JP5557722B2 - PTO lubricator - Google Patents

Description

  The present invention relates to a lubrication device for a PTO (power take-off device) that extracts engine output as power for a work machine or the like.

  In truck mixers and pump vehicles (for example, fire trucks), engine output is used to drive working machines such as agitators and water discharge pumps, and a power take-off device (hereinafter referred to as “PTO”) for taking out the engine output. Abbreviated.) Is equipped. Some PTOs transmit engine output from the engine crankshaft to the PTO output shaft via an idler gear, and a bushing is used as a bearing for the gear as a PTO having an idler gear on such a power transmission path. However, in a PTO equipped with an idler gear, a high load during operation may be applied to the bushes that constitute the bearing, and therefore it is necessary to sufficiently cool the bush. Although bearings are not directly targeted for cooling, there are the following techniques for cooling a hydraulic pump driven by a PTO (Patent Document 1). A cooling fan attached to the PTO output shaft sends air to the housing of the hydraulic pump to cool the entire hydraulic pump.

JP 2006-321339 A

  However, in the PTO including a plurality of gears on the power transmission path including the idler gear, the arrangement of the bearings (bushings) is likely to be restricted due to the layout of the gear train, and the pressure receiving area of the bushings tends to be narrowed. The heat generated by the bush during operation is a problem. In order to ensure sufficient cooling performance against heat generation of the bush due to high load, it is conceivable to adjust the amount of lubricating oil supplied to the bush by devising the oil passage structure inside the PTO. Since measures such as design changes are necessary for the response by, it cannot be easily achieved. On the other hand, in the technique described in Patent Document 1, since the entire hydraulic pump is cooled by the cooling fan and the bush cannot be cooled locally, the required cooling performance cannot always be ensured.

  Therefore, the present invention achieves cooling of the bush by a simple method that does not require a change in the internal oil supply passage structure or the like in a PTO that includes an idler gear on the power transmission path and uses a bush for the bearing of the idler gear. Objective.

The present invention provides a lubrication device for a PTO (power take-off device). The apparatus which concerns on this invention has the idler gear which transmits an engine output to a PTO output shaft in the form, The apparatus which supplies lubricating oil to the said bush of PTO comprised by the bearing of this idler gear including a bush A housing for housing the bush, wherein an oil supply port that receives supply of lubricating oil, and an internal oil supply passage that extends from the oil supply port to the inside of the housing and supplies the lubricating oil to the bushing, A formed housing; a first cooler that cools the lubricating oil upstream of an oil gallery associated with the flow of the lubricating oil inside the engine; and an external oil supply passage that branches off from the oil gallery and connects to the oil supply port of the housing And a second cooler that cools the lubricating oil supplied to the oil supply port to a temperature lower than the cooling temperature of the first cooler. It is.

  According to the present invention, in the PTO that includes the idler gear on the path (power transmission path) for transmitting the engine output to the PTO output shaft and uses the bush for the bearing that supports the idler gear, the first provided on the upstream side of the oil gallery. The lubricating oil cooled to a predetermined temperature (temperature sufficient for cooling the engine itself) by the cooler is cooled to a lower temperature by the second cooler interposed in the external oil supply path outside the housing, and this low temperature lubrication is performed. Oil can be supplied to the bush through the internal oil supply passage of the housing to cool the bush. Therefore, the bushing constituting the idler gear bearing can be cooled by a simple method that does not require a change in the internal oil supply passage structure and the durability of the bushing can be improved.

Schematic which shows the whole structure of the lubrication apparatus of PTO (power take-off apparatus) which concerns on 1st Embodiment of this invention. Schematic diagram mainly showing changes from the first embodiment of the PTO according to the second embodiment of the present invention. Schematic diagram mainly showing changes from the first embodiment of the PTO according to the third embodiment of the present invention.

Embodiments of the present invention will be described below with reference to the drawings.
FIG. 1 shows the overall configuration of a lubricating device for a PTO (power take-off device) according to a first embodiment of the present invention as seen from the front side of the vehicle.
The PTO according to the present embodiment is mounted on the rear side of the engine in a vehicle with a work machine such as a truck mixer, and is used, for example, to extract power for driving the mixer of the truck mixer. Of course, as another application example, it may be used to drive a pump in a pump vehicle such as a fire engine. This means that the present invention can also be applied to a PTO that operates when the vehicle is running or stopped.

  In the PTO according to the present embodiment, the PTO output shaft 4 extends toward the back side of the vehicle (backward with respect to the plane of FIG. 1), and the water discharge pump is connected via a power connection / disconnection device (not shown) such as an electromagnetic clutch. (Specifically, the drive shaft). The engine output (torque) is transmitted to the driven gear 14 coupled to the PTO output shaft 4 from the drive gear 6 attached coaxially to the crankshaft of the engine (the center is indicated by reference numeral 2). A plurality of idler gears 8, 10, 12 are provided on a power transmission path for transmitting engine output from the crankshaft 2 to the PTO output shaft 4. In this embodiment, among these gears 8-12, a gear is provided. A bearing of a relatively small-diameter idler gear 12 that meshes with the driven gear 14 located at the last stage in the row includes a bush 22. It goes without saying that bushes may be used for bearings of the gears 8 and 10 other than the idler gear 12.

  The bush 22 and the bearings of all the idler gears 8 and 10 located on the power transmission path in this embodiment are accommodated in the housing H, are fixed in the housing H, and support the rotation shafts of the idler gears 8 to 12. (FIG. 1 conceptually shows only the positional relationship between the housing H and the gears 6 to 14, and the frame indicated by the symbol H in the drawing does not mean the exact shape of the housing H). . The lubrication device for PTO according to the present embodiment includes a part of the housing H as a component.

The housing H is provided on the side surface of the housing H, and receives an oil supply port h1 that receives supply of engine oil that is “lubricating oil”. The housing H extends inward from the oil supply port h1 to the housing H and communicates with the friction surface of the bush 22 to supply oil. And an internal oil supply passage p <b> 1 for supplying the engine oil supplied to the port h <b> 1 to the bush 22. Here, the engine oil is cooled to a predetermined temperature (for example, 100 ° C.) by an engine oil cooler (not shown) which is a “first cooler” (located upstream of the oil gallery related to the flow of engine oil). After that, it is supplied to the engine. The engine oil supplied to the engine is guided from the oil gallery inside the engine to the oil supply port h1 through an external oil supply path that is connected to the oil supply port h1. In the present embodiment, a PTO local cooling oil cooler 32a that is a “second cooler” is provided in the middle of the external oil supply passage, and engine oil cooled by the engine oil cooler is used as the PTO local cooling oil cooler 32a. Is cooled to a lower temperature (for example, 70 ° C.) and supplied to the fuel filler h1. Therefore, in the present embodiment, engine oil having a lower temperature than that in the oil gallery is supplied to the oil supply port h1, and the bush 22 is lubricated and cooled by such low-temperature engine oil.

  In the present embodiment, the PTO local cooling oil cooler 32a is a first heat transfer tube (for example, made of metal such as copper and carbon steel) formed in a spiral shape (or meandering shape) as shown in FIG. The pipe member 322 extends the substantial passage length of the external oil supply passage, and is disposed at a position where the traveling wind hits on the vehicle, so that the engine oil after cooling by the engine oil cooler can be reduced. , Allowing cooling to lower temperatures. In the present embodiment, the first cooling pipe member 322 of the PTO local cooling oil cooler 32 a is disposed adjacent to the side of the housing H.

  Thus, according to the present embodiment, PTO local cooling is performed on the bush 22 of the bearing that supports the relatively small diameter idler gear 12 among the idler gears provided on the power transmission path that transmits the engine output to the PTO output shaft 4. By supplying engine oil cooled to a lower temperature by the oil cooler 32a, appropriate cooling of the bush 22 can be achieved by a simple method that does not require measures such as a design change regarding the internal oil supply passage p1, and the bush 22 Durability can be improved. According to the present embodiment, the engine oil supplied to the bushing 22 is not increased, but the engine oil supplied to the bushing 22 is reduced by reducing the temperature of the engine oil. Compared with the case of cooling only with an oil cooler, the flow rate of engine oil required to obtain a required cooling effect can be reduced. In the present embodiment, the cooling itself by the PTO local cooling oil cooler 32a is performed by the traveling wind, so that efficient cooling is possible.

Hereinafter, other embodiments of the present invention will be described.
FIG. 2 schematically shows the configuration of a lubricating device for PTO according to a second embodiment of the present invention only for the main part thereof. In this embodiment (FIG. 2) and the third embodiment (FIG. 3) of the present invention described later, the configuration of the gear train provided in the engine output transmission path is the same as that of the first embodiment (FIG. 1). The engine output is transmitted to the driven gear 14 coupled to the PTO output shaft 4 from the drive gear 6 mounted coaxially with the crankshaft 2 through a plurality of idler gears 8, 10, 12 supported by the bush 22. The

  In the present embodiment, the PTO local cooling oil cooler 32b, which is the “second cooler”, includes a heat-conductive second cooling pipe member 324 formed in a spiral shape and a cooling fan attached to the PTO output shaft 4 ( 326, which corresponds to a “first cooling fan” and indicated by a dotted line in the drawing. The second cooling pipe member 324 is disposed substantially concentrically with the PTO output shaft 4 between a housing H (not shown) and the cooling fan 326, and the cooling air generated by the cooling fan 326 is applied to the pipe member 324 to force it. To cool down. Although not clearly shown in FIG. 2, the downstream end of the second cooling pipe member 324 is connected to the oil supply port h <b> 1 on the side surface of the housing H.

  According to the present embodiment, the cooling fan 326 is attached to the PTO output shaft 4, and the engine oil flowing through the second cooling pipe member 324 is cooled by the cooling air from the cooling fan 326. Even when the work is performed while the vehicle is stopped, the engine oil can be cooled, and the bush 22 can be sufficiently cooled.

  FIG. 3 schematically shows the configuration of a lubricating device for PTO according to a third embodiment of the present invention only for the main part thereof. 3A shows the configuration of the main part of the PTO in a state where the housing H is viewed from the side, and FIG. 3B shows the configuration of the main part in a state where the housing H is viewed from the front. Yes.

  In the present embodiment, the PTO local cooling oil cooler 32c, which is a “second cooler”, is disposed adjacent to the housing H on the front side of the vehicle, and has a cooling casing 328 that is flange-coupled to the housing H. , And a cooling fan (corresponding to a “second cooling fan”) 330 attached to the PTO output shaft 4. The cooling casing 328 is formed therein with a cooling passage p2 (indicated by a dotted line in FIG. 3b) connected to the internal oil supply passage p1 of the housing H, and a plurality of heat radiation fins f, f. It has been. The cooling fan 330 is attached to the PTO output shaft 4 so as to be able to blow air toward the outer surface of the cooling casing 328 provided with the radiation fins f. An oil inlet h2 is formed in the upper peripheral surface of the cooling casing 328, and engine oil supplied from the oil gallery via the external oil supply passage flows into the cooling passage p2 of the cooling casing 328 from the oil inlet h2. Then, it is cooled in the process of passing through the cooling passage p2. The cooled engine oil is supplied to the bush 22 of the idler gear 12 through the internal oil supply path p1 of the housing H, and lubricates and cools the bush 22.

  According to the present embodiment, the cooling casing 328 is installed adjacent to the housing H, the engine oil that has passed through the cooling passage p2 of the cooling casing 328 is supplied to the bush 22, and the radiation fins f are provided. Cooling air is sent to the outer surface of the cooling casing 328 by the cooling fan 330, and the engine oil is cooled in the process of passing through the cooling passage p2, so that the engine oil is supplied during the stop operation as in the second embodiment. Cooling of the bushing 22 can be achieved.

  2 ... Center of crankshaft, 4 ... PTO output shaft, 6 ... Drive gear, 8 ... Idler gear, 10 ... Idler gear, 12 ... Idler gear, 14 ... Drive gear, 22 ... Bearing (bush), 32a, 32b, 32c ... PTO local cooling Oil cooler (second cooler), 322, first cooling pipe member, 324, second cooling pipe member, 326, first cooling fan, 328, cooling casing, 330, second cooling fan, H, housing, h1 ... oil supply port, p1 ... internal oil supply path, f ... heat radiation fin, h2 ... oil inlet, p2 ... cooling passage.

Claims (4)

An apparatus for supplying lubricating oil to a bushing of a PTO having an idler gear for transmitting engine output to a PTO output shaft, and a bearing of the idler gear including the bushing,
A housing for housing the bush,
An oil supply port that receives the supply of lubricating oil ;
An internal oil supply passage extending from the oil supply port to the inside of the housing and supplying the lubricating oil to the bush;
A housing formed with,
A first cooler that cools the lubricating oil upstream of an oil gallery associated with the flow of lubricating oil inside the engine;
The lubricating oil that is branched from the oil gallery and is connected to the external oil supply passage connected to the oil supply port of the housing and is supplied to the oil supply port is cooled to a temperature lower than the cooling temperature by the first cooler. A second cooler;
A PTO lubrication device comprising:   The second cooler is configured to include a first cooling pipe member that is formed in a spiral shape or a meandering shape, extends the substantial passage length of the external oil supply passage, and is disposed at a position on the vehicle where the traveling wind hits. The lubricating device for PTO according to claim 1. The second cooler is
A second cooling pipe member formed in a spiral shape and disposed substantially concentrically with the PTO output shaft;
A first cooling fan attached to the PTO output shaft so as to be able to induce cooling air that strikes the second cooling pipe member;
The lubricating device for PTO according to claim 1, comprising: The second cooler is
A cooling casing in which a cooling passage connected to the internal oil supply passage of the housing is formed, the cooling casing being disposed adjacent to the housing and provided with a plurality of radiation fins on the outer surface thereof;
A second cooling fan attached to the PTO output shaft so as to be capable of inducing cooling air hitting the heat dissipating fins;
The lubricating device for PTO according to claim 1, comprising: