# US 8,769,797 B2 · Method for mounting a bush around a part of a shaft by means of a tight fitting

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- Number: US 8,769,797 B2
- Document ID: US8769797B2
- Status: Granted
- Kind: B2
- Application number: 12/996,793
- Filed: 2009-06-09
- Published: 2011-05-05
- Granted: 2014-07-08
- Earliest claimed: 2008-06-13
- Assignees: Atlas Copco Airpower, Naamloze Vennootschap
- Applicants: Aleksandr Pulnikov
- Inventors: Aleksandr Pulnikov
- Web page: https://patentgrep.com/patent/US8769797B2

## CPC

- A46B 5/00: Brush bodies; Handles integral with brushware
- B23P 11/00: Connecting or disconnecting metal parts or objects by metal-working techniques not otherwise provided for (connecting sheet metal or metal tubes, rods or profiles B21D39/00; riveting B21J; soldering, unsoldering, welding B23K; hand tools for connecting wire or strip B25B25/00; connecting metal parts by adhesives F16B11/00)
- B23P 19/02: for connecting objects by press fit or for detaching same (B23P19/10 takes precedence)
- F16C 23/00: Bearings for exclusively rotary movement adjustable for aligning or positioning (F16C27/00 takes precedence {; hydrostatic bearings F16C32/067})
- F16C 33/04: Brasses; Bushes; Linings
- F16C 33/08: Attachment of brasses, bushes or linings to the bearing housing
- F16C 35/063: Fixing them on the shaft (with interposition of an element F16C35/07)
- F16D 1/0858: {due to the elasticity of the hub (including shrink fits)}
- H02K 7/003: {Couplings; Details of shafts (means for mounting rotors on shafts H02K1/28)}
- H02K 15/03: having permanent magnets
- F16D 2300/12: Mounting or assembling
- Y10T 29/49012: Rotor
- Y10T 29/49895: Associating parts by use of aligning means [e.g., use of a drift pin or a "fixture"]
- Y10T 29/49945: by driven force fit
- Y10T 29/53143: Motor or generator
- A46B: BRUSHES (handles not integral with brushware B25G)
- B23P: METAL-WORKING NOT OTHERWISE PROVIDED FOR; COMBINED OPERATIONS; UNIVERSAL MACHINE TOOLS (arrangements for copying or controlling B23Q)
- F16C: SHAFTS; FLEXIBLE SHAFTS; ELEMENTS OR CRANKSHAFT MECHANISMS; ROTARY BODIES OTHER THAN GEARING ELEMENTS; BEARINGS
- F16D: COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})
- Y10T: TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION

## Abstract

Method for mounting a bush round a part (2) of a shaft with a force fit, which method comprises the following steps: providing a guide element (7, 23) with an outer surface (8) which is at least partly conical; providing the guide element (7, 23) in the extension of the aforesaid part (2) of the shaft (1); pushing the bush (5) over the guide element (7, 23) on the part (2) of the shaft (1).

## Claims

### Claim 1

A method for mounting a bush around a part of a shaft with a force fit, comprising the steps:
providing a bush with different layers of composite and having an axis, which either are or are not fibre-reinforced, wherein the layers which are located near an outer perimeter of the bush have a greater elasticity than the layers located near an inner wall of the bush, wherein providing the bush includes making the bush of a fibre-reinforced composite with at least one of the following layers or a combination thereof:
an inner layer whose fibres are wound in a direction extending between +/−70° and 90° in relation to the axis of the bush, wherein the inner layer is made with carbon fibre;
an intermediate layer whose fibres are wound in a direction extending according to a direction between +/−70° and 90° in relation to the shaft;
an axial layer whose fibres are wound in a direction extending according to a direction between 0 and +/−70° in relation to the shaft; and,
an outer layer whose fibres are wound in a direction extending between +/−70° and 90° in relation to the shaft;
providing a guide element on the extension of said part of the shaft, said guide element having an outer surface which is at least partly conical and whose largest diameter deviates maximally five percent from the outer diameter of said part of the shaft;
positioning the guide element such that the largest diameter of the conical part is directed to said part of the shaft;
pushing the bush over the guide element, on the side of the guide element with the smallest diameter, and to said part of the shaft;
moving a press axially towards the conical part during a first step in sliding the bush over the guide element, wherein the press is provided with a bearing face on which the entire end face of the bush rests during the pressing;
using a press element with an inner diameter which is equal to or larger than the outer diameter of said part of the shaft during another step in sliding the bush over the guide element; and
partly or entirely removing the outer layer, the axial layer and/or the intermediate layer after the bush has been applied over the part of the shaft.

### Claim 2 (depends on 1)

Method according to claim 1, wherein, during the said first step to axially slide the bush over the guide element, axially moving the press up to the conical part of the guide element.

### Claim 3 (depends on 1)

The method according to claim 1, wherein the smallest diameter of the conical part is smaller than or just as large as the inner diameter of the bush; and
wherein, the outer surface of the guide element of the bush has an initial contact surface between the bush and the guide element that has a rounded edge, said initial contact surface being configured to contact the bush when the bush is initially fitted over the guide element.

### Claim 4 (depends on 3)

The method according to claim 3, wherein the radius of the rounded edge is located within a range of 10−10 times the smallest diameter of the conical part to 10−1 times the smallest diameter of the conical part.

### Claim 5 (depends on 1)

Method according to claim 1, wherein the bush is made of a plastic.

### Claim 6 (depends on 1)

The method according to claim 1, wherein an apical angle (α) of the conical part of the guide element is selected to be smaller than or as large as α, and wherein:
α=k·|ε|·D4/(h·(D1−D4))
where:
α=the maximal apical angle of the conical part in °;
k=a factor which is selected on the basis of the way in which the bush is made and the material out of which the bush is made, which factor is within a range of 10−6 to 10−2;
|ε|=the absolute value of the maximally possible elongation for the least elastic material component of the bush or the plasticity limit of the metal of the shaft if the shaft is made of metal;
h=the thickness of the wall of the bush in m;
D4=the inner diameter of the bush in m; and
D1=the outer diameter of the part of the shaft in m.

### Claim 7 (depends on 6)

Method according to claim 6, wherein the guide element comprises a number of successive conical parts over its longitudinal direction, wherein every conical part meets the formula of claim 6, whereby D1 is each time determined by the largest outer diameter of the conical part.

### Claim 8 (depends on 1)

Method according to claim 1, wherein the shaft is stepped and the guide element is at least partly hollow, including centering the guide element on the shaft by providing it with its hollow part over a shaft part with a smaller diameter than the part of the shaft over which the bush is to be received.

### Claim 9 (depends on 1)

Method according to claim 1, wherein the shaft is provided with a recess at a far end thereof and the guide element is provided with an axially protruding part which is complementary to the recess in the shaft, wherein the guide element is centred on the shaft by introducing it at least partly in the recess of the shaft with its axially protruding part.

### Claim 10 (depends on 1)

Method according to claim 1, wherein the outer surface of the guide element is provided with a cylindrical part which connects to the conical part, on the side of this conical part with the smallest diameter.

### Claim 11 (depends on 10)

Method according to claim 10, wherein the outer diameter of the cylindrical part of the guide element is smaller than or equal to the smallest diameter of the conical part.

### Claim 12 (depends on 1)

Method according to claim 1, wherein, in order to push the bush over the guide element and on the part of the shaft, using a cylindrical press which is at least partly hollow.

### Claim 13 (depends on 12)

Method according to claim 12, wherein the hollow press is provided with a recess having an inner diameter which corresponds practically to the diameter of the cylindrical part of the guide element, wherein the hollow press is moved over the cylindrical part of the guide element during the axial movement.

### Claim 14 (depends on 12)

Method according to claim 12, wherein the hollow press is provided with an overhang which rests against an end face of the bush during the first step to facilitate axially shifting the bush over the guide element.

### Claim 15 (depends on 14)

The method according to claim 14, wherein, in a following step, a second press is first provided between the press and the guide element, wherein the second press has a recess with an inner diameter which is larger than the inner diameter of the bush before the bush is fitted over the shaft.

### Claim 16 (depends on 14)

Method according to claim 14, wherein several successive steps are used when axially sliding the bush over the guide element, wherein at least a second press with an ever increasing inner diameter is used in every subsequent step.

### Claim 17 (depends on 1)

Method according to claim 1, wherein the guide element is an integral part of the shaft.

### Claim 18 (depends on 1)

Method according to claim 1, wherein the part of the shaft on which the bush is to be mounted with a force fit has a cylindrical shape.