Ningbo Demy (D&M) Bearings Co., Ltd. is the manufacturer behind the BMT Bearings brand, specializing in the development, manufacturing, and export of automotive bearings. Its products are primarily used in wheel hubs, engine auxiliaries, transmission systems, electric motors, pumps, steering mechanisms, and other rotating components. The company entered the bearing manufacturing sector in 2004 and is currently equipped with automated grinding and assembly production lines, as well as advanced testing equipment such as roundness gauges, surface roughness meters, hardness testers, bearing vibration testers, noise testers, coordinate measuring machines (CMMs), and automated inspection lines. Its annual production capacity reaches 100 million sets.
Used in components such as automotive A/C compressors and electromagnetic clutches; these require low noise, stability at high speeds, and excellent temperature resistance.
Used in clutch release systems; these must withstand axial loads and frequent start-stop operations, requiring smooth operation and good wear resistance.
Used in engine belt tensioner systems; suitable for high-speed rotation and continuous long-term operation, requiring stable lubrication and low noise.
Used in turbocharger assemblies; these demand high resistance to heat and high speeds, as well as high manufacturing precision.
Used in automotive water pump systems; these require excellent sealing, rust resistance, and durability against coolant exposure.
Used in wheel hub systems; these withstand combined radial and axial loads, requiring high load-bearing capacity, reliable sealing, and a long service life.
Different vehicle systems impose varying requirements on automotive bearings. Selection depends on factors such as load, rotational speed, temperature, installation space, lubrication conditions, and expected service life.
Wheel hub assemblies: Support wheel rotation and withstand radial/axial loads while ensuring smooth operation.
Drivetrain systems: Used for rotating shafts and gears, where dimensional accuracy and friction control are critical.
Engine auxiliary systems: Suitable for rotating components such as pulleys, tensioners, pumps, and other support mechanisms.
Steering systems: Facilitate controlled, low-friction movement for rotating or pivoting parts.
Electric motors: Used in applications requiring high speeds, low noise, and stable operational performance.
Automotive pumps: Applied to the rotating shafts of water pumps, fuel-related equipment, and other pump assemblies, depending on operating conditions.
Special or non-standard applications: BMT Bearings offer custom-sized or specially configured bearings when standard bearings do not meet equipment requirements.
| Vehicle System | Bearing Type | Key Requirements |
|---|---|---|
| A/C System | A/C Bearings | Low noise, high-speed stability |
| Clutch System | Clutch Release Bearings | Axial load, wear resistance |
| Engine Auxiliary System | Tensioner Bearings | High-speed operation, low noise |
| Turbocharger | Turbocharger Bearings | High temperature, high speed |
| Cooling System | Water Pump Bearings | Sealing, corrosion resistance |
| Wheel End | Wheel Hub Bearings | Radial & axial load capacity |
Selecting the right automotive bearing requires considering the specific application point, load, rotational speed, and operating environment. Different applications—such as wheel hubs, water pumps, belt tensioners, clutch systems, and A/C compressors—impose varying requirements regarding bearing structure, grease, and seal design.
Determine whether the load is radial, axial, or combined.
Consider operating speed and acceleration conditions.
Evaluate both normal and peak operating temperatures.
Consider the type of grease or oil and the lubrication conditions.
Select an appropriate sealing method based on contamination levels, humidity, and the operating environment.
Verify the inner diameter, outer diameter, width, shaft fit, and housing dimensions before selection; the bearing size must match the available space in the housing and on the shaft.
Service life is a critical factor for components requiring long-term durability. Load capacity, seal quality, grease stability, and installation precision all influence the bearing's service life.
Established in 2004, BMT Bearings has continuously enhanced its manufacturing capabilities over the past two decades; the company produces standard bearings and possesses the expertise to develop non-standard, custom automotive bearings.
With an annual production capacity of approximately 100 million units, BMT Bearings meets both routine customer demands and large-scale OEM supply requirements.
BMT Bearings collaborates with clients to determine technical specifications based on provided drawings, samples, dimensions, and application requirements.
BMT Bearings's quality management system covers ISO 9001 and IATF 16949:2016 certifications.
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Established in 2004, BMT Bearings has more than 20 years of bearing manufacturing experience, with automotive air conditioner bearings being one of our main product lines. This bearing series features a fully sealed double-row angular contact ball bearing design and is mainly used in the electromagnetic clutch pulley of automotive A/C compressors.
