Claims:We claim:

1. A fixture for pressing bearings in a crankshaft for automotive engines, the fixture comprising:

• a metallic C-section plate for supporting the crankshaft web and the metallic C-section plate;

• a hardened dolly with a boss for supporting the crankshaft bearing thereon;

• a guide fitted between the C-section plate and the middle plate for aligning the crankshaft bearing;

• a middle plate for supporting the hardened dolly;

• a plurality of extension blocks disposed between the C-section plate and middle plate;

• a hydraulic cylinder mounted on a base plate and extends therefrom for supporting the middle plate and the C-section plate by appropriate stiffeners;

• a Teflon C-section plate fixed on the metallic C-section plate for cushioning both the crankshaft web and the C-section plate;

• a handle fitted on the crankshaft; and

• a locating pin for proper alignment of the fixture;

wherein the fixture is mounted on a suspended spring balancer and after fitting the bearing on the dolly, the fixture is adjusted on the suspended spring balancer by means of the handle provided on the crankshaft and the fixture is accurately self-aligned by manually engaging the locating pin inside the locating hole of the crankshaft and thereafter the hydraulic cylinder is actuated in a forward movement to press the bearing inside the crankshaft pilot bearing hole.

2. Fixture as claimed in claim 1, wherein the hardened dolly slid inside a bush inserted fitted in the middle plate.
3. Fixture as claimed in claim 1, wherein the extension blocks are selected and disposed between the metallic C-section plate and middle plate for providing the required gap between these plates and for supporting the flywheel side flange of the crankcase.

4. Fixture as claimed in claim 1, wherein the journal of the crankshaft bearing is loaded inside the C-section plate with a plurality of brass bushes placed into the inner faces thereof, to avoid any metal to metal contact of the journal of the crankshaft bearing with the C-section plate.

5. Fixture as claimed in claim 4, wherein the C-section plate is loaded with at least one bush each on either side and at the bottom thereof.

6. Fixture as claimed in claim 1, wherein the crankshaft and pilot bearing are aligned inside the dolly by means of the hydraulic compact cylinder applying a required force therefor.

7. Fixture as claimed in claim 1, wherein the hardened dolly is engaged with the thread stud in the piston rod of the hydraulic cylinder.

8. Fixture as claimed in claim 6, wherein the crankshaft bearing is aligned by means of the guide using the dolly.

9. Fixture as claimed in claim 1, wherein the internal diameter of the bearing has the same internal diameter as that of the boss of the dolly for guiding the bearing concentric with respect to the center of the crankshaft bearing counter.

10. A method for pressing a crankshaft bearing by means of a fixture as claimed in anyone of the claims 1 to 9, the method comprises the steps of:

(a) fitting the bearing inside the dolly bush;

(b) adjusting the fixture on the suspended spring balancer by the handle provided on the crankshaft for adjusting a self-alignment of the fixture;
(c) manually engaging a locating pin inside the locating hole of the crankshaft;

(d) aligning the bearing before press-fitting thereof inside the dolly fitted with bush inside thereof; the aligning step comprises the sub-steps of:

(i) loading the crankshaft bearing journal inside the C-section plate fitted with the plurality of brass bush supports for avoiding any metal to metal contact of the journal of the crankshaft bearing;

(ii) locating the flywheel side flange of the crankcase between the C-section plate and the middle plate;

(iii) assembling a plurality of extension blocks between the C-section plate and the middle plate for providing an adequate gap and for supporting the flywheel side flange of the crankcase;

(v) engaging the hardened dolly with the thread stud of the hydraulic cylinder piston rod; and

(f) pressing the bearing by means of the hydraulic cylinder attached to the fixture; the pressing step comprises the sub-steps of:

(I) applying the required force by means of the hydraulic compact cylinder after aligning the crankshaft and pilot bearing inside the dolly; and

(II) guiding the bearing concentric with respect to the center of the crankshaft bearing counter for pressing the crankshaft bearing in place.

Dated: this day of 31st December, 2016. SANJAY KESHARWANI
APPLICANT’S PATENT AGENT , Description:FIELD OF INVENTION

The present invention relates to a mechanical system for pressing bearings in machined components. In particular, the present invention relates to a system for pressing bearings in automotive engines. More particularly, the present invention relates to a fixture for pressing bearings in crankshafts in automotive engines.

BACKGROUND OF THE INVENTION

In engine assembly, conventionally the roller bearing is press-fitted manually with the help of a hammer and dolly set. Sometimes, it results in a skew fitment of the bearing. So, the transmission input shaft assembly is not possible. In terms of skew fitment, the roller bearing must be pulled out by using a bearing puller and to be fitted again. This further distorts the pilot bearing location.

The crankshaft fits with the pilot ball bearing to support the end of the transmission input shaft, which includes a small journal machined on the end thereof. This journal slides inside the pilot bearing. The pilot bearing prevents the transmission shaft and the clutch disc from wobbling up and down, when the clutch is released. It also assists the input shaft in centering the disc on the flywheel.

PRIOR ART

CN 102152098 A discloses a crankcase bearing pressing tool. The lower end of a stand column is fixed to a positioning plate; the axis line of the stand column is vertical to the plate surface of the positioning plate; a first pressing shaft is arranged on one side of the stand column, and a second pressing shaft is arranged on the other side of the stand column; the upper ends of the first pressing shaft and the second pressing shaft are fixed to the positioning plate; the bottom face of the first pressing shaft and the bottom face of the second pressing shaft are abreast basically; the axis lines of the first pressing shaft, the second pressing shaft and the stand column are parallel to one another; the first pressing shaft is tightly leaned to the stand column; and the distance between the first pressing shaft and the stand column is less than the distance between the stand column and the second pressing shaft. However, the document discloses the use of two pressing shafts for pressing the crankshaft bearing.

WO 2003091011 A1 discloses a support adaptor assembly for a bearing press comprising a rectangular shaped header plate, a pair of adjustable support rods each with an adaptor on one end for providing a means of supporting an object to be worked on with a bearing press either above or below the support members of the bearing press. However, the construction and working of the bearing pressing mechanism disclosed in this document is quite different from that provided by the present invention.

CN 101733625 B discloses a device for press-fitting crankcase bearing. An upper die plate is arranged above a lower die plate in parallel, the left and right ends of the upper and lower die plates are connected by a guide rod, the upper die plate can move up and down along the guide rod; the center of the upper die plate is opened with a through hole connected with a press machine, the left and right sides of the through hole are respectively provided with a group of pressure head shafts, each group of pressure head shafts are distributed by the position of bearing chamber in the crankcase body, the pressure head shaft is vertical to the upper die plate, the upper end of the pressure head shaft is fixedly connected with the upper die plate, the lower end of the pressure head shaft points at the board of the lower die plate,; and the center at the lower end of the pressure head shaft is provided with a round locating boss. However, the construction and working of the bearing pressing mechanism disclosed in this document is also substantially different from that provided by the present invention.

DISADVANTAGES WITH THE PRIOR ART

However, the problem with the conventional crankshaft bearing pressing arrangements is that on an average, 1 in 20 crankshafts (about 5%) need to be reworked due to such skew fitment of the crankshaft bearing.
Secondly, in the conventional bearing pressing method, the bearing is fitted by using a hammer-dolly set, which may result in unsafe conditions for the personnel carrying out this bearing pressing operation.

Although, the possibility of near miss is quite low due to this manual operation, still there is a probability of unsafe conditions to the operator conducting this method.

Therefore, there is an existing need to develop a foolproof method for pressing bearings, e.g. in crankshafts of automobile engines, which avoids or rather eliminates the skewed fitting of bearings therein. This would also lead to reduced or even zero reworking of the bearing pressing. Moreover, this also requires safer working conditions for the operator carrying out the bearing pressing operations, which are likely due to manual bearing pressing by using hammer-dolly sets.

OBJECTS OF THE INVENTION

Some of the objects of the present invention - satisfied by at least one embodiment of the present invention - are as follows:

An object of the present invention is to provide a safer bearing pressing mechanism for automotive components, e.g. crankshafts, which does not cause injury to the operators.

Another object of the present invention is to provide a mechanism for conducting bearing pressing operation, e.g. in the automotive engines crankshafts, whereby skewed bearing pressing is avoided or eliminated.

Still another object of the present invention is to provide a mechanism for conducting bearing pressing operation, e.g. in the automotive engines crankshafts, whereby the reworking of the bearing pressing operation is reduced or eliminated.

These and other objects and advantages of the present invention will become more apparent from the following description, when read with the accompanying figures of drawing, which are however not intended to limit the scope of the present invention in any way.

DESCRIPTION OF THE INVENTION

Accordingly, with the self-aligned bearing pressing fixture configured in accordance with the present invention, the skew fitment of the bearing is completely eliminated. This results in zero rework of the bearing pressing operation. This way, the manual hammering is also eliminated, which prevents any unsafe conditions to the operator conducting the bearing pressing. The inventive bearing pressing fixture is light-weight. A large selection of light-weight alloys is available, which are quite user friendly due to such lighter material.

Therefore, the present invention ensures accurate alignment of the crankshaft with the bearing being pressed. This also assures the concentricity of the crankshaft bearing location and the bearing can be properly aligned before press-fitting the bearing at the desired bearing location. Subsequently, the bearing is fitted by using a hydraulic cylinder attached to this fixture.

SUMMARY OF THE INVENTION

In accordance with the present invention, there is provided a fixture for pressing bearings in a crankshaft for automotive engines, the fixture comprising:

• a metallic C-section plate for supporting the crankshaft web and the metallic C-section plate;

• a hardened dolly with a boss for supporting the crankshaft bearing thereon;

• a guide fitted between the C-section plate and the middle plate for aligning the crankshaft bearing;

• a middle plate for supporting the hardened dolly;

• a plurality of extension blocks disposed between the C-section plate and middle plate;

• a hydraulic cylinder mounted on a base plate and extends therefrom for supporting the middle plate and the C-section plate by appropriate stiffeners;

• a Teflon C-section plate fixed on the metallic C-section plate for cushioning both the crankshaft web and the C-section plate;

• a handle fitted on the crankshaft; and

• a locating pin for proper alignment of the fixture;

wherein the fixture is mounted on a suspended spring balancer and after fitting the bearing on the dolly, the fixture is adjusted on the suspended spring balancer by means of the handle provided on the crankshaft and the fixture is accurately self-aligned by manually engaging the locating pin inside the locating hole of the crankshaft and thereafter the hydraulic cylinder is actuated in a forward movement to press the bearing inside the crankshaft pilot bearing hole.

In an embodiment of the present invention, the hardened dolly slid inside a bush inserted fitted in the middle plate.

In an embodiment of the present invention, the extension blocks are selected and disposed between the metallic C-section plate and middle plate for providing the required gap between these plates and for supporting the flywheel side flange of the crankcase.

In an embodiment of the present invention, the journal of the crankshaft bearing is loaded inside the C-section plate with a plurality of brass bushes placed into the inner faces thereof, to avoid any metal to metal contact of the journal of the crankshaft bearing with the C-section plate.

In an embodiment of the present invention, the C-section plate is loaded with at least one bush each on either side and at the bottom thereof.

In an embodiment of the present invention, the crankshaft and pilot bearing are aligned inside the dolly by means of the hydraulic compact cylinder applying a required force therefor.

In an embodiment of the present invention, the hardened dolly is engaged with the thread stud in the piston rod of the hydraulic cylinder.

In an embodiment of the present invention, the crankshaft bearing is aligned by means of the guide using the dolly

In an embodiment of the present invention, the internal diameter of the bearing has the same internal diameter as that of the boss of the dolly for guiding the bearing concentric with respect to the center of the crankshaft bearing counter.

In accordance with the present invention, there is also provided a method for pressing a crankshaft bearing by means of a fixture for pressing bearings in a crankshaft for automotive engines, the method comprises the steps of:

(a) fitting the bearing inside the dolly bush;

(b) adjusting the fixture on the suspended spring balancer by the handle provided on the crankshaft for adjusting a self-alignment of the fixture;

(c) manually engaging a locating pin inside the locating hole of the crankshaft;

(d) aligning the bearing before press-fitting thereof inside the dolly fitted with bush inside thereof; the aligning step comprises the sub-steps of:

(i) loading the crankshaft bearing journal inside the C-section plate fitted with the plurality of brass bush supports for avoiding any metal to metal contact of the journal of the crankshaft bearing;

(ii) locating the flywheel side flange of the crankcase between the C-section plate and the middle plate;

(iii) assembling a plurality of extension blocks between the C-section plate and the middle plate for providing an adequate gap and for supporting the flywheel side flange of the crankcase;

(iv) engaging the hardened dolly with the thread stud of the hydraulic cylinder piston rod; and

(e) pressing the bearing by means of the hydraulic cylinder attached to the fixture; the pressing step comprises the sub-steps of:

(I) applying the required force by means of the hydraulic compact cylinder after aligning the crankshaft and pilot bearing inside the dolly; and

(II) guiding the bearing concentric with respect to the center of the crankshaft bearing counter for pressing the crankshaft bearing in place.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

The present invention will be briefly described with reference to the accompanying drawings.

Figure 1 shows the assembly of the fixture for pressing crankshaft bearings, which is configured in accordance with the present invention.

Figure 2 shows a fixture for pressing crankshaft bearings, which is configured in accordance with the present invention.

Figure 3 shows the home position of the fixture for pressing crankshaft bearings depicted in Figure 2.

Figure 4 shows the pressing condition the fixture for pressing crankshaft bearings depicted in Figure 2 in a forward stroke thereof.

Figure 5 shows a cross-sectional side view of the fixture for pressing crankshaft bearings depicted in Figure 2, depicted before the bearing pressing operation.

Figure 6 shows a cross-sectional side view of the fixture for pressing crankshaft bearings depicted in Figure 2, depicted after the bearing pressing operation.
DETALED DESCRIPTION OF THE ACCOMPANYING DRAWINGS

Figure 1 shows the assembly of the fixture for pressing crankshaft bearings, which is configured in accordance with the present invention. The fixture ensures an accurate alignment of the crankshaft with the bearing being pressed, its concentricity with respect to the crankshaft bearing location. Accordingly, the bearing is aligned before press-fitting thereof and subsequently, the bearing is pressed with the help of a hydraulic cylinder 1 attached to the fixture. The hydraulic compact cylinder 1 is used for applying force, when the crankshaft 17 and pilot bearing are aligned inside the dolly 12. The hydraulic compact cylinder 1 is mounted on the mild steel plate 14 and with proper stiffening and strengthening thereof, it supports the middle plate 3 and metallic C- section LM24 plate 8. The hardened dolly 12 is fitted by sliding inside the bush 16. The hardened dolly 12 is engaged with the thread stud 18 in the piston rod of the hydraulic cylinder 1. The journal of the crankshaft bearing 22 is loaded inside the C-section plate 8 with the brass bush supports, two bushes 7 from both the sides and one bush 21 at the bottom. This is done to avoid any metal to metal contact of the journal of the crankshaft bearing 22. Otherwise, the bearing 22 will not fit properly on the crankshaft bearing journal.

Figure 2 shows the fixture of Figure 1 including a compact hydraulic cylinder 1 mounted on a mild steel plate 14. A flywheel side flange of the crankcase (not shown here) can be properly located between C section plate 8 and the middle plate 3. To avoid any metal to metal contact; a brass bush 7 each is provided on either side at the bottom 21 (Figure 4). The extension blocks 5, 9 and 10 can be assembled between the C-section plate 8 and the middle plate 3 for providing an adequate gap and support for the flywheel side flange of the crankcase (not shown here). A Teflon C-section plate 15 is also screwed to LM 24 material C-section plate 8, which cushions the crankshaft web and the metallic C-section plate 8.

Figure 3 shows the bearing pressing process. Here, the fixture is in its home position for pressing the crankshaft bearing as depicted in Figure 2. Here, the hydraulic cylinder 1 is shown extending from the mild steel plate 14 and by proper stiffeners, it can support middle plate 3 and C- section plate 8. The hardened dolly 12 is fitted by sliding inside the bush 16. The hardened dolly 12 is engaged with the thread stud 18 in the piston rod of the hydraulic cylinder 1. The bearing 22 is fitted in the dolly 12. The bearing can be aligned by means of a guide 19. The alignment is carried out with the help of the dolly 12. Since the internal diameter of the bearing 22 is hollow, the dolly 12 has a boss of the same internal diameter, which guides the bearing 22 concentric with respect to the center of the crankshaft bearing counter. A handle 13 is provided on the crankshaft for adjusting the fixture on the suspended spring balancer. For a proper self-alignment of the fixture, a locating pin 2 can be manually engaged inside the locating hole of the crankshaft.

Figure 4 shows the bearing pressing process. Once the fixture is properly aligned, the hydraulic cylinder 1 is actuated in a forward stroke F thereof for pressing the bearing 22 inside the desired crankshaft pilot bearing hole.

Figure 5 shows a cross-sectional side view of the fixture for pressing crankshaft bearings depicted in Figure 2, depicted before the bearing pressing operation.

Figure 6 shows a cross-sectional side view of the fixture for pressing crankshaft bearings depicted in Figure 2, depicted after the bearing pressing operation.

BEARING PRESSING PROCESS:

The bearing pressing process sequence is shown in Fig 3 and 4, which is as follows:
• Bearing is fitted in the dolly 12.

• Fixture is adjusted on the suspended spring balancer with the help of a handle 13 on the crankshaft.

• Locating pin 2 is manually engaged inside the locating hole of the crankshaft, for proper self-alignment of the fixture.
• Once the fixture is aligned, the hydraulic cylinder 1 is actuated to press the bearing 22 inside the crankshaft pilot bearing hole.
TECHNICAL ADVANTAGES AND ECONOMIC SIGNIFICANCE

The fixture for pressing crankshaft bearings configured in accordance with the present invention has the following technical and economic advantages:

• Saves substantial reworking costs.

• Provides a safer bearing pressing mechanism thus preventing any injury to the operators.

• Avoids/eliminates any skewed bearing pressing.

• Light Weight fixture for user friendly operation and material selection

• Modular design for multimodal application.

• Compact and robust design.

• Elimination of hammer operation.

In the claims and the description, the terms “containing” and “having” are used as linguistically neutral terminologies for the corresponding terms “comprising”. Furthermore, the use of the term “one” shall not exclude the plurality of such features and components described.

Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising”, shall be understood to implies including a described element, integer or method step, or group of elements, integers or method steps, however, does not imply excluding any other element, integer or step, or group of elements, integers or method steps.

The use of the expression “a”, “at least” or “at least one” shall imply using one or more elements or ingredients or quantities, as used in the embodiment of the disclosure in order to achieve one or more of the intended objects or results of the present invention.

The exemplary embodiments described in this specification are intended merely to provide an understanding of various manners in which this embodiment may be used and to further enable the skilled person in the relevant art to practice this invention.

Although, only the preferred embodiments have been described herein, the skilled person in the art would readily recognize to apply these embodiments with any modification possible within the spirit and scope of the present invention as described in this specification.

Therefore, innumerable changes, variations, modifications, alterations may be made and/or integrations in terms of materials and method used may be devised to configure, manufacture and assemble various constituents, components, subassemblies and assemblies according to their size, shapes, orientations and interrelationships.

The description provided herein is purely by way of example and illustration. The various features and advantageous details are explained with reference to this non-limiting embodiment in the above description in accordance with the present invention. The descriptions of well-known components and manufacturing and processing techniques are consciously omitted in this specification, so as not to unnecessarily obscure the specification.

In the previously detailed description, different features have been summarized for improving the conclusiveness of the representation in one or more examples. The exemplary embodiments were selected and described in order to be able to best represent the principles and their possible practical application underlying the invention. However, it should be understood that the above description is merely illustrative, but not limiting under any circumstances. It helps in covering all alternatives, modifications and equivalents of the different features and exemplary embodiments. Many other examples are directly and immediately clear to the skilled person because of his/her professional knowledge in view of the above description.