Rotor (Electric) / Rotor Group (Hydraulic)

Product Specifications

Technical details and manufacturing context for Rotor (Electric) / Rotor Group (Hydraulic)

Definition

The rotor is the rotating part of an electric motor or the rotor group in a hydraulic motor, serving as the core moving element that converts input energy into mechanical rotation. In electric motors, the rotor interacts with the stator's magnetic field to produce torque, typically through electromagnetic induction or permanent magnets. In hydraulic motors, the rotor group consists of rotating elements such as gears, vanes, or pistons that convert hydraulic pressure into rotational mechanical energy via fluid displacement and pressure differentials. This component is essential for the operation of various machinery, including pumps, compressors, and industrial drives. The rotor's design and materials are selected based on application requirements such as load torque, speed, and environmental conditions. Common materials include electrical steel laminations, copper windings, permanent magnets (for some electric types), alloy steel, and cast iron. Key parameters to consider when selecting a rotor include rated power (0.75–250 kW), rated speed (750–3000 rpm), rotor diameter (50–500 mm), rotor length (80–800 mm), balancing grade (G2.5–G6.3), eccentricity (0.02–0.10 mm), surface roughness (Ra 0.8–1.6 μm), insulation class (F–H), operating temperature (-20–80 °C), operating pressure (1.0–1.6 MPa), material grade (20CrMnTi–42CrMo), and weight (5–200 kg). These values are reference ranges and must be verified for the specific model and application. Standards such as IEC 60034-1, ISO 21940-11, ISO 1302, IEC 60085, and GB/T 3077 are referenced for testing and verification. Always confirm model-specific values and standards with the legal manufacturer or supplier.

Working Principle

In electric motors, the rotor operates through electromagnetic induction or permanent magnets interacting with the stator's magnetic field to create rotational force. In hydraulic motors, the rotor group uses pressurized hydraulic fluid to act on rotating elements (gears, vanes, pistons), creating torque through fluid displacement and pressure differentials. The rotor converts energy into mechanical motion, driving the connected load.

Common Materials

Electrical steel laminations, Copper windings, Permanent magnets (for some electric types), Alloy steel, Cast iron

Technical Parameters

Parameter	Typical range	Notes & selection driver
Rated Power	0.75–250 kW	Select based on load torque and speed.IEC 60034-1
Rated Speed	750–3000 rpm	Higher speed reduces torque for same power.IEC 60034-1
Rotor Diameter	50–500 mm	Affects torque and inertia.
Rotor Length	80–800 mm	Determines power density and axial space.
Balancing Grade	G2.5–G6.3	Higher grade (lower number) for high-speed operation.ISO 21940-11
Eccentricity	0.02–0.10 mm	Tighter tolerance reduces vibration and noise.
Surface Roughness	Ra 0.8–1.6 μm	Affects fit and fatigue life.ISO 1302
Insulation Class	F–H	Determines maximum winding temperature.IEC 60085
Operating Temperature	-20–80 °C	Exceeding range may degrade insulation or lubrication.
Material Grade	20CrMnTi–42CrMo	Select for strength and wear resistance.GB/T 3077
Weight	5–200 kg	Affects handling and dynamic response.

Ranges are indicative industry figures for RFQ preparation, not a supplier commitment. Confirm every value and standard with the legal manufacturer before ordering.

Components / BOM

Rotor Core Part
Provides the magnetic path and structural support for windings or magnets in electric rotors, or forms the fluid displacement chambers in hydraulic rotors

Material: Electrical steel laminations or alloy steel
Windings (Electric) Part
Conduct electrical current to create electromagnetic fields in induction motors

Material: Copper or aluminum
Shaft Part
Transmits torque from the rotor to the driven load and provides mounting interface

Material: Alloy steel
Bearings
Support the rotor assembly and allow smooth rotation with minimal friction

Material: Steel with various coatings
Balance Weights Part
Counteract imbalances to ensure smooth operation at high speeds

Material: Steel or lead
Permanent Magnets Optional
Provide the rotor field on PM machines instead of windings.
Vanes Optional
Take the fluid pressure on vane-type hydraulic rotor groups.
Pistons Optional
Take the fluid pressure on piston-type hydraulic rotor groups.

Industry Taxonomies & Aliases

Commonly used trade names and technical identifiers for Rotor (Electric) / Rotor Group (Hydraulic).

Applied To / Applications

This component is essential for the following industrial systems and equipment:

Electric or Hydraulic Motor

View system integration details

Manufacturers of Rotor (Electric) / Rotor Group (Hydraulic)

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Frequently Asked Questions

What is the difference between an electric rotor and a hydraulic rotor group?

An electric rotor converts electrical energy into mechanical rotation via electromagnetic interaction, while a hydraulic rotor group converts hydraulic pressure into rotation using fluid displacement. Both serve as the rotating core in their respective motor types.

What materials are commonly used for rotors?

Common materials include electrical steel laminations, copper windings, permanent magnets (for some electric types), alloy steel, and cast iron. Material selection depends on application requirements such as strength, wear resistance, and magnetic properties.

How do I select the right rotor for my application?

Consider parameters such as rated power, speed, rotor diameter and length, balancing grade, eccentricity, surface roughness, insulation class, operating temperature and pressure, material grade, and weight. These values must be verified against the specific application and confirmed with the manufacturer.

What standards apply to rotor testing and verification?

Relevant standards include IEC 60034-1 for power and speed, ISO 21940-11 for balancing, ISO 1302 for surface roughness, IEC 60085 for insulation class, and GB/T 3077 for material grades. These are references for procurement and verification, not proof of compliance.

Data Basis

Editorial classification, named public sources where available, and source-reviewed manufacturer records.

Preliminary Technical Classification

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pressure:	N/A (electric), Up to 350 bar (hydraulic)
other spec:	Max speed: 20,000 RPM (electric), Flow rate: 0.5-500 L/min (hydraulic), Slurry concentration: <5% solids by weight
temperature:	-40°C to 150°C (electric), -20°C to 120°C (hydraulic)

Rotor (Electric) / Rotor Group (Hydraulic)

Product Specifications

Industry Taxonomies & Aliases

Applied To / Applications

Industrial Ecosystem & Supply Chain Structure

Application Fit & Sizing Matrix

Reliability & Engineering Risk Analysis

Compliance & Manufacturing Standards