Automated Cylinder Rod Surface Grinding and Polishing Line

Buffing and Polishing Line and Centerless Grinder

We provide automated grinding systems for manufacturers of metal rods and shafts used in hydraulic cylinders, construction equipment, and automotive parts for transmission and ride control systems. LPR Global grinding solutions are custom designed and built by a consortium of South Korean grinding machine specialists, automation system designers and spindle manufacturers. Such partnership allows us to offer the best suited grinding solutions based on application, budget, and scalability.

 

Our automated buffing and polishing lines with motorized spindles offer a cost-efficient and flexible solution for grinding rods and shafts used in hydraulic cylinders, construction and mining equipment. Grinding head count and surface roughness can be tailored to clients’ requirements.

 

With patented heat-resistant spindles and vibration-dampening technology, our centerless grinders are operating globally in plants producing bearings, shock absorbers and drive shafts.

 

In addition to these outer diameter grinding lines, we also offer internal grinders and micro-finishing surface grinders such as superfinishers. All machines are built in ISO 9001:2015 and ISO 14002:2015 certified facilities in South Korea.

High-Torque Geared Motor Spindles for Stable Grinding

Our grinding line is specially designed for large shafts and rods used in hydraulic cylinders and heavy equipment. The standard system consists of 8 grinding heads; 6 heads for rough grinding and 2 for final finishing. Grinding work is controlled by geared motor spindles. These spindles deliver high torque and stable cutting performance under heavy rod or shaft loads.

 

Excavator, Drilling, and Large Cylinder Production

 

Our buffing or grinding lines are used by Hyundai Construction Equipment, DY Power, and Taewon Heavy Industries to produce rods for excavators, drilling machines, and large hydraulic cylinders.  Our systems offer cost advantages through flexible layout.  The number of grinding heads can be scaled up or down, depending on your models, specifications, cycle times and surface roughness. The simple design also makes maintenance and grinding-media replacement fast and user-friendly.

 

Automated Standard Grinding Line Specifications

Grinding Capacity:

Shaft and rod diameters: Ø70mm–Ø170mm

Lengths: 700mm – 2900mm

Weights: 20 kg –750 kg

 

8-Grinding Head Configuration:

6 for rough grinding and 2 for finishing

 

Surface Roughness:

Ra 0.2 µm – 0.5 µm, but finishing can be customizable

 

Wheel Type:

Abrasive cloth wheel or flap wheel with wax-based polishing compound

 

Geared Motor Spindle Ratings:

Rough grinding: 5.5 kW / 4-pole / 2200 rpm

Finishing grinding: 7.5 kW / 4-pole / 2200 rpm

 

Automated and Semi-Automated Loading Options

Ramp magazines for feed-in and out are included.

 

Customizable Cycle Time 

Automatic Grinding Line Layout for Hydraulic Cylinder Shafts
Automatic Grinding Line Layout for Hydraulic Cylinder Shafts
Grinding Line Showing Inside
Grinding Line Showing Inside

Buffing and Polishing Machine Video

Through-Feed Grinding Technology for Automotive Industry

We make customized grinding machines and fully automated grinding lines based on clients’ workpiece dimensions, cycle time, surface roughness, workpiece feeding systems and PLC brands. Since centerless grinding machines don’t need any fixtures to secure the position of a workpiece, they are popularly used in mass production lines.

 

Automotive part manufacturers use centerless grinders to make high-volume automotive components to achieve roundness and accuracy of cylindrical surfaces in less than one second per workpiece. We offer end-to-end grinding machinery for automotive clients, from pre-grinding to centerless grinding to final micro-finishing grinding for surface treatment of shock absorber rods, bearings, piston pins, camshafts and valves.

6-axis CNC Centerless Grinders with Siemens SINUMERIK 840DSL
6-axis CNC Centerless Grinders with Siemens SINUMERIK 840DSL

Hydrostatic Slides for Grinding and Regulating Wheels for Vibration Protection

During the centerless grinding process, pre-ground workpieces are placed on an angled support work-rest and fed between a grinding wheel and a regulating wheel. The grinding wheel spins to remove chips of the workpiece or profile the surface of the workpiece while the regulating wheel rotates it. It’s critical to precisely adjust the location of the grinding wheel and regulating wheel as the workpiece loses its surface and becomes smaller during the grinding process.

 

Our centerless grinders have hydrostatic V flat-shaped sliders to control the wheel position, which are better suited to handle vibration than linear motion guide bearings.

 

Work-Rest Automatic Height Adjustment Option for Off-Set Value Compensation

We also offer an option for automatic height adjustment of the work-rest to compensate for the off-set value of workpiece due to material loss.

 

While the regulating wheel rotates the workpiece at a certain speed, the grinding wheel removes the surface of the workpiece. The simultaneous rotating and grinding of both wheels creates heat, vibration, and force. Our centerless grinders are built and designed to minimize vibration and impact from heat and force. All of the machine mechanisms and critical components such as spindles are made to last in our clients’ grinding process.

 

Single or Twin Grip Spindles for Precise Spinning of Centerless Grinders

When we design centerless grinders, we select the best suited spindles for the client’s requirement. Backed by our knowledge of spindle design, we make spindles that perform single-grip, double-grip or hydrostatic spinning for the centerless grinding process.

 

With continuous investment in research and development, we focus on advancing our capabilities and improving existing technology, demonstrated by our recent patents for rotary diamond dressers and automatic loading and unloading systems.

 

Centerless Grinder Models and Specifications PDF Icon

Model SGC 500 Series

  •   Grinding Type: Centerless through-feed or in-feed
  •   Workpiece Mounting: Work-rest support
  •   Machining Dia. Range: 10 – 150
  •   Machining Length Range: Max. 500mm
  •   Loading: Through-feed or In-feed
  •   Dress Type: Traverse type point diamond dresser
  •   G.W. (mm): 610 (D) x 510 (W) x 304.8 (B)
  •   R.W. (mm): 380 (D) x 510 (W) x 254 (B)
  •   G.W. Table: AC servo 3.5kW
  •   R.W. Table: AC servo 0.75kW
  •   G.W. Drive: 45kW(37kW) 4P AC motor
  •   R.W. Drive: 5.5kW 4P (gear reducer type)
Centerless Grinder Model SGC 500 Series

Model SGI 200W

  • Grinding Type: NC Oscillation or Plunge
  • Workpiece Mounting: Diaphragm or hydraulic chuck
  • OD Range: 90 – 220
  • Machining Width Range: 20 – 80
  • Machining Bore Range: 60 – 200
  • Loading: Double arm by servo
  • Dress Type: Fixed rotary by hydraulic
  • Spindle Rotating Angle: ±1°/-2 to +30°
  • Spindle Height: About FL 1200
  • Work Spindle RPM: 4000 RPM Max
  • Cross Slide: AC Servo 3.5kW
  • W. Table: AC Servo 3.5kW
  • Main Drive: AC Servo 7.0kW
  • Hydraulic: 1.5kW 4P AC motor
  • W.: High frequency spindle
Internal grinders driven by high speed spindles

Model SGE 400 External Grinder Series

  • Grinding Type: NC Controlled Plunge
  • Workpiece Mounting: Two-shoe & Magnet chuck
  • Machining Dia. Range: 10 – 65
  • Machining Width Range: 6 – 50
  • Loading: Single or double arm type
  • Dresser: Forming dresser spindle
  • Spindle Angle Range: -6 to +35°
  • Grinding Spindle: Hydrostatic or Rolling bearing type
  • Spindle Height: About FL 1150
  • Work Spindle RPM: 150 – 1800rpm
  • Grinding Wheel Spindle: Max. 2500rpm
  • W.: 510(450)(D) x 50(W) x 304.8(B)mm
  • W. Table: AC Servo 1.5kW
  • Dress Table: AC Servo 1.5kW
  • Spindle Drive: 1.5kW 4P AC motor
  • W. (Belt Drive): 7.5kW 4P AC motor
External Grinder Driven by High Frequency Spindles

Experienced Centerless Grinder Manufacturer | Types of Grinding Machines Manufactured

The following grinders are manufactured at an ISO 9001:2000 and ISO 14001:2004 certified facility in South Korea.

  • Centerless Grinding Machines
  • Cylindrical Grinding Machines
  • Angular Grinding Machines
  • Drum Grinding / Surface Grinding Machines
  • Tool Grinding Machines

Automotive Industry Applications | Centerless Grinding Machines | Grinding Solutions

  • Crankshaft
  • Camshaft
  • Piston
  • Engine valve
  • Piston pin
  • Steering rack bar

Other Applications | Centerless Grinding Machines

  • Bearing
  • Ferrule
  • Micro drill
Centerless Grinding Machines Applications | Crank Shaft and Cam Shaft
Centerless Grinding Machines Applications | Crank Shaft and Cam Shaft

In-Feed Centerless Grinding Machines for Shafts, Pins and Bearings

Centerless Grinding Machine | Through Feed Auto Loading & Unloading System

Custom Through-Feed Centerless Grinding Line for Automotive Shock Absorber Rods and Piston Pins Manufacturing

A global automotive parts manufacturer selected our automated centerless grinding machines when they sought to increase capacity of their shock absorber rods and piston pins production plants that are based in Europe.

 

The client provides automotive parts to vehicle manufacturers in commercial and passenger automotive sectors, such as BMW, Ford, Toyota, PSA Peugeot Citroen, John Deere, and Caterpillar. As the client was already familiar with the benefits of centerless grinding, they were looking to replace their existing grinders for the finish grinding of their magnesium-chromium piston pins (diameter Ø30 – Ø63.5, length 70-135mm, surface roughness 0.0015-0.002mm) and their shock absorber rods before chrome-plating (diameter 18-22mm, length 200-500mm, surface roughness 0.003mm max.).

 

We suggested our fully automated Centerless Grinder 500 series through-feed centerless grinders equipped with 6-axes Siemens CNC software. These grinders accommodate workpiece diameters of Ø20 to Ø150 and lengths of up to 500mm. The client wanted an option of dressing unit for the grinding and regulating wheels units and automated work in/out system in addition to coolant supply and filtration systems.

Through Feed Centerless Grinder Machine

Side view of through-feed centerless grinder model 500 series

Automated Centerless grinding line layout that consists with 3 centerless grinders

Automated Centerless grinding line layout that consists with 3 centerless grinders

As with all our centerless grinders, these grinders were equipped with automatic off-set adjustment for wheel positioning, controlled by servo motors, and hydrostatic slides to freely control wheel movement against vibration. Keyence laser gauge and monitoring system was interfaced with the machine for diameter measurement and auto compensation.

 

A pre-acceptance test was run for 4-6 uninterrupted hours. The centerless grinding machines went through a test batch with 500 rods with diameters of 18mm, 20mm and 22mm at a rate of 5m/min; the surface roughness of these rods was then examined for roundness tolerance within 2mm. When rod diameter changed, tooling change over time was less than 20 minutes.

 

If you are interested in a full centerless grinding solution for your manufacturing needs, or a retrofitting of your existing Cincinnati centerless grinders, please contact us with details at [email protected].

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