Washing machine appliances and methods of using counterweight amplitude to limit basket speed

Patent metadata

Field	Value
Publication number	US-10753030-B2
Application number	US-201816032125-A
Country	US
Kind code	B2
Filing date	Jul 11, 2018
Priority date	Jul 11, 2018
Publication date	Aug 25, 2020
Grant date	Aug 25, 2020

Abstract

A washing machine appliance, including one or more methods of operation, is provided herein. The washing machine appliance includes a wash basket rotatably mounted within a wash tub and being supported by a front bearing and a rear bearing. A method of operating the washing machine appliance includes rotating the wash basket within the wash tub at a basket speed and obtaining a front displacement amplitude, a rear displacement amplitude, and a wobble angle of the wash tub. Based at least in part on these measured values, front and rear bearing force amplitude thresholds and virtual bearing force values are calculated and compared. If the virtual bearing force value of either the front or rear bearing exceeds the respective bearing force amplitude threshold, an operating parameter of the washing machine appliance is adjusted to limit bearing forces resulting from out-of-balance loads.

First claim

What is claimed is:

1. A method for operating a washing machine appliance, the washing machine appliance having a wash tub, a wash basket rotatably mounted within the wash tub by a drive shaft, and a front bearing and a rear bearing for supporting the drive shaft, the method comprising:
rotating the wash basket within the wash tub at a basket speed;
obtaining at least one displacement amplitude of the wash tub;
obtaining a wobble angle of the wash tub;
determining a bearing force amplitude threshold;
calculating a virtual bearing force value based in part on at least one of the displacement amplitude and the wobble angle;
determining that the virtual bearing force value is greater than the bearing force amplitude threshold; and
adjusting at least one operating parameter of the washing machine appliance in response to determining that the virtual bearing force value is greater than the bearing force amplitude threshold.

2. The method of claim 1 , wherein the bearing force amplitude threshold is a function of a bearing force limit and the basket speed.

3. The method of claim 2 , wherein the bearing force amplitude threshold is a front bearing force amplitude threshold calculated using the following equation:

AMP
FRT

=

F

LMT
⁢
_
⁢
FRT

ω
2

⁢

C
3

where:
AMP FRT =the front bearing force amplitude threshold;
F LMT_FRT =a front bearing force limit;
ω=the basket speed (radians/second); and
C 3 =mass rr , a known system constant.

4. The method of claim 3 , wherein the at least one displacement amplitude comprises a front displacement amplitude at a front of the wash tub and a rear displacement amplitude at a rear of the wash tub.

5. The method of claim 4 , wherein the virtual bearing force value is a front virtual bearing force value calculated using the following equation:
|δ frt C 4 +cos(β)δ rr |

where:
δ frt =the front displacement amplitude;
δ rr =the rear displacement amplitude;
cos(β)=a component of δ rr that is collinear with δ frt ; and

C
4

=

mass
frt

mass
rr

⁢

(

1
+

l
frt

l
rr

)

,

a known system constant.

6. The method of claim 5 , wherein cos(β) is calculated as follows:

cos
⁡

(
β
)

=

δ
frt
2

+

δ
rr
2

-

(

Φ
·

l
frt

)

2

2
⁢

δ
frt

⁢

δ
rr

where:
Φ=the wobble angle; and
l frt =the distance between a tub front and the front bearing.

7. The method of claim 2 , wherein the bearing force amplitude threshold is a rear bearing force amplitude threshold calculated using the following equation:

AMP
RR

=

F

LMT
⁢
_
⁢
RR

ω
2

⁢

C
5

where:
AMP RR =the rear bearing force amplitude threshold;
F LMT_RR =a rear bearing force limit;
ω=the basket speed (radians/second); and

C
5

=

mass
frt

⁡

(

l
frt

l
rr

)

,

a known system constant.

8. The method of claim 7 , wherein the at least one displacement amplitude comprises a front displacement amplitude at a front of the wash tub.

9. The method of claim 8 , wherein the virtual bearing force value is a front virtual bearing force value calculated using the following equation:
|δ frt |

where:
δ frt =the front displacement amplitude.

10. The method of claim 9 , wherein the bearing force amplitude threshold is a front bearing force amplitude threshold and the virtual bearing force value is a front virtual bearing force value, the method further comprising:
determining a rear bearing force amplitude threshold;
calculating a rear virtual bearing force value;
determining that the front virtual bearing force value is greater than the front bearing force amplitude threshold or the rear virtual bearing force value is greater than the rear bearing force amplitude threshold; a

Assignees

• Haier Us Appliance Solutions Inc

Inventors

• Davis Paul Owen

Classifications

• D06F37/00

  Details specific to washing machines covered by groups D06F21/00 - D06F25/00 · CPC title

• D06F33/76

  Preventing or reducing imbalance or noise · CPC title

• D06F2105/48

  Drum speed · CPC title

• D06F2103/26

  Imbalance; Noise level · CPC title

• D06F34/16

  Imbalance · CPC title