UNISON HOUSING TYPE SPRING MOUNT (HSM)

SPECIFICATION

Type HSM spring isolators consist of high deflection, color coded stable springs assembled into plated, telescoping cast iron housings complete with 0.25”(6mm) thick neoprene friction pads beneath the housing and an adjusting and leveling bolt as a part of the top assembly. UNISON Engineering Co., Ltd. Manufactures type HSM for this mountings.

MOUNTINGS

Type HSM spring isolators provide an excellent solution to trouble and complicated vibration problems. These units perform when the establishing of low natural frequencies is required, and are specially designed for critical areas where the floors are light materials such as thin concrete, steel base or wood in order to free from noise and vibration.
The limit of movement during start-up and shutdown and prevention of contact between the projections of the upper part and lower steel casting shall be performed by inserting the semi-circular sponge which are designed for a minimum damping in all directions to allow the springs to function adequately and achieve efficiencies as possible to theoretical efficiency. Inserts are recommended not adjustable for all air conditioning application with compressors, air handlers, centrifugal type fans, and most other vibration problems with constant frequency.

DESIGN CONDITION

Type HSM spring mountings perform where it is required to establish low natural frequencies or to use a mounting whose yielding point is higher than that of the supporting floor because the static deflection of the spring element is much greater than that provided by most rubber materials, and are specially designed for noise and vibration free application in critical areas such as on light concrete or wooden floors.

1. Neoprene Sponge Inserts
It is required to limit the movement during start and stop of the mountings and to prevent any contact, and for this purpose, semi-circular neoprene sponge shall be inserted into the gap between the projections of the super and lower semi-steel castings. A minimum of damping in all directions shall be considered in the design in order to allow the springs to function properly and develop installed efficiencies as close as possible to the theoretical efficiency.
These inserts shall be recommended not to be adjustable for all air conditioning applications such as compressors, air handling units, centrifugal fans and most other equipment which produce constant frequency vibration.
In order to avoid the direct friction between ground concrete and HSM spring mounting housing, acoustical friction pad is attached on the bottom of housings.

2. External Adjustment Mountings
For the equipment whose mounting holes are well centered and mounting leveling and adjustment bolt is easily accessible from above external adjustment mountings shall be installed

3. Internal Adjustment Mountings
The equipment which is preferable to change the center of the mounting according to its mounting hole or has no access for adjustment from above, internal adjustment mountings shall be provided, An open end wrench will work successfully for adjustment of internal spring through the side opening. Type W. acoustical friction pads on the bottom of the mountings for both external and internal shall eliminated the need for bolting down on most installations.