Pump equipment

Abstract

To provide a pump device which is well adaptable to uses for which discharge ports of a plurality of pump mechanisms are arranged in the same radial direction of a drive shaft.SOLUTION: A plurality of external tooth gears 2E-5E are engaged with a drive shaft 8 in the rotating direction while being spaced therefrom in the axial direction. In a pump body 1, suction ports 2H1-5H1 are formed corresponding to the respective external tooth gears 2E-5E to suck fluid into one side in the radial direction of the drive shaft 8, and discharge ports 2L1-5L1 opposed to the suction ports 2H1-5H1 via the drive shaft 8 in the radial direction to discharge the fluid are formed in the other side in radial direction of the drive shaft 8. The drive shaft 8 is journaled by two bearings 9, 10 arranged at a space in the axial direction. Out of the external tooth gears 2E-5E, the external gears 2E, 3E, 4E are arranged between both bearings 9, 10 and the external gear 5E is arranged on the end side of the drive shaft 8 further than one bearing 9.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a pump device in which a single drive shaft rotates and drives a plurality of pump mechanisms. [Background technology]

[0002] This type of pump device has a single drive shaft supported by bearings on a pump body, an external gear (inner rotor) as a pump rotor connected to the drive shaft with an axial gap for rotational engagement, and an internal gear (outer rotor) with internal teeth meshing with the external teeth of each external gear arranged eccentrically with each external gear to form multiple internal gear pump mechanisms, each of which has an inlet port for drawing in fluid and an outlet port for discharging fluid. When the drive shaft rotates each external gear, the internal gear rotates, drawing in fluid through the inlet port and transporting it between the external and internal gears, and discharging it from the outlet port. The outlet ports of each pump mechanism are located at different radial positions on the drive shaft, so that forces based on the pressure of the fluid discharged from the outlet ports act on the drive shaft from different directions, preventing bending forces from acting on the drive shaft in a specific direction. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-85377 Summary of the Invention [Problem to be solved by the invention]

[0004] However, in such conventional pump devices, the discharge ports of the multiple pump mechanisms are arranged at different radial positions on the drive shaft, which means that they cannot be effectively used in applications where the discharge ports must be arranged in the same radial direction on the drive shaft.

[0005] An object of the present invention is to provide a pump device that can be suitably applied to an application in which the discharge ports of a plurality of pump mechanisms are arranged in the same radial direction of the drive shaft. [Means for solving the problem]

[0006] In order to achieve this object, the present invention takes the following measures: In a pump device in which a single drive shaft drives and rotates a plurality of pump mechanisms, the drive shaft is rotatably supported by the pump body, and the drive shaft has an axial gap and engages with the rotors of the plurality of pump mechanisms in the rotational direction. The pump body has suction ports on one radial side of the drive shaft corresponding to each pump rotor, which draw in fluid, and discharge ports on the other radial side of the drive shaft, which are radially opposed to each suction port via the drive shaft, and which discharge fluid. The drive shaft is supported by two bearings arranged with a gap in the axial direction, and each pump rotor is arranged between the two bearings. Multiple The pump rotor and one of the bearings are located closer to the end of the drive shaft. One As a pump rotor The drive shaft has a free end at the end side where one pump rotor is arranged from one bearing. The pump device is characterized by the above. [Effects of the Invention]

[0008] As described above in detail, the invention described in claim 1 is such that the pump body has suction ports formed on one radial side of the drive shaft corresponding to each pump rotor, which suck in fluid, and discharge ports formed on the other radial side of the drive shaft, which are radially opposed to each suction port via the drive shaft, and which discharge fluid, the drive shaft is supported by two bearings arranged with a gap in the axial direction, and each pump rotor is arranged between the two bearings. Multiple The pump rotor and one of the bearings are located closer to the end of the drive shaft. One As a pump rotor The drive shaft has a free end at the end side where one pump rotor is arranged from one bearing.Therefore, the acting force based on the pressure of the fluid at the discharge port of the pump rotor located between the two bearings and the acting force based on the pressure of the fluid at the discharge port of the pump rotor located closer to the end of the drive shaft than one of the bearings act in directions opposite to the drive shaft with one of the bearings as a fulcrum, so the drive shaft does not bend in a specific direction, making this suitable for use in applications where the discharge ports of multiple pump mechanisms are arranged in the same radial direction of the drive shaft.

[0009] Also, Claim 1 In the invention described in (1), multiple pump rotors are arranged between the two bearings, and one pump rotor is arranged closer to the end of the drive shaft than one of the bearings. As a result, the length from one bearing to the end of the drive shaft can be made short enough to accommodate one pump rotor, and the end of the drive shaft closer to one bearing can be well supported by one bearing. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a vertical cross-sectional view of a pump device according to an embodiment of the present invention. [Figure 2] FIG. 2 is a cross-sectional view taken along line AA in FIG. DETAILED DESCRIPTION OF THE INVENTION

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 and 2, the pump device includes four pump mechanisms 2 to 5: a first pump mechanism 2, a second pump mechanism 3, a third pump mechanism 4, and a fourth pump mechanism 5. Each of the pump mechanisms 2 to 5 is an internal gear pump mechanism, and includes a rectangular parallelepiped first housing 2A, a second housing 3A, a third housing 4A, and a fourth housing 5A. The pump body 1 of the pump device is configured by connecting the housings 2A to 5A, disposing a cover member 6 at the rear end, and fastening the housings 2A to 5A to the cover member 6 with a plurality of bolt members 7.

[0012] A single drive shaft 8 rotates and drives each pump mechanism 2-5. It penetrates each housing 2A-5A, protruding its tip from the first housing 2A, and is covered at its rear end by a cover member 6. The drive shaft 8 is rotatably supported on the pump body 1 by two bearings 9 and 10. One bearing, 9, is a cylindrical roller bearing located in the fourth housing 5A. The other bearing, 10, is a ball bearing located in the first housing 2A. 2B is a first internal gear, 3B is a second internal gear, 4B is a third internal gear, and 5B is a fourth internal gear, which are rotatably housed in housing holes 2C, 3C, 4C, and 5C drilled in the first housing 2A-fourth housing 5A, respectively. Each internal gear 2B-5B protrudes radially inward and has five internal teeth 2D. 11 is a seal member that seals the drive shaft 8 and is disposed adjacent to the axially outer side of the bearing 10 in the first housing 2A.

[0013] One end opening of the mounting hole 2C formed in the first housing 2A is closed by the adjacent second housing 3A. Similarly, one end opening of the mounting hole 3C formed in the second housing 3A is closed by the adjacent third housing 4A, one end opening of the mounting hole 4C formed in the third housing 4A is closed by the adjacent fourth housing 5A, and one end opening of the mounting hole 5C formed in the fourth housing 5A is closed by the cover member 6.

[0014] Reference numeral 2E denotes a first external gear, 3E denotes a second external gear, 4E denotes a third external gear, and 5E denotes a fourth external gear, all of which serve as pump rotors and are disposed eccentrically in the mounting holes 2C to 5C relative to the internal gears 2B to 5B, respectively, and have four external teeth 2F that mesh with the internal teeth 2D of the internal gears 2B to 5B. Each of the external gears 2E to 5E is disposed with a gap in the axial direction of the drive shaft 8 and is engaged with the drive shaft 8 in the rotational direction by keys 2G, 3G, 4G, and 5G. The first external gear 2E, second external gear 3E, and third external gear 4E are disposed between the two bearings 9 and 10. One of the fourth external gears 5E is disposed closer to the end of the drive shaft 8, closer to the cover member 6 than one of the bearings 9. Each pump mechanism 2 to 5 defines a pump chamber P by the internal teeth 2D of each internal gear 2B to 5B and the external teeth 2F of each external gear 2E to 5E, and the volume of each pump chamber P increases in the expansion region space and decreases in the contraction region space as both gears 2B to 5B and 2E to 5E rotate.

[0015] In the first housing 2A constituting the pump body 1, an intake port 2H1 for drawing in fluid is formed in the bottom surface of the mounting bore 2C on one radial side of the drive shaft 8, and the intake port 2H1 is connected to the expansion region of the pump chamber P. Furthermore, an intake port 2H2 for drawing in fluid is formed in the closed side surface of the second housing 3A, which closes one end opening of the mounting bore 2C. The intake port 2H2 is connected to the expansion region of the pump chamber P and is axially opposed to the intake port 2H1 via the gears 2B and 2E. The intake port 2H1 and the intake port 2H2 are connected by a connecting flow path 2I formed in the first housing 2A, and are further connected to an intake flow path 2J for fluid. The intake flow path 2J is formed in the first housing 2A and opens to one side surface 2K of the first housing 2A, which is on one radial side of the drive shaft 8.

[0016] Like the first housing 2A, the second to fourth housings 3A to 5A constituting the pump body 1 have suction ports 3H1, 4H1, and 5H1 formed in the bottom surfaces of the mounting holes 3C, 4C, and 5C on one radial side of the drive shaft 8, and each suction port 3H1 to 5H1 is connected to the expansion zone of the corresponding pump chamber P. In addition, suction ports 3H2, 4H2, and 5H2 are formed in the closed side surfaces of the housings 4A and 5A and the cover member 6 that close one end opening of each mounting hole 3C to 5C, respectively. Each suction port 3H2 to 5H2 is connected to the expansion zone of the corresponding pump chamber P, and is positioned axially opposite the corresponding suction port 3H1 to 5H1 via the gears 3B to 5B and 3E to 5E. Each of the suction ports 3H1 to 5H1 is connected to each of the suction ports 3H2 to 5H2 by a connecting flow path 3I, 4I, 5I formed in each of the housings 3A to 5A, and is further connected to a fluid suction flow path 3J, 4J, 5J. Each of the suction flow paths 3J to 5J is formed in each of the housings 3A to 5A, and opens to one side surface 3K, 4K, 5K of each of the housings 3A to 5A, which is on one radial side of the drive shaft 8.

[0017] Discharge ports 2L1, 3L1, 4L1, and 5L1 are formed in each of the housings 2A to 5A that constitute the pump body 1, and open to the bottom surfaces of the respective mounting holes 2C, 3C, 4C, and 5C on the other radial side of the drive shaft 8 that is radially opposed to each of the suction ports 2H1 to 5H1 via the drive shaft 8, and communicate with the contraction zone space of each of the pump chambers P. Recesses 2L2, 3L2, 4L2, and 5L2 are recessed and formed in the closed side surfaces of the housings 3A to 5A and the cover member 6 that close the one-end openings of the mounting holes 2C to 5C at positions axially opposed to the discharge ports 2L1 to 5L1 via the gears 2B to 5B, 2E to 5E, and each of the recesses 2L2 to 5L2 communicates with the compression zone space of each of the pump chambers P. The gears 2B-5B and 2E-5E are subjected to an axial balance between the force based on the fluid pressure at each discharge port 2L1-5L1 and the force based on the fluid pressure at each recess 2L2-5L2. Each discharge port 2L1-5L1 is connected to a fluid discharge flow path 2M, 3M, 4M, or 5M. Each discharge flow path 2M-5M is formed in each housing 2A-5A and opens to the other side surface 2N, 3N, 4N, or 5N of each housing 2A-5A, which is on the other radial side of the drive shaft 8.

[0018] Next, the operation of this configuration will be explained. 1, when the drive shaft 8 is rotated, the external gears 2E to 5E rotate together with the drive shaft 8. As the external gears 2E to 5E rotate, the internal gears 2B to 5B, whose external teeth 2F and internal teeth 2D are internally meshed, rotate, and the volume of each pump chamber P increases or decreases.

[0019] Fluid is drawn into each pump chamber P in the expansion region space, where the volume increases with the rotation of both gears 2B-5B and 2E-5E, from each suction passage 2J-5J through each suction port 2H1-5H1 and 2H2-5H2. Fluid in each pump chamber P in the contraction region space, where the volume decreases with the rotation of both gears 2B-5B and 2E-5E, flows through each discharge port 2L1-5L1 and is discharged from each discharge passage 2M-5M. In this way, the pump operates by continuously drawing in and discharging fluid as both gears 2B-5B and 2E-5E rotate. When the rotation of drive shaft 8 is stopped, the pump operation stops.

[0020] In this operation, each housing 2A to 5A constituting the pump body 1 is formed with suction ports 2H1 to 5H1 that suck in fluid on one radial side of the drive shaft 8 corresponding to each external gear 2E to 5E as each pump rotating body, and discharge ports 2L1 to 5L1 that discharge fluid are formed on the other radial side of the drive shaft 8, radially opposing each suction port 2H1 to 5H1 via the drive shaft 8. The drive shaft 8 is journaled by two bearings 9, 10 arranged with a gap in the axial direction, and each external gear 2E to 5E is made up of external gears 2E, 3E, 4E arranged between the two bearings 9, 10, and an external gear 5E arranged closer to the end of the drive shaft 8 than one of the bearings 9. Therefore, the acting force based on the fluid pressure at the discharge ports 2L1, 3L1, 4L1 of the external gears 2E, 3E, 4E arranged between the two bearings 9, 10 and the acting force based on the fluid pressure at the discharge port 5L1 of the external gear 5E arranged closer to the end of the drive shaft 8 than one of the bearings 9 act in a direction opposite to the drive shaft 8 with one of the bearings 9 as a fulcrum, so that the drive shaft 8 does not bend in a particular direction, and this can be well applied to applications in which the discharge ports 2L1 to 5L1 of multiple pump mechanisms 2 to 5 are arranged in the same radial direction of the drive shaft 8.

[0021] Furthermore, multiple external gears 2E, 3E, and 4E are arranged between the two bearings 9 and 10, and one external gear 5E is arranged closer to the end of the drive shaft 8 than one bearing 9. As a result, the length from one bearing 9 to the end of the drive shaft 8 can be made short enough to accommodate one external gear 5E, and the end of the drive shaft 8 closer to one bearing 9 can be well supported by one bearing 9.

[0022] In the above embodiment, the pump mechanisms 2 to 5 are internal gear pump mechanisms and the pump rotors are external gears 2E to 5E, but the pump mechanisms may be vane pump mechanisms and the pump rotors may be rotors equipped with vanes. Place However, two or three or more pump rotors are placed between the two bearings. Place Of course, it is also good to [Explanation of symbols]

[0023] 1: Pump body 2: First pump mechanism 3: Second pump mechanism 4: Third pump mechanism 5: 4th pump mechanism 2E: 1st external gear (pump rotor) 3E: Second external gear (pump rotor) 4E: 3rd external gear (pump rotor) 5E: 4th external gear (pump rotor) 2H1, 2H2, 3H1, 3H2, 4H1, 4H2, 5H1, 5H2: Intake port 2L1, 3L1, 4L1, 5L1: Discharge port 8: Drive shaft 9, 10: Bearings

Claims

[Claim 1] a pump device in which a single drive shaft drives and rotates a plurality of pump mechanisms, the drive shaft being rotatably supported by a pump body, the drive shaft being rotationally engaged with rotors of the plurality of pump mechanisms with an axial gap therebetween, the pump body being formed with suction ports for drawing in fluid on one radial side of the drive shaft corresponding to each pump rotor, and discharge ports for discharging fluid on the other radial side of the drive shaft, radially opposing each suction port via the drive shaft, the drive shaft being supported by two bearings arranged with an axial gap therebetween, the pump rotors being made up of a plurality of pump rotors arranged between both bearings and one pump rotor arranged closer to one end of the drive shaft than one of the bearings, and the end of the drive shaft closer to the one pump rotor than the one bearing is a free end.

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