Magnetic field generator for a magnetocaloric thermal appliance and process for assembling such generator

• US 8,378,769 B2
• Filed: 08/16/2010
• Issued: 02/19/2013
• Est. Priority Date: 08/16/2010
• Status: Active Grant

• Current Assignee: France Brevets SAS
• Original Assignee: Cooltech Applications S.A.S.
• Inventors: Heitzler, Jean-Claude, Muller, Christian
• Primary Examiner(s): Talpalatski, Alexander
• Application Number:
  US12/857,019
• Publication Number:
  US 20120038442A1
• Time in Patent Office: 918 Days
• Field of Search: 335/306
• US Class Current: 335/306
• CPC Class Codes: F25B 21/00 Machines, plants or systems, using electric or magnetic effects
• CPC Class Codes: F25B 2321/0021 with a static fixed magnet
• CPC Class Codes: F25B 2321/0023 with modulation, influencing or enhancing an existing magnetic field
• CPC Class Codes: H01F 7/0278 for generating uniform fields, focusing, deflecting electrically charged particles for magnetic separation by Lorentz force B03C1/023; specially adapted for NMR applications G01R33/383
• CPC Class Codes: Y02B 30/00 Energy efficient heating, ventilation or air conditioning [HVAC]
• CPC Class Codes: Y10T 29/49826 Assembling or joining

Abstract

A magnetic field generator (1) for a magnetocaloric thermal appliance comprising at least one magnetising structure (2) creating a constant magnetic field in at least one air gap (3) in which at least one magnetocaloric element (4) is arranged. The magnetising structure (2) comprises first (5) and second (6) magnetic poles arranged facing each other on each side of a symmetry plane (P) and each made up of an assembly of permanent magnets (7, 8) and of a ferromagnetic element (9). The magnetic field generator is characterised in that the ferromagnetic element (9) presents a face (F1) protruding with respect to the assembly forming the magnetic pole (5, 6) and the two ferromagnetic elements (9) of the magnetising structure (2) are arranged face to face with a distance forming the at least one air gap (3, 13, 23) of the magnetising structure (2).

Claims

1. A magnetic field generator (1, 10, 20, 30, 40, 50) for a magnetocaloric thermal appliance, the magnetic field generator (1, 10, 20, 30, 40, 50) comprising at least one magnetising structure (2) creating a constant magnetic field in at least one air gap (3) in which at least one magnetocaloric element (4) is arranged, the magnetising structure (2) containing first (5) and second (6) magnetic poles arranged facing each other on each side of a symmetry plane (P) and each made up of an assembly of permanent magnets (7, 8) and of a ferromagnetic element (9), the ferromagnetic element (9) of each of the first and the second magnetic poles (5, 6) presenting one face (F1) protruding with reference to the assembly forming the first and second magnetic poles (5, 6) and the ferromagnetic elements (9) of the first (5) and second (6) magnetic poles being arranged face to face with a distance forming the at least one air gap (3, 13, 23) of the magnetising structure (2), wherein a further permanent magnet (14) is placed in the plane (P), between the first (5) and second (6) magnetic poles and forms an air gap (13, 23) with each of the two corresponding faces (F1) of the ferromagnetic elements (9) of the first (5) and second (6) magnetic poles.

2. The generator according to claim 1, wherein in each magnetic pole (5, 6), the ferromagnetic element (9) has a quadrangular transversal cross-section and each of its three lateral faces (F2, F3, F4) located outside the air gap (3, 13, 23) is in contact with a face of the corresponding permanent magnets (7, 8).

3. The generator according to claim 2, wherein two lateral faces (F2, F4) of the ferromagnetic element (9) are approximately perpendicular to the face (F1) located in the air gap (3, 13, 23) and are in contact with a face of the permanent magnets called lateral magnets (7) whose direction of magnetisation is approximately perpendicular to the lateral faces (F2, F4).

4. The generator aocording to claim 3, wherein one lateral face (F3) of the ferromagnetic element (9), opposite the face (F1) located in the air gap (3, 13, 23) and called opposite face (F3), is in contact with the permanent magnet called opposite magnet (8) whose direction of magnetisation is approximately perpendicular to the opposite face (F3).

5. The generator according to claim 4, wherein the faces of the permanent magnets (7, 8) and of the ferromagnetic element (9) that are in contact have an identical shape and dimension.

6. The generator according to claim 4, wherein the first magnetic pole (5), the direction of magnetisation of the lateral magnets (7) and of the opposite magnet (8) respectively in contact with the corresponding ferromagnetic element (9) is oriented in an opposite direction to the ferromagnetic element (9) and, in the second magnetic pole (6), the direction of magnetisation of the lateral magnets (7) is oriented in a direction towards the ferromagnetic element (9), which is opposite to that of the lateral magnets (7) of the first magnetic pole (5) and the direction of magnetisation in the opposite magnet (8) is the same as that of the opposite magnet (8) of the first magnetic pole (5).

7. The generator according to claim 4, wherein each magnetic pole (5, 6), the lateral magnets (7) in contact with the corresponding ferromagnetic element (9) have a parallelepipedic transversal cross-section and the opposite magnets (8) in contact with the same ferromagnetic element (9) present two faces in contact with corresponding faces of the lateral magnets (7), the faces that are in contact have identical shape and dimension.

8. The generator according to claim 4, wherein the first (5) and second (6) magnetic poles contain respectively a first magnetic field-conductive fastening device (11) and a second magnetic field-conductive fastening device (12) made of a ferromagnetic material and presenting a contact surface with a corresponding face of the opposite magnet (8) of the first (5) and second (6) magnetic poles.

9. The generator according to claim 8, wherein the generator comprises two mounting armatures (15, 16) laterally closing the magnetic field generator (1, 10, 20, 30, 40, 50) and arranged in a plane approximately perpendicular to the symmetry plane (P).

10. The generator according to claim 9, wherein the generator contains a single magnetising structure (2) and the mounting armatures (15) are made of a ferromagnetic material and laterally connect the first (5) and second (6) magnetic poles.

11. The generator according to claim 10, wherein the mounting armatures (15) are in contact with an opposite magnet (8) and a lateral magnet (7) of the first and second magnetic poles (5, 6) and the fastening devices (11, 12) present a boss (17) in zones which are adjacent to the surfaces in contact between each mounting armature (15) and the corresponding opposite magnet (8).

12. The generator according to claim 10, wherein the mounting armatures (15) are made up of two parts (18 and 19) that are connected with one another and have an adjustable distance.

13. The generator according to claim 10, wherein each mounting armature (15) comprises a permanent magnet (21) on its lateral wall located facing the magnetising structure (2) and whose orientation and magnetisation direction of the permanent magnet (21) are identical to those of the opposite magnets (7) of the magnetising structure (2).

14. A magnetic field generator for a magnetocaloric thermal appliance, the magnetic field generator comprising at least one magnetising structure (2) having first and second magnetic poles (5, 6) that are symmetrically arranged with respect to a plane of symmetry (P), each of the first and the second magnetic poles (5, 6) comprises permanent magnets (7, 8) and a ferromagnetic element (9), the permanent magnets (7, 8) of each the first and the second magnetic poles (5, 6) abut the respective ferromagnetic element (9) such that each of the ferromagnetic elements (9) has only one exposed face (F1), the ferromagnetic elements (9) are aligned with each other and arranged within the respective one of the first and the second magnetic poles (5, 6) such that the exposed faces (F1) face each other, the exposed faces (F1) are spaced from each other and the plane of symmetry (P) and form an extended air gap (3) therebetween, an additional permanent magnet (14) is aligned with and located between the first and the second magnetic poles (5, 6) in the plane of symmetry (P) such that a first smaller air gap (13) is formed between the additional permanent magnet (14) and the exposed face (F1) of the ferromagnetic element (9) of the first magnetic pole (5) and a second smaller air gap (23) is formed between the additional permanent magnet (14) and the exposed face (F1) of the ferromagnetic element (9) of the second magnetic pole (6).