Claims:
1. An oil immersed brake system (100) comprising:
an actuating unit (120) having a pair of transmission levers (124), the pair of transmission lever (124) includes a first transmission level (124A) and a second transmission lever (124B); and
an actuator disc assembly (130) connected to the actuating unit (120), the actuating disc assembly (130) having:
a first actuator disc (132) and a second actuator disc (134), the first transmission lever (124A) connected to the first actuator disc (132) and the second transmission lever (124B) connected to the second actuator disc (134), each actuator disc (132, 134) having a plurality of acclivities (202, 302) configured on a first surface (133, 135) thereof, the first surfaces (133, 135) of each actuator disc (132, 134) positioned facing each other, each acclivity (202) of the first actuator disc (132) is aligned with the acclivity (302) of the second actuator disc (134) for forming a gap between the aligned acclivities; and
a ball (402) positioned in each gap formed between the aligned acclivities (202, 302), for allowing movement of said acclivities about the ball thereby increasing the distance between the first and second actuator disc (132, 134) for applying brake when the pair of transmission lever (124) is displaced by the actuating rod (123).

2. The oil immersed brake system (100) as claimed in claim 1, wherein the acclivity (202, 302) includes a concave portion (204A, 304A) configured on the first surface of the actuator discs (132, 134) at an end portion of a slope (204B, 304B) of the acclivity (202, 302).

3. The oil immersed brake system (100) as claimed in claim 2, wherein angle of the slope (204B, 304B) ranges from 21 degrees to 23 degrees.

4. The oil immersed brake system (100) as claimed in any one of the claims 1 or 2, wherein the first actuator disc (132) and the second actuator disc (134) rotate in opposite directions with equal magnitude to increase or decrease the distance therebetween.

5. The oil immersed brake (100) system as claimed in any one of the claims 1 to 3, wherein a ratio of the diameter of the ball (402) to a length of the slope (204B, 304B) is 1: 1.4.

6. The oil immersed brake (100) system (100) as claimed in any one of the claims 1 to 4, wherein a ratio of the diameter of the ball (402) to a diameter of the actuator discs (132, 134) is 1: 7.5.

7. The oil immersed brake (100) system (100) as claimed in claim 1, wherein the system includes a plurality of friction discs (140) and a plurality of intermediate discs (150) positioned in alternate configuration on a second surface of the first and second actuator discs (132, 134).

8. The oil immersed brake system (100) as claimed in claim 1, wherein the material of the ball (402) is selected from High carbon chromium bearing steels, high carbon steel or chromium containing low alloy steel.
, Description:FORM 2
THE PATENTS ACT, 1970
(39 OF 1970)
&
THE PATENTS RULE, 2003
COMPLETE SPECIFICATION
[See section 10, Rule 13]

“AN OIL IMMERSED BRAKE SYSTEM”

MAHINDRA & MAHINDRA LIMITED, A COMPANY REGISTERED UNDER THE INDIAN COMPANIES ACT, 1913, HAVING ADDRESS AT MAHINDRA RESEARCH VALLEY (MRV), MAHINDRA WORLD CITY, PLOT NO: 41/1, ANJUR P.O., CHENGALPATTU – 603004, KANCHEEPURAM DIST., TAMIL NADU, INDIA

THE FOLLOWING SPECIFICATION PARTICULARLY DESCRIBES THE INVENTION AND THE MANNER IN WHICH IT IS TO BE PERFORMED

FIELD OF THE INVENTION:
The present invention relates to an oil immersed brake system.

BACKGROUND OF THE INVENTION:
Braking systems used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion. Braking system is broadly categorized in two types: dry brakes and wet brakes. Dry brakes are the usual braking system found in cars that are cooled more by air. Dry brakes have low life because of more wear and tear. Dry brakes lack same level of braking power as that of wet brakes.
Oil immersed brakes is an effective replacement of dry brakes. The Oil immersed brake is used to decelerate or decrease the speed of a vehicle and specially in heavy vehicles such as tractor, work vehicle, bulldozer, trailer, excavator, harvester, cultivator, cargo vehicle, utility vehicle, multifunctional vehicle, multipurpose vehicle, leisure vehicle, pickup vehicle, load vehicle, transport vehicle, agricultural vehicle. In current state of art, oil immersed brake has a split or single housing oil-immersed brake consists of housing, an actuator assembly, intermediate discs, friction discs, and a cover. Such conventional split/single housing oil-immersed brakes do not work in expected efficient manner, have heavy weight components. The components and the brake wear out easily and dissipate high heat.
Accordingly, there is need of an oil immersed brake system that overcomes drawbacks of the conventionally used oil immersed brake system.
SUMMARY OF THE INVENTION
The present invention provides an oil immersed brake system. The system includes an actuating unit having a pair of transmission levers. The pair of transmission lever includes a first transmission level and a second transmission lever. An actuator disc assembly is connected to the actuating unit. The actuating disc assembly includes a first actuator disc and a second actuator disc. The first transmission lever is connected to the first actuator disc and the second transmission lever is connected to the second actuator disc. Each actuator disc has a plurality of acclivities are configured on a first surface thereof. The first surfaces of each actuator disc are positioned facing each other. Each acclivity of the first actuator disc is aligned with the acclivity of the second actuator disc for forming a gap between the aligned acclivities. A ball is positioned in each gap formed between the aligned acclivities for allowing movement of said pair of acclivities about the ball for applying brake when the pair of transmission lever is displaced by the actuating rod. The acclivity includes a concave portion configured on the first surface of the actuating discs at an end portion of a slope of the acclivity. The angle of the slope of the acclivity ranges from about 21 degrees to about 23 degrees. The first actuating disc and the second actuating disc rotate in equal and opposite direction of each other. A ratio of a diameter of the ball to a length of the slope is approximately 1: 14. A ratio of the diameter of the ball to a diameter of the actuator discs is approximately 1:70. A plurality of friction discs and a plurality of intermediate discs are positioned in alternate configuration on either side of the actuating disc assembly.

BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a perspective view of an oil-immersed brake system in accordance with a preferred embodiment of the present invention;
FIG. 2 is an exploded view of the oil-immersed brake of FIG. 1;
FIG. 3A is a front view of actuator discs of the oil-immersed brake system of FIG. 1;
FIG. 3B-3C show details of acclivity configured on the actuator discs of FIG. 3A;
FIG. 4A-4B show a side view of an actuator disc assembly of the oil-immersed brake of FIG. 1;
FIG. 5A is a front view of the oil-immersed brake of FIG. 1 in working mode; and
FIG. 5B shows side view of working of the oil-immersed brake of FIG. 5A.

DETAILED DESCRIPTION OF THE INVENTION
Although specific terms are used in the following description for sake of clarity, these terms are intended to refer only to particular structure of the invention selected for illustration in the drawings, and are not intended to define or limit the scope of the invention.
References in the specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
In general aspect, the present invention relates to a single housing oil immersed brake system. The system includes an actuator disc assembly having a pair of discs. The pair of discs have a plurality of acclivities configured on a surface thereof that are positioned facing each other. The acclivities hold a ball that has limited movement within the surface of acclivities. The acclivities have unique upward slope that facilitates actuation of the brake. The acclivities provided on the actuator discs have a hybrid variable angle that essentially provide improved brake performance even after significant wear of friction liners and help to increase the effectivity of the brake. The actuator disc assembly provides higher sensitivity at the time of partial braking and also provide lesser pedal effort for complete braking.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers in brackets indicate corresponding parts in the various figures.
Referring to FIG. 1 and 2, an assembly of an oil immersed brake system (100) is shown. The oil immersed brake system (100) includes a housing, an actuating unit (120), an actuator disc assembly (130), a plurality of friction discs (140) and a plurality of intermediate discs (150). The housing is filled with transmission oil and equipped with the actuator unit (120). The actuator unit (120) is connected to a brake pedal at one end thereof and to the actuator disc assembly (130) at other end thereof. The actuator disc assembly (130) includes a first actuator disc (132) and a second actuator disc (134). The plurality of friction discs (140) and the plurality of intermediate discs (150) are positioned alternately on both sides of the actuator disc assembly (130) in the housing. The friction disc (140) positioned at end of the assembly is connected to the brake shaft.
In accordance with an embodiment, the actuator unit (120) includes a pair of levers (122), one lever connected with a bolt in parallel configuration with another lever. The pair of levers (122) is connected to an actuating rod (123) having a rubber boot (123A) positioned thereon. The actuating rod (123) is connected to a pair of transmission levers (124). The pair of transmission lever (124) includes a first transmission lever (124A) and a second transmission lever (124B). First end of each transmission lever (124) is connected to the actuating rod (123) using suitable connecting means. Second ends of the transmission levers (124) face in opposite directions from one another. The second end of the first transmission lever (124A) is connected to the first actuator disc (132) and the second end of second transmission lever (124B) is connected to the second actuator disc (134) using an eye-bolt (126) and a spring (127). In an embodiment, the second end of each transmission levers (124A, 124B) is connected to an extended portion (131A, 131B) of the first actuator disc (132) and the second actuator disc (134) respectively. Each extended portion (131A, 131B) has a hole configured thereon. The second end of the each transmission lever (124) is fixed in the hole of the extended portion (131A, 131B) using a connecting means such as bolt and nut.
Referring to FIG. 3A to 3D, a front view of the first and second actuator discs (132, 134) in accordance with an embodiment of the present invention is shown. The actuator discs (132, 134) have a circular shape. The actuator discs (132, 134) includes a plurality of projection (202, 302) of a predefined shape configured on a first surface (133, 135) thereof. A second surface of each actuator discs (132, 134) have a friction disc (140) attached thereto followed by intermediate disc (150) and friction disc (140) attached in alternate configuration. In an embodiment, the projection (202) is an acclivity touching at base of the disc (132) at one end portion thereof. The upper surface of the acclivity (202, 302) has a predefined shape configured thereon.
In an embodiment, the acclivity (202, 302) has a spoon shaped cross-section. A concave portion (204A, 304A) is configured on the first surfaces (133, 135) of the actuator discs (132, 134) at an end portion of a slope (204B, 304B) of the acclivity (202, 302). The acclivity (202, 302) has a triangular shape wherein the slope (204B, 304B) acts as a hypotenuse of the triangle. In an embodiment, the angle of acclivity i.e angle of the slope (204B, 304B) ranges from about to about 21 degrees to about 23 degrees. In an embodiment, there are five acclivities (202,302) configured equidistantly on the surface of the actuator disc (132, 134). However, it is understood here that the number of acclivities and distance between acclivities may vary in alternative embodiments of the present invention.
Referring to FIGS. 4A-4B, a cross-sectional view of the housing in accordance with an embodiment is shown. The first actuator disc (132) and the second actuator disc (134) are positioned such the first surface (133) of the first actuator disc (132) faces the first surface (135) of the second actuator disc (134). The acclivity (202) configured on the first actuator disc (132) gets aligned with the respective acclivity (302) configured on the second actuator disc (134) thereby forming a gap (404) between the aligned acclivities. A ball (402) is positioned between the gap (404) formed between each set of acclivity (202, 302) such that the ball (402) is sandwiched between two acclivities (202, 302) with a limited degree of movement. In an embodiment the ball (402) is made up of materials selected from the list of JIS G4805- High carbon chromium bearing steels, SUJ2 - High Carbon Steel, SAE52100 - high carbon, chromium containing low alloy steel or EN31 and the like.
In accordance with an embodiment, the ratio of a diameter of the ball (402) to a diameter of the actuator discs (132/134) is approximately 1:7.5. It is understood here, that the angle of acclivity may vary in alternative embodiments based on the weight and power of the vehicle.The ratio of a diameter of the ball to a length of the slope (204B, 304B) is approximately 1: 1.4. This ration may vary in alternative embodiments as the angle of slope and length of slope is calculated based on the weight of vehicle and power required for the vehicle. The ball (402) is positioned between concave portions (204A, 304A) of respective acclivities (202, 302). The amount of movement of the ball (402) depends on the angle of acclivity (202, 302) i.e the angle of slope (204B, 304B). The angle of acclivity (202, 302) depends on weight and power of the vehicle. It is to be noted here that the angle of acclivity (202, 302) is inversely proportional to the weight and power of the vehicle.
In accordance with an embodiment, the plurality of friction discs (140) and the plurality of intermediate discs (150) are positioned in alternate configuration on both sides of the actuator disc assembly (130). In an embodiment, four friction discs (140) and three intermediate discs (150) are placed alternatively on either side of the actuator disc assembly (130). The outermost friction disc (140) is attached to a brake shaft of the vehicle.
Referring to FIGS. 1-5B, in operation, as a user presses the brake pedal, the actuating unit (120) attached to the brake pedal gets pulled in upward direction. The second ends of the transmission levers (124) connected to the first and second actuator discs (132, 134) get pulled in upward direction thereby causing rotational movement of the first and second actuator disc (132, 134) in equal and opposite direction. As the first and second actuator disc (132, 134) rotate in opposite direction, the ball (402) gets pressed between acclivities (202, 302) of the discs (132, 134) thereby pushing the first and second actuating discs (132, 134) away from each other. As the first and second actuator discs (132, 134) are pushed away from each other, the distance between the actuator discs (132, 134) increases and the friction discs (140) and the intermediate discs (150) also get pushed away in outward direction thereby applying the brake.
The distance between the first and second actuator disc (132, 134) increases as the ball (402) gets pressed between slope (204B, 304B) portion of the acclivities (202, 302). When the brake pedal is released, the first and second actuator discs (132, 134) again come back to default position wherein the ball (402) gets placed in the concave portion (204A, 304A) of the acclivities (202, 302) respectively.
In accordance with the present invention, the acclivities (202, 302) having unique upward slope (204B, 304B) facilitates actuation of the brake. The acclivities (202, 302) provided on the actuator discs (132, 134) have a hybrid variable angle that essentially provide improved brake performance even after significant wear of friction liners and help to increase the effectivity of the brake. The hybrid angle is achieved by machining process performed on the slope (204B, 304B). The angle of is varied between 210 to 230. The actuator disc assembly (130) provides higher sensitivity at the time of partial braking and also provide lesser pedal effort for complete braking.
References in the specification to “one embodiment” or “an embodiment” mean that a particular feature, structure, characteristic, or function described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrase “in one embodiment” in various places in the specification are not necessarily all referring to the same embodiment.
The present invention is illustrated with reference to the accompanying drawings, throughout which reference numbers in brackets indicate corresponding parts in the various figures.
The embodiments were chosen and described in order to best explain the principles of the present invention and its practical application, 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 omission and substitutions of equivalents are contemplated as circumstance may suggest or render expedient, but such are intended to cover the application or implementation without departing from the spirit or scope of the present invention.

List of Reference Numerals

Reference Numerals Element
100 an oil immersed brake system
120 an actuating unit
122 a pair of levers
123 An Actuating rod
124 A pair of transmission lever
126 An eye bolt
127 A spring
130 An actuator disc assembly
132 A first actuator disc
133 A first surface of first actuator disc
134 A second actuator disc
135 A first surface of second actuator disc
140 A plurality of friction disc
150 A plurality of intermediate disc
202 A plurality acclivity configured on first actuator disc
204A, 304A A concave portion of the acclivities 202 and 302 respectively
204B, 304B a slope of acclivity of the acclivities 202 and 302 respectively
302 A plurality of acclivity configured on second actuator disc
402
A ball
404 A gap between two acclivities