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crank grinder machine

-- Steady & Reliable Manufacturer --

Intro

Our crank grinder machines are CNC crankpin grinders built for precision grinding of eccentric crankpins and main journals on automotive, marine and compressor crankshafts. The machine handles the offset/eccentric geometry of crankpins directly, so both roughing and finishing can be completed in a single clamping without repositioning the workpiece.

Core Capability

The orbital CNC work-head follows the pin's eccentric path while a fixed or twin grinding wheel head removes stock, holding roundness within 0.003mm and surface finish down to Ra 0.2µm. This is the go-to solution for buyers who need dedicated crankpin grinding rather than a general-purpose cylindrical grinder.

Premium Materials and Components

Materials and components are the most critical elements to affect the performance of the equipment.

We use high-quality raw materials and branded components to ensure that our high-performance machines have a long service life and short downtime.

  • External grinding wheel chuck
  • Flat grinding wheel chuck
  • Φ 400 or Φ 600 balance frame
  • M7130-5006 front bearing
  • Rapid advance and retreat cylinder
  • Pressure valve plate assembly
  • Feed box assembly
  • Overflow valve
  • Table control box
  • Grinding head box
  • Control panel assembly
Design for High Performance

The performance of a machine is the result of the combined effect of all its components.

Our technical team consists of experienced engineers and technicians who are not only proficient in the operation and maintenance of grinders, but also have a deep understanding of material properties and processing technology. This enables us to provide customers with customized solutions to meet their specific processing needs.

By deeply studying the design and manufacturing process of precision grinding machines and paying great attention to configuration and construction from the beginning, our R&D team is able to provide high-performance equipment.

Specification

Item Value
Model MQ8260A
Max. distance between centers 1500–3000mm
Max. swing over table Ø500mm
Crankpin throw radius range 10–120mm
Max. grinding diameter Ø120mm
Max. workpiece weight 800kg
Grinding wheel size Ø600 x 63 x Ø305mm
Wheel spindle speed 900–1800rpm (variable)
Roundness accuracy ≤0.003mm
Surface finish Ra0.2µm
CNC system Siemens 828D / Fanuc 0i-F (optional)
Main motor power 11kW
Machine weight approx. 9.5 tons
Overall dimensions (L x W x H) 5800 x 2200 x 1900mm

Parameters above are for the standard 3000mm-bed version; longer bed lengths and larger throw radii are available on request — see customization below.

Workpiece Range

Suitable for automotive, light-truck, marine diesel and compressor crankshafts made from forged steel, ductile cast iron or induction-hardened alloy steel. Typical pin diameters run Ø30–120mm with throw radii from 10 to 120mm, covering everything from small four-cylinder engine crankshafts to mid-size marine and generator crankshafts.

Tolerance & Output

Achievable tolerance is IT5–IT6 with roundness ≤0.003mm and cylindricity ≤0.005mm. Cycle time for a typical automotive crankpin (rough + finish) is around 3–5 minutes depending on stock removal, making the machine viable for both job-shop repair work and mid-volume production runs.

Core Functions

  • CNC orbital pin grinding with programmable throw radius, eliminating manual eccentric fixture changes
  • Automatic wheel wear compensation to keep pin diameter within tolerance across a full batch
  • Built-in dynamic balance correction for the eccentric rotating mass at high spindle speed
  • Rotary diamond dresser with programmable dressing cycle for wheel profile and sharpness
  • Hydraulic steady rests supporting long, slender crankshafts during grinding to control deflection
  • Interlocked enclosure with coolant mist extraction for operator safety and a cleaner shop floor

Quality Control

  • Incoming inspection of castings/forgings and purchased components (guideways, spindles, motors)
  • In-process CNC gauge monitoring during grinding, not only a post-process check
  • Final roundness, cylindricity and pin-to-pin positional accuracy verified on CMM before packing
  • 48-hour no-load run-in plus a customer-sample trial grind before shipment
  • ISO9001-certified manufacturing process with calibration certificates issued for each machine

FAQ

  • Q: How is a crank grinder different from a standard cylindrical grinder?
  • A: A crank grinder's work-head moves the crankpin in an orbital (eccentric) path so the off-center pin stays on-axis relative to the wheel, which a standard fixed-center cylindrical grinder cannot do without a special eccentric jig.
  • Q: Can one machine grind both main journals and crankpins?
  • A: Yes, most orders include both a fixed-center mode for main journals and an orbital mode for pins; tell us your crankshaft drawing and we will confirm the exact work-head configuration.
  • Q: What is the typical lead time for a standard machine?
  • A: Standard configurations usually ship in 45–60 days; machines with custom throw-radius range or added automation may need 70–90 days.
  • Q: Do you provide installation and operator training?
  • A: Yes, our engineers can install and commission on site or guide remote installation, followed by hands-on operator and maintenance training.
  • Q: Can the machine be adapted for crankshafts longer than the standard bed?
  • A: Yes, bed length, center distance and steady-rest positions can be extended for longer marine or generator crankshafts — share the crankshaft drawing for a tailored quotation.

Structural Configuration

  • Meehanite cast-iron bed, stress-relieved and box-way reinforced for grinding rigidity
  • Hydrodynamic or hydrostatic wheel-spindle bearings (buyer's choice) for vibration-free finishing
  • Servo axes driven by Fanuc or Yaskawa motors with PMI/THK precision ballscrews
  • Built-in high-frequency spindle motor for the grinding wheel head, reducing belt-drive noise and slip
  • Closed-loop coolant filtration system (paper-band or magnetic separator) to protect wheel and workpiece finish
  • Optional in-process active gauge (Marposs or TESA compatible) for automatic size feedback during grinding

Where It Is Used

  • Automotive and light-truck engine crankshaft manufacturing
  • Marine diesel engine builders and shipyard repair workshops
  • Reciprocating compressor and generator set crankshaft producers
  • Motorcycle and small-engine crankshaft makers
  • Independent crankshaft regrinding and engine remanufacturing shops

Automation Options

  • Robotic loading/unloading interface for unattended batch grinding
  • Automatic in-process gauge with closed-loop size correction
  • Custom fixtures and jaw sets for non-standard crankpin geometry
  • Extended throw-radius range or twin-wheelhead layout on request
  • PLC/CNC program customization to match customer crankshaft drawings

Most orders are engineered around the customer's own crankshaft drawing rather than sold off a fixed catalogue — send us the drawing and duty cycle and we will confirm the matching configuration.

  • 35000 m²+
    Total Factory Area
  • 2003
    Was Founded In
  • 210+
    Precision Equipment
  • 45+
    Exporting Countries & Regions
Zhejiang Quanshun Machine Tool Co., Ltd.

Zhejiang Quanshun Machine Tool Co., Ltd.

Zhejiang Quanshun Machine Tool Co., Ltd. is a professional manufacturer of precision grinding machines. It is located in Zhuji, Zhejiang Province, the main economic development area of the Yangtze River Delta. It is 65km away from Hangzhou, 180km away from Shanghai, 60km away from Hangzhou International Airport, and 60km away from expressways such as Hangjinqu, Zhuyong, and Shaozhu, with convenient transportation and unique geographical location.

The company covers an area of 35000 square meters and a building area of 32000 square meters. Zhejiang Quanshun Machine Tool Co., Ltd. is a professional wholesale crank grinder machine Manufacturers and crank grinder machine Factory. It has a machine tool production base and a hydraulic parts production base. The main products are various specifications of ordinary (CNC) cylindrical grinding machines, CNC end face cylindrical grinding machines, automatic loading and unloading CNC (end face) cylindrical grinding machines, composite grinding machines，high-precision ordinary (CNC) cylindrical grinding machines, and we can design and develop various kinds of non-standard special grinding machines according to the needs of users and provide relevant technology, software, training services and automation solutions. Our company has complete product research and development capabilities, passed IS09001-2015 quality system and CE safety certifications, and was named "National High-tech Enterprise".In 2021, it was rated as a specialized and new small and medium-sized enterprise in Zhejiang Province. We also have self-export qualifications. Our company adheres to the concept of "quality first, reputation first, service first", so that our products have a good reputation in the market. At present, our products have been exported to more than 20 countries, such as the United States, Germany, Japan, and Southeast Asia.

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Certificate

Believe In Our Strength

Zhejiang Quanshun Machine Tool Co., Ltd. has more than 20 years of industry experience, we specialize in the manufacture of high-quality precision grinding machines.
  • Advanced manufacturing procedures.
  • Full quality management system.
  • Thoughtful after-sales service.

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