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Title:
IMPROVED DOUBLE AND TRIPLE CONE SYNCHRONIZER
Document Type and Number:
WIPO Patent Application WO/2018/235093
Kind Code:
A1
Abstract:
An improved synchronizer 1 mainly comprises of a modified outer ring 13; an improved intermediate ring 11 and an improved inner ring 12. Said modified outer ring 13 is steel made outer ring with no frictional surfaces. Said improved intermediate ring 11 further comprises of steel made intermediate body 11a, and a friction cap 14b or inner friction strip 15b and outer friction strip 16b made of Cu-Zn alloy; where an inner face 142a and an outer face 143a of friction cap 14b or inner friction strip 15b and outer friction strip 16b provides friction property. Said improved steel made inner ring 12 comprises of inner body 12a and friction ring 17a on inner face. Said a friction cap 14b or inner friction strip 15b and outer friction strip 16b is pressed to the intermediate body 11a with the help of proper die and punch to form present improved synchronizer.

Inventors:
MAKWANA, Vishal (B-804, Shapath-4Opp. Karnavati Club,S.G.Highway, Ahmedabad 1, 380051, IN)
Application Number:
IN2017/050389
Publication Date:
December 27, 2018
Filing Date:
September 09, 2017
Export Citation:
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Assignee:
TEXSPIN BEARINGS LIMITED (B-804, Shapath-4Opp. Karnavati Club,S.G.Highway, Ahmedabad 1, 380051, IN)
International Classes:
F16D23/02; F16D69/02
Domestic Patent References:
WO2010130366A12010-11-18
WO2008025585A12008-03-06
Foreign References:
DE102012214025A12013-08-29
DE202007004069U12007-05-24
JPH094652A1997-01-07
US4770283A1988-09-13
US4944378A1990-07-31
Attorney, Agent or Firm:
KHURANA, Tarun (Khurana & Khurana Advocates and IP Attorneys, E-13 UPSIDC Site-IV, Behind Grand Venice,Kasna Road,Greater Noida, UP National Capital Region, 380015, IN)
Download PDF:
Claims:
CLAIMS:

1. The present improved synchronizer mainly comprises of a modified outer ring 13; an improved intermediate ring 11 and an improved inner ring 12; wherein:

Said modified outer ring 13 is an outer ring with no frictional surfaces i.e. annular grooves 135 and axial grooves 136 are eliminated; which eliminates the machining part while manufacturing the ring; Said modified outer ring is made of materials including made of stamped steel, cast steel, sinter steel or forged steel;

Said improved intermediate ring 11 further comprises of an

• intermediate body 11a made of steel, and

• a friction cap 14b or inner friction strip 15b and outer friction strip 16b made of Cu-Zn alloy;

wherein, in this hybrid structure, the intermediate body 11a made of stamped steel, cast steel, sinter steel or forged steel provides structural strength where an inner face 142a and an outer face 143a of friction cap 14b or inner friction strip 15b and outer friction strip 16b provides friction property; The said friction surfaces can be provided by means of strips, ring or cap of friction; Said inner and outer face have plurality of axially embossed streaks 144, 152 and 163 to provide friction force on mating member and to provide the means of lubricating oil drainage;

Said improved inner ring 12 comprises of inner body 12a and friction ring 17a on inner face; Said inner body 12a do not have annular and axial grooves; the inner body 12a is made of stamped steel, cast steel, sinter steel or forged steel to provide better structural strength; the friction ring 17a comprises of axially embossed streaks 172 to provide better friction force and purpose of oil drainage.

Wherein further, said improved intermediate ring 11 and inner ring 12 comprised of intermediate body 11a and inner body 12a having least two or more lugs 111 and/or slots 121 to engage corresponding parts.

2. an improved double and triple cone synchronizer; An inner face 142a and an outer face 143a of friction cap 14b or inner friction strip 15b and outer friction strip 16b and friction ring 17a in claim 1 , made of sheet, pipe or bar of Cu-Zn alloy.

3. an improved double and triple cone synchronizer wherein; An inner face 142a and an outer face 143a of friction cap 14b or inner friction strip 15b and outer friction strip 16b and friction ring 17a in claim 1 to 2, made from Cu-Zn alloy, which may be in form of friction cap 14, friction strip 15 and 16 or friction ring 17.

4. An improved double and triple cone synchronizer; wherein;

An inner face 142a and an outer face 143a of friction cap 14b or inner friction strip 15b and outer friction strip 16b and friction ring 17a in claim 1 to 3, having axially formed streaks 144, 152, 163 or 172. The method of fixing the assembly of present improved synchronizer 1 involves following steps: a) Said intermediate ring 11a inserted on friction cap 14 such that the lugs 111 of intermediate ring accommodate in slots 141 of friction cap such that the cone angle of inner face 142 of friction cap 14 and inner face 112 of intermediate body 11a are same so that these face get matched; b) said intermediate ring 1 la and the friction cap 14 is pressed with the help of a die and punch to bend the outer surface 143 to get cone angle of a, which will constrain the relative axial and radial movement of intermediate body with respect to friction cap 14;

Wherein said punch is so designed that its axially protruded plurality of streaks penetrate in friction cap 14 to provide plurality of axially embossed streaks 144;

Wherein further, when the friction strips are mechanically attached to the intermediate body, the steps involved are: a) The inner friction strip 15 is bended to form inner friction strip 15a ; said inner friction strip 15a, comprising of flange 151, is then inserted in the intermediate body 11a to constrain relative axial movement of intermediate body 11a and inner friction strip 15a in one direction; After inserting inner friction strip 15a in intermediate body 11a, the assembly of both an intermediate body 1 la and an inner friction strip 15a is to be pressed with the help of proper die and punch to constrain the axial and radial movement of inner friction strip 15b and intermediate body 11a ; an outer friction strip 16 comprises of slots 161 is bended to form inner friction strip 16a; said outer friction strip 16a, comprises of flange 162, is then inserted in the intermediate body l lasuch that the slots 161 accommodate with lugs 111 of intermediate body 11a, to constrain relative axial movement of intermediate body 11a and inner friction strip 16a in one direction;

After this the assembly of both an intermediate body 11a and an outer friction strip 16a is to be pressed with the help of proper die and punch to constrain the axial and radial movement of outer friction strip 16b with respect to intermediate body 11a;

Wherein said punch is so designed that its protruded streaks penetrate in outer friction strip 16b to provide axially embossed streaks 163 for better friction force intermediate ring 11;

Wherein the steps for joining the inner ring to the intermediate body involves the following steps: the friction ring 17 is inserted in the inner body 12a; said outer friction strip 17 is inserted in the inner body 12a such that the projections 171 accommodate with slots 121 of inner body 12a, to constrain relative axial movement of inner body 11a and friction ring 17 in one direction;

After this the assembly of both inner body 12a and an friction ring 17 is to be pressed with the help of proper die and punch to constrain the axial and radial movement of friction ring 17a with respect to inner body 11a said punch is so designed that its axially protruded streaks penetrate in friction ring 17a to provide axially embossed streaks 172 for better friction force to inner ring 11.

AMENDED CLAIMS

received by the International Bureau on 29 May 2018 (29.05.2018)

We Claim:

1. A synchronizer for transmission assembly, the synchronizer comprising:

an outer ring (13) having an inner conical surface;

an intermediate ring( 11) having an outer conical surface adapted to engage with the inner conical surface of the outer ring (13), and an inner conical surface; and

an inner ring(12) having an outer conical surface adapted to engage with the inner conical surface of the intermediate ring (11); wherein the intermediate ring (11) is made up of an intermediate body (11a) and a friction cap (14); the intermediate body having an inner conical surface (112) and an outer conical surface (113), the inner conical surface and the outer conical surface defining a larger first side and a smaller second side, with the first side incorporating a plurality of circumferentially spaced lugs (111) extending in axial direction; wherein the friction cap (14) is having a generally U shaped cross section, the U shape aligned generally in direction of axis of the intermediate ring (11) and having a closed side and an open side; the closed side having a plurality of circumferentially spaced slots (141) in positions matching the plurality of lugs (111) on the intermediate body (11a) and sized to receive the plurality of lugs (111); and wherein the U shaped cross section of the friction cap (14) envelopsat least a part of the first side, the inner conical surface (112) and the outer conical surface(113) of the intermediate body (11a) with the plurality of lugs (111) of the intermediate body passing through the plurality of slots (141) of the friction cap (14); and wherein engagement of the plurality of lugs with the plurality of slots provides mechanical bonding between the intermediate body and the friction cap.

2. The synchronizer as claimed in claim 1, wherein the inner conical surface of the outer ring (13) and the outer conical surface of the inner ring (12) are characterized by absence of any friction causing features.

3. The synchronizer as claimed in claim 1, wherein the intermediate body (1 la) is made of a material selected out of group consisting of stamped steel, cast steel, sinter steel and forged steel.

4. The synchronizer as claimed in claim 1, wherein the friction cap(14) is made of a Cu- Zn alloy.

5. The synchronizer as claimed in claim 1, wherein the friction cap (14) comprises an inner portion and an outer portion, the inner portion and the outer portion being two generally parallel sides of the generally U shaped cross section; and wherein the inner portion has an inner face (142a), and theouter portion has an outer face (143a), the inner face and the outer faceincorporating embossed streaks (144).

6. The synchronizer as claimed in claim 1 , wherein the plurality of lugs (111) on the first side of the intermediate body (11a) are adapted to engage with a corresponding part of the transmission.

7. The synchronizer as claimed in claim 1, wherein the inner ring (12) is made up of an inner body (12a) and a friction ring (17a); the inner body having an outer conical surface that works as the outer conical surface of the inner ring (12); and further having an inner conical surface which is enveloped by the friction ring (17a).

8. The synchronizer as claimed in claim 7, wherein one side of the friction ring (17a) incorporates a plurality of outward radial projections (171) that engage with a plurality of slots (121) on a corresponding end face of the inner body (12a) to restrain relative rotation between the inner body (12a) and the friction ring (17a).

9. The synchronizer as claimed in claim 7, wherein the inner body (12a) is made of any of stamped steel, cast steel, sinter steel or forged steel; and wherein the friction ring (17a) is made of a Cu-Zn alloy, and incorporates embossed streaks (172) on an inner face to provide friction and for purpose of oil drainage.

10. A method for manufacturing an intermediate ring (11) of a synchronizer for transmission, the method comprising the steps of: manufacturing a steel intermediate body ( 11 a) by any of the stamping, casting, sintering or forging process; the intermediate body having an inner conical surface (112) and an outer conical surface (113), the inner conical surface and the outer conical surface defining a larger first side and a smaller second side, with the first side incorporating a plurality of circumferentially spaced lugs (111) extending in axial direction; manufacturing a friction cap (14) from a sheet or bar or pipeof a Cu-Zn alloy, the friction cap having an inner portion of conical shape having same cone angle as the inner conical surface (112)of the intermediate body (11a), and an outer portion that is parallel to axis of the intermediate ring; the inner portion and the outer portion connected to each other at a closed side thus forming a generally U shaped cross section of the friction cap (14), with an open side opposite the closed side; wherein the closed side incorporates a plurality of circumferentially spaced slots (141) in positions matching the plurality of lugs (111) on the intermediate body (11a) and sized to receive the plurality of lugs (111); inserting the intermediate body (1 la) in the friction cap (14) through the open side with the first side of the intermediate body entering the U shaped cross section first, such that the plurality of luges (111) engage with and pass through the plurality of slots (141) of the friction cap (14) till the first end of the intermediate body (11a) rests against inner side of the closed end of the friction cap (14), and an inner face of the inner portion of the friction cap (14)rests against the inner conical surface (112) of intermediate body; pressing the friction cap (14)against the intermediate body(l la) using a die and punch to bend the outer portion to an angle that matches cone angle of the outer conical surface (113) of the intermediate body (11a) to restrain the relative axial and radial movement of between the intermediate body (1 la)and the friction cap (14);

11. The method as claimed in claim 10, wherein the method further comprises a step ofgenerating plurality of embossed streaks (144) on outer surfaces(142a and 143a) of the inner portion and the outer portion of the friction cap (14), wherein the die and punch used for bending the outer portion, are adapted to simultaneously generate the plurality of embossed streaks.

12. The method as claimed in claim 10, wherein the method further comprises a step of providing a plurality of embossed axial streaks (114) on the inner conical surface 112 and the outer conical surface (113) of the intermediate body (11a), wherein the plurality of embossed axial streaks (114) are adapted to restrain relative movement between the friction cap (14) and the intermediate body(l la).

13. A method for manufacturing aring of a synchronizer for transmission, the method comprising the steps of:

manufacturing a inner body (12a) by any of the stamping, casting, sintering or forging process; the inner body having an inner conical surface, the inner conical surface defining a larger first side and a smaller second side, with the second side incorporating a plurality of circumferentially spaced slots (121);

manufacturing a friction ring(17) from a sheet or bar or pipe or forging of a Cu- Zn alloy, the friction ring(17) having acylindrical shape sized to facilitate entry into the innerbody(12a) from the second side of the inner body; the friction ring,on one side, incorporates a plurality of circumferentially spaced, outwardly extending radial projections (171) in positions matching the plurality of circumferentially spaced slots(121) and sized to fit within the plurality of slots (121);

inserting the friction ring(17) in the inner body(12a) through the second side till the plurality of projections (171) engage with the plurality of slots (121) in the inner body (12a);

pressing the friction ring(17) against the inner conical surface of the inner body (12a) using a die and punch to bend the friction ring(17) to an angle that matches cone angle of the inner conical surface of the inner body (12a) to restrain the relative axial and radial movement of between the inner body and the friction ring.

14. The method as claimed in claim 13, wherein the method further comprises a step of generating plurality of embossed streaks (172) on inner surface of the friction ring (17), wherein the die and punch used for bending the friction ring, are adapted to simultaneously generate the plurality of embossed streaks (172).

15. The method as claimed in claim 13, wherein the ring is an inner ring (12) of the synchronizer.

Description:
IMPROVED DOUBLE AND TRIPLE CONE

SYNCHRONIZER"

FIELD OF THE INVENTION:

The present invention relates to improved double and triple cone synchronizer. More particularly, the present invention relates to an improved double and triple cone synchronizer which involves mechanical method of joining of friction surface and ring providing a mechanically combined brass-steel components; in particular the intermediate ring and the inner ring of the double and triple cone synchronizer; such that the obtained synchronizer is light in weight yet having high structural strength, easy to manufacture, and is cost effective.

Moreover, said light weight synchronizer achieves the requisite decrease in moment of inertia and decreased requirement of shifting force while synchronization. The process also provides a high production rate yet has highly consistent dimensions and quality. Further accuracy in dimensions is achievable by grinding and machining.

BACKGROUND OF THE INVENTION:

The manual transmission gear box is generally provided in all automobiles with manual transmission and automatic manual transmission for providing different speed and torque to the moving automobile as per the requirement of driving condition. A Gear box comprises of more than three gear pairs for decreasing or increasing speed of the vehicle. In order to change the speed of vehicle, gear engaged with the output shaft must be altered with nearby gear. This process of altering gears is called synchronization. To achieve this, synchronizer ring are used in manual transmission gear box.

The transmission system of the gears play an important role in determining the behavior of automobile with respect to gear shift comfort. Said Synchronizer mechanisms are provided for the smooth and noiseless synchronization while gear shift. The key characteristics required for the synchronizer ring to function effectively are: (i) that the coefficient of dynamic friction with respect to a mating member is large in order to synchronize two gears by frictionally engaging a tapered portion which is the mating member, and (ii) that the synchronizer ring has high wear resistance, i.e., sufficient mechanical strength and anti-abrasion characteristic in sliding with the mating member.

There are three different types of synchronizer ring, according to number of friction surfaces, that are in common use i.e., i) single cone which have only one ring with only one friction surface, ii) double cone which have an assembly of three rings with two friction surfaces and iii) triple cone having three rings assembly with three friction surfaces. i) Single cone synchronizer ring:

This type of ring comprises of only one ring with only one friction surface. This type of synchronizer used when torque difference between synchronizing gears is small and requirement of shifting comfort is less. ii) Double cone synchronizer ring:

This type of synchronizer ring comprises of three rings in which total two friction surfaces are there i.e., outer ring and inner ring have one friction surface or intermediate ring have two friction surface. This type of synchronizer used when torque difference between synchronizing gear is medium and requirement of shifting comfort is needed. iii) Triple cone synchronizer ring:

This type of synchronizer ring comprises of three rings in which total three friction surfaces are there i.e., outer ring have one friction surface and inner ring have two friction surface. This type of synchronizer is used when torque difference between synchronizing gears is high and requirement of shifting comfort is high.

In manual transmission gear box the selection of type of synchronizer ring is based on torque difference between mating component and requirement of shifting comfort.

Popularly used conventional double and triple cone synchronizer mainly comprises of outer ring, intermediate ring and inner ring as shown in Fig. 1. The synchronizers developed so far, widely available and popularly used establishes a requisite of synchronizer rings to be made of frictional material; wherein mostly it is made of with Brass is used to obtain good frictional property. However, the strength of brass is lesser; moreover it has limitations to heat treatments which are required for strengthening of the rings. In this situation, rings made from brass are made larger in size in order to obtain requisite strength. This makes it bulky; which imparts more moment of inertia resulting in higher shifting force requirement.

Thus, the conventional synchronizer assembly provides the outer and inner synchronizer rings made from hot forging of brass and the intermediate ring made of steel. This is done to provide two good frictional surfaces through inner and outer ring made of brass and steel intermediate ring with high strength. The hot forging process of brass used in manufacturing of outer and inner ring of the synchronizer assembly includes shrinkages which ultimately affecting the consistency of said components of the synchronizer.

These rings comprises of annular grooves, for providing friction force, and axial grooves for drainage of lubricating oil. Said grooves are provided by machining process.

There were many types of heat treatment available for steel component to improve strength and anti- abrasion characteristics in turns of hardness of components as per requirement:

1. Through hardening

2. Case carburizing

3. Carbo-nitriding

4. Induction hardening

5. Anodizing

Said heat treatments are given to the components of the synchronizer assembly based on the requirement of strength of the component and based on its target application. PRIOR ART:

1. Patent publication WO/2008/025585A1 describes synchronizing devices comprising of steel and brass element combined with friction coating. The device described in this invention has a set of three rings made of brass and steel and it also has carbon coating at the interface with the other ring. However, the invention disclosed in said prior art involves carbon coating which has a risk of getting peeled off as this coating is applied by means of adhesive, which leads to failure of gear box. In addition, the process is very expensive. Further, the heat treatment process of this rings is limited to induction hardening and anodizing only as carbon coating requires special surface roughness operation. Moreover, dimensional accuracy (grinding operation to achieve accurate dimensions and final machining) of product is not possible after carbon coating is applied. After coating no heat treatment is possible.

2. In US patent 4770283 describes that the friction linings are directly sintered onto at least one cylindrical or conical friction surface of the annular element itself, the initially planar friction surfaces being formed, after applying the spray-sintered friction lining, into cylindrical or conical shape by a non- cutting shaping process such as stamping, deep- drawing or the like. However, sintering process used in manufacturing said product is complex and expensive. Also, for further processing, said ring can only be subjected to anodizing heat treatment because other types of heat treatment incorporated with very high temperature which melt down the friction surface as the friction surface is sinter- bonded to the blank. Moreover, grinding or machining process of this product is not possible as there is very thin layer of sinter-bonded friction surface. The consistency of the product dimensions cannot be guaranteed.

3. To provide improved frictional surface intermediate ring have been produced from sheet steel blank with vertical grooves to provide friction coating of molybdenum or sinter coated, such as described in US patent 4944378. However, an intermediate rings produced by this process have long useful life, but synchronizer rings exhibit average frictional characteristics. Moreover, the product can only be subjected to induction hardening process as molybdenum coating requires special roughness operation. Further, product proposed by the invention has an occasional issue of peeling off of molybdenum coating, which drastically reduces the useful life of synchronizer ring. Further, the final machining and grinding of product is not possible as molybdenum coating thickness is very thin. Furthermore, the manufacturing costs associated with this process are high such that an intermediate rings are expensive. Therefore, there is an unmet need to provide an improved double and triple cone synchronizer which provide improved synchronizer which is light in weight yet having high structural strength, easy to manufacture and is cost effective. DISADVANTAGES OF PRIOR ART:

1. Conventional rings comprises of machined annular grooves and axial groove for higher friction force and oil drainage purpose.

a. Machining process is time consuming process. b. Further in machining process wastage of material is there.

2. Conventional rings have brass limitations with the heat treatment process and have lesser strength that is why rings are made larger in size in order to obtain requisite strength. This makes it bulky; which imparts more moment of inertia resulting in higher shifting force requirement.

3. Said bulky rings are made of brass, making conventional product is expensive.

4. Said conventional rings are made by hot forging process which is inconsistent process as it includes shrinkages.

5. Product of WO/2008/025585A1 invention comprises carbon coating which is expensive and have limitations with heat treatments and have occasional issue of peeling of carbon coating. Moreover, the grinding and machining of product can not be done.

6. Product of US4770283 invention comprises spray-sintered friction surface wherein sintering process is complex and expensive. In addition, can only be subjected to anodizing heat treatment. Moreover, the grinding and machining of product can not be done.

7. Product of US4944378 invention comprises of molybdenum coating which suffers from the risk of peeling off and the process is complex and expensive. Further, the product can only be subjected to induction hardening process. This drastically reduces the useful life of synchronizer rings. Further, machining and grinding of product is not possible.

OBJECTS OF THE PRESENT INVENTION:

The main object of the present invention is to provide improved double and triple cone synchronizer which involves mechanical method of joining of friction surface and ring providing a mechanically combined brass-steel components; in particular the intermediate ring and the inner ring of the double and triple cone synchronizer; such that the synchronizer is light in weight yet having high structural strength, easy to manufacture and is cost effective.

Another object of the present invention is to provide an improved double and triple cone synchronizer; wherein the obtained light weight synchronizer achieves the requisite decrease in moment of inertia and decreased requirement of shifting force while synchronization .

Still another object of the present invention is to provide improved double and triple cone synchronizer; in which product can be subjected to any heat treatment process as per requirement of application.

Still another object of the present invention is to provide improved double and triple cone synchronizer; in which further accuracy in dimensions is achievable by grinding and machining.

Still another object of the present invention is to provide method of manufacturing improved double and triple cone synchronizer that has a high production rate.

Still another object of the present invention is to provide an improved double and triple cone synchronizer which provide good frictional property.

Yet, the object of the present invention is to provide an improved double and triple cone synchronizer with intermediate ring and inner ring having friction surface on inner and/or outer face thereby minimizing the complexity and cost of manufacturing operations.

Yet another object of the present invention is to provide an improved double and triple cone synchronizer wherein intermediate ring and inner ring which improves the strength, useful life and performance of synchronizer assembly. BRIEF DESCRIPTION OF THE DRAWINGS:

Fig. 1 discloses the fragmented view of the conventional synchronizer set.

Fig. 2 shows the fragmented view of the synchronizer assembly of present improved synchronizer.

Fig. 3 shows the fragmented view of present improved synchronizer assembly illustrating the first step of manufacturing of present invention to provide friction surface by friction cap on intermediate ring.

Fig. 4 shows perspective view and sectional view of present improved synchronizer assembly illustrating first step of manufacturing of present invention to provide friction surface by friction cap on intermediate ring.

Fig. 5 shows perspective view and sectional view of present improved synchronizer assembly illustrating final step of manufacturing of present invention to provide friction surface by friction cap on intermediate ring.

Fig. 6 shows perspective view of friction strip used in the present method for manufacturing improved double and triple cone synchronizer to be pressed on inner surface of intermediate ring.

Fig. 7 shows the fragmented view of present improved synchronizer assembly illustrating first step of manufacturing of present invention to provide an inner friction surface by friction strip on intermediate ring.

Fig. 8 shows perspective view and sectional view of present improved synchronizer assembly illustrating first step of manufacturing of present invention to provide an inner friction surface by friction strip on intermediate ring.

Fig. 9 shows perspective view and sectional view of present improved synchronizer assembly illustrating final step of manufacturing of present invention to provide an inner friction surface by friction strip on intermediate ring.

Fig. 10 shows perspective view of friction strip to provide an outer friction surface on intermediate ring.

Fig. 11 shows the fragmented view of present improved synchronizer assembly illustrating first step of manufacturing of present invention to provide an outer friction surface by friction strip on intermediate ring.

Fig. 12 shows perspective view and sectional view of present improved synchronizer assembly illustrating first step of manufacturing of present invention to provide an outer friction surface by friction strip on intermediate ring.

Fig. 13 shows perspective view and sectional view of present improved synchronizer assembly illustrating final step of manufacturing of present invention to provide an outer friction surface by friction strip on intermediate ring. Fig. 14 shows the fragmented view of present improved synchronizer assembly illustrating first step of manufacturing of present invention to provide an inner friction surface by friction ring on inner ring.

Fig. 15 shows perspective view and sectional view of present improved synchronizer assembly illustrating first step of manufacturing of present invention to provide an inner friction surface by friction strip on inner ring.

Fig. 16 shows perspective view and sectional view of present improved synchronizer assembly illustrating final step of manufacturing of present invention to provide an inner friction surface by friction strip on inner ring.

References used for the parts of the present invention illustrated in drawings:

1 : Present Synchronizer Assembly

2 : Alternate embodiment of present invention for double cone

3 : Alternate embodiment of present invention for triple cone

1A : Conventional Synchronizer Assembly

1 1 : Improved Intermediate ring

11A : Conventional intermediate ring

1 1a : Intermediate body

1 11 : Lugs of inner ring

112 : Inner face of intermediate ring

1 13 : Outer face of intermediate ring

1 14 : Axial streaks on intermediate ring Improved Inner ring

a Inner body

b Inner body for alternate embodiment of double conec Inner body for alternate embodiment of triple coneA Conventional Inner ring

1 Slots of inner ring

2 Outer face of inner ring

3 Inner face of inner ring

4 Axial grooves

Modified Outer ring

a Outer body for alternate embodiments

A Conventional outer ring

1 Plurality of teeth

2 Outer face

3 Inner face

4 Lugs of outer ring

5 Annular grooves

6 Axial grooves of outer ring

7 Projection

Friction cap

a Friction cap after forming process

1 Slots of friction cap

2 Inner face of friction cap

2a Inner face of friction cap after forming process3 Outer face of friction cap

3a Outer face of friction cap after forming process4 Axial streaks on friction cap

Inner friction strip

a Inner friction strip after bending

b Inner friction strip after forming process 151 Flange of inner friction strip

152 Axial streaks on inner friction strip

16 Outer friction strip

16a Outer friction strip after bending

16b Outer friction strip after forming process

161 Slots on outer friction strip

162 Flange in outer friction strip

163 Axial streaks on outer friction strip

17 Friction ring

17a Friction ring after forming process

171 Projection

172 Axial streaks on friction ring

SUMMARY OF INVENTION

The embodiment of the present invention is to provide an improved double and triple cone synchronizer which is light in weight yet having high structural strength, easy to manufacture, cost effective and is highly consistent. Further, the invention allows to provide any heat treatment process to rings and machining and grinding of the rings is possible without affecting the quality of the product.

To provide mechanical bonding of friction surface and intermediate body 11a and inner body 12a it is require to constrain their relative axial and radial movement. The method to constrain these relative movement involves fixing the intermediate steel body with friction cap 14b with help of slots 141 of friction cap 14 and lugs 111 of intermediate body 11a. The method is described in description in detail, which is comparatively easy, cost effective and have high production rate. The improved synchronizer mainly comprises of the improved intermediate ring 11 and improved inner rings 12 with frictional surfaces which are provided by mechanical joining of frictional surface of Cu-Zn alloy on high strength steel intermediate body 11a and inner body 12a (see Fig. 2). This is to provide friction force on corresponding synchronizer components; while providing strength to the rings. Here, inner body of the intermediate ring and outer ring is made from steel thereby making it high in strength and lighter in weight.

The said friction surface is made of Cu-Zn alloy, which is in the form of cap, ring or strip. This friction surface is joined mechanically on the intermediate body 11a and inner body 12a, which comparatively easy to manufacture and inexpensive method of manufacturing the synchronizer with friction surface unlike the complex methods of the prior art. The axially formed streaks 144, 152, 163, and 172 on friction surface serves purpose of friction force and drainage of lubricating oil.

The said purpose of friction force and drainage of lubricating oil can be provided by means of annular grooves and axial grooves on Cu- Zn alloy friction surface if required by the application. Thus, the product of the invention serves all the requisite aspects of synchronization. In addition to that light weight synchronizer allows smoother shifting of gear shifting. Yet present invention provides the improved synchronizer and improved method of manufacturing of synchronizer, with relatively easy, highly consistent and inexpensive manufacturing process. Further accuracy in dimensions is achievable by grinding and machining. DETAILED DESCRIPTION OF THE PRESENT INVENTION:

Present invention provides an improved double and triple cone synchronizer which involves mechanical method of joining of friction surface and ring providing a mechanically combined brass- steel components; in particular the improved intermediate ring 11 and the improved inner ring 12 of the double and triple cone synchronizer; such that the obtained synchronizer is light in weight yet having high structural strength, easy to manufacture and is cost effective. Moreover, the obtained light weight synchronizer achieves the requisite decrease in moment of inertia and decreased requirement of shifting force while synchronization. Further, the invention allows to provide any heat treatment process to rings and reshaping of rings. The process also provides a high production rate and is consistent.

The preferred embodiment of present synchronizer is as shown in Fig. 2. Said mechanical method of joining of friction surface and ring providing a mechanically combined brass-steel components is described later in this specification to obtain an improved synchronizer structure as explained herein below. Referring to Fig. 2; the present improved synchronizer mainly comprises of a modified outer ring; an improved intermediate ring and an improved inner ring; wherein: Said modified outer ring is an outer ring with no frictional surfaces i.e. annular grooves 135 and axial grooves 136 are eliminated unlike the prior art; which eliminates the machining part while manufacturing the ring. Said modified outer ring is made of materials including made of stamped steel, cast steel, sinter steel or forged steel.

Said improved intermediate ring 11 further comprises of an

• intermediate body 11a made of steel,

• an inner friction surface 142a made of Cu-Zn alloy and

• an outer friction surface 143a made of Cu-Zn alloy;

In this hybrid structure, the intermediate body 11a of steel provides structural strength where an inner face 142a and an outer face 143a of Cu-Zn alloy provides well known friction property. The said friction surfaces can be provided by means of strips, ring or cap of Cu-Zn alloy. Said inner and outer face have plurality of axially embossed streaks 144 to provide friction force on mating member and to provide the means of lubricating oil drainage.

The improved inner ring 12 comprises of inner body 12a and friction ring 17a on inner face. Said inner body 12a do not have annular and axial grooves. The inner body 12a is made of stamped steel, cast steel, sinter steel or forged steel to provide better structural strength. The friction ring 17a comprises of axially embossed streaks 172 to provide better friction force and purpose of oil drainage.

THE IMPROVED INTERMEDIATE RING FOR DOUBLE AND TRIPLE CONE SYNCHRONIZER: Said improved synchronizer assembly as shown in Fig. 5; wherein said improved intermediate ring 11 comprises of intermediate body 11a and friction cap 14a. The intermediate body 11a further comprises of at least two or more axially embossed streaks 114, lugs 111, inner face 112 and outer face 113. The axially embossed streaks 114 are provided to constrain relative radial movement of friction cap 14 and intermediate body 11a. Number of axially embossed streaks 114 depends on torque capacity of synchronizer set i.e., higher the torque capacity the more number of vertical streaks required. The inner face 112 and outer face 113 have a cone angle of a.

The friction cap 14 comprises of slots 141, an inner face 142 and outer face 143. The slots 141 are provided to incorporate friction cap 14 with the lugs 111 of intermediate body 11a as shown in Fig. 3. The inner face 142 have a cone angle of a same as the cone angle of inner face 112 of intermediate body 11a, as shown in Fig. 3. An outer face 143 is kept straight as shown in Fig. 4. The said friction cap 14 made from sheet, pipe or forged Cu-Zn alloy.

The method of fixing the present assembly involves following steps:

• First step: To join friction cap 14 with intermediate body 11a mechanically the intermediate ring 11a inserted on friction cap 14 such that the lugs 111 of intermediate ring accommodate in slots 141 of friction cap as shown in Fig. 3 and Fig. 4. Further the cone angle of inner face 142 of friction cap 14 and inner face 112 of intermediate body 11a are same so that these face get matched. • Second step: After inserting intermediate body 11a in the cap 14, as shown in Fig. 4, the assembly of both is pressed with the help of proper die and punch (not shown) to bend the outer surface 143 to get cone angle of a, which will constrain the relative axial and radial movement of intermediate body with respect to friction cap 14 as shown in Fig. 5. Further a punch is so designed that its axially protruded plurality of streaks penetrate in friction cap 14 to provide plurality of axially embossed streaks 144, as shown in Fig. 5, for better friction force. Also the said axially embossed streaks 144 serves the purpose of oil drainage.

ANOTHER EMBODIMENT:

Another embodiment of the present invention is as shown in Fig. 13 the improved intermediate ring 11 comprises of intermediate body 11a, inner friction strip 15b and outer friction strip 16b. The intermediate body 11a is same as described in previous embodiment. The inner friction strip 15 is shown in the Fig. 6.

The method of fixing the present assembly involves following points:

• First step: To join inner friction strip 15 with intermediate body 11a mechanically, the inner friction strip 15 is bended to form inner friction strip 15a as shown in Fig. 7. This inner friction strip 15a, comprises of flange 151, is then inserted in the intermediate body 11a to constrain relative axial movement of intermediate body 11a and inner friction strip 15a in one direction as shown in Fig. 8. Second step: After inserting inner friction strip 15a in intermediate body 11a, the assembly of both an intermediate body 11a and an inner friction strip 15a is to be pressed with the help of proper die and punch to constrain the axial and radial movement of inner friction strip 15b and intermediate body 11a Fig. 9. Further a punch is so designed that its axially protruded streaks penetrate in inner friction strip 15b to provide axially embossed streaks 152 for better friction force of intermediate ring 11 as shown in Fig. 9. These axially embossed streaks 152 also serve the purpose of oil drainage.

Third step: The outer friction strip 16 comprises of slots 161 as shown in Fig. 10. To join outer friction strip 16 with intermediate body 11a mechanically, the outer friction strip 16 is bended to form inner friction strip 16a as shown in Fig. 11. This outer friction strip 16a, comprises of flange 162, is then inserted in the intermediate body 11a such that the slots 161 accommodate with lugs 111 of intermediate body 11a, to constrain relative axial movement of intermediate body 11a and inner friction strip 16a in one direction as shown in Fig. 11.

Fourth step: After this the assembly of both an intermediate body 11a and an outer friction strip 16a is to be pressed with the help of proper die and punch to constrain the axial and radial movement of outer friction strip 16b with respect to intermediate body 11a as shown in Fig. 13. Further a punch is so designed that its protruded streaks penetrate in outer friction strip 16b to provide axially embossed streaks 163 for better friction force intermediate ring 11 as shown in Fig. 13. These axially embossed streaks 163 also serve the purpose of oil drainage. THE IMPROVED INNER RING FOR DOUBLE CONE

SYNCHRONIZER:

As shown in Fig. 14 the inner body 12a of improved inner ring 12 comprises of slots 121. In double cone synchronizer ring the improved inner ring 12 do not have any friction surface and is made of stamped steel, cast steel, sinter steel or forged steel.

THE IMPROVED INNER RING FOR TRIPLE CONE SYNCHRONIZER:

As shown in Fig. 16 the improved inner ring 12 comprises of inner body 12a and friction strip 17a. The inner body 12a is made of forged steel, cast steel, sintered steel or stamped steel comprises of at least two or more axially embossed streaks 125, slots 121, inner face 123 and outer face 122 as shown in Fig. 14. The friction ring 17 comprises of projection 171, made of sheet, pipe or bar of Cu-Zn alloy, as shown in the Fig. 14.

• First step: To join friction ring 17 with inner body 12a mechanically, the friction ring 17 is inserted in the inner body 12a as shown in Fig. 15. This outer friction strip 17 is inserted in the inner body 12a such that the projections 171 accommodate with slots 121 of inner body 12a, to constrain relative axial movement of inner body 11a and friction ring 17 in one direction as shown in Fig. 15. • Second step: After this the assembly of both inner body 12a and an friction ring 17 is to be pressed with the help of proper die and punch to constrain the axial and radial movement of friction ring 17a with respect to inner body 11a as shown in Fig. 16. Further a punch is so designed that its axially protruded streaks penetrate in friction ring 17a to provide axially embossed streaks 172 for better friction force to inner ring 11 as shown in Fig. 16. These axially embossed streaks 172 also serve the purpose of lubricating oil drainage.

In described embodiments the purpose of friction force and the purpose of drainage of lubricating oil is served by axially formed streaks 144, 152, 162 and 172, which can be provided by providing annular grooves on friction cap 14b, friction strip 15b and 16b or friction ring 17b.

The foregoing description of the specific embodiments will so fully reveal the general nature of the embodiments herein that others can, by applying current knowledge, readily modify and/or adapt for various applications such specific embodiments without departing from the generic concept, and, therefore, such adaptations and modifications should and are intended to be comprehended within the meaning and range of equivalents of the disclosed embodiments. It is to be understood that the phraseology or terminology employed herein is for the purpose of description and not of limitation. Therefore, while the embodiments herein have been described in terms of preferred embodiments, those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein.

COMPARISON OF PRESENT INVENTION WITH THE PRIOR ART:

Cost very expensive Cost expensive effective manufactu

- - ring yet inexpensiv e product

Weight Convention - - - Present al product product is made of made

Cu-Zn combined alloy that steel and is why it is Cu-Zn larger to alloy yet is provide light in enough weight as strength steel have yet have more more strength weight. per unite weight.

ADVANTAGES OF PRESENT INVENTION

Present invention provides mechanical method of joining of friction surface and ring providing a mechanically combined brass-steel components; in particular the intermediate ring and the inner ring of the double and triple cone synchronizer; such that the obtained synchronizer is light in weight yet having high structural strength, easy to manufacture, highly consistent and is cost effective.

The obtained light weight synchronizer achieves the requisite decrease in moment of inertia and decreased requirement of shifting force while synchronization.

The product of invention can be subjected to any heat treatment as per requirement.

To achieve accurate dimensions the grinding and machining of present product possible. The proposed manufacturing method has a high production rate.

The synchronizer provide good frictional property.

The present method of manufacture minimizes the complexity and cost of manufacturing operations.

The intermediate ring improves the strength, useful life and performance of synchronizer assembly.

The present synchronizer assembly has high wear resistance, i.e., sufficient mechanical strength and anti-abrasion characteristic in sliding with the mating member.