Title of Invention

"LUBRICATING DEVICE FOR TRANSMISSION FOR VEHICLE"

Abstract

A lubricating device for a transmission for a vehicle having a crankcase (2) of an engine (E), said crankcase (2) accommodating said transmission (T) having input and output shafts (5, 6) and a plurality of shift gear trains (Gl to G4) arranged in axial directions of the input and output shafts, said crankcase (2) being provided with an oil reservoir groove (11) extending in the direction of arrangement of said shift gear trains (Gl to G4) and supplied with oil (O) from a lubricating oil supply source and an oil guide wall (14) for guiding the oil (O) overflowing from an upper end portion of said oil reservoir groove (11) onto said shift gear trains (Gl to G4), the oil (O) stored in said oil reservoir groove (11) being capable of flowing out form the upper end portion of said oil reservoir groove (11) towards said oil guide wall (14) at a stroke due to an inertia force when the vehicle is accelerated or decelerated or vertically vibrated, said lubricating device characterized in that: said oil reservoir groove (11) is composed of a deep first storing portion (11a) lying at a position corresponding to a high speed gear train (G3, G4) of said shift gear trains (Gl to G4) and a shallow second storing portion (11b) lying at a position corresponding to a low speed gear train (Gl, G2) of said shift gear trains (Gl to G4), so that when the vehicle is accelerated or decelerated or is vertically vibrated, an amount of the oil flowing out from said first storing portion (11a) toward said oil guide wall (14) at a stroke is greater than that from said second storing portion (1 lb) towards said oil guide wall (14) at a stroke.

Full Text

[Name of Document] Specification [Title of the Invention] Lubricating Device for Transmission for Vehicle [Technical Field] [0001] The present invention relates to an improvement in a lubricating device for a transmission for a vehicle having a crankcase of an engine, the crankcase accommodating the transmission having a plurality of shift gear trains, the crankcase being provided with an oil reservoir groove extending in the direction of arrangement of the shift gear trains and supplied with oil from a lubricating oil supply source and an oil guide wall for guiding the oil overflowing from the oil reservoir groove onto the shift gear trains. [Background Art] [0002] Such a lubricating device for a transmission for a vehicle is known as disclosed in Patent Document 1. [Patent Document 1] Japanese Patent No. 3596675 [Disclosure of the Invention] [Problem to be Solved by the Invention] [0003] In the conventional lubricating device, the depth of the oil reservoir groove is constant. Accordingly, the amount of oil overflowing from the oil reservoir groove to the oil guide wall at acceleration or deceleration of the vehicle or by vibrations of the vehicle is uniform over the length of the oil reservoir groove, so that the amount of oil to be supplied to the shift gear trains is also uniform in the direction of arrangement thereof. [0004] However, in general, the frequency of use of a high speed gear train of the shift gear trains is higher than that of a low speed gear train of the shift gear trains. Accordingly, a high degree of lubrication for the high speed gear train is required, and the amount of oil to be supplied to the shift gear trains is set according to the required degree of lubrication for the high speed gear train. As a result, it is necessary to provide a large-capacity oil pump as the lubricating oil supply source. [0005] It is accordingly an object of the present invention to provide a lubricating device for a transmission for a vehicle which can supply oil to a plurality of shift gear trains in different amounts according to the required degree of lubrication for each shift gear train, thereby ensuring the durability of the shift gear trains and avoiding an increase in capacity of a lubricating oil supply source. [Means for Solving the Problem] [0006] In accordance with a first aspect of the present invention, there is provided a lubricating device for a transmission for a vehicle having a crankcase of an engine, the crankcase accommodating the transmission having a plurality of shift gear trains, the crankcase being provided with an oil reservoir groove extending in the direction of arrangement of the shift gear trains and supplied with oil from a lubricating oil supply source and an oil guide wall for guiding the oil overflowing from the oil reservoir groove onto the shift gear trains; the depth of the oil reservoir groove being changed along the direction of arrangement of the shift gear trains. [0007] In accordance with a second aspect of the present invention including the configuration of the first aspect, the oil reservoir groove is composed of a first storing portion having a first depth and a second storing portion having a second depth smaller than the first depth; the first storing portion is formed at a position Corresponding to a high speed gear train of the shift gear trains; and the second storing portion is formed at a position corresponding to a low speed gear train of the shift gear trains. [0008] In accordance with a third aspect of the present invention including the configuration of the second aspect, the high speed gear train includes a third speed gear train to a top gear train of the shift gear trains. [0009] In accordance with a fourth aspect of the present invention including the configuration of the second aspect, the oil reservoir groove and the oil guide wall are formed so as to correspond to a second speed gear train to a top gear train except a low gear train of the shift gear trains; the first storing portion is formed at a position corresponding to a third speed gear train to the top gear train; the second storing portion is formed at a position corresponding to the second speed gear train; and the low gear train is supplied with a splash oil from a crankshaft of the engine, the crankshaft extending adjacent to the shift gear trains along the direction of arrangement thereof.In accordance with a fifth aspect of the present invention including any one of the second to fourth aspects, the bottom surface of the oil reservoir groove is formed with a shoulder portion at the boundary between the first storing portion and the second storing portion. [Effect of the Invention] [0011] According to the first aspect, the depth of the oil reservoir groove may be set different according to the frequency of use of the shift gear trains, whereby when the oil stored in the oil reservoir groove overflows at a stroke onto the oil guide wall and is supplied to the shift gear trains in the case of acceleration or deceleration of the vehicle or in the case of vertical vibrations of the vehicle, a relatively large amount of oil is supplied to a part of the shift gear trains which is used more frequently and a relatively small amount of oil is supplied to the remainder of the shift gear trains which is used less frequently. Thus, a limited amount of oil fed from the lubricating oil supply source to the oil reservoir groove can be rationally used to thereby uniformly ensure the durability of the shift gear trains and to avoid an increase in capacity of the lubricating oil supply source. According to the second aspect, in the case of acceleration or deceleration of the vehicle or in the case of vertical vibrations of the vehicle, a relatively large amount of oil can be reliably supplied from the first storing portion to the high speed gear train which is used more frequently and a relatively small amount of oil can be reliably supplied from the second storing portion to the low speed gear train which is used less frequently, thereby contributing to the improvement in durability of all the shift gear trains. [0013] According to the third aspect, in the case of acceleration or deceleration of the vehicle or in the case of vertical vibrations of the vehicle, a relatively large amount of oil can be supplied from the first storing portion to the third speed gear train to the top gear train which are used more frequently in particular, thereby improving the durability of these gear trains. [0014] According to the fourth aspect, in the case of acceleration or deceleration of the vehicle or in the case of vertical vibrations of the vehicle, a relatively large amount of oil can be supplied from the first toring portion to the third speed gear train to the top gear train which are used more frequently and a relatively small amount of oil can be supplied from the second storing portion to the second speed gear train which is used less frequently. Further, the low gear train is supplied with a splash oil from the crankshaft of the engine. Accordingly, the amount of oil to be supplied to the third speed gear train to the top gear train can be increased by the amount of oil not supplied from the oil reservoir groove to the low gear train, thereby further improving the durability of the third speed gear train to the top gear train. [0015] According to the fifth aspect, in the case of acceleration or deceleration of the vehicle or in the case of vertical vibrations of the vehicle, it is possible to provide a difference in oil overflow amount between the first storing portion and the second storing portion, so that the distribution of a limited amount of oil to the shift gear trains can be effected more rationally. [Best Mode for Carrying out the Invention] [0016] Some preferred embodiments of the present invention will now be described with reference to the drawings. [Brief Description of the Drawings] [0036] [FIG. 1] FIG. 1 is a longitudinal sectional side view of a motorcycle engine having a lubricating device according to a preferred embodiment of the present invention. [FIG. 2] FIG. 2 is an enlarged view of an essential part including a transmission shown in FIG. 1. [FIG. 3] FIG. 3 is a cross section taken along the line 3-3 in FIG. 2. [FIG. 4] FIG. 4 is a view similar to FIG. 3, showing another preferred embodiment of the present invention.[0017] FIG. 1 is a longitudinal sectional side view of a motorcycle engine having a lubricating device according to a preferred embodiment of the present invention, FIG. \ 2 is a,n enlarged view of an essential part including a transmission shown in FIG. 1, FIG. 3 is a cross section taken along the line 3-3 in FIG. 2, and FIG. 4 is a view similar to FIG. 3, showing another preferred embodiment of the present invention. [0018] Referring first to FIG. 1, reference symbol E denotes a four-cycle engine for a motorcycle. The engine E has a cylinder portion 1 extending in the longitudinal direction of the motorcycle so as to be inclined slightly upward toward the front side of the motorcycle in the condition where the engine E is mounted on the vehicle body of the motorcycle. In the following description, the front, rear, right, and left sides of the engine E will be hereinafter referred to as those in the condition where the engine E is mounted on the motorcycle. [0019] A crankcase 2 is connected to the rear end of the cylinder portion 1. A crankshaft 3 and a transmission Tare accommodated in the crankcase 2. Accordingly, a portion of the crankcase 2 for accommodating the transmission T serves also as a transmission case. [0020] As shown in FIGS. 1 to 3, the crankcase 2 is composed of a first case half 2a as a left case half and a second case half 2b as a right case half. The first and second case halves 2a and 2b are connected to each other by bolts on a vertical plane containing the axis of the cylinder portion 1. The crankshaft 3 extends horizontally in the lateral direction of the engine E. An input shaft 5 extends parallel to the crankshaft 3 on the rear side thereof. An output shaft 6 extends parallel to the input shaft 5 on the rear side thereof. The crankshaft 3, the input shaft 5, and the output shaft 6 are supported to the first and second case halves 2a and 2b. [0021] The transmission T includes the input shaft 5, the output shaft 6, and a plurality of shift gear trains provided between the input shaft 5 and the output shaft 6. The shift gear trains are composed of a low gear train Gl, a second speed gear train G2, a third speed gear train G3, and a top gear train G4. [0022] In this preferred embodiment, these shift gear trains Gl to G4 are arranged in the order of the low gear train Gl, the third speed gear train G3, the top gear train G4, and the second speed gear train G2 from the right side of the transmission T as shown in FIG. 3. The establishment of any gear position by these shift gear trains Gl to G4 is selected by a change mechanism 8 known in the art. In running of the motorcycle, the gear positions by the shift gear trains Gl to G4 are sequentially established to thereby stepwise change the speed of rotation transmitted from the crankshaft 3 to the input shaft 5 and to transmit the rotation to the output shaft 6. A chain drive device 7 is mounted on the output shaft 6 at the left end thereof, and the rotation of the output shaft 6 is transmitted through the chain drive device 7 to a rear wheel of the motorcycle. [0023] The first and second case halves 2a and 2b are formed with a vertical wall 10 projecting downward from the inner wall of an upper portion of the crankcase 2 toward a front upper portion of a drive gear group constituting the shift gear trains Gl to G4. The vertical wall 10 is formed at its lower end portion with an oil reservoir groove 11 opening rearward and obliquely upward and extending in the direction of arrangement of the shift gear trains Gl to G4. One of the joining surfaces of the first and second case halves 2a and 2b is formed with an oil supply groove 12 opening to the oil reservoir groove 11. The oil supply groove 12 is supplied with a part of oil O discharged from a lubricating oil pump (not shown) for the engine E, and the oil 0 supplied from the oil supply groove 12 is stored in the oil reservoir groove 11. [0024] The vertical wall 10 is integrally formed with a dam 13 forming the rear edge of the oil reservoir groove 11 and an eaveslike oil guide wall 14 projecting rearward from the dam 13 to a position directly over the drive gear group of the shift gear trains Gl to G4 so as to be inclined downward. The oil guide wall 14 functions to guide the oil 0 overflowing the dam 13 to the shift gear trains Gl to G4. [0025] The depth of the oil reservoir groove 11 is changed along the direction of arrangement of the shift gear trains Gl to G4. More specifically, the oil reservoir groove 11 is composed of a first storing portion lla having a first depth and a pair of second storing portions lib each having a second depth smaller than the first depth. The second storing portions lib are formed on the opposite sides of the first storing portion lla in the direction of arrangement of the shift gear trains Gl to G4 . A vertical shoulder portion lie is formed at the boundary between the first storing portion lla and each of the second storing portions lib. The first storing portion lla is formed at a position corresponding to the medium speed and high speed gear trains, e.g., the third speed gear train G3 and the top gear train G4. The second storing portion lib is formed at a position corresponding to the low speed gear trains, e.g., the low gear train Gl and the second speed gear train G2. [0026] The operation of this preferred embodiment will now be described. [0027] In the case that the motorcycle is operated relatively gently at low speeds, the oil 0 supplied from the lubricating oil pump for the engine E through the oil supply groove 12 fills the oil reservoir groove 11 and thereafter overflows the dam 13. The oil O overflowing the dam 13 is guided by the oil guide wall 14 to fall down to the drive gear group of the shift gear trains Gl to G4, thereby lubricating the drive gear group. [0028] In the case that the motorcycle is accelerated or decelerated or it is vertically vibrated, the oil 0 stored in the oil reservoir groove 11 jumps the dam 13 onto the oil guide wall 14 at a stroke due to an inertia force, and is supplied to the drive gear group of the shift gear trains Gl to G4, thereby lubricating the drive gear group. Actually, such a lubricated condition occurs more frequently. [0029] The oil reservoir groove 11 is composed of the first storing portion lla having the first depth and the second storing portions lib each having the second depth smaller than the first depth. Accordingly, a relatively large amount of oil 0 is stored in the first storing portion lla and a relatively small amount of oil 0 is stored in the second storing portions lib. As a result, when the oil 0 stored in the oil reservoir groove 11 overflows the dam 13 at a stroke in the case of acceleration or deceleration of the motorcycle or in the case of vertical vibrations of the motorcycle, the amount of oil O overflowing from the first storing portion lla is relatively large and the amount of oil O overflowing from the second storing portions lib is relatively small. As a result, the amount of oil 0 to be supplied to the third speed gear train G3 and the top gear train G4 corresponding to the first storing portion lla becomes relatively large, and the amount of oil O to be supplied to the low gear train Gl and the second speed gear grain G2 corresponding to the second storing portions lib becomes relatively small. [0030] In the transmission T, the high speed gear trains including the third speed gear train G3 and the top gear train G4 are used more frequently than the low speed gear trains including the low gear train Gl and the second speed gear train G2. Therefore, by setting the amount of oil to be supplied to the high speed gear trains G3 and G4 larger than the amount of oil to be supplied to the low speed gear trains Gl and G2, a limited amount of oil supplied from the oil supply groove 12 can be distributed to the shift gear trains Gl to G4 according to the required degree of lubrication for each shift gear train. Accordingly, the durability of the shift gear trains Gl to G4 can be uniformly ensured, so that it is not necessary to increase the capacity of the lubricating oil pump for the engine E as a lubricating oil supply source. [0031] In the oil reservoir groove 11, the boundary between the first storing portion lla and each of the second storing portions lib is formed as the vertical shoulder portion lie. Accordingly, in the case of acceleration or deceleration of the motorcycle or in the case of vertical vibrations of the motorcycle, it is possible to provide a difference in oil overflow amount between the first storing portion lla and each second storing portion lib, so that the distribution of a limited amount of oil to the shift gear trains Gl to G4 can be effected more rationally. [0032] Another preferred embodiment of the present invention will now be described with reference to FIG. 4, [0033] In this preferred embodiment, an oil reservoir groove 11 and an oil guide wall 14 are formed so as to correspond to the second speed gear train G2 to the top gear train G4 except the low gear train Gl of the shift gear trains Gl to G4. More specifically, the oil reservoir groove 11 in this preferred embodiment is composed of a first storing portion lla having a first depth and a second storing portion lib having a second depth smaller than the first depth. The second storing portion lib is formed on the left side of the first storing portion lla. The first storing portion lla is formed at a position corresponding to the third speed gear train G3 and the top gear train G4, and the second storing portion lib is formed at a position corresponding to the second speed gear train G2. Further, the supply of oil to the low gear train Gl is effected by splashing of oil by the rotation of the crankshaft 3 of the engine E. The other configuration is similar to that of the previous preferred embodiment, so in FIG. 4 the same reference numerals as those shown in FIGS. 1 to 3 denote the same or like parts, and the description thereof will be omitted herein. [0034] According to this preferred embodiment, a relatively large amount of oil is supplied from the first storing portion lla to the third speed gear train G3 and the top gear train G4 which are used more frequently, thereby improving the durability of these gear trains G3 and G4. On the other hand, a relatively small amount of oil is supplied from the second storing portion lib to the second speed gear train G2 which is used less frequently, and the low gear train Gl is lubricated by the splash oil from the crankshaft of the engine rather than \he oil supplied from the oil reservoir groove 11. Accordingly, the amount of oil to be supplied to the third speed gear train G3 and the top gear train G4 can be increased by the amount of oil not supplied from the oil reservoir groove 11 to the low gear train Gl, thereby improving the durability of these high speed gear trains G3 and G4. [0035] While some preferred embodiments of the present invention have been described, it should be noted that the present invention is not limited to the above preferred embodiments, but various modifications may be made without departing from the scope of the present invention. For example, the number of shift positions is not limited to four, but may be changed to three or five or more. Further, the present invention is also applicable to any vehicle engines other than a motorcycle engine. We claim: 1. A lubricating device for a transmission for a vehicle having a crankcase (2) of an engine (E), said crankcase (2) accommodating said transmission (T) having input and output shafts (5, 6) and a plurality of shift gear trains (Gl to G4) arranged in axial directions of the input and output shafts, said crankcase (2) being provided with an oil reservoir groove (11.) extending in the direction of arrangement of said shift gear trains (Gl to G4) and supplied with oil (O) from a lubricating oil supply source and an oil guide wall (14) for guiding the oil (O) overflowing from an upper end portion of said oil reservoir groove (11) onto said shift gear trains (Gl to G4), the oil (O) stored in said oil reservoir groove (11) being capable of flowing out form the upper end portion of said oil reservoir groove (11) towards said oil guide wall (14) at a stroke due to an inertia force when the vehicle is accelerated or decelerated or vertically vibrated, said lubricating device characterized in that: said oil reservoir groove (11) is composed of a deep first storing portion (11a) lying at a position corresponding to a high speed gear train (G3, G4) of said shift gear trains (Gl to G4) and a shallow second storing portion (11b) lying at a position corresponding to a low speed gear train (Gl, G2) of said shift gear trains (Gl to G4), so that when the vehicle is accelerated or decelerated or is vertically vibrated, an amount of the oil flowing out from said first storing portion (11a) toward said oil guide wall (14) at a stroke is greater than that from said second storing portion (11b) towards said oil guide wall (14) at a stroke. 2. The lubricating device for a transmission for a vehicle as claimed in claim 1, wherein said crankcase (2) is formed with a dam (13) at a lateral edge, adjacent to said oil guide wall (14), of said oil reservoir groove (11). 3. The lubricating device for a transmission for a vehicle as claimed in claim 1 or 2, wherein said high speed gear train comprises a third speed gear train (G3) or a top gear train (G4) of said shift gear trains (Gl to G4). 4. The lubricating device for a transmission for a vehicle as claimed in any one of claims 1 to 3, wherein said oil reservoir groove (11) and said oil guide wall (14) are formed so as to correspond to a second speed gear train (G4) except a low gear train (Gl) of said shift gear trains; said first storing portion (11a) is formed at a position corresponding to a third speed gear train (G3) to said top gear train (G4); said second storing portion (11b) is formed at a position corresponding to said second gear train (G2); and said low gear train (Gl) is supplied with a splash oil from a crankshaft (3) of said engine (E), said crankshaft (3) extending adjacent to said shift gear trains (Gl to G4). 5. The lubricating device for a transmission for a vehicle as claimed in any one of claims 1 to 4, wherein the bottom surface of said oil reservoir groove (11) is formed with a shoulder portion (11c) at the boundary between said first storing portion (11a) and said second storing portion (11b). 6. The lubricating device for a transmission for a vehicle as claimed in any one of claims 1 to 5, wherein oil supply groove (12) formed in said crankcase (2) and adapted to supply oil (O) from a lubricating oil supply source to the oil reservoir groove (11) communicate with said first storing portion (11a).

Documents:

608-DEL-2007-Abstract-(03-11-2011).pdf

608-del-2007-abstract.pdf

608-DEL-2007-Claims-(03-11-2011).pdf

608-del-2007-claims.pdf

608-DEL-2007-Correspondence Others-(03-11-2011).pdf

608-del-2007-correspondence-others 1.pdf

608-del-2007-correspondence-others.pdf

608-del-2007-description(complete).pdf

608-del-2007-drawings.pdf

608-DEL-2007-Form-1-(03-11-2011).pdf

608-del-2007-form-1.pdf

608-del-2007-form-18.pdf

608-del-2007-form-2.pdf

608-DEL-2007-Form-3-(03-11-2011).pdf

608-del-2007-form-3.pdf

608-del-2007-form-5.pdf

608-DEL-2007-GPA-(03-11-2011).pdf

608-del-2007-gpa.pdf

608-DEL-2007-Petition-137-(03-11-2011).pdf

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