JP2015090213A - Pump spline lubrication structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a pump spline lubrication structure that can supply lubricating oil to a pump spline of a hydraulic pump without providing another hydraulic pump and without reducing the amount of clutch lubricating oil.SOLUTION: Relief oil of a relief valve 19 for protecting a torque converter is supplied to a spline fitting part 22 between a pump shaft 17a of a hydraulic pump 17 and a pump drive gear 16 from an oil supply port 13a through a pump spline lubricating oil passage. The oil supplied from the oil supply port 13a is stored in gaps X1 and X2 by bearings 20 and 21 with seals.

Description

  The present invention relates to a pump spline lubrication structure for supplying lubricating oil to a spline engaging portion of a pump shaft of a hydraulic pump mounted on an industrial vehicle or a cargo handling vehicle.

  2. Description of the Related Art Conventionally, industrial vehicles such as forklifts and construction vehicles are equipped with a hydraulic pump that sends hydraulic oil to hydraulic equipment for performing cargo handling work, a hydraulic pump that sends wet brakes and oil that cools axles, and the like.

  Generally, in this type of hydraulic pump, the pump shaft and the shaft hole of the pump shaft drive gear are connected by spline fitting, and the spline fitting portion (hereinafter also referred to as pump spline) is poorly lubricated. Problems such as fretting wear occur. There are two types of lubrication for pump splines: natural lubrication due to splash of oil adhering to the pump shaft drive gear, and forced lubrication by branching clutch lubrication oil.

Japanese Patent Laid-Open No. 4-839099

  Natural lubrication has a simple structure, but it needs to be confirmed by a bench test. Forced lubrication can secure the amount of lubricating oil, but a separate hydraulic pump and lubricating oil circuit are required to supply lubricating oil to the pump spline. There's a problem. Especially in the bench test, the spline part of the pump shaft of the hydraulic pump is completely degreased before installing the hydraulic pump, rotating the torque converter, sweeping from idle rotation to maximum speed, stopping and disassembling. Therefore, a very laborious work of checking the lubrication state of the spline part at all speed stages including neutral is required. In forced lubrication, if the clutch lubricating oil is branched to lubricate the pump spline, the amount of clutch lubricating oil is reduced, and the cooling performance of the clutch may be impaired.

  Therefore, a main object of the present invention is to provide a pump spline lubrication structure that can solve the above problems.

  In order to achieve the above object, the pump spline lubrication structure according to the present invention supplies a relief oil for a torque converter protection relief valve to a spline fitting portion between a pump shaft of a hydraulic pump and a pump drive gear. A road is provided.

  Oil reservoirs for storing relief oil discharged from the pump spline lubricating oil passage so that at least a part of the spline fitting part of the pump shaft is immersed are formed on both axial sides of the pump drive gear. Is preferred.

  The oil reservoir is sealed by a pair of sealed bearings interposed between bosses on both sides in the axial direction of the pump drive gear and bosses protruding on the inner wall surface of the casing that houses the pump drive gear. Preferably it is.

  It is preferable that an overflow portion for allowing the oil in the oil reservoir portion to overflow at a predetermined level is formed on a boss protruding from the inner wall surface of the casing.

  The pump spline lubricating oil passage is preferably formed by perforation of the casing from the relief port of the torque converter protection relief valve to the outlet of the pump spline lubricating oil passage.

  According to the present invention, since the relief oil of the relief valve for protecting the torque converter is supplied to the spline fitting portion between the pump shaft of the hydraulic pump and the pump drive gear, without providing a separate hydraulic pump, In addition, the lubricating oil can be supplied to the pump spline of the hydraulic pump without reducing the clutch lubricating oil amount.

  When the engine speed is low, the amount of relief oil discharged is reduced or eliminated. However, lubricating oil can be secured by storing the relief oil in the oil reservoir.

  Further, by sealing the oil reservoir with a bearing with a seal, the lubricating oil can be stored with a simple seal structure.

  Further, by providing the overflow part, a predetermined amount of lubricating oil can be secured in the oil reservoir part.

1 is a hydraulic circuit diagram showing an embodiment of a hydraulic circuit of a torque converter transmission (power shift transmission) of a cargo handling vehicle to which a spline lubrication structure according to the present invention is applied. 1 is a schematic front view showing an embodiment of a torque converter type transmission to which a spline lubrication structure according to the present invention is applied. It is a horizontal sectional view which follows the III-III line of FIG. It is a principal part longitudinal cross-sectional front view which follows the IV-IV line of FIG.

  An embodiment of a pump spline lubrication structure according to the present invention will be described below with reference to FIGS. In addition, the same code | symbol was attached | subjected to the same component through the whole figure.

  FIG. 1 is a hydraulic circuit diagram of a torque converter transmission (power shift transmission) of a cargo handling vehicle to which a spline lubrication structure is applied, and includes a torque converter 1, forward and reverse 1-speed clutches F 1 and R, and forward 2. The hydraulic circuit diagram which supplies the clutch lubricating oil while disengaging the speed clutch F2 is shown. The pressurized pressure oil in the oil tank 4 at the bottom of the transmission casing (see reference numeral 15 in FIG. 2) by the charge pump 3 to which power is transmitted from the engine 2 is supplied to the torque converter 1 and passes through the oil cooler 5. Each clutch F1, R is supplied as lubricating oil, and also supplied to the clutch F2 as lubricating oil. On the other hand, the pressure oil branched from the charge pump 3 on the upstream side of the main pressure regulating valve 6 passes through the inching valve 7 and further back and forth. Through the first forward speed solenoid valve 8 and the forward second speed solenoid valve 9, the wet multi-plate clutch F 1, R, F 2 is supplied as intermittent hydraulic fluid.

  The hydraulic fluid supplied from the charge pump 3 to the torque converter 1 is regulated by the main pressure regulating valve 6 and the torque converter protecting relief valve 10. A lubrication relief valve 11 is also provided for protecting a lubricating oil circuit that sends lubricating oil from the torque converter 1 to each of the clutches F1, R, and F2. Reference numeral 12 denotes an accumulator.

  As will be described later, the relief oil relieved from the relief port 10a of the torque converter protection relief valve 10 passes through the pump spline lubricating oil passage 13 to a spline fitting portion between the pump shaft of the cargo handling hydraulic pump and the pump drive gear. Supplied.

  2 is a front view showing a schematic external view of a transmission case to which a cargo handling hydraulic pump is attached, FIG. 3 is a horizontal sectional view taken along line III-III in FIG. 2, and FIG. 4 is a longitudinal front view taken along line IV-IV in FIG. FIG.

  A casing 15A (15a, 15b) for accommodating the pump drive gear 16 is attached to the upper part of the transmission case 15 in which the torque converter 1 and the clutch (see FIG. 1) are accommodated, and the pump drive gear 16 is attached to the casing 15A. A cargo handling hydraulic pump 17 that is spline-fitted to is attached. The casing 15 </ b> A constitutes a part of the transmission case 15.

  In the illustrated example, the cargo handling hydraulic pump 17 is provided at a position higher than the oil level H in the oil tank (drain tank) in the transmission case 15 and for cooling a brake and an axle (not shown). Arranged above the hydraulic pump 18 for supplying oil. The rotating shaft of the hydraulic pump 18 is at a position lower than the oil level H and is always immersed in the oil in the oil tank, so that the lubricating oil is constantly supplied to the spline fitting portion of the rotating shaft. Although not shown in FIG. 2, the charge pump (reference numeral 3 in FIG. 1) is installed in the casing coaxially with the rotating shaft of the hydraulic pump 18.

  The pump drive gear 16 has bosses 16b and 16c formed on both sides in the axial direction of the gear 16a, a through hole 16d formed in the rotational axis direction, and a spline 16e formed on the inner peripheral surface of the through hole 16d. A spline 17 b is also formed on the peripheral surface of the pump shaft 17 a of the cargo handling hydraulic pump 17. When the spline 16e of the pump drive gear 16 and the spline 17b of the pump shaft 17a of the cargo handling hydraulic pump 17 are engaged with each other and engaged with each other, the two are driven and connected. The pump drive gear 16 is transmitted with the rotational drive force from the torque converter 1 through the meshing gear 19 and the torque converter gear (not shown).

  The pump drive gear 16 is rotatably supported by bosses 15c and 15d protruding from the inner wall surface of the casing 15A via bearings 20 and 21 with seals. Steps 15e and 15f are formed on the inner peripheral surfaces of the bosses 15c and 15d of the casing 15A, while step portions 16f and 16g are also formed on the outer peripheral surfaces of the bosses 16b and 16c of the pump drive gear 16, and these steps are formed. The bearings 20 and 21 with seals are attached so as not to move in the axial direction of the bosses 16b and 16c by the portions 15e, 15f, 16f, and 16g.

  The bearings 20 and 21 with seals are provided with seals 20a and 21a on one side, particularly on the side close to the gear 16a, to prevent oil leakage by closing the space between the inner ring and the outer ring of the bearing. , 21 is also supplied with lubricating oil. On the other hand, the pump drive gear 16 can be supported by a bearing having a seal attached to the side far from the gear 16a. As this type of seal, a known contact seal or the like can be used.

  Gaps X1 and X2 are provided on both axial sides of the pump drive gear 16. The gap X1 is formed by a recess 15g that forms a step 15e of the casing 15A. A lubricating oil inlet 13a is formed on the inner wall surface of the casing 15A facing the gap X1. The oil filling port 13 a is an outlet of the pump spline lubricating oil passage 13. The pump spline lubricating oil passage 13 is formed by drilling from the relief port 10a of the torque converter protection relief valve 10 into the plate thickness forming the casing 15A without using external piping. The relief valve 10 for protecting the torque converter is disposed on the upper part of the casing 15A.

  The oil discharged from the oil filling port 13a through the pump spline lubricating oil passage 13 flows into the gap X1, and the gap X1 is closed by the bearing 20 with the seal. The spline fitting portion 22 is reached. The oil is accumulated in the gap X2 on the opposite side by the bearing 21 with the seal. In this way, oil reservoirs capable of storing oil are formed in the gaps X1 and X2 closed by the sealed bearings 20 and 21, and lubricating oil can be supplied to the spline fitting portion 22.

  Referring to FIG. 4, an overflow portion 23 for discharging the oil accumulated in the oil reservoir X from the oil reservoir X at a predetermined liquid level is formed on the boss 15c of the casing 15A. In the illustrated example, the overflow portion 23 is formed so as to dent a part of the protruding end surface of the boss 15c protruding in an annular shape from the inner wall surface of the casing 15A, as shown in FIGS. For example, it can be formed by providing a hole in the side wall of the boss 15c. The overflow portion 23 is formed at a height position where at least a part of the spline fitting portion 22 of the pump shaft 17 a is immersed by the relief oil discharged from the pump spline lubricating oil passage 13. The oil that overflows from the overflow section 23 flows down to the drain tank at the bottom of the transmission case 15.

  As described above, in the present invention, the relief oil of the torque converter protection relief valve 10 is supplied to the spline fitting portion 22 between the pump shaft 17a of the cargo handling hydraulic pump 17 and the pump drive gear 16. The lubricating oil can be supplied to the pump spline fitting portion 22 of the cargo handling hydraulic pump 17 without providing a hydraulic pump for separately feeding the lubricating oil and without reducing the clutch lubricating oil amount.

  Further, when the engine speed is low, the amount of relief oil discharged from the torque converter protection relief valve 10 is reduced or eliminated. However, by storing the relief oil in the oil reservoir X, lubricating oil can be secured. it can.

  Further, by sealing the oil reservoir portion X with the sealed bearings 20 and 21, the lubricating oil can be stored with a simple seal structure. By providing the overflow portion 23, a predetermined amount of lubricating oil can be stored in the oil reservoir portion X. Can be stored.

  In the above embodiment, the pump spline lubrication structure of the cargo handling hydraulic pump has been described. However, when the hydraulic pump 18 is provided at a position higher than the oil level H in the oil tank, the same pump spline lubrication as the cargo handling hydraulic pump is performed. A structure can be adopted.

DESCRIPTION OF SYMBOLS 1 Torque converter 10 Relief valve 10a for torque converter protection Relief port 13 Pump spline lubricating oil path 15d, 15d Boss 16 Pump drive gear 16b, 16c Boss 17 Hydraulic pump 17a for cargo handling Pump shaft 20, 21 Bearing 22 with seal Spline fitting part 23 Overflow section X Oil reservoir

Claims (5)

  A pump spline lubrication structure comprising a pump spline lubricating oil passage for supplying relief oil of a torque converter protection relief valve to a spline fitting portion between a pump shaft of a hydraulic pump and a pump drive gear.   Oil reservoirs for storing relief oil discharged from the pump spline lubricating oil passage so that at least a part of the spline fitting part of the pump shaft is immersed are formed on both axial sides of the pump drive gear. The pump spline lubrication structure according to claim 1.   The oil reservoir is sealed by a pair of sealed bearings interposed between bosses on both sides in the axial direction of the pump drive gear and bosses protruding on the inner wall surface of the casing that houses the pump drive gear. The pump spline lubrication structure according to claim 2, wherein the pump spline lubrication structure is provided.   4. The pump spline lubrication according to claim 3, wherein an overflow portion for allowing the oil in the oil reservoir portion to overflow at a predetermined level is formed on a boss protruding from an inner wall surface of the casing. Construction. The pump spline lubricating oil passage is formed by perforation of a casing from a relief port of a relief valve for protecting a torque converter to an outlet of the pump spline lubricating oil passage. Pump spline lubrication structure according to the above.

Images