning oil flows back into it.