JP2016145539A - Pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent oil leakage from an oil seal.SOLUTION: An oil pump 11 for discharging a fluid by rotating an inner rotor 24 includes a case body 21 and a case cover 22 opposing to the same. It also includes: a pump case 20 for accommodating the inner rotor 24 between the case body 21 and the case cover 22; a crank shaft 15 for penetrating the case body 21 and the case cover 22 and connected to the inner rotor 24; and an oil seal 25 provided at a through-hole 21a of the case body 21 through which the crank shaft 15 penetrates, and for blocking a gap between the through-hole 21a and the crank shaft 15. At a fitting shaft part 30 of the crank shaft 15 fitted in the inner rotor 24, a flow passage groove 40 is formed for partitioning a communication flow passage 41 between the inner rotor 24 and the fitting shaft part 30. The communication flow passage 41 includes a first opening end opening to the case body 21 side and a second opening end opening to the case cover 22 side. The flow passage groove 40 extends to the oil seal 25 side over the inner rotor 24.SELECTED DRAWING: Figure 3

Description

  The present invention relates to a pump device that discharges fluid by rotating a pump rotor.

  Examples of pump devices that discharge fluid include an oil pump and a water pump. For example, an engine or a transmission is provided with an oil pump that discharges oil for lubrication or control as a pump device. Further, the engine is provided with a water pump that discharges cooling water as a pump device.

  These pump devices often include a sealing member such as an oil seal from the viewpoint of preventing oil leakage and water leakage. For example, an oil pump for an engine has a pump case attached to an end face of an engine block. The crankshaft of the engine is connected to the pump rotor housed in the pump case. As described above, the crankshaft connected to the pump rotor has its tip exposed to the outside from the engine block, and an oil seal is assembled to the tip of the crankshaft (see Patent Document 1).

  By the way, as described in Patent Document 1, a seal chamber is defined between the pump rotor and the oil seal, and oil leaked from the gap between the pump rotor flows into the seal chamber. Further, if oil flows excessively into the seal chamber, there is a risk that oil leakage will occur from the oil seal. Therefore, in the oil pump described in Patent Document 1, a groove is formed on the inner peripheral surface of the pump rotor fitted to the crankshaft, and oil is discharged from the seal chamber to the crank chamber through the groove.

Japanese Utility Model Publication No. 4-104182

  When a groove is formed in the pump rotor as in the oil pump described in Patent Document 1, the oil in the seal chamber is taken in from the side surface of the pump rotor. However, it is difficult to take in oil from the side surface of the rotating pump rotor, and it is difficult to positively discharge the oil in the seal chamber.

  An object of the present invention is to prevent leakage of fluid from a seal member.

  The pump device according to the present invention is a pump device that rotates a pump rotor to discharge a fluid, and includes a first case portion and a second case portion facing the first case portion, and the first case portion and the second case. A pump case that accommodates the pump rotor between the first portion, the first case portion and the second case portion, and a pump drive shaft connected to the pump rotor, and the pump drive shaft passes therethrough A fitting shaft portion of the pump drive shaft that is provided in the through hole of the first case portion and has a seal member that closes a gap between the through hole and the pump drive shaft, and is fitted to the pump rotor. A channel groove for defining a communication channel is formed between the pump rotor and the fitting shaft portion, and the communication channel includes a first opening end that opens to the first case portion side and the first 2 with a second opening end that opens to the case part side, Kiryuromizo extends the sealing member side beyond the pump rotor.

  According to the present invention, since the flow path groove formed in the fitting shaft portion of the pump drive shaft extends to the seal member side beyond the pump rotor, the fluid is positively discharged from the seal member side. Can do. Thereby, fluid leakage from the seal member can be prevented.

It is the schematic which shows an example of the power unit mounted in a vehicle. It is sectional drawing which shows an oil pump along the AA line of FIG. (A) is sectional drawing which shows an oil pump along the AA line of FIG. 2, (b) is sectional drawing which shows an oil pump along the BB line of FIG. (A) is a disassembled perspective view which shows a part of oil pump, (b) is a perspective view which shows a part of oil pump. (A) is an enlarged view showing a crankshaft and an inner rotor of FIG. 3 (a), (b) is a sectional view taken along line BB of FIG. 5 (a), and (c) is FIG. It is sectional drawing in alignment with CC line | wire. It is an image figure which shows the flow of the oil taken in into a communication flow path. It is sectional drawing which shows an oil pump along the AA line of FIG. (A) is sectional drawing which shows an oil pump along the AA line of FIG. 7, (b) is sectional drawing which shows an oil pump along the BB line of FIG. (A) is a disassembled perspective view which shows a part of oil pump, (b) is a perspective view which shows a part of oil pump. It is an image figure which shows the flow of the oil taken in into a communication flow path. It is sectional drawing which shows an oil pump along the BB line of FIG. (A) is sectional drawing which shows an oil pump along the AA line of FIG. 11, (b) is sectional drawing which shows an oil pump along the BB line of FIG. It is a disassembled perspective view which shows a part of oil pump. It is an image figure which shows the flow of the oil taken in into a communication flow path. (A) is an enlarged view showing the crank pulley and the inner rotor of FIG. 12 (a), (b) is a sectional view taken along line BB of FIG. 15 (a), and (c) is FIG. 15 (a). It is sectional drawing in alignment with CC line | wire.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. FIG. 1 is a schematic diagram showing an example of a power unit 10 mounted on a vehicle. The power unit 10 shown in FIG. 1 is provided with an oil pump (pump device) 11 according to an embodiment of the present invention. As shown in FIG. 1, the power unit 10 includes an engine 12 and a transmission 13. A crankshaft (pump drive shaft) 15 is rotatably supported on the engine block 14 constituting the engine 12. A crank pulley 16 is connected to one end of the crankshaft 15, and a torque converter 17 is connected to the other end of the crankshaft 15.

  An oil pump 11 driven by a crankshaft 15 is provided at the end of the engine block 14. The oil pump 11 that discharges oil (fluid) has a pump case 20 in which a suction port and a discharge port (not shown) are formed. The pump case 20 includes a case main body (first case portion) 21 provided in the engine block 14 and a case cover (second case portion) 22 facing the case main body 21. An outer rotor 23 and an inner rotor (pump rotor) 24 are rotatably accommodated between the case main body 21 and the case cover 22. Further, through holes 21 a and 22 a are formed in the center of the pump case 20, and the crankshaft 15 is accommodated in the through holes 21 a and 22 a of the pump case 20. Thus, the inner rotor 24 in the pump case 20 is connected to the crankshaft 15 that penetrates the pump case 20. Furthermore, an oil seal (seal member) 25 that closes the gap between the through hole 21a and the crankshaft 15 is provided in the through hole 21a of the case body 21 through which the crankshaft 15 passes.

  FIG. 2 is a cross-sectional view showing the oil pump 11 along the line AA in FIG. 3A is a sectional view showing the oil pump 11 along the line AA in FIG. 2, and FIG. 3B is a sectional view showing the oil pump 11 along the line BB in FIG. FIG. Further, FIG. 4A is an exploded perspective view showing a part of the oil pump 11, and FIG. 4B is a perspective view showing a part of the oil pump 11.

  As shown in FIGS. 2 and 3, the case main body 21 is formed with a rotor accommodating portion 26, and the rotor accommodating portion 26 is closed by the case cover 22. An outer rotor 23 and an inner rotor 24 are rotatably accommodated in the rotor accommodating portion 26 of the case main body 21. A plurality of inner teeth 23 a are formed on the annular outer rotor 23, and a plurality of outer teeth 24 a are formed on the inner rotor 24 that is inscribed in the outer rotor 23. The inner teeth 23 a of the outer rotor 23 and the outer teeth 24 a of the inner rotor 24 mesh with each other, and the outer rotor 23 can be rotated together with the inner rotor 24. A plurality of pumping chambers 27 are defined between the outer rotor 23 and the inner rotor 24. These pumping chambers 27 move in the circumferential direction while changing their volumes as the outer rotor 23 and the inner rotor 24 rotate. Thus, by moving the pumping chamber 27 in the circumferential direction, oil is pumped from a suction port (not shown) of the pump case 20 to the discharge port.

  As described above, the crankshaft 15 is accommodated in the through holes 21 a and 22 a formed at the center of the case main body 21 and the case cover 22. The crankshaft 15 includes a fitting shaft portion 30 that fits into the inner rotor 24 and a seal shaft portion 31 that contacts the oil seal 25. The outer peripheral portion 32 of the fitting shaft portion 30 has a pair of plane portions 32a that are parallel to each other and an arcuate surface portion 32b that connects these plane portions 32a. Similarly to the fitting shaft portion 30, the fitting hole 33 formed in the inner rotor 24 has a pair of plane portions 33a that are parallel to each other and an arcuate surface portion 33b that connects these plane portions 33a. Yes. By fitting the fitting shaft portion 30 of the crankshaft 15 and the fitting hole 33 of the inner rotor 24, the crankshaft 15 and the inner rotor 24 can be rotated integrally. Note that the rotational force of the crankshaft 15 is transmitted to the inner rotor 24 through the flat portions 32a and 33a.

  As shown in FIGS. 3A and 3B, the case body 21 is slidably in contact with one surface 34 of the inner rotor 24, and the other surface 35 of the inner rotor 24 is slid on the case cover 22. Touching freely. An oil seal 25 is in contact with the through hole 21 a of the case body 21. Thus, since the case main body 21 comes into contact with the inner rotor 24 and the oil seal 25, a seal chamber 36 is defined between the inner rotor 24 and the oil seal 25. That is, a seal chamber 36 is defined in the oil pump 11 by the crankshaft 15, the inner rotor 24, the case body 21, and the oil seal 25. The oil in the pumping chamber 27 leaks into the seal chamber 36 through the gap between the inner rotor 24 and the case body 21, but oil leakage from the seal chamber 36 to the outside is prevented by the oil seal 25.

  As shown in FIGS. 2 to 4, a pair of flow channel grooves 40 extending in the axial direction are formed in the arc surface portion 32 b of the fitting shaft portion 30 constituting the crankshaft 15. In this way, the communication channel 41 is defined between the inner rotor 24 and the fitting shaft portion 30 by the channel groove 40 formed in the fitting shaft portion 30. In addition, the communication flow path 41 opens on one surface 34 and the other surface 35 in the thickness direction of the inner rotor 24. That is, the communication flow path 41 includes a first opening end 42 that opens to the case body 21 side and a second opening end 43 that opens to the case cover 22 side, as shown in FIG. 5 described later. As described above, the seal chamber 36 of the oil pump 11 and the crank chamber 44 in the engine block 14 communicate with each other via the communication flow path 41 defined between the inner rotor 24 and the fitting shaft portion 30. As a result, oil can be discharged from the seal chamber 36 to the crank chamber 44 via the communication channel 41, and an excessive pressure rise in the seal chamber 36 can be prevented to prevent oil leakage from the oil seal 25. it can.

  The oil pump 11 according to an embodiment of the present invention has a structure in which oil is positively discharged from the seal chamber 36 in order to prevent oil leakage from the oil seal 25 more effectively. Hereinafter, a structure for positively discharging oil from the seal chamber 36 will be described.

  5 (a) is an enlarged view showing the crankshaft 15 and the inner rotor 24 of FIG. 3 (a), and FIG. 5 (b) is a sectional view taken along line BB of FIG. 5 (a). (C) is sectional drawing which follows the CC line of Fig.5 (a). In FIGS. 5A to 5C, the rotation direction of the crankshaft 15 and the inner rotor 24 is shown by using an arrow R.

  As shown in FIGS. 5A to 5C, the channel groove 40 formed in the fitting shaft portion 30 includes a channel bottom surface 45 parallel to the central axis CL of the crankshaft 15, and a channel bottom surface 45. And a flow path wall surface 46 that is substantially orthogonal to. 5A, the flow path groove 40 of the fitting shaft portion 30 is formed so as to extend beyond the inner rotor 24 to the oil seal 25 side. That is, as shown in FIGS. 3A and 3B, the channel groove 40 is formed in the fitting shaft portion 30 of the crankshaft 15 so that the channel groove 40 protrudes from the one surface 34 of the inner rotor 24. Has been. That is, a part of the flow path groove 40 formed in the fitting shaft portion 30 is disposed in the seal chamber 36 defined between the inner rotor 24 and the oil seal 25.

  As shown in FIG. 5A, the flow path groove 40 includes a first groove end portion 51 located on the case body 21 side and a second groove end portion 52 located on the case cover 22 side. Further, the first groove end portion 51 has a front end 51 f positioned forward in the rotational direction of the crankshaft 15 and a rear end 51 r positioned rearward in the rotational direction of the crankshaft 15. Similarly, the second groove end portion 52 has a front end 52f positioned forward in the rotation direction of the crankshaft 15 and a rear end 52r positioned rearward in the rotation direction of the crankshaft 15. The rear end 51r of the first groove end 51 is provided in front of the rear end 52r of the second groove end 52 in the rotational direction of the crankshaft 15. That is, the flow channel wall surface (wall surface) 46 constituting the flow channel groove 40 of the fitting shaft portion 30 is inclined with respect to the central axis CL of the crankshaft 15. In other words, the channel wall surface 46 constituting the channel groove 40 is inclined with respect to the axial direction of the crankshaft 15. Furthermore, as shown in FIGS. 5B and 5C, the flow path cross-sectional area of the second opening end 43 of the communication flow path 41 is larger than the flow path cross-sectional area of the first opening end 42 of the communication flow path 41. , Is formed large. That is, the channel cross-sectional area of the communication channel 41 increases from the first opening end 42 at the inlet toward the second opening end 43 at the outlet.

  As described above, the channel groove 40 of the fitting shaft portion 30 is formed so as to protrude into the seal chamber 36. As a result, a large amount of oil can be taken into the communication channel 41 from the seal chamber 36. Here, FIG. 6 is an image diagram showing the flow of oil taken into the communication channel 41. In FIG. 6, the rotation direction of the crankshaft 15 and the inner rotor 24 is shown using an arrow R, and the oil flow direction is shown using an arrow F. As shown in FIG. 6, when the oil pump 11 is driven by rotating the crankshaft 15, the oil in the seal chamber 36 is captured by the channel wall surface 46 of the rotating channel groove 40. Thus, by capturing the oil in the seal chamber 36 by the flow channel wall surface 46, the oil can be actively taken into the communication flow channel 41 from the seal chamber 36. Thereby, the pressure rise in the seal chamber 36 can be suppressed, and oil leakage from the oil seal 25 can be prevented.

  Further, the channel wall surface 46 of the channel groove 40 is inclined with respect to the central axis CL of the crankshaft 15. Thereby, the oil captured by the flow path wall surface 46 can be actively guided toward the first opening end 42 of the communication flow path 41. Furthermore, the flow passage cross-sectional area of the communication flow passage 41 for discharging the oil increases from the first opening end 42 at the inlet toward the second opening end 43 at the outlet. As a result, an increase in pressure near the second opening end 43 can be suppressed, and the oil can be discharged to the crank chamber 44 side without retaining the oil in the communication flow path 41.

  In this way, the channel wall surface 46 is inclined with respect to the central axis CL of the crankshaft 15, and the channel cross-sectional area of the communication channel 41 is expanded from the first opening end 42 toward the second opening end 43. The pressure rise in the seal chamber 36 can be suppressed, and oil leakage from the oil seal 25 can be prevented. Further, the channel groove 40 that divides the communication channel 41 is formed not in the flat surface portion 32 a of the fitting shaft portion 30 but in the circular arc surface portion 32 b. Thereby, the flow-path groove | channel 40 can be formed in the fitting shaft part 30, without reducing the intensity | strength of the plane part 32a which transmits a rotational force.

  Subsequently, an oil pump (pump device) 60 according to another embodiment of the present invention will be described.

  FIG. 7 is a sectional view showing the oil pump 60 along the line AA in FIG. 8A is a cross-sectional view showing the oil pump 60 along the line AA in FIG. 7, and FIG. 8B is a cross-sectional view showing the oil pump 60 along the line BB in FIG. is there. FIG. 9A is an exploded perspective view showing a part of the oil pump 60, and FIG. 9B is a perspective view showing a part of the oil pump 60. Further, FIG. 10 is an image diagram showing the flow of oil taken into the communication channel 41. 8 and 10, the direction of rotation of the crankshaft 15 and the inner rotor 24 is indicated by using an arrow R. In FIG. 10, the direction of oil flow is shown using arrows F. Moreover, in FIGS. 7-10, about the member similar to the member shown in FIGS. 2-6, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 7 to 9, a channel groove 40 is formed in the fitting shaft portion 30 of the crankshaft 15, and a plate-like blade member 61 is fixed to the channel wall surface 46 of the channel groove 40. Has been. In this case, the surface 63 of the blade member 61 functions as a wall surface that is inclined with respect to the central axis CL of the crankshaft 15. 8A and 9A, the end 62 of the blade member 61 protrudes into the seal chamber 36 toward the oil seal 25 so as to protrude into the seal chamber 36. Projects axially from the end face. That is, the end portion 62 of the blade member 61 is configured as a wall portion protruding in the axial direction from the fitting shaft portion 30. As described above, by projecting the end portion 62 of the blade member 61 in the axial direction from the fitting shaft portion 30, a large amount of oil can be taken into the communication channel 41 from the seal chamber 36.

  That is, as shown in FIG. 10, when the crankshaft 15 is rotated and the oil pump 60 is driven, the oil in the seal chamber 36 is captured by the blade member 61 and the end 62 of the rotating flow channel groove 40. It is done. As described above, the oil in the seal chamber 36 is captured by the blade member 61, whereby the oil can be actively taken into the communication channel 41 from the seal chamber 36. Thereby, the pressure rise in the seal chamber 36 can be suppressed, and oil leakage from the oil seal 25 can be prevented. In the case shown in the drawing, the wall member protruding in the axial direction from the fitting shaft portion 30 is formed by fixing the blade member 61 to the flow channel groove 40. However, the present invention is not limited to this. Absent. For example, by cutting the fitting shaft portion 30, the flow passage groove 40 may be formed in the fitting shaft portion 30 and the wall portion protruding in the axial direction from the end surface of the fitting shaft portion 30 may be formed. good.

  Subsequently, an oil pump (pump device) 70 according to another embodiment of the present invention will be described.

  FIG. 11 is a cross-sectional view showing the oil pump 70 along the line BB in FIG. 12A is a sectional view showing the oil pump 70 along the line AA in FIG. 11, and FIG. 12B is a sectional view showing the oil pump 70 along the line BB in FIG. is there. FIG. 13 is an exploded perspective view showing a part of the oil pump 70, and FIG. 14 is an image diagram showing the flow of oil taken into the communication flow path 41. In FIGS. 12 and 14, the rotation direction of the crankshaft 15 and the inner rotor 24 is shown by using an arrow R. In FIG. 14, the direction of oil flow is shown using arrows F. Moreover, in FIGS. 11-14, about the member similar to the member shown in FIGS. 2-6, the same code | symbol is attached | subjected and the description is abbreviate | omitted.

  As shown in FIGS. 11 and 13, a crank pulley (pump drive shaft) 71 is connected to the tip of the crankshaft 15. The crank pulley 71 includes a fitting shaft portion 72 that fits into the inner rotor 24 and a seal shaft portion 73 that contacts the oil seal 25. The outer peripheral portion 74 of the fitting shaft portion 72 has a pair of plane portions 74a that are parallel to each other, and an arcuate surface portion 74b that connects these plane portions 74a. By fitting the fitting shaft portion 72 of the crank pulley 71 and the fitting hole 33 of the inner rotor 24, the crank pulley 71 and the inner rotor 24 can be rotated together. The rotational force transmitted from the crankshaft 15 to the crank pulley 71 is transmitted from the crank pulley 71 to the inner rotor 24 via the flat surface portion 74a. Further, similarly to the oil pumps 11 and 60 described above, a seal chamber 36 is defined between the inner rotor 24 and the oil seal 25. That is, the seal chamber 36 is defined in the oil pump 70 by the crank pulley 71, the inner rotor 24, the case body 21, and the oil seal 25.

  As shown in FIGS. 11 to 13, a pair of flow channel grooves 75 extending in the axial direction are formed in the arcuate surface portion 74 b constituting the fitting shaft portion 72 of the crank pulley 71. As described above, the communication channel 76 is defined between the inner rotor 24 and the fitting shaft portion 72 by the channel groove 75 formed in the fitting shaft portion 72. Further, the communication flow path 76 is open to one surface 34 and the other surface 35 in the thickness direction of the inner rotor 24. That is, the communication flow path 76 includes a first opening end 81 that opens to the case body 21 side and a second opening end 82 that opens to the case cover 22 side, as shown in FIG. As described above, the seal chamber 36 of the oil pump 11 and the crank chamber 44 in the engine block 14 communicate with each other through the communication flow path 76 defined between the inner rotor 24 and the fitting shaft portion 72.

  The channel groove 75 formed in the fitting shaft portion 72 includes a channel bottom surface 83 that is parallel to the central axis CL of the crank pulley 71 and a channel wall surface 84 that is substantially orthogonal to the channel bottom surface 83. Have. Further, as indicated by reference numeral Z in FIGS. 12B and 13, the flow path groove 75 of the fitting shaft portion 72 is formed to extend to the oil seal 25 side beyond the inner rotor 24. That is, the channel groove 75 is formed in the fitting shaft portion 72 of the crankshaft 15 so that the channel groove 75 protrudes from the one surface 34 of the inner rotor 24. Further, a blade member 86 having a fin portion 85 is fixed to the channel wall surface 84 of the channel groove 75. The fin portion 85 of the blade member 86 protrudes in the radial direction from the outer peripheral surface of the fitting shaft portion 72 so as to protrude toward the seal chamber 36. In other words, the fin portion 85 of the blade member 86 is configured as a wall portion protruding in the radial direction from the fitting shaft portion 72. In this manner, by causing the fin portion 85 to protrude in the radial direction from the fitting shaft portion 72, the fin portion 85 can be increased in size, and the fin portion 85 causes a large amount from the seal chamber 36 to the communication channel 76. Of oil.

  When the fitting shaft portion 30 having the flow channel 40 is formed on the crankshaft 15 as in the oil pumps 11 and 60 described above, the fitting shaft portion 30 is inserted into the inner rotor 24 from the case cover 22 side. There is a need. That is, since the outer diameter of the fitting shaft 30 is limited by the inner diameter of the fitting hole 33 of the inner rotor 24, it is difficult to project the wall portion such as the fin portion 85 from the fitting shaft 30 in the radial direction. Met. On the other hand, in the oil pump 70 of the present embodiment, the fitting shaft portion 72 provided with the flow channel groove 75 is formed in the crank pulley 71. It can be inserted into the inner rotor 24 from the side. Thus, the fin portion 85 that protrudes in the radial direction with respect to the fitting shaft portion 72 can be formed without being limited by the inner diameter size of the fitting hole 33 of the inner rotor 24, and the fin portion 85 that captures oil. An increase in size can be achieved.

  As shown in FIG. 14, when the crank pulley 71 is rotated to drive the oil pump 11, the oil in the seal chamber 36 is captured by the fin portion 85 of the blade member 86 that rotates together with the crank pulley 71. In this way, by capturing the oil with the large fin portion 85, the oil can be actively taken into the communication channel 76 from the seal chamber 36. Thereby, the pressure rise in the seal chamber 36 can be suppressed, and oil leakage from the oil seal 25 can be prevented. Moreover, as shown in the enlarged part of FIG. 11, the fin part 85 is provided with the curved surface which becomes concave shape in a rotation direction. Thereby, most of the oil caught by the fin portion 85 can be fed into the communication flow path 76, and the oil can be positively discharged from the seal chamber 36 to the crank chamber 44. In the case shown in the drawing, the wall member protruding in the radial direction from the fitting shaft portion 72 is formed by fixing the blade member 86 to the flow channel groove 75. However, the present invention is not limited to this. Absent. For example, by cutting the fitting shaft portion 72, the flow passage groove 75 is formed in the fitting shaft portion 72, and the wall portion protruding in the radial direction from the outer peripheral surface of the fitting shaft portion 72 is formed. Also good.

  15 (a) is an enlarged view showing the crank pulley 71 and the inner rotor 24 of FIG. 12 (a), and FIG. 15 (b) is a sectional view taken along line BB of FIG. 15 (a). (C) is sectional drawing which follows the CC line of Fig.15 (a). In FIGS. 15A to 15C, the rotation direction of the crank pulley 71 and the inner rotor 24 is shown by using an arrow R.

  As shown in FIGS. 15A to 15C, the flow channel groove 75 formed in the crank pulley 71 has the same shape as the flow channel groove 40 formed in the crankshaft 15 described above. That is, the flow channel 75 includes a first groove end 91 located on the case body 21 side and a second groove end 92 located on the case cover 22 side. Further, the first groove end portion 91 has a front end 91 f positioned in front of the crank pulley 71 in the rotation direction and a rear end 91 r positioned in the rear of the crank pulley 71 in the rotation direction. Similarly, the second groove end portion 92 has a front end 92 f positioned forward in the rotational direction of the crank pulley 71 and a rear end 92 r positioned rearward in the rotational direction of the crank pulley 71. The rear end 91r of the first groove end 91 is provided in front of the rear end 92r of the second groove end 92 in the rotational direction of the crank pulley 71. That is, the flow path wall surface 84 constituting the flow path groove 75 of the fitting shaft portion 72 is inclined with respect to the center axis CL of the crank pulley 71. In other words, the channel wall surface 84 constituting the channel groove 75 is inclined with respect to the axial direction of the crank pulley 71. Further, since the blade member 86 is fixed to the flow wall surface 84, the surface 87 of the blade member 86 functions as a wall surface that is inclined with respect to the central axis CL of the crank pulley 71 in the oil pump 70. . Furthermore, the flow path cross-sectional area of the second open end 82 of the communication flow path 76 is formed larger than the flow path cross-sectional area of the first open end 81 of the communication flow path 76. That is, the channel cross-sectional area of the communication channel 76 increases from the first opening end 81 at the inlet toward the second opening end 82 at the outlet.

  In this way, the surface 87 of the blade member 86 is inclined with respect to the central axis CL of the crank pulley 71, and the flow path cross-sectional area of the communication flow path 76 is enlarged from the first opening end 81 toward the second opening end 82. As a result, an increase in pressure in the seal chamber 36 can be suppressed, and oil leakage from the oil seal 25 can be prevented. Further, the flow channel groove 75 that defines the communication flow channel 76 is formed not in the flat surface portion 74 a of the fitting shaft portion 72 but in the circular arc surface portion 74 b. Thereby, the flow channel groove 75 can be formed in the fitting shaft portion 72 without reducing the strength of the flat surface portion 74a that transmits the rotational force.

  It goes without saying that the present invention is not limited to the above-described embodiment, and various modifications can be made without departing from the scope of the invention. For example, in the above description, the present invention is applied to the oil pumps 11, 60, and 70 that discharge oil (fluid). However, the present invention is not limited to this, and water (fluid) such as cooling water is discharged. The present invention may be applied to a water pump. In the above description, the present invention is applied to the oil pumps 11, 60, 70 provided in the engine 12. However, the present invention is not limited to this, and the present invention is applied to an oil pump provided in another device such as a transmission. The invention may be applied. In the illustrated case, the present invention is applied to the inscribed oil pumps 11, 60, 70 including the outer rotor 23 and the inner rotor 24. However, the present invention is not limited to this. The present invention may be applied to a pump or a water pump.

  In the above description, the pair of flow channel grooves 40 and 75 are formed on the fitting shaft portions 30 and 72 of the crankshaft 15 and the crank pulley 71. However, the present invention is not limited to this, and the fitting shaft portion One channel groove 40, 75 may be formed in 30, 72, and two or more channel grooves 40, 75 may be formed in the fitting shaft portions 30, 72. 8A, the end 62 of the blade member 61 is formed in a flat plate shape. However, the present invention is not limited to this, and the end 62 of the blade member 61 is curved. May be. In addition, as indicated by a symbol Z in FIG. 13, the fin portion 85 of the blade member 86 is curved, but the present invention is not limited to this, and the fin portion 85 may be formed in a flat plate shape. In the above description, the pair of flat portions 32 a and 74 a are formed on the fitting shaft portions 30 and 72. However, the present invention is not limited to this, and one flat portion 32 a is provided on the fitting shaft portions 30 and 72. 74a may be formed. Further, the inner rotor 24 and the crankshaft 15 and the crank pulley 71 may be connected using a spline connection or may be connected using a key connection.

11 Oil pump (pump device)
12 Engine 15 Crankshaft (pump drive shaft)
20 Pump case 21 Case body (first case part)
21a Through hole 22 Case cover (second case part)
23 Outer rotor 24 Inner rotor (pump rotor)
25 Oil seal (seal member)
30 fitting shaft portion 32 outer peripheral portion 32a flat surface portion 32b arc surface portion 40 channel groove 41 communication channel 42 first opening end 43 second opening end 45 channel bottom surface 46 channel wall surface (wall surface)
51 First groove end portion 51r Rear end 52 Second groove end portion 52r Rear end 60 Oil pump (pump device)
61 Blade member 62 End (wall)
63 Surface (wall surface)
70 Oil pump (pump device)
71 Crank pulley (pump drive shaft)
72 fitting shaft portion 74 outer peripheral portion 74a flat surface portion 74b arcuate surface portion 75 channel groove 76 communication channel 81 first opening end 82 second opening end 85 fin portion (wall portion)
87 Surface (wall surface)
91 First groove end portion 91r Rear end 92 Second groove end portion 92r Rear end

Claims (9)

A pump device that discharges fluid by rotating a pump rotor,
A pump case including a first case portion and a second case portion facing the first case portion, and housing the pump rotor between the first case portion and the second case portion;
A pump drive shaft passing through the first case portion and the second case portion and connected to the pump rotor;
A seal member provided in a through hole of the first case portion through which the pump drive shaft passes, and closing a gap between the through hole and the pump drive shaft;
Have
On the fitting shaft portion of the pump drive shaft that fits into the pump rotor, a channel groove that defines a communication channel is formed between the pump rotor and the fitting shaft portion,
The communication channel includes a first opening end that opens to the first case portion side and a second opening end that opens to the second case portion side,
The flow path groove extends to the seal member side beyond the pump rotor. The pump device according to claim 1, wherein
The outer peripheral part of the fitting shaft part is constituted by a flat part and an arcuate surface part,
The said flow-path groove | channel is a pump apparatus formed in the said circular arc surface part. The pump device according to claim 1 or 2,
The flow path cross-sectional area of the second opening end is larger than the flow path cross-sectional area of the first opening end. In the pump device according to any one of claims 1 to 3,
The said flow-path groove | channel is a pump apparatus provided with the wall surface which inclines with respect to the central axis of the said pump drive shaft. In the pump device according to any one of claims 1 to 4,
The flow path groove includes a first groove end portion located on the first case portion side and a second groove end portion located on the second case portion side,
The first groove end includes a rear end located rearward in the rotational direction of the pump drive shaft,
The second groove end includes a rear end located rearward in the rotational direction of the pump drive shaft,
The pump device, wherein a rear end of the first groove end portion is provided in front of a rotation direction of the pump drive shaft with respect to a rear end of the second groove end portion. The pump device according to any one of claims 1 to 5,
A pump device, wherein the channel groove is provided with a wall portion protruding in the axial direction from the fitting shaft portion. The pump device according to any one of claims 1 to 5,
A pump device, wherein a wall portion that projects radially from the fitting shaft portion is provided in the flow channel groove. In the pump device according to any one of claims 1 to 7,
The pump device, wherein the pump drive shaft is an engine crankshaft or a crank pulley attached to the crankshaft. In the pump device according to any one of claims 1 to 8,
The pump device, wherein the pump rotor is an inner rotor inscribed in an annular outer rotor.

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