NMR-MAS turbine assembly

Patent metadata

Field	Value
Publication number	US-10241162-B2
Application number	US-201615086395-A
Country	US
Kind code	B2
Filing date	Mar 31, 2016
Priority date	Oct 14, 2015
Publication date	Mar 26, 2019
Grant date	Mar 26, 2019

Abstract

A nuclear magnetic resonance-magic angle spinning (NMR-MAS) turbine assembly has a MAS rotor with turbine cap having a stopper region and a turbine region. The stopper region allows feeding into a rotor tube and has at least one sealing section for resting against an inner wall of the rotor tube. The turbine region has a collar section for resting against a face side of the rotor tube and a turbine section that forms the turbine blades, which protrude axially from the collar section without extending radially further than the collar section. The arrangement of the rotor allows for very high rotation frequencies that, correspondingly, reduce line broadening in NMR measurements.

First claim

The invention claimed is:

1. A turbine cap for an NMR-MAS rotor comprising:
a stopper region for feeding into a rotor tube of the NMR-MAS rotor, the stopper region having at least one sealing section for resting against an inner wall of the rotor tube, wherein the sealing section has an outside diameter SDAD between 0.303 mm and 0.603 mm; and
a turbine region, which projects radially with respect to the stopper region and which is formed with five turbine blades, the turbine region having a collar section for resting against a face side of the rotor tube, said collar section having an outside diameter TBAD, with TBAD>SDAD, and wherein the turbine region further has a turbine section which forms the turbine blades, which protrude axially from the collar section, and which do not extend radially beyond the collar section, the turbine blades being formed with a blade tip having a radius of curvature SSKR between 0.0020 mm and 0.0045 mm, and a concave first blade piece (S 1 ) connecting to the blade tip having a first circular contour with a radius of curvature S 1 KR between 0.050 mm and 0.150 mm.

2. The turbine cap according to claim 1 , wherein the collar section of the turbine region has an outside diameter TBAD between 0.650 mm and 0.695 mm.

3. The turbine cap according to claim 1 wherein the first circular contour extends over a central angle (α) between 135° and 160°.

4. The turbine cap according to claim 1 wherein a total contour length TSKL of a particular turbine blade is between 0.40 mm and 0.75 mm.

5. The turbine cap according to claim 1 wherein the turbine blades further comprise a straight blade piece (SG), which is connected to the first blade piece (S 1 ), a convex, second blade piece (S 2 ), which is connected to the straight blade piece (SG) and has a second circular contour with a radius of curvature S 2 KR between 0.180 mm and 0.260 mm, and a convex, third blade piece (S 3 ), which is connected to the second blade piece (S 2 ) and leads to the blade tip ( 16 , 20 ), having a third circular contour with a radius of curvature S 3 KR between 0.065 mm and 0.095 mm.

6. The turbine cap according to claim 5 , wherein the following applies for the radius of curvature S 1 KR of the first blade piece (S 1 ) and the radius of curvature S 3 KR of the third blade piece (S 3 ): 0.6*S 1 KR≤S 3 KR≤1.0*S 1 KR.

7. The turbine cap according claim 5 wherein a contour length GSKL of the straight blade piece (SG) is between 0.055 mm and 0.095 mm, a contour length S 2 KL of the second blade piece (S 2 ) is between 0.110 mm and 0.160 mm, and a contour length S 3 KL of the third blade piece (S 3 ) is between 0.060 mm and 0.110 mm.

8. The turbine cap according to claim 1 wherein a central axis (M 1 ) of the first circular contour of the first, concave blade piece (S 1 ) is arranged at a distance S 1 AB from a rotor axis (A) of the turbine cap ( 1 ) between 0.24 mm and 0.32 mm.

9. The turbine cap according to claim 1 , wherein a central axis (M 1 ) of the first circular contour of the first, concave blade piece (S 1 ) is arranged at a distance S 1 AB from a rotor axis (A) of the turbine cap, wherein the following applies: 0.70*TBAD/2≤S 1 AB≤0.95*TBAD/2.

10. The turbine cap according to claim 1 wherein the collar section has an axial height BAH between 0.15 mm and 0.30 mm, and the turbine section has an axial height TAH between 0.32 mm and 0.55 mm.

11. An NMR-MAS rotor comprising:
a turbine cap according to claim 1 ; and
a rotor tube having an outside diameter RRAD between 0.675 mm and 0.725 mm, and an inside diameter RRID, wherein the outside diameter SDAD of the at least one sealing section of the stopper region of the turbine cap is greater than RRID by an excess UEM, wherein UEM is between 0.015 mm and 0.045 mm, and the rotor tube has a length RRL between 4.15 mm and 5.15 mm.

12. The NMR-MAS rotor according to claim 11 , wherein the following applies: 0.64≤RRID/RRAD≤0.80.

13. The NMR-MAS rotor according to claim 11 , wherein the rotor tube is open on both sides, and the NMR-MAS rotor has a bottom cap with an insertion region for feeding into the rotor tube and a bearing region for forming a Bernoulli bearing, the insertion region having at least one sealing section for resting against the inner wall of the rotor tube, wherein the outside diameter EDAD of the sealing section is greater than the inside diameter RRID of the rotor tube by the excess UEM.

14. The NMR-MAS rotor according to claim 13 , wherein the bearing region forms a flat face surface with an axial runout of 0.005 mm or better.

15. The NMR-MAS rotor according to claim 11 wherein TBAD<RRAD.

16. An NMR-MAS stator for accommodating an NMR-MAS rotor according to claim 11 , the stator comprising a bottom bearing with at least one bearing nozzle, at least two radial bearings each comprising a plurality of bearing nozzles, and at least one drive nozzle system comprising a plurality of drive nozzles, wherein a first ventilation slot is provided between the topmost radial bearing and the drive nozzle system in order to dissipate at least part of a compressed drive gas, and wherein a drive distance (AA) that is the axial distance between the bottom edge of the first ventilation slot and the central plane (ME) of the drive nozzles of the drive nozzle system is between 0.5 mm and 1.0 mm.

17. The NMR-MAS stator according to claim 16 , wherein the first ventilation slot is formed with a first rear ventilation space which widens downwards away from the drive nozzle system.

18. The NMR-MAS stator according to claim 17 , wherein a second ventilation slot is provided above the drive nozzle system in order to dissipate at least part of the compressed drive gas, and wherein the second ventilation slot is formed with a second rear ventilation space which widens upwards away from the drive nozzle system.

19. The NMR-MAS stator according to claim 16 wherein a number of drive nozzles of the drive nozzle system is between four and nine.

20. The NMR-MAS stator according to claim 16 wherein a diameter of the drive nozzles of the drive nozzle system is between 0.1 mm and 0.15 mm.

21. An NMR-MAS system comprising an NMR-MAS rotor and an NMR-MAS stator according to claim 16 , wherein an inside diameter RLID of the radial bearings is between 0.02 mm and 0.10 mm greater than an outside diameter RRAD of the rotor tube.

Assignees

• Bruker Biospin Gmbh

Inventors

• Osen David
• Knott Benno

Classifications

• F05D2250/141

  circular · CPC title

• F01D9/02

  Nozzles; Nozzle boxes; Stator blades; Guide conduits {, e.g. individual nozzles (nozzle boxes F01D9/047)} · CPC title

• F01D5/141

  Shape, i.e. outer, aerodynamic form (F01D5/148 - F01D5/20 take precedence; blade construction F01D5/147) · CPC title

• G01R33/307 Primary

  specially adapted for moving the sample relative to the MR system, e.g. spinning mechanisms, flow cells or means for positioning the sample inside a spectrometer · CPC title

• F01D25/16

  Arrangement of bearings; Supporting or mounting bearings in casings (bearings per se F16C) · CPC title