JP2006063889A - Pump device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a pump device reducing oil leak rate of oil internally leaking in a pump main body leaking to an outside from a shaft seal and obtaining cooling effect of internal leak oil. <P>SOLUTION: A gear 12 of a gear pump is rotatably supported by a pump shaft 13 which is one unit with the gear 12 in a pump main body 11 and a shaft seal 14 preventing oil leak to the outside is provided between the pump shaft 13 and the pump main body 11. The pump shaft 13 is rotatably retained by a bearing 15 fitted on a pump main body 11 via the gear 12 in an opposite side of the shaft seal 14 side. The gear 12 is provided with a pumping means 25 transferring oil internally leaking to a gap 23 in a shaft seal 14 side from the gear 12 to a gap 24 in an opposite side of the gear 12. This pumping means 25 has a through hole 27 formed to obliquely penetrate in a reverse direction of a rotation direction in relation to an axial direction between both side surfaces of the gear 12. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a pump device that can cope with internal leakage fluid.

  The gear pump device meshes a pair of gears rotatably supported by a pair of pump shafts inside the pump body, with the meshing portion between these gears sandwiched between one side and the pump suction side on the other side. A pump discharge side is provided, and one of the pump shafts is projected to the outside of the pump main body to be a drive shaft that is rotated by an engine or the like.

A shaft seal (gland packing) is provided between the drive shaft and the pump body, and this shaft seal prevents internal leakage fluid from leaking to the outside (see, for example, Patent Document 1).
Japanese Patent Laid-Open No. 9-280182 (page 2-3, FIG. 1-2)

  In this type of pump device, the internal leakage fluid in the pump body may leak from the shaft seal to the outside of the pump body. On the other hand, if leakage to the outside is completely eliminated, the internal leakage fluid in the pump body stagnate, so that the cooling action cannot be obtained and the shaft seal or the like is affected by heat.

  The present invention has been made in view of the above points, and provides a pump device capable of reducing the leakage rate of internal leakage fluid in the pump body from the shaft seal to the outside and obtaining the cooling effect of the internal leakage fluid. It is intended to do.

  The invention according to claim 1 is a pump main body, a pump rotating body provided rotatably inside the pump main body, a pump shaft that rotatably supports the pump rotating body with respect to the pump main body, and the pump A shaft seal provided between the shaft and the pump body to prevent leakage of the internal leakage fluid to the outside, and provided in at least one of the pump rotor and the pump shaft and leaked into the gap on the shaft seal side from the pump rotor. And a pumping means for transferring the fluid to the gap on the opposite side of the pump rotor, and the fluid leaking from the pump rotor to the gap on the shaft seal side is transferred to the gap on the opposite side by the pumping means. By doing so, the pumping means prevents the internal leakage fluid pressure applied to the shaft seal from becoming higher than necessary. In, along with internal leakage leakage of the fluid to the outside from the shaft seal is lowered, that it does not stagnate inside fluid leakage in the pump body, the cooling effect of suppressing temperature rise in the shaft seal is obtained.

  According to a second aspect of the present invention, the pump rotating body in the pump device according to the first aspect is formed in a disk shape, and the pumping means is opposite to the rotational direction with respect to the axial direction between both side surfaces of the pump rotating body. The pump shaft is provided with a through hole formed obliquely in the direction, and when the pump shaft is rotated in one direction, a pumping action is obtained in the through hole formed obliquely in the direction opposite to the rotation direction. Pumping action is obtained in which the internal leakage fluid in the gap on the shaft seal side from the pump rotating body is transferred to the gap on the opposite side through the through hole, and by making the pumping means an oblique through hole, Processing formation is easy.

  The invention according to claim 3 is the pump device according to claim 1 or 2, wherein the bearing is fitted to the pump body on the side opposite to the shaft seal side via the pump rotating body and rotatably holds the pump shaft. A low-pressure part provided on the opposite side of the pump rotor through this bearing and communicated to the drain port to the outside, and on the opposite side by the pumping means from the gap on the shaft seal side of the pump rotor The internal leakage fluid that has been transferred to the gap of the gas further flows through the bearing to the low pressure part that communicates with the drain port, so that the cooling effect of cooling the bearing with fresh internal leakage fluid can be obtained, resulting in a long bearing life. Leading to

  According to a fourth aspect of the present invention, in the pump device according to the third aspect, an internal leakage fluid discharge passage is provided which communicates between the gap opposite to the shaft seal and the low pressure portion via the pump rotating body. Then, after the fluid leaking from the pump rotor to the gap on the shaft seal side is transferred to the gap on the opposite side by the pumping means, it is further flowed to the low pressure part through the internal leakage fluid discharge passage, so that the fluidity of the internal leakage fluid As a result, the leakage of the internal leakage fluid from the shaft seal to the outside is eliminated, and the cooling effect of cooling the shaft seal with the fresh internal leakage fluid is obtained, leading to a longer life of the shaft seal.

  According to the first aspect of the present invention, the internal leakage fluid pressure applied to the shaft seal is more than necessary by transferring the fluid leaking from the pump rotor to the gap on the shaft seal side to the gap on the opposite side by the pumping means. Since the pumping means prevents the increase, the leakage rate of the internal leakage fluid from the shaft seal to the outside can be reduced, and the internal leakage fluid in the pump body is not stagnated to suppress the temperature rise of the shaft seal. A cooling effect that can be obtained.

  According to the second aspect of the present invention, when the pump shaft is rotated in one direction, a pumping action can be obtained in a through hole formed obliquely in a direction opposite to the rotation direction. It is possible to obtain a pumping action in which the internal leakage fluid in the gap on the seal side is transferred to the gap on the opposite side through the through hole, and the machining means can be easily formed by making the pumping means an oblique through hole. it can.

  According to the third aspect of the present invention, the internal leakage fluid transferred from the gap on the shaft seal side of the pump rotor to the gap on the opposite side by the pumping means is further communicated with the drain port through the bearing. As a result, the cooling effect of cooling the bearing with fresh internal leakage fluid can be obtained, and the life of the bearing can be extended.

  According to the fourth aspect of the present invention, after the fluid that has leaked from the pump rotor to the gap on the shaft seal side is transferred to the gap on the opposite side by the pumping means, it is further flowed to the low pressure section through the internal leak fluid discharge passage. Since the fluidity of the internal leakage fluid can be increased, the leakage of the internal leakage fluid from the shaft seal to the outside can be prevented, and the cooling effect of cooling the shaft seal with fresh internal leakage fluid can be obtained. The life of the seal can be extended.

  Hereinafter, the present invention will be described in detail with reference to the embodiment shown in FIGS.

  FIG. 1 shows a first embodiment of a pump device according to the present invention, which is a gear pump device provided coaxially with a variable displacement axial piston pump device.

  This gear pump device is used as an auxiliary hydraulic pump or the like for supplying pilot pressure oil, and a gear 12 as a pump rotor formed in a disk shape is provided inside the pump main body 11. A shaft seal 14 is provided between the pump shaft 13 and the pump body 11 to prevent leakage of internal leakage oil as internal leakage fluid to the outside. It has been.

  A bearing 15 is fitted to the pump body 11 on the opposite side of the shaft seal 14 via the gear 12, and the pump shaft 13 is rotatably held by the bearing 15.

  A swash plate storage portion 17 is provided on the opposite side of the gear 12 via the bearing 15 as a low pressure portion for tilting the swash plate 16 of the variable displacement axial piston pump device. The drain port (not shown) for discharging the internal leakage oil of the variable displacement type axial piston pump device to the outside. The drain port communicates with the oil tank of the pump device through a pipe.

  The pump shaft 13 is a drive shaft that is driven by an engine or the like, and a spline groove portion 21 that is coupled to the engine output shaft is formed in a shaft portion that protrudes to the outside from the pump main body 11, and via the gear 12 Inside, a spline groove portion 22 is provided for mounting a cylinder block or the like of the variable displacement type axial piston pump device.

  Further, the gear 12 is a drive gear, and a driven gear (not shown) rotatably supported by the pump body 11 by a driven shaft (not shown) is engaged with the gear 12. A pump suction part (not shown in the figure) is provided on one side across the meshing part between the gears, and a pump discharge part (not shown in the figure) is provided on the other side. The pump suction part is communicated with an oil tank, and the pump discharge part is communicated with a pilot oil pipe or the like.

  The gear 12 is provided with pumping means 25 for transferring oil leaking from the gear 12 into the gap 23 on the shaft seal 14 side to the gap 24 on the opposite side of the gear 12.

  As shown in FIG. 2A, the pumping means 25 has a plurality of oval through holes 27 arranged concentrically with the pump shaft 13 on the inner peripheral side of the tooth groove 26 of the gear 12. As shown in FIG. 2 (b), the through hole 27 is formed between the both side surfaces of the gear 12 so as to penetrate obliquely in the direction opposite to the rotational direction R with respect to the axial direction.

  Alternatively, as shown in FIG. 3A, a plurality of oval through holes 27 are arranged concentrically with the pump shaft 13 on the inner peripheral side of the tooth groove 26 of the gear 12. 3B, the both sides of the gear 12 are formed so as to penetrate diagonally in the direction opposite to the rotational direction R with respect to the axial direction between the both side surfaces of the gear 12, and further, on the shaft seal 14 side of these through holes 27 Pumping means 25a in which fins 28 are provided in a hook shape along the side surface of gear 12 from one end of the opened ellipse may be used.

  As described above, when there is the gear 12 protruding in the direction intersecting the pump shaft 13 near the shaft seal 14 of the pump shaft 13, a through hole 27 having a pumping action is formed between both side surfaces of the gear 12.

  Next, the function and effect of the embodiment shown in FIG. 1 will be described.

  Pumping means 25 prevents the oil pressure applied to shaft seal 14 from becoming higher than necessary by transferring oil leaking from gear 12 to gap 23 on the side of shaft seal 14 to gap 24 on the opposite side by pumping means 25. To do.

  As a result, the leakage rate of the internal leakage oil from the shaft seal 14 to the outside can be reduced, and the internal leakage oil in the pump main body 11 is not stagnated, so that a cooling effect that can suppress the temperature rise of the shaft seal 14 is obtained. It is done.

  At this time, when the pump shaft 13 is rotated in one direction, as shown in FIG. 2 or FIG. 3, a pumping action is obtained in a through hole 27 formed obliquely in a direction opposite to the rotation direction, and the gear is Thus, a pumping action is obtained in which the internal leakage oil in the gap 23 on the shaft seal 14 side from 12 is transferred to the gap 24 on the opposite side through the through hole 27. Further, by forming the pumping means 25 as the oblique through holes 27, the processing and formation thereof can be facilitated, and the pumping action can be easily obtained.

  Further, as shown in FIG. 3, if a projection-like or blade-like fin 28 is provided for each through-hole 27, the oil leaked from the gear 12 to the gap 23 on the shaft seal 14 side by these fins 28. It can be efficiently guided into the through hole 27, and the pumping efficiency can be increased.

  Further, the internal leakage oil transferred from the gap 23 on the shaft seal 14 side of the gear 12 to the gap 24 on the opposite side by the pumping means 25 further passes through the bearing 15 and is communicated with the drain port. Therefore, the cooling effect of cooling the bearing 15 with fresh internal leakage oil can be obtained, and the life of the bearing 15 can be extended.

  Next, FIG. 4 shows a second embodiment of the pump device according to the present invention. In addition, the same code | symbol is attached | subjected to the part similar to embodiment shown by FIG. 1, and the description is abbreviate | omitted.

  An internal leakage oil discharge passage 29 is formed between the gap 24 opposite to the shaft seal 14 via the gear 12 and the swash plate storage portion 17 as a low pressure portion, and serves as an internal leakage fluid discharge passage that communicates these. ing. That is, an oil return path is formed on the side opposite to the shaft seal 14 via the pumping means 25.

  Then, after the oil leaked from the gear 12 to the gap 23 on the shaft seal 14 side is transferred to the gap 24 on the opposite side by the pumping means 25, the oil is further flowed to the swash plate storage portion 17 through the internal leakage oil discharge passage 29. Since the fluidity of the internal leakage oil can be enhanced, oil leakage from the shaft seal 14 to the outside can be prevented, and a cooling effect for cooling the shaft seal 14 with fresh internal leakage oil can be obtained. Can extend the service life.

  As shown in the first and second embodiments described above, the pumping means 25 prevents the hydraulic pressure applied to the shaft seal 14 from becoming higher than necessary, thereby reducing the oil leakage rate from the shaft seal 14. In addition, it is possible to obtain a cooling effect capable of suppressing the temperature rise of the shaft seal 14 by not stagnating the internal leakage oil in the pump body 11. Further, the internal leakage oil flows through the bearing 15, so that a cooling effect of the bearing 15 can be obtained and the life of the bearing 15 can be extended.

  The present invention is not limited to that shown in the above embodiment, and the pumping means 25 may be provided on the pump shaft 13 near the shaft seal 14. For example, a pumping groove or the like may be formed on the pump shaft 13 itself, or a pumping blade or the like may be formed on the pump shaft 13 itself.

It is sectional drawing which shows 1st Embodiment of the pump apparatus which concerns on this invention. (a) is a perspective view which shows an example of the pump rotary body of a pump apparatus same as the above, (b) is the IIb-IIb sectional view taken on the line of (a). (a) is a perspective view which shows the other example of the pump rotary body of a pump apparatus same as the above, (b) is the IIIb-IIIb sectional view taken on the line of (a). It is sectional drawing which shows 2nd Embodiment of the pump apparatus which concerns on this invention.

Explanation of symbols

11 Pump body
12 Gear as pump rotor
13 Pump shaft
14 Shaft seal
15 Bearing
17 Swash plate storage as a low-pressure part
23, 24 gap
25 Pumping means
27 Through hole
29 Internal leakage oil discharge passage as internal leakage fluid discharge passage

Claims (4)

A pump body;
A pump rotator provided rotatably inside the pump body;
A pump shaft that rotatably supports the pump rotating body with respect to the pump body;
A shaft seal provided between the pump shaft and the pump body to prevent leakage of the internal leakage fluid to the outside;
A pump comprising: pumping means provided on at least one of the pump rotor and the pump shaft and configured to transfer the fluid leaked into the gap on the shaft seal side from the pump rotor to the gap on the opposite side of the pump rotor. apparatus. The pump rotor is formed in a disk shape,
The pumping device according to claim 1, wherein the pumping means includes a through-hole formed so as to penetrate obliquely in a direction opposite to the rotational direction with respect to the axial direction between both side surfaces of the pump rotating body. A bearing that is fitted to the pump body on the side opposite to the shaft seal side via the pump rotor, and rotatably holds the pump shaft;
The pump device according to claim 1, further comprising: a low-pressure portion provided on a side opposite to the pump rotating body via the bearing and communicated with an external drain port. 4. The pump device according to claim 3, further comprising an internal leakage fluid discharge passage communicating between the gap opposite to the shaft seal and the low pressure portion via the pump rotating body.

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