METHOD OF MOUNTING A BEARING TO AN AIR COMPRESSOR, AND AIR COMPRESSOR HAVING A BEARING MOUNTED BY THE METHOD

Abstract

A method of mounting a bearing to an air compressor including a shaft element having a first end and a second is disclosed, which includes the steps of: fixing the second end of the shaft element to a center of a gear; inserting the first end of the shaft element through a central hole of a bearing to have an annular step of the shaft element abutted an inner ring of the bearing; and hitting the first end of the shaft element by a striking tool to form an expanded or flared edge on a top face of the first end of the shaft element. With the method, the bearing can be firmly fixed between the expanded or flared edge and the annular step of the shaft element.

Claims

1. An air compressor, comprising: a base frame defining a first mounting hole, which allows a pinion driven by a motor to pass, and a second mounting hole for receiving therein a bearing which includes an outer ring, an inner ring defining a central hole, and a plurality of rolling balls disposed therebetween; a cylinder fixed to or formed integrally with the base frame; an air storage container provided with one or more outlet tubes (411, 412), and connected and communicated with the cylinder; a gear in mesh with the pinion; and a crank mechanism including a counterweight provided on the gear, a crankpin connected with a piston, and a shaft element having a first end and a second end, wherein the second end has a diameter greater than the first end, thus forming an annular step therebetween, the second end of the shaft element being fixed to a center of the gear, the first end of the shaft element being inserted through the central hole of the inner ring of the bearing and being hitted by a striking tool to form an expanded or flared edge on a top face of the first end of the shaft element, so that the bearing is firmly fixed between the expanded or flared edge and the annular step of the shaft element.

2. The air compressor of claim 1, wherein a cutout is defined at the second end of the shaft element to form a non-circular portion to be engaged with a non-circular hole defined at the center of the gear.

3. The air compressor of claim 1, wherein a plurality of equally spaced indentations extending outwardly from a central portion of the top face of the first end of the shaft element are formed by the striking tool in addition to the expanded or flared edge.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] FIG. 1 shows a 3-dimensional view of a main structure of an air compressor.

[0010] FIG. 2 shows a partially exploded view of the main structure of the air compressor.

[0011] FIG. 3 shows a schematic working view of the present invention, wherein a striking tool is employed to hit one end of a shaft element for fixing a bearing in place.

[0012] FIG. 4 shows a 3-dimensional view of the striking tool.

[0013] FIG. 5 shows a partial sectional view of the main structure of the air compressor, wherein the striking tool is approaching the shaft element to conduct a hitting operation.

[0014] FIG. 6 shows a partial sectional view of the main structure of the air compressor, wherein the striking tool has completed the hitting operation.

[0015] FIG. 7 shows a partial exploded view of a main structure of a prior-art air compressor.

[0016] FIG. 8 shows a partial exploded view of a main structure of a second prior-art air compressor.

[0017] FIG. 9 shows an exploded view of a third prior-art air compressor.

[0018] FIG. 10 shows a schematic plan view of the third prior-art air compressor, wherein the motion path of the piston is indicated by dashed lines.

[0019] FIG. 11 shows a schematic view of the motion paths of the crankshaft and the crankpin used in a prior-art air compressor.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0020] FIGS. 1 and 2 show a main structure of a typical air compressor, through which a method of mounting a bearing to an air compressor, which is especially used together with a sealant dispenser for repairing a punctured tire, will be illustrated. As shown, the air compressor, indicated by reference numeral 2, generally includes a base frame 3, a cylinder 4 with an air storage container 41, a gear 5, and a crank mechanism including a counterweight (not shown), a crankpin (not labeled) connected with a piston (not shown), and a shaft element 52.

[0021] The base frame 3 defines a first mounting hole 31, which allows a pinion (not shown) driven by a motor (not shown) to pass, and a second mounting hole 32 for receiving therein a bearing 6 which has an outer ring 61, an inner ring 62, and a plurality of rolling balls 63 disposed therebetween (see FIG. 5).

[0022] The cylinder 4 is fixed to or formed integrally with the base frame 3. The air storage container 41 is provided with one or more outlet tubes 411, 412, and connected and communicated with the cylinder 4. The outlet tubes 411, 412 can be connected with a hose, a relief valve, or a pressure gauge.

[0023] The gear 5 is disposed in mesh with the pinion (not shown). The counterweight (not shown) is provided on the gear 5. The shaft element 52, which serves as a crankshaft for the air compressor 2, can be made of a metal or alloy and has a first end and a second end opposite to the first end, wherein the second end has a diameter greater than the first end, thus forming an annular step 521 therebetween. The shaft element 52 has a circular top face 523 on its first end, and defines a cutout 522 at its second end so that the second end can be shaped as a non-circular portion, such as a semicircular portion. The gear 5 defines at its center a non-circular hole, such as a semicircular hole, corresponding to the non-circular portion formed at the second end of the shaft element 52.

[0024] The method of the present invention comprises the following steps:

[0025] Step 1: fixing the second end of the shaft element 52 to a center of the gear 5; for example, the second end of the shaft element 52 being snugly fitted into the corresponding hole defined at the center of the gear 5;

[0026] Step 2: inserting the first end of the shaft element 52 through the central hole of the bearing 6 to have the annular step 521 of the shaft element 52 abutted the inner ring 62 of the bearing 6 (see FIG. 5); and

[0027] Step 3: hitting the first end of the shaft element 52 by a striking tool 7 to form an expanded or flared edge 524 on the top face 523 of the first end of the shaft element 52 (see FIG. 6.); as a result, the bearing 6 can be firmly fixed between the expanded edge 524 and the annular step 521 of the shaft element 52.

[0028] To facilitate forming an expanded or flared edge on the first end of the shaft element 52, it is preferred that, as shown in FIG. 4, the striking tool 7 includes a shank having a press head 71 at one end defining a central recess 73 and provided with an annular protrusion 74 around the central recess 73 and a plurality of radial protrusions 75 spaced at equal intervals and extending outwardly from the annular protrusion 74 to form a plurality of flat surface sections 72 between the radial protrusions 75. With the tool, a plurality of equally spaced indentations extending outwardly from a central portion of the top face 523 of the first end of the shaft element 52 can be formed by the radial protrusions 75 of the striking tool 7 in addition to the expanded or flared edge 524.

[0029] By using the method of the present invention, the bearing 6 can be firmly mounted with the shaft element 52 in the second mounting hole 32 to prevent damages, and the reciprocating motion of the piston 14 can follow its normal straight path. An air compressor, in which the bearing associated with the crankshaft is mounted according to the method of the present invention, the piston thereof can conduct reciprocating motion more smoothly, and thus the performance and service life of the air compressor can be increased.

[0030] As a summary, the present invention provides a method of mounting a bearing to an air compressor, and an air compressor, in which a bearing is mounted by using the method. By using a striking tool hitting one end of a shaft element, the bearing can be firmly fixed between an expanded or flared edge and an annular step of the shaft element.