Claims:WE CLAIM:

1. A system (200) for inserting a circlip (60) in an axle shaft assembly (100), the system (200) being used with an existing workstation (300) of a previous operation, the existing workstation (300) having a pressing machine (220) and a fixture (260), the pressing machine (220) having a hydraulic ram, the fixture (260) having a base (230), a dolly locator (240) positioned on the base (230) and a pressing dolly (250) pressing the dolly locator (240) on the base (230), the system (200) comprising:
• a bottom locator (110) replacing the dolly locator (240) from the base (230) of the fixture (260) during a circlip fitment operation, the bottom locator (110) allowing a bearing carrier sub-assembly (90) of the axle shaft assembly (100) to be placed thereon;
• a circlip locator (120) placed onto the bearing carrier sub-assembly (90) during the circlip fitment operation to have a locating diameter thereof and an inner reducing taper side thereof positioned onto a bearing carrier for inserting and locating the circlip (60) thereon from a top side of the circlip (60); and
• a circlip pressing dolly (140) placed from a top side onto the circlip locator (120) for being moved therein in a downward direction by a hydraulic ram of the pressing machine (220) to engage with the bottom locator (110) and locate on the base (230) of the fixture (260), the bottom locator (110) allowing the circlip pressing dolly (140) to move in vertical direction only, the circlip pressing dolly (140) having an external taper for moving the circlip (60) therewith in a downward direction inside the circlip locator (120), the circlip (60) upon reaching the inner reducing taper side of the circlip locator (120) collapses therein to enter inside the bearing carrier wherein the circlip (60) expands again as per design requirement thereby positioning at a centre of the bearing carrier.

2. The system (200) as claimed in claim 1, wherein the circlip pressing dolly (140) is located on a central guide block of the base (230) of the fixture (260) during the downward movement thereof.
3. A method (400) for inserting a circlip (60) in an axle shaft assembly (100), the method (400) comprising the steps of:
• replacing a dolly locator (240) from a base (230) of a fixture (260) of an existing workstation (300) of a previous operation with a bottom locator (110);
• placing a bearing carrier sub assembly (90) of the axle shaft assembly (100) on the bottom locator (110);
• placing a circlip locator (120) onto the bearing carrier sub assembly (90);
• inserting the circlip (60) from a top side thereof into middle of the circlip locator (120);
• inserting a circlip pressing dolly (140) from a top side in the circlip locator (120); and
• pressing and moving the circlip pressing dolly (140) in the circlip locator (120) in a vertically downward direction by a hydraulic ram of a pressing machine (220) of the existing workstation (300) to engage the circlip pressing dolly (140) with the bottom locator (110) thereby locating the circlip pressing dolly (140) on the base (230) of the fixture (260), the bottom locator (110) allowing the circlip pressing dolly (140) to move in vertical direction only, the circlip pressing dolly (140) pushing the circlip (60) downwards therewith inside the circlip locator (120), the circlip (60) upon reaching the inner reducing taper side of the circlip locator (120) collapses therein to enter inside the bearing carrier wherein the circlip (60) expands again as per design requirement thereby positioning at a centre of the bearing carrier.

4. The method (400) as claimed in claim 3, wherein the circlip locator (120) is placed onto the bearing carrier sub-assembly (90) to locate the locating diameter thereof and the inner reducing taper side thereof onto the bearing carrier and to have the circlip fitment position on top side.

5. The method (400) as claimed in claim 3, wherein the circlip pressing dolly (140) is located on a central guide block of the base (230) of the fixture (260) during the downward movement thereof.

6. The method (400) as claimed in claim 3, wherein the circlip pressing dolly pushes down the circlip (60) therewith by using an external taper thereof.

Dated this 29th day of June, 2017

Priya Pandey
(Agent for Applicant)
IN/PA-2018 , Description:FIELD OF THE INVENTION

The present invention generally relates to a rear axle assembly of a vehicle, and more particularly to a system and a method for inserting a circlip in an axle shaft assembly.

BACKGROUND OF THE INVENTION

In general practice, circlip fitment is done either with a conventional circlip plier or with a special purpose machine in an automobile industry. Many patented and currently available systems such as those disclosed in Chinese patent publications: CN202934518 U and CN2889599Y are suitable for external circlip applications. However, such systems need high capital investments. Another Chinese patent publication: CN104723052 discloses a complex spring fixture which is not suitable for application.

The manual circlip insertion with conventional plier has several drawbacks, first being that the process is completely dependent on associate’s skill and efforts. The cycle time for fitment of each circlip varies depending on the associate’s skill and this variability in cycle time together with interrupted assembly availability affects mass production process flow. Further, the manual process is a highly unsafe process as the associate uses the plier with one hand and holds the circlip by other hand to avoid flying / slipping thereof which if occurs may hit the associate with high velocity and force causing potential damage. Besides requiring extra manpower deployment, circlip fitment also requires a separate workstation which includes space for fitment, storage trolley etc.

Accordingly, there exists a need to provide a system and a method for inserting a circlip in an axle shaft assembly that overcomes the above mentioned drawbacks of the prior art.

OBJECT OF THE INVENTION

An object of the present invention is to safely fit a circlip on an axle shaft assembly in a fast and fixed cycle time without requiring extra manpower or a separate workstation.

SUMMARY OF THE INVENTION

Accordingly, in an aspect, the present invention provides a system for inserting a circlip in an axle shaft assembly. The system is used with an existing workstation of a previous operation. The existing workstation includes a pressing machine and a fixture. The pressing machine includes a hydraulic ram. The fixture includes a base, a dolly locator positioned on the base and a pressing dolly for pressing and positioning the dolly locator on the base. The system comprises a bottom locator, a circlip locator and a circlip pressing dolly.

The bottom locator replaces the dolly locator from the base during a circlip fitment operation. The bottom locator allows a bearing carrier sub-assembly of the axle shaft assembly to be placed thereon.

The circlip locator is placed onto the bearing carrier sub-assembly during the circlip fitment operation to have a locating diameter thereof and an inner reducing taper side thereof positioned onto a bearing carrier for inserting and locating the circlip thereon from a top side of the circlip.

The circlip pressing dolly is placed from a top side onto the circlip locator for being moved therein in a downward direction by a hydraulic ram of the pressing machine to engage with the bottom locator and locate on a central guide block of the base of the fixture. The bottom locator allows the circlip pressing dolly to move in vertical direction only. The circlip pressing dolly includes an external taper for moving the circlip therewith in a downward direction inside the circlip locator. The circlip upon reaching the inner reducing taper side of the circlip locator collapses therein to enter inside the bearing carrier wherein the circlip expands again as per design requirement thereby positioning at a centre of the bearing carrier.

Accordingly, in another aspect, the present invention provides a method for inserting the circlip in the axle shaft assembly.

BRIEF DESCRIPTION OF THE DRAWINGS

Other features as well as the advantages of the invention will be clear from the following description.
In the appended drawings:
Figure 1 shows an assembly view of an axle shaft assembly with a circlip fitted therein, in accordance with the present invention;

Figure 2 shows a side-view of an existing workstation used for circlip fitment, in accordance with the present invention;

Figure 3 shows details of a system for inserting the circlip into the axle shaft assembly, in accordance with the present invention;

Figures 4-7 show pictorial illustrations of various steps of a method for inserting the circlip into the axle shaft assembly, in accordance with the present invention; and

Figure 8 shows a flowchart illustrating the method of inserting the circlip into the axle shaft assembly, in accordance with the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The foregoing objects of the present invention are accomplished and the problems and shortcomings associated with the prior art, techniques and approaches are overcome by the present invention as described below in the preferred embodiment.

The present invention provides a system and a method for inserting a circlip in an axle shaft assembly. The system and the method safely fit the circlip on the axle shaft assembly in a fast and fixed cycle time without requiring extra manpower or a separate workstation.

The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers indicate corresponding parts in the various figures.

Referring to figures 1 - 3, in an aspect, a system (200) for inserting a circlip (60) in an axle shaft assembly (100), in accordance with the present invention is shown.

The axle shaft assembly (100) comprises an axle shaft (10), wheel bolts (15), a bearing carrier oil seal (20), a bearing carrier (not numbered), a bearing carrier housing (25), a bearing (30), a locknut (35), a lock washer (40), bearing carrier bolts (6 no.s) (45), a plain washer (50), the circlip (60) and an anti-lock braking sensor (ABS) ring (70) as shown in figure 1. Specifically, the bearing carrier, the bearing carrier oil seal (20), the bearing carrier housing (25), the bearing (30) and the bearing carrier bolts (6 no.s) (45) form a bearing carrier sub assembly (90) of the axle shaft assembly (100). The bearing carrier sub assembly (90) is assembled onto the axle shaft (10). The bearing carrier sub assembly (90) starts with pressing the bearing (30) into the bearing carrier followed by pressing of the bearing carrier oil seal (20) and pressing of the 6 bearing carrier bolts (45) from the opposite side, and lastly the circlip (60) is pressed on the bearing carrier.

Specifically, the system (200) is a circlip pressing fixture/apparatus for inserting or arranging the circlip (60), particularly an internal circlip into the bearing carrier sub-assembly (90) of the axle shaft assembly (100) using an existing workstation/setup (300) of a previous circlip fitment operation as shown in figure 2.

The existing workstation (300) comprises a pressing machine (220) and a fixture (260) for the bearing carrier sub assembly (90) before fitment of the circlip (60). The pressing machine (220) includes a hydraulic ram (not shown) configured therein. The fixture (260) includes a base (230), a dolly locator (240) and a pressing dolly (250) configured thereon. The base (230) has a central guide block (not numbered) configured therein to hold the system (200) in place i.e. on top of the base (230) during a circlip fitment operation. The dolly locator (240) is pressed and positioned on the base (230) of the fixture (260) by the pressing dolly (250) of the fixture (260). Thus, figure 2 shows a previous setup before pressing the circlip (60). In this setup, the bearing carrier sub assembly (90) is made and subsequently used in circlip setup as a next operation.

The system (200) comprises a bottom locator (110), a circlip locator (120), and a circlip pressing dolly (140) as shown in figure 3.

During the circlip fitment operation, the bottom locator (110) replaces the existing dolly locator (240) of the previous operation. This is required due to a 180 degrees change in position of the bearing carrier sub assembly (90) for circlip fitment. Thereafter, the bearing carrier sub assembly (90) is placed on the bottom locator (110).

The circlip locator (120) is placed onto the bearing carrier sub-assembly (90) during the circlip fitment operation. Specifically, the circlip locator (120) is placed onto the bearing carrier sub-assembly (90) in such a way that a locating diameter thereof and an inner reducing taper side (not numbered) thereof are located onto the bearing carrier. The inner reducing taper side is configured at a bottom end (not numbered) of the circlip locator (120) which rests just above the bearing carrier. The circlip locator (120) once placed on the bearing carrier sub-assembly (90) serves to insert and locate the circlip (60) thereon from a top side. In other words, the circlip (60) is placed from the top side onto the locator (120).

The circlip pressing dolly (140) is placed from a top side thereof onto the circlip locator (120) for being moved therein in a downward direction by the hydraulic ram of the pressing machine (220). The downward movement of the circlip pressing dolly (140) results in engagement thereof with the bottom locator (110) and thus locating the circlip pressing dolly (140) on the base (230) of the fixture (260) and more specifically on the central guide block of the base (230) of the fixture (260). The bottom locator (110) allows the circlip pressing dolly (140) to move precisely in vertical direction only.

The circlip pressing dolly (140) while moving downward causes downward movement of the circlip (60) inside the circlip locator (120). Specifically, the circlip pressing dolly (140) includes an external taper (not numbered) for moving the circlip (60) in downward direction. The circlip (60) upon reaching the inner reducing taper side of the circlip locator (120) shrinks and collapses to enter inside the bearing carrier, wherein the circlip (60) expands again as per design requirement thereby installing and positioning itself exactly at the center of the bearing carrier.

The operation of circlip fitment is described herein as follows: For fitting the circlip (60) into the axle shaft assembly (100), an associate first replaces the existing dolly locator (240) with the new bottom locator (110) thus placing the bottom locator (110) on existing base (230) used in previous operation. Thereafter the associate assembles the bearing carrier sub-assembly (90) on the bottom locator (110). Thereafter, the circlip locator (120) is placed on the bearing carrier sub assembly (90) on which the circlip (60) is to be assembled. The circlip (60) is inserted from top inside the circlip locator (120). Thereafter, the circlip pressing dolly (140) is inserted from top side on the circlip locator (120) for being moved downward therein by the hydraulic ram of the existing pressing machine (220) such that the circlip pressing dolly (140) engages with the bottom locator (110). The bottom locator (110) allows the circlip pressing dolly (140) to move precisely in vertical direction only and locate on the base (230) of previous operation. The downward movement of the circlip pressing dolly (140) causes the circlip (60) to move down and collapse in the circlip locator’s inner reducing taper side to enter inside the bearing carrier. The circlip (60) once inserted in the bearing carrier expands again as per design requirement and installs and positions itself at the centre of the bearing carrier.

Referring now to figures 4 - 8, in another aspect, a method (400) for inserting the circlip (60) in the axle shaft assembly (100), in accordance with the present invention is shown. Specifically, the method (400) is described in conjunction with the system (200) of figures 1-3. The method (400) begins at step (310).

At step (320) (refer figure 4), the method (400) involves replacing the existing dolly locator (240) with the bottom locator (110) while using the base (230) and the pressing machine (220) of the previous operation as it is.

At step (330) (refer figure 4), the method (400) involves placing the bearing carrier sub assembly (90) of the axle shaft assembly (100) on the bottom locator (110).

At step (340), (refer figure 4) the method (400) involves placing the circlip locator (120) onto the bearing carrier assembly (90) on which the circlip (60) is to be assembled. The circlip locator (120) is placed onto the bearing carrier sub-assembly (90) such that the locating diameter thereof is located onto the bearing carrier so that the circlip fitment position is on top side.

At step (350) (refer figure 5), the method (400) involves inserting the circlip (60) from the top side thereof into the middle of the circlip locator (120).

At step (360) (refer figure 6), the method (400) involves inserting the circlip pressing dolly (140) in the circlip locator (120).

At step (370) (refer figure 7), the method (400) involves pressing and moving the circlip pressing dolly (140) in the circlip locator (120) in a vertically downward direction by pushing the hydraulic ram of the pressing machine (220) in downward direction. The downward movement engages the circlip pressing dolly (140) with the bottom locator (110) and thus locates the circlip pressing dolly (140) on the base (230) of the fixture (260). Specifically, the circlip pressing dolly (140) is located on the central guide block of the base (230) of the fixture (260). The bottom locator (110) allows the circlip pressing dolly (140) to move in vertical direction only. The circlip pressing dolly (140) pushes the circlip (60) downwards therewith inside the circlip locator (120) using the external taper thereof. The circlip (60) upon reaching the inner reducing taper side of the circlip locator (120) collapses/shrinks therein while retaining a circlip diameter enough to enter the bearing carrier wherein the circlip (60) expands again as per design requirement thereby positioning at a centre of the bearing carrier as shown in figure 7. Thus, at the end of stroke, the circlip (60) opens up and fits into the assembly location. The method (400) ends at step (380).

ADVANTAGES OF THE INVENTION

1. The system (200) and the method (400) provide a safe working zone by achieving deskilling i.e. by eliminating human skill dependency for circlip fitment and overcoming the manual insertion process.
2. The system (200) and the method (400) provide fast and fixed cycle time for fitment of each circlip (60).
3. The system (200) and the method (400) do not require creation of a new stage/workstation and extra manpower. The fitment of the circlip (60) is achieved with the previous assembly stage or existing workstation (300), wherein existing stage facility (300) like the pressing machine (220) and the fixture (260) are used as it is with a new top locator in the form of the bottom locator (110) and the dolly concept for circlip insertion. Thus, there is no change in the pressing machine (220) and the fixture (260) to adopt new circlip pressing apparatus as a top tooling.

The foregoing descriptions of specific embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the present invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teaching. The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, and to thereby enable others skilled in the art to best utilize the present invention and various embodiments with various modifications as are suited to the particular use contemplated. It is understood that various omissions and substitutions of equivalents are contemplated as circumstances may suggest or render expedient, but such omissions and substitutions are intended to cover the application or implementation without departing from the spirit or scope of the claims of the present invention.