Abstract
The present invention highlights a lemon shaped guide that may be used in a rotating machine to suppress excessive rubbing. Rubbing, between a rotor and a guide, is critical in industries; since, it may even lead to severe damages. The lemon shaped guide is based solely on the mechanical design, that is more economical and quickly implementable than the other traditional techniques, such as circular guide, or more advanced sophisticated devices, for example, magnetic bearings. The lemon shaped guide is designed from two circles—having the same radius, and centers on the same line with some distances—which are the most significant designing parameters. Once equipped with a rotating machine, the lemon shaped guide may perform better at minimizing rubbing, between rotor and stator operating at higher speed, than the traditional circular shaped guide.
Claims
1. A Lemon shaped guide performs better in minimizing rubbing between rotor and guide in a rotating machine than the traditional circular shaped guide.
2. The lemon shaped guide may further be modified to a lemon shaped bearing that is similar to a regular angular contact ball or roller bearing configuration.
3. This is a cost-effective solution compared to the advanced magnetic bearing technology since it is a pure mechanical way to suppress excessive rubbing and easy to implement.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] FIG. 1 shows the procedure to design a lemon shaped guide.
[0006] FIG. 2 highlights the detailed technical drawings of the lemon shaped guide.
[0007] FIG. 3 illustrates some photographs of the manufactured lemon shaped guide.
[0008] FIG. 4 presents implementation of the manufactured lemon shaped guide in a rotor dynamic experiment.
[0009] FIG. 5 shows the design of the experimental test rig used to implement the lemon shaped guide.
DETAILED DESCRIPTION AND BEST MODE OF IMPLEMENTATION
[0010] A lemon shaped guide is formed by drawing two circles (circle-1 and circle-2 in FIG. 1). Circle-1 and circle-2 both have the same radius R. Here, o.sub.1 is the center for circle-1, and o.sub.2 is the center for circle-2. Both the centers are on the same line. φ.sub.1 denotes the angle between R and O.sub.1M, and φ is the angle between δ′ and MO.sub.2. M is the center of the lemon type guide. The distance between points M and o.sub.2 and points M and o.sub.1 is represented by α. The equations of circle-1 and -2 are (x+α).sup.2+y.sup.2=R.sup.2 and (x−α).sup.2+y.sup.2=R.sup.2. From FIG. 1, the subtraction of R and α is the ‘nearest gap’ from the center M to the wall of the lemon shaped guide. The lemon shape may be modified by changing the two parameters R and α. So, these two are the most significant parameters for designing a lemon shaped guide.
[0011] FIG. 2 shows the detailed technical drawings of the lemon shaped guide. Here, all the dimensions are considered depending on the specifications of the particular experimental test rig. This dimensions need to be updated based on the individual experimental setup.
[0012] Photographs in FIG. 3 show a physical lemon shaped bearing, which is manufactured from brass material. For this particular shape, the ‘nearest gap’ (subtraction of R and α in FIG. 1) is kept 2 mm, and the ‘longest gap’ (from center M to one of the two edges, top or bottom, in FIG. 1) is 4 mm.
[0013] Photographs in FIG. 4 highlight the implementation of a lemon shaped guide in a rotor dynamic experiment. From FIG. 3, we see that the lemon shape is formed by two separate slices where each slice has a hole. This hole is created to install the slice in the support of the experimental test rig, which is seen in FIG. 3. However, this configuration is not mandatory for all setups as individual technique may differ depending on the type of rotating machines.
[0014] FIG. 5 demonstrates the experimental setup that has been used to evaluate the performance of both circular and lemon shaped guides. This test rig is the simplified form of a rotating machine, which is motivated from the theoretical ‘Jeffcott rotor’ model. An elastic shaft with a radius of 8 mm and a length of 970 mm is supported vertically by the ball bearings at both ends. The inside diameter, outside diameter, and thickness of the upper and lower bearing are 16 mm, 35 mm, and 11 mm, respectively. A disk (rotor) with the radius of 100 mm is attached just at the mid position of the shaft. The disk is supported by a bush, which is then attached to the shaft with the help of a pin. The disk displacements on the plane (x and y directions) are measured by an eddy current sensor. The backup bearing or guide (circular or lemon shaped) is set at the position of 50 mm below the disk with a clearance of 2 mm between the shaft and guide. The overall experimental setup is attached to the wall. It should be noted that to check the performance of a lemon shaped guide, any configurations of rotating machines may be used.
