CA1155896A

CA1155896A - Unit bearing motor

Info

Publication number: CA1155896A
Application number: CA000369522A
Authority: CA
Inventors: Kenneth H. B. Glass
Original assignee: Electrohome Ltd
Current assignee: Electrohome Ltd
Priority date: 1981-01-28
Filing date: 1981-01-28
Publication date: 1983-10-25

Abstract

Abstract of the Disclosure A unit bearing motor has a bearing assembly mounted on the shaft of the motor on one side only of the rotor.
The bearing assembly includes spaced-apart spherical bear-ings rotatably mounted on the shaft, spring retainers mounted in facing relationship to each other on the sides of the bearings that are adjacent to each other, a com-pression spring positioned between the spring retainers and urging the bearings away from each other, and bearing seats against which the bearings are urged by the spring.
One of the bearing seats is formed in a cup-shaped wall of a casing of the motor which is mounted on one side of the stator of the motor. This cup-shaped wall defines an open-ended cavity in which the bearing assembly is located. The other bearing seat is formed on a closure member that closes the open end of the cavity, the latter containing suitable material for retaining oil to lubricate the bearings. The cup-shaped wall includes a rim surround-ing the closure member, the rim being rolled over or swaged over the closure member to hold it in place.

Description

1 15~8g6 UNIT BEARING MOTOR
Background of the Invention This invention relates to a unit bearing motor, i.e., to an electric motor having a stator, rotor and shaft, the latter being secured to and driven by the rotor and being journalled in a bearing on one side only of the rotor, as opposed to the more conventional arrangement where the shaft is journalled in bearings on each side of the rotor.
While unit bearing motors are not new, such unit bearing motors of which we are aware are composed of a substantial number of parts and are relatively complex to assemble. In accordance with the instant invention there is provided a simple, unit bearing motor that is com-posed of a minimum number of components and that is simple to assemble.
Summary of the Invention According to one aspect of this invention there is provided a unit bearing electric motor comprising a stator;
a rotor having a shaft secured thereto, said rotor being rotatably mounted within said stator; a motor casing mounted on said stator on one side thereof; a bearing assembly mounted on one side only of said rotor and located on said one side of said stator, said bearing assembly including first and second spherical bearings rotatably mounted in spaced-apart relationship with respect to each other on said shaft, spring means mDunted in Gcm~ression het~een said kearings and urging said bearings away from each other, and first and second bearing seats against which said first and second bearings respectively are urged by said spring means; said first bearing seat being formed on a cup-shaped wall of said casing which extends inwardly toward said rotor and defines an open-ended cavity in which said bearing assembly is located, said second bearing seat being formed on a closure member extending over and closing said open end of said cavity, said cavity containing material for retaining oil to lubricate said bearings, said shaft extending through said cup-shaped wall, cavity and closure member, said cup-shaped wall including a rim surrounding said closure member and physically deformed over said closure member to hold said closure member in place.
Brief Description of the Drawings This invention will become more apparent from the following detailed description, taken in conjunction with the appended drawing which is a section through a motor embodying the instant invention.
Detailed Description_of the Invention Including the Preferred Embodiment A unit bearing motor embodying the instant inven-tion includes a rotor 10, a shaft 11, a stator 12, a casing 13, end pieces 14a and 14b, the latter being an end bell, and a bearing assembly 15.
Rotor 10 is of conventional configuration and is mounted on and secured to shaft 11 to drive the shaft.
As is conventional, rotor 10 is mounted within a circular opening defined by stator 12, and the latter is provided with poles and windings of a conventional nature.
Shaft 11 is journalled in two, spherical bearings 16a and 16b of bearing assembly 15 on one side only of rotor 10. Bearing assembly 15 also includes two spring retainers 17a and 17b, a spring 18 and bearing seats l9a and 19b.
In accordance wit`h an important aspect of this 1 15~96 invention, only two components are employed to provide bearing seats l9a and l9b, and both of these components, namely end piece 14a and casing 13, perform additional functions.
As may be seen from the drawing, spring retainers 17a and 17b are mounted facing each other on the sides of bearing 16a and 16b respectively that are adjacent to each other. Spring 18 is positioned in compression between the spring retainers and this urges bearings 16a and 16b into engagement with bearing seats l9a and l9b.
In order to limit lateral movement (end play) of shaft 11, a "C" clip 20 is mounted in a suitable groove provided in the periphery of shaft 11 and located between bearings 16a and 16b, and washers 21a and 21b are mounted on shaft 11 between the "C" clip and bearings 16a and 16b respectively.
In order to assemble the motor, casing 13 is mounted on shaft 11. Subsequently bearing 16b, washer 21b, spring retainer 17b, "C" clip 20, spring 18, spring retainer 17a, washer 21a and bearing 16a are assembled on shaft 11 in the named order. Any suitable oil retaining material such as felt or PERMAWICK (trade mark) then may be packed into the cavity 23 which is formed by end piece 14a and the cup-shaped wall 24 of casing 13, and oil may be added thereto to lubricate bearings 16a and 16b. An oil hole (not shown) may be provided in casing 13 communicating with cavity 23 so that additional oil may be added after the motor has been in use.
The end of casing 13 facing end piece 14a has a circular opening therein into which end piece 14a fits, the latter being seated on an annular step 25 formed in casing 13. Surrounding step 25 is an annular rim 26 that is formed integral with casing 13. End piece 14a is placed on step 25, and rim 26 then is physically deformed, e.g., by staking or rolling over thereof to hold end piece 14a in position.

1 1 5~8g~

The final step in the assembly of the motor involve placing rotor 10 within stator 12, bringing end bell 14b and the bearing assembly including casing 13 into the positions thereof shown in the drawing, and passing bolts 22 through openings in end bell 14b and stator 12 and into threaded engagement with casing 13 to firmly secure these components together.
It will be observed that bearings 16a and 16b are of the self-aligning type and thus self-adjust to accommodate small degrees of component misalignment.
In a less preferred embodiment of the invention spring retainer 17a and 17b may be omitted and the adjacent faces of bearing 16a and 16b may be stepped to provide flat surfaces for seating the ends of spring 18.
With this configuration spring 18 directly biases the bearings away from each other.
While a preferred embodiment of this invention has been described, those skilled in the art will appre-ciate that changes and modifications may be made therein without departing from the spirit and scope of the invention as defined in the appended claims.

Claims

CLAIMS:

1. A unit bearing electric motor comprising a stator; a rotor having a shaft secured thereto, said rotor being rotatably mounted within said stator; a motor casing mounted on said stator on one side thereof; a bearing assembly mounted on one side only of said rotor and located on said one side of said stator, said bear-ing assembly including first and second spherical bearings rotatably mounted in spaced-apart relationship with respect to each other on said shaft, spring means mounted in compression between said bearings and urging said bearings away from each other, and first and second bearing seats against which said first and second bearings respectively are urged by said spring means, said first bearing seat being formed on a cup-shaped wall of said casing which extends inwardly toward said rotor and defines an open-ended cavity in which said bearing assembly is located, said second bearing seat being formed on a closure member extend-ing over and closing said open end of said cavity, said cavity containing material for retaining oil to lubricate said bearings, said shaft extending through said cup-shaped wall, cavity and closure member, said cup-shaped wall including a rim surrounding said closure member and physically deformed over said closure member to hold said closure member in place.

2. A unit bearing electric motor according to claim 1 including means for limiting movement of said shaft and rotor back and forth parallel to the axis of rotation of said shaft and rotor.

3. A unit bearing electric motor according to claim 2 wherein said movement limiting means comprises stop means mounted on said shaft between said bearings.

4. A unit bearing electric motor according to claim 3 wherein said stop means is a C ring.

5. A unit bearing electric motor according to any of claims 1, 2 or 4 wherein said rim is rolled over said closure member.

6. A unit bearing electric motor according to any of claims 1, 2 or 4 wherein said rim is staked over said closure member.

7. A unit bearing electric motor according to any one of claims 1, 2 or 4 including an end bell mounted on said side of said stator opposite to said one side thereof and belt means securing said end bell, stator and casing together.

8. A unit bearing electric motor according to any of claims 1, 2 or 4 wherein said bearing assembly includes first and second spring retainer means mounted in facing relationship to each other on the sides of said bearings that are adjacent to each other, said spring means being mounted in compression between said spring retainer means and thereby urging said bearingsaway from each other via said spring retainer means.