Two-component seal for a washing machine spin tub

• US 6,354,115 B1
• Filed: 10/21/1999
• Issued: 03/12/2002
• Est. Priority Date: 10/21/1999
• Status: Expired due to Term

• Current Assignee: Clark Seals Limited
• Original Assignee: Clark Seals Limited
• Inventors: Zahn, Henry W.
• Primary Examiner(s): Stinson, Frankie L.
• Application Number:
  US09/421,900
• Time in Patent Office: 873 Days
• Field of Search: 681/33, 68/232, 68/233, 68/237, 681/40
• US Class Current: 68/23.7
• CPC Class Codes: D06F 37/00 Details specific to washing machines covered by groups D06F21/00 - D06F25/00

Abstract

A two-component seal for the spin tub of a washing machine. The two-component seal is disposed about the tub opening and a metal shroud seal to prevent water in the washer from entering a motor and bearing space. The top seal includes a metal case with multiple sealing surfaces. The presence of multiple sealing surfaces provides a sealing force against the shaft shroud seal to seal during operation and compensate for seal wear over time, extending the seal life. The top seal has a stiffener made of metal. A resilient elastomeric cover encloses the stiffener, except for top and bottom tabs. A bottom tab prevents slipping between the tub seal and bottom assembly. The bottom tabs additionally have a lip which engages the shroud seal made from materials which allow sealing lips to seal on a softer metal shaft. The bottom seal also has a resilient metallic stiffener enclosed by a resilient bottom cover. The bottom seal further has a vertical wall and a horizontal flange. Annular wedges on the bottom seal bias the bottom seal vertical wall inwardly, forming a resiliently expansible annular hub. The resilient biasing of the hub make the two-component seal self aligning because any forces acting on the bearings to cause misalignment are counteracted and dampened by reactive resilient biasing forces of the two-component seal.

Claims

1. A two-component seal for a washing machine tub to seal water in an outer tub from getting into the washing machine motor and bearing assembly located generally below the tub, wherein said tub has an interior wall, and said washing machine has an agitator with a shroud seal positioned about a drive shaft of the agitator, said two-component seal comprising:

(a) an annular top seal having a metal case with a plurality of sealing lips biased against said shroud seal; and

(b) an annular bottom seal positioned between a washing machine spin tub and outer tub, said section and wherein a plurality of resilient wedges bias said bottom seal against said bearing assembly.

2. The two component seal of claim 1, wherein the top seal further comprises:

(a) a metal top stiffener of said top seal;

(b) a resilient elastomeric top cover substantially covering said top stiffener; and

(c) a lip to engage an interior bottom opening in said tub to facilitate attachment of said top seal to said tub.

3. A sealing assembly for an outer tub of a washing machine, said washing machine having an agitator shaft which oscillates during a wash cycle and remains stationary during a spin cycle, said washing machine also having a spin tub which remain stationary during a wash cycle and which rotates during a spin cycle, said assembly comprising:

(a) a shroud seal surrounding a spin tube, said shroud seal rotates stationary during a spin cycle of said washing machine;

(b) an annular top seal positioned against said shroud seal, wherein said annular top seal remains stationary when said spin tub rotates; and

(c) an annular bottom seal wherein said annular bottom seal remains stationary when said spin tub rotates.

4. The sealing assembly of claim 3 wherein said bottom seal defines an annular hub which receives and aligns a bearing assembly for a spin tube of said washing machine.

5. The sealing assembly of claim 4 further comprising annular wedges on said bottom seal to resiliently bias said circular hub inwardly to secure the bearing assembly.

6. The sealing assembly of claim 3 further comprising multiple sealing lips that stretch and provide a sealing force against said shroud seal.

7. The sealing assembly of claim 3 wherein multiple sealing lips seal water in the outer tub during the wash cycle.

8. A two-component seal assembly for a washing machine which washes clothes during a wash cycle and which centrifugally removes water from the clothes in a spin cycle, said washing machine having (i) an agitator which agitates the clothes, (ii) an agitator shaft attached to the agitator to oscillate the shaft during the wash cycle, said shaft remaining substantially stationary during the spin cycle, (iii) a spin into which the clothes are placed for washing, wherein said spin tub is substantially stationary during the wash cycle and rotates during the spin cycle, (iv) a spin tube attached to the spin tub to rotate the spin tub during the spin cycle, and (v) a seal assembly aligns with the spin tube, said assembly comprising:

(a) a metal case annular upper seal and a shroud seal attached to said spin tube, wherein said shroud seal rotates when the spin tub rotates; and

(b) an annular lower seal wherein said annular lower seal remains stationary when said spin tube rotates.

9. The two-component seal assembly of claim 8, wherein the top seal further comprises:

(a) a resilient elastomeric upper cover substantially covering said upper metal case; and

(b) a sealing lip to engage the interior wall of an outer tub.

10. The two-component seal assembly of claim 9, wherein the lower seal further comprises:

(a) a metal case of said lower seal; and

(b) a resilient elastomeric bottom cover substantially covering said lower stiffener.

11. The two-component seal assembly of claim 10 further comprising a bottom tab to prevent slippage of the resilient elastomeric bottom cover with respect to the bottom metal case.

12. The two-component seal assembly of claim 10, wherein the lower seal further comprises:

(a) an annular shoulder which pivotally retracts from the shroud seal when said upper seal rotates about said shaft.

13. The two-component seal assembly of claim 9 further comprising a top tab to prevent slippage of the resilient elastomeric top cover with respect to the top metal case.

14. The two-component seal assembly of claim 8 wherein said lower seal defines an annular hub which receives and aligns the bearing assembly for the spin tube of the washing machine.

15. The two-component seal assembly of claim 14 further comprising annular wedges on said lower seal to resiliently bias said circular hub inwardly to secure the bearing assembly.

16. The two-component seal assembly of claim 8 wherein the upper seal further comprises a metal case resiliently biased against the inner wall of a washing machine outer tub by hydrostatic water pressure in the tub during a wash cycle, and retracts from the shroud seal during a spin cycle.