Screw compressor element and machine

Patent metadata

Field	Value
Publication number	US-11828284-B2
Application number	US-201917042595-A
Country	US
Kind code	B2
Filing date	Mar 26, 2019
Priority date	Mar 29, 2018
Publication date	Nov 28, 2023
Grant date	Nov 28, 2023

Abstract

A screw compressor element may have a housing; a cylinder bearing including an inner ring, an outer ring, a raceway, and a cylindrical rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof; and a ball bearing including an inner ring, an outer ring, a raceway, and a ball shaped rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof, wherein a rotor is rotatably arranged by way of the cylinder bearing and the ball bearing.

First claim

The invention claimed is:

1. A screw compressor element comprising:
a housing;
a cylinder bearing including an inner ring, an outer ring, a raceway, and a cylindrical rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof;
a ball bearing including an inner ring, an outer ring, a raceway, and a ball shaped rolling element that contacts the inner ring and the outer ring at a location of the raceway thereof; and
a nozzle arranged in a space, between the cylinder bearing and the ball bearing, and comprising a first outlet, positioned and configured to direct a first jet of lubrication fluid into the cylinder bearing, and a second outlet positioned and configured to direct a second jet of lubrication fluid into the ball bearing, wherein
portions of each of the inner rings of the respective cylinder bearing and the ball bearing, at respective locations next to the respective raceways of the cylinder bearing and the ball bearing and facing away from the other of the respective cylinder bearing and the ball bearing, have greater outer diameters than diameters of the respective raceways,
portions of each of the outer rings of the respective cylinder bearing and the ball bearing, at respective locations next to the respective raceways of the cylinder bearing and the ball bearing and both facing to and away from the other of the respective cylinder bearing and the ball bearing, have smaller inner diameters than the diameters of the respective raceways of the cylinder bearing and the ball bearing,
wherein a rotor is rotatably arranged by way of the cylinder bearing and the ball bearing, and
the smaller inner diameters of the portions of the outer ring of the ball bearing are at least one of:
a. equal to each other, and
b. at least one of the smaller inner diameters of the portions of the outer ring of the ball bearing is smaller than each of the smaller inner diameters of the portions of the outer ring of the cylindrical ball bearing.

2. The screw compressor element according to claim 1 , wherein the inner diameters of the inner rings of the cylinder bearing and the ball bearing are identical.

3. The screw compressor element according to claim 1 , wherein the cylinder bearing is provided with two fixed collars on the outer ring thereof and one fixed collar on the inner ring thereof, or the cylinder bearing is provided with two fixed collars on the outer ring thereof and one loose collar on the inner ring thereof.

4. The screw compressor element according to claim 1 , wherein a difference between diameters of the cylindrical rolling element and the ball shaped rolling element is not greater than 20%.

5. The screw compressor element according to claim 4 , wherein the difference between the diameters of the cylindrical rolling element and the ball shaped rolling element is not greater than 10%.

6. The screw compressor element according to claim 4 , wherein the difference between the diameters of the cylindrical rolling element and the ball shaped rolling element is not greater than 5%.

7. The screw compressor element according to claim 1 , wherein at least one of the cylindrical rolling element and the ball shaped rolling element is made out of a ceramic material.

8. The screw compressor element according to claim 7 , wherein both of the cylindrical rolling element and the ball shaped rolling element are made out of a ceramic material.

9. The screw compressor element according to claim 1 , wherein the outer ring of the ball bearing is provided with two raceways.

10. The screw compressor element according to claim 9 , wherein contact angles on the two raceways of the outer ring of the ball bearing are different.

11. The screw compressor element according to claim 1 , wherein the cylindrical bearing and the ball bearing are suitable for being used at speeds higher than 1*106 ndm [millimeters×revolutions per minute].

12. The screw compressor element according to claim 11 , wherein the cylindrical bearing and the ball bearing are suitable for being used at speeds higher than 1.25*106 ndm.

13. The screw compressor element according to claim 11 , wherein the cylindrical bearing the ball bearing are suitable for being used at speeds higher than 1.5*106 ndm.

14. A machine comprising the screw compressor element according to claim 1 , wherein the machine is one of the group of:
a compressor;
a blower;
an expander; and
a vacuum pump.

15. The screw compressor element according to claim 1 ,
wherein the smaller inner diameters of the portions of the outer ring of the ball bearing are both of:
a. equal to each other, and
b. such that at least one of the smaller inner diameters of the portions of the outer ring of the ball bearing is smaller than each of the smaller inner diameters of the portions of the outer ring of the cylindrical ball bearing.

Assignees

• Atlas Copco Airpower Nv
• Skf Ab

Inventors

• De Bock Simon
• De Rooster Tom

Classifications

• F04C18/16 Primary

  with helical teeth, e.g. chevron-shaped, screw type {(for non-parallel axes of movement F04C18/48)} · CPC title

• F16C19/49

  Bearings with both balls and rollers · CPC title

• F16C19/546

  Systems with spaced apart rolling bearings including at least one angular contact bearing · CPC title

• F16C19/56

  in which the rolling bodies of one bearing differ in diameter from those of another · CPC title

• F01C21/02

  Arrangements of bearings (bearing constructions F16C) · CPC title