Home | Links | Contact Us | More About Intellectual Property | Bookmark

Search patents:

Home

Generators or Motors

Magnetic-fluid-seal-containment-shield

Rotating electric machine and cooling method thereof

1. A rotating electric machine comprising: a plurality of ventilating passages formed between a ...

Dynamic pressure bearing

The present invention was specifically attempted for fully overcoming the above-mentioned problems. ...

Rotating rectifier assembly

This invention provides a rotating rectifier assembly which is compact in size and rugged in ...

Rotating rectifier assembly

I claim: 1. A rotating rectifier assembly comprising: a generally tubular housing; at least one ...

Direct current motor assembly with rectifier module

Among the several aspects and features of the present invention may be noted the provision of an ...

Rotating rectifier assembly

I claim: 1. In a method of assembling a rotating rectifier assembly comprising axially loading ...

Generator rotor cooling

What is claimed is: 1. A generator comprising: a stator including a main armature; a rotor ...

Transformer and rectifier module with half-turn secondary windings

I claim: 1. A transformer module, having a half-turn secondary winding, comprising: a transformer ...

Heat sink for rectifier

The primary object of the present invention is to provide an improved heat sink to uniformly ...

Hydrodynamic bearing apparatus and method for manufacturing same

This invention aims to provide a hydrodynamic bearing apparatus wherein the amount of the lubricant ...

Magnetic fluid seal containment shield

Details

Inventors: Cossette, Luke A.; Delagardelle, Craig A.;
Assignee: International Business Machines, Corp. (Armonk, NY)
Primary Examiner: Cuchlinski, Jr.; William A.
Assistant Examiner: Folker; James K.
Attorney, Agent or Firm: Letson; Laurence R.

A magnetic seal for a disk drive data storage unit is described where the magnet assembly comprising an annular magnet and two annular pole pieces are adhesively attached with the magnet intermediate the pole pieces and the assembly thereof then forcibly inserted, creating a force fit, into a shield which is formed as an annulus with an interior cylindrical surface engaging the exterior cylindrical surfaces of the magnet assembly. The force fit insures electrical continuity between the shield and the pole pieces. The shield extends into close proximity with the shaft being sealed and is provided with a relieved region immediately adjacent the interior cylindrical surface of the pole pieces to form a reservoir for receiving, trapping and retaining any ferromagnetic fluid which may escape from the gap between the pole pieces and the shaft. A mating shield is then assembled onto the previously assembled components after the introduction of the ferromagnetic fluid into the seal gaps. All elements of the seal assembly are adhesively sealed to adjacent elements to prevent the formation of gaps or capillaries which may act to attract and transport ferromagnetic fluid away from the seal gap between the pole pieces and the shaft. At least one of the shields is in reliable electrical contact with the hub into which the entire assembly is inserted.

DETAILED DESCRIPTION The present invention has a significant aspect in that it captures the ferromagnetic seal fluid, which may be spun away from the magnetic seal gap, and holds that fluid within proximity of the magnetic field so that the fluid is available for reattraction into the seal gap.
Another significant aspect of the invention is that by designing the engagement of the magnet and pole pieces with one of the shielding member as an interference or force fit, the need for an adhesive seal between the parts to retain the parts in their assembled state and the possibility of complications resulting from a defective adhesive assembly seal are reduced, and overcome when the adhesive seal is used in addition to a press fit.
The use of adhesive seals only to hold the assembly together defeats or at least limits electrical continuity between the pole pieces and the shielding pieces and between the shielding pieces and the hub.
A force fit insures good electrical continuity between several elements of the design.
The present invention utilizes a magnet placed between two annularly shaped pole pieces which in turn surround a shaft.
The two pole pieces are adhesively bonded to the annularly shaped magnet to form a single assembly; then the pole pieces are seated with a press fit or bonded within a cylindrical surface in a bottom shield member.
The bottom shield member then is positioned with a force fit or bonded within the hub of the magnetic disk storage unit.
The annular interface between the bottom shield and the bottom pole is sealed with an adhesive material, gasket, 0-ring or other seal approach to restrict the capillary flow of the ferromagnetic material into the gap between the bottom pole and the bottom shield.
A top shield member is then adhesively sealed onto the bottom shield and the top pole to further contain the ferromagnetic fluid at the seal region to prevent its migration by capillary action radially outward from the shaft.
Accordingly, the ferromagnetic fluid is restricted to and contained in the region immediately adjacent to the seal gap between the pole pieces and the motor shaft, thereby assuring a reliable magnetic seal as well as preventing undesired migration of the ferromagnetic material into either the motor cavity or the disk cavity of the magnetic disk storage device

Related patents

	Bearing device with a primary and secondary magnetic fluid sealing mechanism It is therefore an object of the invention to provide a bearing device which can prevent magnetic fluid from leaking, reduce contamination outside of the bearing device ...
	Shock and vibration system A shock and vibration isolation system for an article comprising a set of elastomers circumferentially positioned in a shear mode around a member carried by the article ...
	Cooling system for electric motors I claim: 1. An electromagnetic machine rotor assembly comprising a rotor shaft internally accommodating a heat pipe which extends axially therealong and has an ...
	Rotary electric motor We claim: 1. A structure for use with a rotary electric motor of a sealed type, comprising: a first housing; a second housing having at least one air opening which leads ...
	Electric motor having internal heat dissipator It is therefore an object of the invention to provide an internal heat dissipator for an electric motor or the like which efficiently dissipates heat without drawing ...
	Cooling arrangement of vehicle rotary electric machine Therefore, a main object of the invention is to provide a compact, powerful and highly efficient vehicle rotary electric machine that has an improved cooling arrangement....
	Electric motor having a rotor supported by a holder member which is angularly fixed to a printed circuit board The present invention is devised to solve the foregoing conventional problems. Therefore, it is an object of the present invention to provide a holder member fixing ...
	Electric motor fan seal ring An electric motor cooling fan having a seal ring reduces cooling air recirculation inside the motor which increases the cooling of motor windings for the prevention of ...
	Reorienting treadmill A treadmill has a support structure configured to be freestanding and to stably support the treadmill and more specifically the tread base in multiple orientations. The ...
	Direct driving apparatus for an electric treadmill It is a primary object of the present invention to provide a direct driving apparatus for an electric treadmill which doesn't require a transmission belt, a belt ...

1.144
Archive: All patents - Links Copyright (c)2006 Eipa-patents.org - All rights reserved