Refrigerant Compressor Rotor Ring for Upper Stator Coil Cooling

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Solution Overview

Problem

Existing refrigerant compressors face challenges in efficiently cooling the upper coil of the stator without increasing motor dimensions, as existing solutions are either costly or limited in cooling effectiveness.

Innovation Solution

The refrigerant compressor incorporates lubricant distribution means in the rotor ring that break rotational symmetry, allowing for improved streaming of lubricant to the upper stator section, combined with through-holes and accumulation volumes to enhance lubricant delivery and cooling efficiency.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Temperature

If the stator is dimensioned with a relatively large height to cool the upper coil, then the cooling effectiveness is improved, but the motor dimensions increase

Engineering Contradiction:
Improvestator temperatureVSAvoidstator height
Core Design Contradiction:
TemperatureVSLength of stationary object

Solution Approach 1:

The patent uses lubricant (oil) as a cooling medium delivered through hydraulic channels in the rotor and crankshaft. The lubricant is pumped from the sump, transported through the rotating components, and sprayed onto the stator coils to provide cooling without increasing motor dimensions.

Inventive Principle:
Principle #29Pneumatics and hydraulics

Solution Approach 2:

The patent introduces a new dimension for cooling by delivering lubricant through the rotating rotor and crankshaft to reach the stator coils from the side, rather than relying solely on vertical cooling from the lubricant sump. This radial delivery path enables cooling of upper coils without increasing stator height.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Temperature

If lubricant channels are added to the rotor to transport lubricant to the upper part, then the cooling of the upper coil is improved, but the device complexity and manufacturing cost increase

Engineering Contradiction:
Improveupper coil temperatureVSAvoidrotor design complexity
Core Design Contradiction:
TemperatureVSDevice complexity

Solution Approach 1:

The rotor serves multiple functions: it generates rotational motion for compression and simultaneously acts as a lubricant transport system. The lubricant channels in the rotor and crankshaft serve dual purposes of lubrication and cooling delivery, reducing the need for separate cooling system components.

Inventive Principle:
Principle #6Universality (Multi-functionality)

Solution Approach 2:

The patent merges the lubrication system and cooling system into a single integrated lubricant delivery system. The same lubricant that lubricates the crankshaft and piston also cools the stator coils, eliminating the need for separate cooling channels or components in the rotor.

Inventive Principle:
Principle #5Merging (Combining)

3Strength

If the stator is covered by the compressor block, then the structural integrity is improved, but the upper coil has no cooling

Engineering Contradiction:
Improvecompressor block structural integrityVSAvoidupper coil temperature
Core Design Contradiction:
StrengthVSTemperature

Solution Approach 1:

The lubricant acts as an intermediary cooling medium that reaches the stator coils through the rotor and crankshaft, bypassing the need for direct access from the lubricant sump. This intermediary delivery system allows cooling while maintaining the compressor block's structural coverage over the stator.

Inventive Principle:
Principle #24Intermediary (Mediator)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

This design achieves efficient cooling of the upper stator coil while maintaining a compact compressor size, improving performance and reducing the risk of overheating.

Implementation Method 1

the rotor ring comprises lubricant distribution means that break the rotational symmetry of the rotor ring with respect to the axis of rotation, in order to improve streaming of the lubricant from the gap to the second stator section in the operating state of the refrigerant compressor

Methodology Applied
Scientific EffectCentrifugal force: Centrifugal Force

Implementation Method 2

wherein the lower coil of the stator can be immersed in lubricant and oil, respectively, wherein the oil simultaneously cools the lower coil of the stator

Methodology Applied
Scientific EffectHeat absorption: Absorption (physical)

Data Source

PatentEP4435261B1Refrigerant compressor
Publication Date: 2025.11.26 SECOP GMBH
  • EP4435261B1 patent drawingFigure 1
  • EP4435261B1 patent drawingFigure 2
  • EP4435261B1 patent drawingFigure 3~4

AI summary

Refrigerant compressor (1) with - a hermetically encapsulated compressor housing (2), - an electric drive unit (3) comprising a rotor (4) rotatable about an axis of rotation (14), a stator (5), and a crankshaft (6) connected to the rotor in a torque-proof manner, - a lubricant receptacle (10) for conveying lubricant (11), wherein the crankshaft (6) is partially arranged in a bushlike section (21) of a compressor block (20), wherein, viewed in radial directions (24), an interspace (25) is formed between a second stator section (17) and the compressor block, wherein, viewed in the radial directions, a gap (26) is formed between a second rotor section arranged in the interspace and the compressor block, with lubricant being conveyed into the gap in an operating state. According to the invention, a rotor ring (38) in the second rotor section comprises lubricant distribution means that break the rotational symmetry of the rotor ring with respect to the axis of rotation.