Thomas
®
XTSR52 Installation and Maintenance
(Page 8 of 13)
Sizes 494-5258
CP3-002
September 2017
Supersedes 09-2016
Rexnord
5555 S. Moorland Rd., New Berlin, WI 53151-7953
Phone: 262-796-4060 Fax: 262-796-4064 www.rexnord.com
7. Shaft Alignment
ATTENTION!
Soft foot – the equipment must rest flat on its base. If one or more feet of the machine are shorter, longer, or angled in
some way to prevent uniform contact (a condition commonly known as “soft foot”) it must now be corrected.
ATTENTION!
To improve the life of the coupling, the shafts must be aligned to minimize distortion of the flexing elements. Shaft
alignment is required in the axial, parallel, and angular directions, with each of these values not to exceed the recommended ratings
for the coupling and the alignment values shown in Table 4. Shaft alignment can be measured using various established methods,
including Laser Alignment, Reverse Dial Indicator, and Rim and Face.
7.1 Move the connected equipment to achieve acceptable alignment. When well aligned, the disc packs will be centered and approximately parallel to
their mating flange faces and the flexing elements will have little visible waviness when viewed from the side.
As a guide, the maximum and minimum values for dimension “N” shown in Figure 7 are given in Table 4. These dimensions are suggested for initial
installation. Additional capacity is available to compensate for thermal and structural equipment movement. Maximum axial capacity values for these
couplings are also given in Table 4.
Table 4 shows installation limits for Angular and Parallel Alignment. The Parallel Alignment value “P” is the offset between the centers of the hubs,
as shown in Figure 8. If parallel offset is measured by rotating the hubs with a dial indicator on the outside diameter, as shown in Figure 9 the total
indicated reading should be divided by (2) to calculate “P”. The Angular Alignment Total Indicator Reading value is the maximum difference between
the measurements (X-Y) taken at opposite ends of the hub flange, and spacer flange as shown in Figure 10.
Figure 7 – Disc Gap
Figure 8
Figure 10
Figure 9
