JPH0818496B2 - Lubricating oil intake passage for vehicle transmission - Google Patents

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a transmission mounted on a vehicle, in which the oil level of lubricating oil in the transmission case is inclined with respect to the case in accordance with a change in the attitude of the vehicle, The present invention relates to a lubricating oil suction passage that can suck lubricating oil without being mixed with air without being affected by a change in the posture of the vehicle.

2. Description of the Related Art Vehicles, particularly agricultural tractors, have an engine mounted in the front of the vehicle body and a transmission mounted in the rear, and the output shaft of the engine is connected to the input shaft of the transmission via a propeller shaft. The power of the engine that has been input to is transmitted by the transmission through the output shaft to the wheels.

In addition, the transmission has a large number of various parts such as bearings that require lubrication, and a hydraulic pump that supplies lubricating oil to each of these lubricating parts is attached to this transmission. The lubricating oil that has been fed and lubricated the lubricating portion is stored in the bottom portion of the transmission case, is again sucked into the hydraulic pump, and is recirculated.

Further, in order to make it easier for the lubricating oil accumulated in the mission case to be sucked into the hydraulic pump, an oil reservoir is usually provided in the mission case, and this oil reservoir is generally provided in the rear of the conventional transmission case. Met.

For example, in the agricultural tractor disclosed in Japanese Utility Model Laid-Open No. 54-99225, a hydraulic pump is attached to the front end surface of the mission case, and an oil sump is provided at the rear of the mission case. An oil supply pipe connecting the portion to the hydraulic pump extends vertically through the transmission case from its back wall to front wall.

Further, in the one disclosed in Japanese Utility Model Publication No. 59-16590, the hydraulic pump is provided inside the mission case, but the oil sump portion is also provided at the rear part of the mission case.

However, in the case where the oil sump portion is provided at the rear end portion of the mission case as described above, when the mission case tilts back and forth due to the shaking of the vehicle body, When the oil level of the lubricating oil greatly goes up and down, especially when the vehicle body is significantly inclined forward, the oil level of the lubricating oil falls near the suction end of the oil supply pipe or the suction part of the oil filter leading to the suction port of the hydraulic pump. And the air is easily mixed into the intake lubricating oil, and the oil supply pipe or the intake passage that connects the oil reservoir and the hydraulic pump becomes long, increasing the flow resistance of the intake oil and driving the hydraulic pump. Therefore, power loss is increased and cavitation is likely to occur in the hydraulic pump.

Means for Solving the Problems and Actions and Effects The present invention relates to an improvement of a vehicle transmission that overcomes such difficulties, and the transmission is mounted on the vehicle with the longitudinal direction of the transmission case aligned with the longitudinal direction of the vehicle. In a transmission in which the oil surface of the lubricating oil filled in the transmission case inclines with respect to the case in accordance with the attitude change of the vehicle, the level of the lubricating oil surface in the case changes with the attitude change of the vehicle. A lubricating oil pump is disposed above the level unchanged point regardless of the case regardless of the case, and a horizontal suction passage oriented in the longitudinal direction of the case is provided at the bottom of the case located below the level unchanged point. Bottom wall and one side wall and a cover wall are integrally formed, and the case bottom wall from the level unchanged point The vertical suction line is directed toward the other end of the horizontal suction passage at one end of the horizontal suction passage on the side where the distance from the hanging point where the vertical suction line intersects the horizontal suction passage to the end of the horizontal suction passage is short. A partition plate that divides the passage into two parts in the left-right width direction is provided, and one of the divided horizontal suction passages divided by the partition plate has an inner split horizontal suction passage end near the center in the width direction of the case that opens into the case. As well as
Out of the divided horizontal suction passages, one end of the outer divided horizontal suction passage near one side wall of the case is closed to the case, and the other end of the horizontal suction passage is opened in the case. A vertical suction passage formed by the one side wall and the covering wall of the case so as to communicate with the suction port is opened to the divided horizontal suction passage outside the one side wall of the case.

In the present invention, the transmission is mounted on the vehicle in a state where the longitudinal direction of the transmission case is aligned with the longitudinal direction of the vehicle, and the oil level of the lubricating oil filled in the transmission case changes as the posture of the vehicle changes. In a transmission inclined to the case, a lubricating oil pump is arranged above a level no-change point where the level of the lubricating oil surface in the case does not change with respect to the case regardless of the posture change of the vehicle. A horizontal suction passage oriented in the longitudinal direction of the case is formed integrally with the bottom wall of the case and one side wall and a covering wall at the bottom of the case located below the change point, and the front and rear ends of the horizontal suction passage are formed as described above. Vertical suction formed by one side wall and cover wall of the case so as to open in the case and communicate with the suction port of the lubricating oil pump Since the passage is opened to the horizontal suction passage, when the case is oriented in the horizontal direction, only the lubricating oil is sucked from both ends of the horizontal suction passage opened in the lubricating oil in the case without sucking air. .

Further, in the present invention, as a result of the lubricant oil surface in the transmission case being largely inclined with respect to the case in accordance with a change in the posture of the vehicle, an opening located above the front and rear ends of the horizontal suction passage. Is exposed above the lubricating oil surface in the case, the horizontal suction passage opening located below is immersed in the lubricating oil in the case,
Moreover, since the opening in which the vertical suction passage communicates with the horizontal suction passage is immersed in the lubricating oil in the case, the suction passage of the lubricating oil pump is not opened to the atmosphere and the lubrication in the case is performed. Since it is connected to oil, the lubricating oil pump can surely suck the lubricating oil in the case without sucking the air in the atmosphere, and the lubricating oil pump is sucked into the lubricating oil pump. The aeration of the air is prevented in advance.

Further, in the present invention, the vertical line extending from the level no-change point to the bottom wall of the case intersects with the horizontal intake passage at one end of the horizontal intake passage where the distance from the downward point to the end of the horizontal intake passage is short. A partition plate which divides the horizontal suction passage into two parts in the left-right width direction and is directed toward the other end of the horizontal suction passage, and among the divided horizontal suction passages divided by the partition plate, the width direction of the case. One end of the inner divided horizontal suction passage near the center is opened in the case, and one end of the outer divided horizontal suction passage near one side wall of the case of the divided horizontal suction passage is closed to the case and The other end of the suction passage is opened in the case, and a vertical suction passage formed by one side wall and a cover wall of the case so as to communicate with the suction port of the lubricating oil pump is divided into a horizontal side outside the one side wall of the case. Open in the intake passage Therefore, the vertical line from the level no-change point to the bottom wall of the case intersects the horizontal suction passage at a short distance from the hanging point to the opening end of the horizontal suction passage. The length of the suction passage up to the lower end opening of the vertical suction passage communicated with the vertical suction passage is extended by the partition plate to extend from the other end having a long distance from the hanging point to the opening end of the horizontal suction passage to the lower end opening of the vertical suction passage. The length of the suction passage can be made substantially the same, and even if air is mixed in the lubrication oil, the air in the lubrication oil sucked from the opening of the horizontal suction passage is separated to separate the air from the horizontal suction passage. It can be discharged to the same degree from both the openings (when the case is horizontal) or the higher opening in the case into the case and can be removed from both the front and rear openings of the horizontal suction passage.

As described above, in the present invention, even if the vehicle, that is, the transmission case is in any posture, it is possible to prevent air from being mixed into the intake lubricating oil of the lubricating oil pump. Lubricating oil can be smoothly supplied to surely lubricate each of the lubricating parts, and moreover, the hydraulic clutch provided in the transmission can be reliably operated.

Moreover, in the present invention, the lubricating oil suction passage is not formed in the side wall or the partition wall of the transmission case, and the horizontal suction passage is formed by the bottom wall, the one side wall, and the covering wall of the case, and the one side wall of the case is formed. Since the vertical suction passage is formed by the cover and the cover wall, the cross-sectional area of these suction passages can be made large enough to sufficiently reduce the suction resistance of the suction lubricating oil, and therefore the power for driving the lubricating oil pump. It is possible to reduce the loss and prevent the occurrence of cavitation in the pump.

Example Hereinafter, an example of the present invention illustrated in the drawings will be described.

The agricultural tractor 1 has an engine 3 at the front of the vehicle body 2,
The power of the engine 3 is reduced to a required gear ratio by the transmission 10 via the power transmission shaft 4 and is transmitted only to the front wheels 5 and the rear wheels 6 or the rear wheels 6.

The transmission 10 is a main transmission 11, an auxiliary transmission 12, and a PTO transmission 1.
3 and the mission case 14 is the front case 15
And rear case 16 and control plate 17,
The front case 15 is integrally connected to the rear case 16 via the control plate 17, the clutch cover 18 is attached to the front of the front case 15, and the rear cover 19 is attached to the rear of the rear case 16. As shown in FIG. 2, the upper portion of the rear case 16 is open, but is closed by a hydraulic cylinder 7 (see FIG. 1) for vertically moving the working machine.

Further, as shown in FIG. 4, the approximately front-rear center portion of the rear case 16 is partitioned into front and rear by a partition wall 20, and the rear bottom portion of the front case, the front bottom portion of the rear case 16 and the bottom portion of the control plate 17 are separated by the mission case 14. Is formed lower than the bottom of the other part.

Furthermore, as shown in FIGS. 4 to 6,
At the bottom of the rear case 16 in front of the partition wall 20 and at the bottom of the control plate 17, the covering wall 21 rises upward in the center of the width direction and extends in the front-rear direction, and then to the right of the vehicle body (left in FIG. 6). To the rear case 16 and the right side wall of the control plate 17 so that there is a substantially constant distance to the right wall of the rear case 16 and the control plate 17.
An oil suction chamber 22 is formed by the rear case 16 and the right side wall of the control plate 17.

A rear oil suction port 23 and a front oil suction port 24 are formed in the bottom of the oil suction chamber 22 near the center of the vehicle body, in the partition wall 20 of the rear case 16 and the control plate 17, and the front oil suction port is formed. A partition plate 25 is stretched from the right edge of 24 toward the rear to the center of the front and rear of the oil suction chamber 22.

Further, an end wall 26 and a partition wall 27 that are oriented in the vertical and horizontal directions are erected on the rear side of the oil suction chamber 22 in the rear case 16 and in front of it, and the oil suction chamber is defined by the partition wall 27.
The upper part of 22 is divided into upper and lower parts and the oil filter intake passage
28a, an oil filter discharge passage 28b is formed, the rear oil filter suction passage 28a communicates with the oil suction chamber 22 at its lower end, and communicates with the outer suction chamber 30 of the oil filter 29 at its upper portion, oil filter
The inner discharge chamber 31 of 29 is a front oil filter discharge passage 28
The oil filter 29 is connected to the transmission 10
Mission case 14, front case 15, rear case 1
6, the control plate 17 and the clutch cover 18 are arranged so that the oil level of the lubricating oil in the control plate 17 and the clutch cover 18 is located right above the constant level holding point 88 that maintains a constant level regardless of the inclination of the agricultural tractor 1.

Further, the oil filter discharge passage 28b is communicated with the lift oil suction passage 32 of the lift pump 8 for supplying pressure oil to the hydraulic cylinder 7 at an appropriate height, and the shift oil suction passage 33 of the shift hydraulic pump 9 is connected. Is in communication with.

Further, in the main transmission 11, as shown in FIG. 2, in addition to the input shaft 44, the second shaft 45, the third shaft 46, and the fourth shaft
The shaft 47 is rotatably supported, and the input shaft 44 is a gear pair 48a, 48b.
Is connected to the clutch outer 49a of the main clutch 49 that is rotatably fitted to the second shaft 45, and the clutch inner 49b of the main clutch 49 is integrally fitted to the second shaft 45. And the third shaft 46 are provided with three pairs of gears with hydraulic clutches 50, 51, 52 and a pair of reverse rotation gears / gear 53 with hydraulic clutches. By setting either 51, 52, the reverse rotation gear / gear pair 53 with hydraulic clutch to the connected state, the main transmission 11
Is decelerated or reversely rotated to a predetermined gear ratio.

Further, the PTO input gear 55 fitted to the input shaft 44 via the one-way clutch 54 has a hydraulic clutch loosely fitted to the fourth shaft 47 via the idler gear 56 fitted loosely to the second shaft 45. The fourth shaft 47 is meshed with the gear 57, and the fourth shaft 47 is rotationally driven by setting the gear 57 with the hydraulic clutch to the connected state.

Furthermore, as shown in FIG. 3, the third shaft 46 extends into the auxiliary transmission 12 (actually another shaft, but spline-fitted on the same center line). 12
Inside, the rear wheel drive shaft 58 and the intermediate shaft 5 are parallel to the third shaft 46.
9, a front wheel drive shaft 60, a rear PTO shaft 61, a PTO intermediate shaft 62 are rotatably supported, and a medium speed drive gear 63 and an intermediate shaft drive gear 64 are integrally formed on the third shaft 46 in the auxiliary transmission 12. The high-speed drive gear 65 is integrally formed and formed, and the idler gear 66 is rotatably fitted.

Moreover, the high speed shifter gear 67 is spline fitted to the rear wheel drive shaft 58, and the high speed driven gear 68 and the low speed driven gear 69 are rotatably fitted to the high speed driven gear 68.
Is engaged with the high-speed drive gear 65, the low-speed driven gear 69 is engaged with the small-diameter gear 66a of the idler gear 66, and the high-speed shifter gear 67 is in the rear position I, the central position II,
When shifted to the forward position III, the high-speed shifter gear 67 is spline-fitted to the low-speed driven gear 69, and the medium-speed drive gear
Meshed with 63, spline fitted with high speed driven gear 68,
It can be switched between neutral, medium and high speed.

Further, a low speed driven gear 70, a low speed idler gear 71, and a front wheel idler gear 72 are rotatably fitted to the intermediate shaft 59, a low speed shifter gear 73 is spline fitted to the low speed driven gear 70, and the low speed shifter gear 73 is at a rear position A,
When the center position B is shifted to the front position C, the low speed shifter gear 73 is spline-fitted to the low speed idler gear 71, or only the low speed driven gear 70 is spline fitted, or meshed with the idler gear 75 to make a low speed, a neutral or an ultra low speed. It can be switched.

Furthermore, the driven gear 74 and the idler gear 75 are rotatably fitted to the front wheel drive shaft 60, and the intermittent shifter 76 is spline-fitted.When the intermittent shift 76 is shifted rearward or forward, the front wheel drive shaft 60 is It is adapted to be connected to or disconnected from the driven gear 74.

The front wheel drive gear 77 is spline-fitted to the rear wheel drive shaft 58.The front wheel drive gear 77 is meshed with the driven gear 72a of the front wheel idler gear 72, and the drive gear 72b of the front wheel idler gear 72 is meshed with the driven gear 74. When the rear wheel drive shaft 58 is rotationally driven, the driven gear 74 is also rotationally driven.

The rear wheel drive shaft 58 and the front wheel drive shaft 60 are respectively connected to the rear wheels 6 and the front wheels 5 via a differential device (not shown).

Further, the rear PTO shaft 61 is rotatably fitted to the fourth shaft 47 on the same axis line, the PTO drive gear 78 is integrally formed at the rear end of the fourth shaft 47, and the rear PTO shaft 61 is splined with the PTO shifter gear 79. In addition to being fitted, the PTO driven gear 80 is fitted rotatably.

Further, the PTO intermediate shaft 62 is integrally provided with intermediate gears 81, 82, 83 which can mesh with the PTO drive gear 78, the PTO shifter gear 79, and the PTO driven gear 80, respectively.
When 9 is shifted to the rearmost position α, rear position β, intermediate position γ, and front position δ, respectively, PTO 1st, neutral, 2nd, 3rd
The speed can be switched.

Furthermore, the front PTO drive gear 84 is attached to the front end of the fourth shaft 47.
Are integrally fitted, and the front PTO shaft 85 is rotatably and pivotally supported adjacent to the fourth shaft 47 in parallel and forward.
A front PTO driven gear 86 that meshes with a front PTO drive gear 84 is rotatably fitted to the rear end of the shaft 85, and a shifter 87 that is spline-fitted to the front PTO driven gear 86 is engageable and disengageable.
Is provided on the front PTO shaft 85.

The bearings of the shafts 34, 35, 36, 37 and various hydraulic clutches are provided on the front wall of the front case 15 and the partition wall of the rear case 16.
Pressure oil from the variable speed hydraulic pump 9 is supplied through an oil passage provided in the control plate 17 and the control plate 17.

Since the illustrated embodiment is configured as described above,
As shown in FIG. 1, when the agricultural tractor 1 is located on the horizontal ground, as shown in FIG. 4,
The oil level 89 of the lubricating oil in the transmission 10 passes through a level no-change point 88 at which the level of the oil level 89 does not change with respect to the mission case 14 regardless of the attitude change of the tractor 1, and extends in the longitudinal direction of the transmission 10. As shown in FIG. 7, this lubricating oil is held in parallel, and is sucked into the bottom of the oil suction chamber 22 from the rear oil suction port 23 and the front oil suction port 24, and inside the oil suction chamber 22. Oil filter suction passage 28a
Flows into the outer suction chamber 30 of the oil filter 29, is filtered in the oil filter 29, then flows from the inner discharge chamber 31 to the oil filter discharge passage 28b, and is moved up and down the oil suction passage 32.
Through the shift oil suction passage 33 and the shift hydraulic pump 9 through the shift oil suction passage 33, and through the hydraulic control circuit (not shown) the lubrication portion of the hydraulic cylinder 7 and the transmission 10 and the hydraulic clutch. Is supplied to.

Next, as shown in FIG. 8, when the agricultural tractor 1 tilts forward, as shown in FIG.
The oil surface 89 of the lubricating oil in 10 is inclined forward with respect to the transmission 10, and the depth of the lubricating oil near the rear oil intake port 23 is shallow, but the rear oil intake port 23 is Since it is farther from the vertical line of the level no change point 88, the rear oil suction port 23 is not exposed above the oil level 89, and the bottom of the oil suction chamber 22 is not only the rear oil suction port 23 but also the front. Since the partial oil suction port 24 is also opened, most of the lubricating oil sucked into the variable speed hydraulic pump 9 flows into the oil suction chamber 22 from the front oil suction port 24, and the rear oil suction port with a shallow depth is provided. Since 23, the lubricating oil did not flow in that much, and as a result,
Air is prevented from entering the lubricating oil.

Further, as shown in FIG. 10, when the agricultural tractor 1 is inclined rearward, as shown in FIG.
The oil level 89 of the lubricating oil inside 10 is inclined rearward with respect to the transmission 10, and the depth of the lubricating oil near the front oil intake port 24 becomes shallow, so that the front oil intake port 24 may sometimes become oily. Even if the oil is exposed above the surface 89, the front opening of the oil suction chamber 22 is substantially retracted rearward to the rear end edge 25a of the partition plate 25, so that the air from the front oil suction port 24 is removed. Is mixed in, and most of the lubricating oil sucked into the variable speed hydraulic pump 9 flows into the oil suction chamber 22 through the rear oil suction port 23.

In this way, even if the agricultural tractor 1 is tilted in either the front or rear direction, air is prevented from being mixed into the intake lubricating oil to the variable speed hydraulic pump 9, and the lubricating oil is smoothly applied to each lubricating portion of the transmission 10. To be sufficiently lubricated, and the hydraulic clutch can operate reliably.

Further, lubricating oil is sucked into the oil suction chamber 22 from the bottom of the transmission 10 through the rear oil suction port 23 and the front oil suction port 24, and since the oil suction chamber 22 is wide, even if the oil filter 29 and the variable speed hydraulic pump are used. Even if 9 is positioned considerably higher than the bottom of the transmission 10, the flow resistance of the lubricating oil drawn into the transmission hydraulic pump 9 is small, the power loss of the transmission hydraulic pump 9 is small, and the cavitation inside the transmission hydraulic pump 9 is small. Can be avoided.

[Brief description of drawings]

1 is a side view of a tractor provided with a lubricating oil intake passage of a transmission according to the present invention, FIG. 2 is a vertical side view of a main transmission of the transmission, and FIG. 3 is a vertical side view of an auxiliary transmission thereof. FIG. 4 is a vertical sectional side view showing an embodiment of the lubricating oil suction passage according to the present invention, FIG. 5 is a vertical sectional plan view of a main portion thereof, FIG. 6 is a partially cutaway front view thereof, and FIG. FIG. 8 is a side view showing a front tilted state of the tractor, FIG. 9 is an explanatory view showing a state of an oil level inside the transmission in that state, and FIG. 10 is a rear tilted state of the tractor. And FIG. 11 is an explanatory view showing the state of the oil level in the transmission in that state. 1 ... tractor, 2 ... body, 3 ... engine, 4 ...
Power transmission shaft, 5 ... front wheel, 6 ... rear wheel, 7 ... driving seat, 8 ... lifting hydraulic pump, 9 ... variable speed hydraulic pump,
10 …… Transmission, 11 …… Main transmission, 12 …… Sub transmission, 13…
… PTO transmission, 12 …… Sub transmission, 13 …… PTO transmission, 14…
... mission case, 15 ... front case, 16 ... rear case, 17 ... control plate, 18 ... clutch cover, 19 ... rear cover, 20 ... bulkhead, 21 ... cover wall, 22 ... oil suction chamber , 23 …… Rear oil inlet, 24
...... Front oil suction port, 25 …… Partition plate, 26 …… Partition wall,
27 …… Oil filter suction passage, 28 …… Oil filter discharge passage, 29 …… Oil filter, 30 …… Outer suction chamber, 31 …… Inner discharge chamber, 32 …… Up and down oil suction passage, 33…
… Variation oil intake passage, 34 …… input shaft, 35 …… second shaft, 36…
… Second axis, 37 …… Fourth axis, 38 …… Gear pair, 39 …… Main clutch, 40,41,42 …… Gear pair with hydraulic clutch, 43 ……
Reverse shaft gear / gear pair with hydraulic clutch, 44 …… Input shaft, 45…
… Second axis, 46 …… Third axis, 47 …… Fourth axis, 48 …… Gear pair, 49 …… Main clutch, 50,51,52 …… Gear pair with hydraulic clutch, 53 …… Reverse gear ・Gear pair with hydraulic clutch, 54
…… One-way clutch, 55 …… PTO input gear, 56 ……
Idler gear, 57 …… Gear with hydraulic clutch, 58 …… Rear wheel drive shaft, 59 …… Intermediate shaft, 60 …… Front wheel drive shaft, 61 …… Rear part
PTO shaft, 62 …… PTO intermediate shaft, 63 …… Medium-speed drive gear, 64
...... Intermediate shaft drive gear, 65 …… High speed drive gear, 66
…… Idler gear, 67 …… High speed shifter gear, 68 …… High speed driven gear, 69,70 …… Low speed driven gear, 71 …… Low speed idler gear, 72 …… Front wheel idler gear, 73 …… Low speed shifter gear, 74 …… Driven gear, 75 …… Idler gear, 76 ... Intermittent shifter, 77 ... Front wheel drive gear, 78 ...
… PTO drive gear, 79 …… PTO shifter gear, 80 …… PTO
Driven gear, 81,82,83 …… Intermediate gear, 84 …… Front PTO
Drive gear, 85 …… Front PTO shaft, 86 …… Front PTO driven gear, 87 …… Shifter, 88 …… Level change point, 89 ……
Oil surface.

Claims (1)

[Claims] 1. A transmission is mounted on a vehicle with the longitudinal direction of the transmission case aligned with the longitudinal direction of the vehicle, and the oil level of the lubricating oil filled in the transmission case changes with the posture of the vehicle. In the transmission inclined with respect to the case, the level of the lubricating oil surface in the case does not change with respect to the case regardless of the posture change of the vehicle. A horizontal suction passage oriented in the longitudinal direction of the case is formed integrally with the bottom wall of the case and one side wall and a covering wall at the bottom of the case located below the no-change point, and the case from the level no-change point. The horizontal suction passage on the side where the distance from the hanging point where the perpendicular line descending to the bottom wall intersects with the horizontal suction passage to the end of the horizontal suction passage is short. A partition plate that divides the horizontal suction passage into two parts in the left-right width direction is provided at one end toward the other end of the horizontal suction passage, and among the divided horizontal suction passages divided by the partition plate, One end of the inner divided horizontal suction passage near the center in the width direction is opened in the case, and one end of the outer divided horizontal suction passage of the divided horizontal suction passage near one side wall of the case is closed to the case, Further, the other end of the horizontal suction passage is opened in the case, and a vertical suction passage formed by the one side wall and the covering wall of the case so as to communicate with the suction port of the lubricating oil pump is a side wall of the case. A lubricating oil suction passage for a vehicle transmission, characterized by being opened to an outer divided horizontal suction passage.