JP2014148959A - Hydraulic pump device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a loss of input energy by reducing the resistance of lubrication oil flowing between an engaging portion where a driving gear and a driven gear are engaged and the outside of the engaging portion.SOLUTION: In a casing 2, a block body 26 is provided, which has a gear opposing surface 27A opposing to one side end surfaces 21B and 24B in an axial direction of a driving gear 21 and a driven gear 24. On the gear opposing surface 27A of the block body 26, a recessed communication groove 31 is provided corresponding to an engaging portion 25 between the driving gear 21 and the driven gear 24. By the communication groove 31, a start point side area 25A with high pressure and a terminal side area 25B with low pressure in the engaging portion 25 are communicated. Therefore, by large differential pressure generated between the start point side area 25A and the terminal side area 25B, lubrication oil can be smoothly circulated.

Description

  The present invention relates to a hydraulic pump device that is mounted on a construction machine such as a hydraulic excavator or a hydraulic crane and discharges pressure oil for operation when driven by an engine.

  In general, construction machines such as a hydraulic excavator and a hydraulic crane are roughly constituted by a self-propelled vehicle body and a work device provided on the vehicle body. An engine, a hydraulic pump device, and the like are mounted on the vehicle body of the construction machine, and the hydraulic pump device is driven by the engine to supply operating hydraulic oil to various hydraulic actuators provided in the vehicle body and the working device. It has a configuration.

  Here, as a hydraulic pump device mounted on a construction machine, a parallel type hydraulic pump device in which two piston pumps are arranged in parallel and configured integrally is known. The parallel hydraulic pump device includes a casing, a drive pump accommodated in the casing, a driven pump accommodated in the casing in parallel with the drive pump, and a drive pump for transmitting external power to the drive pump. A main rotating shaft supported by the casing so as to be in series with the driving shaft, a driving gear provided on the driving pump side of the main rotating shaft and rotating integrally with the main rotating shaft and driving the driving pump, and a driven pump in series A driven rotary shaft supported by the casing in parallel with the main rotary shaft, and a driven gear that is provided on the driven pump side of the driven rotary shaft and rotates integrally with the driven rotary shaft and meshes with the drive gear. The lubricating oil for lubricating the drive gear and the driven gear is stored in the casing.

  Here, when the hydraulic pump is driven in a state where the periphery of the drive gear and the driven gear is filled with the lubricating oil, the lubricating oil is brought along with the rotation of the driving gear and the driven gear. Is consumed as the kinetic energy of the lubricating oil flowing through the outer peripheral portions of the drive gear and the driven gear. As a result, as the amount of lubricating oil around each gear increases, the rotational torque of each gear is lost, and the input energy from the main rotating shaft is reduced.

  On the other hand, by setting the distance between the axial end faces of each gear and the inner wall of the casing facing the both end faces to be small, and reducing the amount of lubricating oil around each gear, the drive gear and the driven gear Therefore, it is possible to reduce the amount of lubricating oil that is taken along, and to prevent wasteful consumption of input energy from the main rotating shaft.

  However, the lubricating oil flowing along the outer periphery of the drive gear and the driven gear loses its speed when colliding at the meshing portion of each gear, thereby losing kinetic energy and losing the rotational torque of each gear. It will be.

  Therefore, in the prior art, a concave communication groove that connects the upstream side and the downstream side of the meshing portion is formed on the inner wall of the casing facing the meshing portion on the axial end surface side of each gear, and the drive gear and the driven gear The hydraulic oil flowing along the outer periphery is merged on the upstream side of the meshing portion, and then guided to the downstream side of the meshing portion through the communication groove to circulate the lubricating oil to reduce rotational torque loss. (For example, refer to Patent Document 1).

Japanese Patent Laid-Open No. 2000-220666

  By the way, when the drive gear and the driven gear mesh with each other, the lubricating oil filled in the tooth grooves of each gear enters the tooth grooves on the upstream side of the meshing portion where the drive gear and the driven gear start to mesh. It is pushed out by the teeth of the other gear, and quickly flows out of the tooth gap from the axial end face side of each gear having a relatively large gap.

  Further, when the meshing state of each gear is released downstream of the meshing portion of the drive gear and the driven gear, the gear teeth of one gear are rapidly separated from the gear grooves of the other gear, so the lubricating oil is Thus, the gears rapidly flow into the tooth gap from the axial end face side of each gear having a relatively large gap. In this way, the input energy from the main rotating shaft is consumed as kinetic energy for repeating the outflow and inflow of lubricating oil to the tooth spaces of each gear when the drive gear and the driven gear mesh. Rotational torque will be reduced.

  In this case, at the meshing portion where the drive gear and the driven gear mesh, the lubricant flows more actively between the tooth groove and the casing as the differential pressure between the pressure in the tooth groove and the pressure in the casing is smaller. It needs to be drained. As a result, there is a problem that the kinetic energy of the lubricating oil flowing between the tooth gap and the outside of the tooth gap increases, and the loss of energy input from the main rotation shaft increases.

  The present invention has been made in view of the above-described problems of the prior art, and an object of the present invention is to provide resistance when lubricating oil flows between a meshing portion where the driving gear and the driven gear mesh with each other and the outside of the meshing portion. It is an object of the present invention to provide a hydraulic pump device that can reduce the loss of input energy and efficiently transmit power from the outside to each pump.

  The hydraulic pump device according to the present invention includes a casing, a drive pump housed in the casing, a driven pump housed in the casing in parallel with the drive pump, and the drive pump for transmitting power from the outside. A main rotating shaft supported by the casing so as to be in series with the driving pump, and a driving gear provided on the driving pump side of the main rotating shaft and rotating integrally with the main rotating shaft and driving the driving pump And a driven rotary shaft supported by the casing in parallel with the main rotary shaft so as to be in series with the driven pump, and provided on the driven pump side of the driven rotary shaft and rotated integrally with the driven rotary shaft. And a driven gear meshing with the drive gear, and lubricating oil stored in the casing for lubricating the drive gear and the driven gear.

  And in order to solve the above-mentioned subject, the feature of the composition adopted by the invention of claim 1 is that in the casing, at least one end face of axial end faces of the drive gear and the driven gear is provided. A block body having a gear-opposing surface that faces the gear, and the gear-opposing surface of the block body is provided with a recessed communication groove corresponding to a meshing portion with which the drive gear and the driven gear mesh, The communication groove has a groove width dimension (A) parallel to the direction of the inter-axis distance between the axis of the drive gear and the axis of the driven gear, and the root circle of the drive gear and the root circle of the driven gear. The groove length dimension (B) orthogonal to the direction of the inter-axis distance is set to be equal to or less than the shortest distance connecting the two, and the tooth tip circle of the driving gear and the tooth tip circle of the driven gear intersect This is because the distance is set to be less than the distance between the intersections.

  According to a second aspect of the present invention, the groove length dimension (B) of the communication groove is 40% or more of the distance between two intersections where the tooth tip circle of the drive gear and the tooth tip circle of the driven gear intersect. That is, it is set to a range equal to or less than the distance between two intersections where the tooth tip circle of the driving gear and the tooth tip circle of the driven gear intersect.

  The invention according to claim 3 is that the communication groove is formed such that both groove end portions orthogonal to the direction of the inter-axis distance are R-shaped or chamfered.

  According to a fourth aspect of the present invention, an inner wall that partitions between the main rotating shaft and the driven rotating shaft is provided in the casing, and the block body is provided on one end surface of the driving gear and the driven gear. A partition wall portion having the gear-opposing surface facing with a slight gap, and a pair of leg portions extending from both ends orthogonal to the direction of the inter-axis distance of the partition wall portion toward the inner wall of the casing. The other end surface of the both end surfaces in the axial direction of the drive gear and the driven gear is formed as a letter-shaped frame body, and a pair of leg portions of the block body are brought into contact with the inner wall of the casing. The present invention is configured to face the inner wall of the casing with a slight gap.

  According to a fifth aspect of the present invention, an inner wall that partitions between the main rotating shaft and the driven rotating shaft is provided in the casing, and the block body is provided on one end surface of the driving gear and the driven gear. A first partition wall portion having a first gear-opposing surface facing with a slight gap, and from both ends of the first partition wall portion orthogonal to the direction of the distance between the axes toward the inner wall of the casing A first block body formed as a U-shaped frame body by a pair of first legs extending; and the first block body, the drive gear and the driven gear are sandwiched to face each other and the drive gear A second partition wall portion having a second gear-facing surface facing the other end surface of the driven gear with a slight gap, and orthogonal to the direction of the distance between the axes of the second partition wall portion. One extending from both ends toward the first block body And a second block body formed as a U-shaped frame body with the second leg portion, and the block body includes the first leg portion of the first block body and the second block body. It is to be configured to be attached to the inner wall of the casing in a state where the second leg portion of the block body is in contact with the block body.

  According to the first aspect of the present invention, a block body that separates the periphery of the meshing portion is provided in the casing, and the gear-facing surface of the block body is positioned at a position facing the meshing portion where the driving gear and the driven gear mesh. A communication groove is provided. As a result, the lubricating oil filled between the teeth of one gear (the tooth gap) is pushed out to the teeth of the other gear entering the tooth groove and flows out, When the tooth of the other gear that has entered the tooth groove of the other gear is released, the region that is low in pressure due to the flow of lubricating oil into the tooth groove can be communicated via the communication groove. As a result, the lubricating oil can be smoothly circulated using a large differential pressure generated between the high pressure region and the low pressure region across the meshing portion, so that the meshing portion between the drive gear and the driven gear. The resistance at the time of outflow and inflow of the lubricating oil can be reduced, and the loss of input energy can be reduced. Therefore, power from the outside can be efficiently transmitted to the drive pump and the driven pump, and the reliability and stability of the hydraulic pump can be improved.

  According to the second aspect of the present invention, the communication groove has a groove length dimension B of 40% or more of the distance between the two intersection points of the tooth tip circle of the drive gear and the tooth tip circle of the driven gear. Is set to be equal to or less than the distance of two intersections between the toothed wheel and the toothed circle of the driven gear. Thereby, in the meshing portion of the drive gear and the driven gear, the region on the high-pressure side at the start of meshing and the region on the low-pressure side at the end of meshing can be reliably communicated with each other by the communication groove. The resistance at the time of outflow and inflow of lubricating oil can be reduced. Therefore, power from the outside can be efficiently transmitted to the drive pump and the driven pump, so that the reliability and stability of the hydraulic pump can be improved.

  According to the invention of claim 3, since the communication groove has both groove end portions orthogonal to the direction of the inter-axis distance between the drive gear and the driven gear formed in an R shape or a chamfered shape, It is possible to smoothen the flow of the lubricating oil until the lubricating oil flowing out from the high pressure side region flows into the low pressure side region. Thereby, the loss of input energy can be reduced more effectively.

  According to the fourth aspect of the present invention, the communication groove provided in the partition wall portion (gear facing surface) of the block body on the one end surface of the drive gear and the driven gear is slightly with respect to the meshing portion of the drive gear and the driven gear. The other end faces of the drive gear and the driven gear face each other with a slight clearance, and the inner wall of the casing faces the engagement portion with a slight clearance, and the engagement portion can be sandwiched by the pair of leg portions of the block body. . Thereby, on the other end face of the drive gear and the driven gear, there is little lubricating oil filled in the space surrounded by each leg portion of the block body and the inner wall of the casing, and the outflow amount and the inflow amount of the lubricating oil at the meshing portion are reduced. Can be reduced. Therefore, most of the lubricating oil can flow out and flow into the meshing portion via the communication groove on one end face side of the drive gear and the driven gear. Thereby, since the loss of input energy can be reduced efficiently, the reliability and stability of the hydraulic pump can be improved.

  According to the invention of claim 5, since the first block body corresponding to one axial end face of the drive gear and the driven gear and the second block body corresponding to the other axial end face are provided, The outflow and inflow of the lubricating oil at the meshing portion of each gear can be performed at both end surfaces in the axial direction of each gear via the communication groove of the block body. As a result, since the loss of input energy can be reduced more efficiently, the reliability and stability of the hydraulic pump can be further improved.

1 is a cross-sectional view showing a hydraulic pump device according to a first embodiment of the present invention. It is a longitudinal cross-sectional view which shows a hydraulic pump apparatus. It is sectional drawing which shows a drive gearwheel, a driven gearwheel, and a block body from the arrow III-III direction in FIG. It is a perspective view which shows a block body alone. It is the expanded sectional view which looked at the communicating groove | channel of the block body from the arrow VV direction in FIG. It is a principal part enlarged view which shows the positional relationship of the meshing part of a drive gear and a driven gear, and the communicating groove of a block body. It is the cross-sectional view which looked at the hydraulic pump apparatus by the 2nd Embodiment of this invention from the same position as FIG. It is a longitudinal cross-sectional view which shows a hydraulic pump apparatus. It is an expanded sectional view similar to FIG. 5 which shows the communicating groove | channel of the block body by the modification of this invention.

  Hereinafter, a hydraulic pump device according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

  1 to 6 show a first embodiment of the present invention. In the present embodiment, a parallel type hydraulic pump device in which two inclined shaft type hydraulic pumps are arranged in parallel in one pump casing is illustrated.

  In FIG. 1, reference numeral 1 denotes a hydraulic pump device according to the first embodiment. In this hydraulic pump device 1, two pumps, a drive pump 9 and a driven pump 14 described later, are arranged in parallel in the horizontal direction (left and right directions). The hydraulic pump device 1 is attached to, for example, an engine (none of which is shown) mounted on a hydraulic excavator, and the drive pump 9 and the driven pump 14 are driven by the engine, whereby various hydraulic actuators (whichever The pressure oil for operation is discharged toward the head (not shown). The hydraulic pump device 1 includes a casing 2, a drive pump 9, a driven pump 14, a main rotary shaft 19, a drive gear 21, a driven rotary shaft 22, a driven gear 24, a block body 26, and the like, which will be described later. It is comprised by.

  Reference numeral 2 denotes a casing that constitutes the outer shell of the hydraulic pump device 1, and the casing 2 includes a casing body 3 and a head casing 6 fixed to one end face of the casing body 3.

  Reference numeral 3 denotes a casing main body whose base end side is attached to an engine (not shown). The casing main body 3 includes a cover plate portion 3A that closes one of the left and right sides on the base end side, and a peripheral wall portion extending in the axial direction. 3B. Moreover, the front end side of the casing main body 3 is opened with a surrounding portion as an attachment portion 3C, and a head casing 6 described later is attached to the attachment portion 3C.

  The lid plate portion 3A of the casing body 3 is provided with a shaft insertion hole 3D located substantially in the center, and the shaft insertion hole 3D has a retaining member 4 for retaining a driven rotary shaft 22 described later in the axial direction. Is inserted. Further, on the other side in the left and right directions of the base end side of the casing body 3, a lid attachment hole 3E is provided coaxially with a main rotation shaft insertion space portion 3B3 described later, and the lid attachment hole 3E Covered by the body 5.

  Further, as shown in FIG. 2, the peripheral wall portion 3B of the casing body 3 is bent downward at an intermediate position in the longitudinal direction so as to accommodate a drive pump 9 and a driven pump 14, which will be described later, which are oblique shaft type hydraulic pumps. It is formed as a substantially hemispherical cylindrical body. In the peripheral wall 3B of the casing body 3, the base end side (engine side) from the substantially middle portion in the axial direction is the rotation shaft support portion 3B1, and the head casing 6 side is the pump housing portion 3B2 from the rotation shaft support portion 3B1. Yes. Further, a flange portion 3F is provided around the base end side of the casing main body 3, and the casing main body 3 is attached to an engine (not shown) via the flange portion 3F.

  The rotation shaft support portion 3B1 forms substantially half (base end side) in the length direction (axial direction) of the peripheral wall portion 3B, and is formed as a hollow block body elongated in the left and right directions. The rotation shaft support portion 3B1 is formed with a main rotation shaft insertion space portion 3B3 and a driven rotation shaft insertion space portion 3B4 so as to be aligned in the left and right directions.

  The main rotation shaft insertion space portion 3B3 is formed as a space that is coaxial with the lid attachment hole 3E and penetrates the rotation shaft support portion 3B1 in the axial direction. A main rotation shaft 19 to be described later is rotatably inserted into the main rotation shaft insertion space 3B3 via a plurality of (for example, three) bearings 20. On the other hand, the driven rotation shaft insertion space portion 3B4 is formed as a stepped columnar space that is positioned coaxially with the shaft insertion hole 3D and penetrates the rotation shaft support portion 3B1 in the axial direction, and the driven rotation shaft insertion space portion 3B4. A driven rotary shaft 22 to be described later is rotatably inserted through a plurality of (for example, three) bearings 23.

  Here, as shown in FIGS. 1 and 2, the rotation shaft support portion 3B1 is provided as an inner wall of the casing 2 that partitions the main rotation shaft insertion space portion 3B3 and the driven rotation shaft insertion space portion 3B4. A partition 3G is formed. A surface of the partition portion 3G that faces the pump housing portion 3B2 faces a drive gear 21 and end surfaces 21C and 24C of the driven gear 24 described later with a slight gap. The partition portion 3G is provided with two female screw holes 3G1 for fastening a bolt 30 for attaching a block body 26, which will be described later, upward and downward.

  The pump housing portion 3B2 forms substantially half (the tip side) of the peripheral wall portion 3B in the length direction, and the pump housing portion 3B2 is a horizontally long oval cylindrical body extending from the rotating shaft support portion 3B1 to the tip side. It is formed as. The front end portion of the pump housing portion 3B2 serves as a mounting portion 3C of the casing body 3, and a head casing 6 described later is mounted on the mounting portion 3C. As a result, a common pump chamber 3B5 for accommodating a drive pump 9, a driven pump 14, a drive gear 21, and a driven gear 24, which will be described later, is formed in the pump storage portion 3B2. The pump chamber 3B5 is filled with lubricating oil that lubricates the drive gear 21 and the driven gear 24.

  Reference numeral 6 denotes a head casing attached to the tip (attachment part 3C) of the pump housing part 3B2, and hydraulic oil (pressure oil) flows into the head casing 6 with respect to a drive pump 9 and a driven pump 14 described later. A suction port 6A and a discharge port 6B for flowing out are provided.

  A servo cylinder 6C is formed between the suction port 6A and the discharge port 6B in the head casing 6 at positions corresponding to a drive pump 9 and a driven pump 14 described later. A tilting mechanism 7 described later is provided in the servo cylinder 6C. Further, on the pump chamber 3B5 side of the head casing 6, valve plate mounting holes 6D are respectively provided corresponding to a drive pump 9 and a driven pump 14 described later. A tilting sliding contact surface 6D1 formed in a concave arc shape is formed in the valve plate mounting hole 6D, and a tilting sliding surface 8B of the valve plate 8 described later tilts on the tilting sliding contact surface 6D1. It is configured to slidably contact.

  Reference numeral 7 denotes a tilting mechanism provided in the servo cylinder 6C of the head casing 6. The tilting mechanism 7 is fixed to the servo piston 7A and a servo piston 7A slidably provided in the servo cylinder 6C. It is comprised by the rocking | fluctuation pin 7B which has the spherical part slidably inserted by the insertion hole 8C of the valve plate 8 mentioned later. The servo piston 7A is slid and displaced by pressure oil supplied to the servo cylinder 6C via an oil passage (not shown), and tilts a valve plate 8, a drive pump 9 and a driven pump 14 described later via a swing pin 7B. It is the composition which makes it.

  Denoted at 8 is a valve plate slidably mounted in a valve plate mounting hole 6D of the head casing 6. The valve plate 8 is made of a rectangular plate, and is connected to a cylinder block 10 side and a driven side of a drive pump 9 to be described later. One side end surface of the pump 14 on the cylinder block 15 side is formed as a switching surface 8A formed in a convex spherical shape. The sliding surfaces 10C and 15C of the cylinder blocks 10 and 15 are configured to rotate while being in sliding contact with the switching surface 8A of the valve plate 8, respectively. Further, the other side end surface of the valve plate 8 opposite to the switching surface 8A is formed as a convex curved inclined sliding surface 8B, and the inclined sliding surface 8B is inclined to the valve plate mounting hole 6D. The sliding contact surface 6D1 is slidably contacted so as to be tiltable.

  An insertion hole 8C penetrating from the switching surface 8A toward the tilting sliding surface 8B is formed in the central portion of the valve plate 8. In the insertion holes 8C of the valve plates 8, the other end sides of center shafts 11 and 16, which will be described later, and the spherical portions of the swing pins 7B of the tilt mechanism 7 are respectively inserted. Further, a valve plate side discharge port 8D penetrating from the switching surface 8A toward the tilting sliding surface 8B is formed on the valve plate 8 on the left and right sides from the insertion hole 8C. The discharge port 8 </ b> D is connected to the discharge port 6 </ b> B of the head casing 6. On the other hand, a valve plate side suction port 8E penetrating from the switching surface 8A to the tilting sliding surface 8B is formed inside each valve plate 8 in the left and right directions from the insertion hole 8C. 8E is connected to the suction port 6A of the head casing 6.

  Reference numeral 9 denotes a drive pump housed in the pump chamber 3B5. The drive pump 9 is configured as a variable displacement oblique shaft hydraulic pump, which is one of axial piston hydraulic pumps, for example. The drive pump 9 is disposed on the same axis as the main rotary shaft insertion space 3B3, and discharges the sucked hydraulic oil as pressure oil when a main rotary shaft 19 described later is driven to rotate. And the drive pump 9 is roughly comprised by the cylinder block 10, the center shaft 11, and the piston 13 mentioned later.

  Reference numeral 10 denotes a cylinder block provided in the pump chamber 3B5. The cylinder block 10 rotates together with a main rotating shaft 19 and a drive gear 21 which will be described later. The cylinder block 10 is provided with a center shaft insertion hole 10A that opens at one side end surface along the central axis, and is disposed at a constant interval in the circumferential direction around the center shaft insertion hole 10A. A plurality of cylinders 10 </ b> B extending in the direction are formed. The other end surface of the cylinder block 10 is a sliding surface 10C formed in a concave spherical shape. The cylinder block 10 is formed with a plurality of cylinder ports 10D that open to the sliding surface 10C and communicate with the cylinders 10B.

  Reference numeral 11 denotes a center shaft that is inserted into the center shaft insertion hole 10 </ b> A of the cylinder block 10, and the center shaft 11 performs centering of the cylinder block 10. One end side of the center shaft 11 is swingably connected to a drive gear 21 described later. The other end side of the piston 13 is inserted into the valve plate 8. A spring member 12 is provided between the cylinder block 10 and the center shaft 11, and the spring member 12 applies an initial load to the valve plate 8 to the cylinder block 10.

  Reference numeral 13 denotes a plurality of pistons inserted into the respective cylinders 10B of the cylinder block 10. One end of the piston 13 is swingably connected to a drive gear 21 described later, and the other end is connected to the cylinder block. As the cylinder 10 rotates, the cylinder 10B reciprocates in the axial direction.

  Reference numeral 14 denotes a driven pump which is accommodated in the pump chamber 3B5 and arranged in parallel with the drive pump 9. The driven pump 14 is a variable which is one of, for example, an axial piston type hydraulic pump, like the drive pump 9. It is configured as a displacement-type oblique shaft type hydraulic pump. The driven pump 14 is disposed on the same axis as the driven rotary shaft insertion space 3B4, and discharges the sucked hydraulic oil as pressure oil when a driven rotary shaft 22 described later is driven to rotate. The driven pump 14 is roughly composed of a cylinder block 15, which will be described later, a center shaft 16, and a piston 18.

  Reference numeral 15 denotes a cylinder block provided in the pump chamber 3B5. The cylinder block 15 rotates together with a driven rotating shaft 22 and a driven gear 24, which will be described later. The cylinder block 15 is provided with a center shaft insertion hole 15A that opens on one side end surface along the central axis, and is arranged at regular intervals in the circumferential direction around the center shaft insertion hole 15A. A plurality of cylinders 15 </ b> B extending in the direction are formed. The other end surface of the cylinder block 15 is a sliding surface 15C formed in a concave spherical shape. The cylinder block 15 is formed with a plurality of cylinder ports 15D that open to the sliding surface 15C and communicate with the cylinders 15B.

  Reference numeral 16 denotes a center shaft that is inserted into the center shaft insertion hole 15 </ b> A of the cylinder block 15, and the center shaft 16 performs centering of the cylinder block 15. One end side of the center shaft 16 is swingably connected to a driven gear 24 described later, and the other end side is inserted into the valve plate 8. A spring member 17 is provided between the cylinder block 15 and the center shaft 16. The spring member 17 applies an initial load to the valve plate 8 to the cylinder block 15.

  Reference numeral 18 denotes a plurality of pistons inserted into the respective cylinders 15B of the cylinder block 15, and one end side of the piston 18 is swingably connected to a driven gear 24 described later. The other end side of the piston 18 reciprocates in the axial direction in the cylinder 15B as the cylinder block 15 rotates.

  Reference numeral 19 denotes a main rotation shaft that transmits power from the outside to the drive pump 9, and the main rotation shaft 19 is connected to the drive pump 9 through a plurality of bearings 20 so as to be in series with the main rotation shaft of the rotation shaft support 3 </ b> B <b> 1. The insertion space 3B3 is rotatably supported. A base end portion of the main rotating shaft 19 protrudes from the casing body 3 and is connected to an output side of an engine (not shown). On the other hand, a driving gear 21 (described later) is attached to the tip of the main rotating shaft 19 so as to rotate integrally within the pump chamber 3B5. Thereby, when the engine rotates the main rotating shaft 19, the drive pump 9 can be operated.

  Reference numeral 21 denotes a drive gear provided on the drive pump 9 side of the main rotary shaft 19, and the drive gear 21 is cut, for example, in a direction in which the teeth of each tooth 21A are twisted obliquely with respect to the rotary shaft. It is configured as a gear. The drive gear 21 is integrally attached to the distal end side of the main rotary shaft 19 and is disposed in the pump chamber 3B5 together with the drive pump 9. The drive gear 21 rotates integrally with the main rotary shaft 19 and drives the drive pump 9.

  Specifically, one end surface of the drive gear 21 is connected to one end side of the piston 13 so as to be swingable. When the drive gear 21 is driven to rotate, the cylinder block 10 can be driven to rotate. The piston 13 can be reciprocated in the cylinder 10B.

  The other end face 21 </ b> C side of the drive gear 21 faces the partition portion 3 </ b> G of the casing body 3 with a slight gap. The drive gear 21 meshes with a driven gear 24, which will be described later, in the pump chamber 3B5 and rotates integrally with the main rotary shaft 19, whereby the rotation of the main rotary shaft 19 is driven via the driven gear 24. 22 is transmitted.

  Reference numeral 22 denotes a driven rotary shaft extending in parallel with the main rotary shaft 19 so as to be in series with the driven pump 14, and the driven rotary shaft 22 is inserted into the driven rotary shaft insertion space of the rotary shaft support portion 3 </ b> B <b> 1 via a plurality of bearings 23. The part 3B4 is rotatably supported. The base end portion of the driven rotating shaft 22 abuts against a retaining member 4 attached to the shaft insertion hole 3D of the cover plate portion 3A of the casing body 3 and is retained in the axial direction. On the other hand, a driven gear 24, which will be described later, is attached to the tip of the driven rotating shaft 22 so as to rotate integrally within the pump chamber 3B5.

  Reference numeral 24 denotes a driven gear which is provided on the driven pump 14 side of the driven rotary shaft 22 and rotates integrally with the driven rotary shaft 22, and the driven gear 24 has, for example, teeth of each tooth 24 </ b> A oblique to the rotary shaft. It is configured as a helical gear that is cut in a twisted direction. The driven gear 24 is integrally attached to the distal end side of the driven rotary shaft 22, meshed with the drive gear 21, and disposed in the pump chamber 3 </ b> B 5 together with the driven pump 14. The driven gear 24 rotates integrally with the driven rotary shaft 22 and drives the driven pump 14.

  Specifically, one end surface of the driven gear 24 is connected to one end surface 24B side of the piston 18 so as to be swingable. When the driven gear 24 is driven to rotate, the cylinder block 15 can be driven to rotate. The piston 18 can be reciprocated in the cylinder 15B. The other end face 24 </ b> C side of the driven gear 24 faces the partition part 3 </ b> G of the casing body 3 with a slight gap.

  Reference numeral 25 denotes a meshing portion where the drive gear 21 and the driven gear 24 mesh with each other. When the drive gear 21 and the driven gear 24 mesh with each other by the meshing portion 25, the rotation of the main rotary shaft 19 is transmitted to the driven rotary shaft 22. can do. Here, the meshing portion 25 includes a starting point side region 25A where the teeth 21A of the drive gear 21 and the teeth 24A of the driven gear 24 begin to mesh when the drive gear 21 rotates in the direction indicated by the arrow R in FIG. The end point side region 25B for releasing the engagement between the teeth 21A of the drive gear 21 and the teeth 24A of the driven gear 24 and the engagement region 25C located between the start point side region 25A and the end point side region 25B are roughly divided. can do.

  That is, as shown in FIG. 6, the start point side region 25A is a region on the side where the teeth 24A of the driven gear 24 gradually enter between the adjacent teeth 21A (tooth groove 21D) of the drive gear 21. The end point side region 25B is a region on the side where the teeth 24A of the driven gear 24 gradually move away from between the adjacent teeth 21A of the drive gear 21 (tooth gap 21E). On the other hand, the meshing region 25C is a region where the teeth 21A of the drive gear 21 are completely meshed between the adjacent teeth 24A (tooth groove 24D) of the driven gear 24.

  Next, the block body 26 provided in the casing 2 will be described.

  Reference numeral 26 denotes a block body provided in the partition portion 3G of the casing body 3, and the block body 26 has a gear facing surface 27A described later facing one end face 21B, 24B of the drive gear 21 and the driven gear 24. It is formed as a U-shaped frame and closes the periphery of the meshing portion 25 within the casing body 3. And the block body 26 is comprised by the partition part 27 mentioned later and a pair of leg parts 28 and 29. As shown in FIG.

  Reference numeral 27 denotes a partition portion facing the end surfaces 21B and 24B of the drive gear 21 and the driven gear 24 with a slight gap. The partition wall 27 is formed in a rectangular parallelepiped shape extending in a direction orthogonal to the direction of the inter-axis distance between the axis of the drive gear 21 and the axis of the driven gear 24. In the partition wall portion 27, a communication groove 31 described later is provided on a gear facing surface 27 </ b> A facing one end surface 21 </ b> B, 24 </ b> B of the drive gear 21 and the driven gear 24.

  Reference numeral 28 denotes an upper leg portion extending from the upper end of the partition wall portion 27 in the direction (upward and downward) orthogonal to the direction of the inter-axis distance toward the partition portion 3G of the casing body 3. Covers the upper portion of the meshing portion 25 between the drive gear 21 and the driven gear 24. A bolt insertion hole 28 </ b> A that penetrates in the thickness direction is formed in a substantially central portion of the upper leg portion 28.

  Reference numeral 29 denotes a lower leg portion extending from the lower end of the partition wall portion 27 in a direction orthogonal to the direction of the inter-axis distance toward the partition portion 3G of the casing body 3, and the lower leg portion 29 includes the drive gear 21 and the driven gear. The lower part of the meshing part 25 with 24 is covered. That is, the lower leg portion 29 and the upper leg portion 28 face each other with the meshing portion 25 between the drive gear 21 and the driven gear 24 interposed therebetween. A bolt insertion hole 29 </ b> A that penetrates in the thickness direction is formed in a substantially central portion of the lower leg portion 29.

  The block body 26 is then tightened by tightening the bolt 30 inserted through the bolt insertion hole 28A of the upper leg portion 28 and the bolt insertion hole 29A of the lower leg portion 29 into the female screw hole 3G1 provided in the partition portion 3G of the casing body 3. Is mounted in the casing 2. That is, the block body 26 is attached so as to cover (straddle) the meshing portion 25 in which the drive gear 21 and the driven gear 24 mesh with the partition wall portion 27, the upper leg portion 28, and the lower leg portion 29. Yes.

  In this state, in the partition wall portion 27 of the block body 26, a communication groove 31 described later is provided on a gear facing surface 27 </ b> A that faces one end surfaces 21 </ b> B and 24 </ b> B of the drive gear 21 and the driven gear 24.

  Reference numeral 31 denotes a communication groove provided on the gear facing surface 27A constituting the partition wall portion 27 of the block body 26. The communication groove 31 is provided on the drive gear 21 and the driven gear 24 side as shown in FIGS. It is formed in an open concave shape and faces the meshing portion 25 between the drive gear 21 and the driven gear 24 with a slight gap. The communication groove 31 has a groove width parallel to the direction of the inter-axis distance between the axis of the drive gear 21 and the axis of the driven gear 24 and a groove length perpendicular to the direction of the inter-axis distance. The bottom surface 31A facing the meshing portion 25 between the drive gear 21 and the driven gear 24, and extending from the bottom surface 31A toward the gear facing surface 27A of the block body 26 along the groove length direction, sandwiching the meshing portion 25 A pair of length side surfaces 31B facing each other, a pair of width direction side surfaces 31C extending from the bottom surface 31A toward the gear facing surface 27A of the block body 26 along the groove width direction and facing each other with the meshing portion 25 interposed therebetween It is comprised by.

  4 and 6, the groove width dimension A on the open end side of the communication groove 31 is the shortest distance connecting the root circle 32A of the drive gear 21 and the root circle 32B of the driven gear 24. It is set as follows. On the other hand, the groove length dimension B on the opening end side of the communication groove 31 is set to be equal to or less than the distance L between the two intersections C and D where the tooth tip circle 33A of the drive gear 21 and the tooth tip circle 33B of the driven gear 24 intersect. Has been.

  Specifically, the groove length dimension B of the communication groove 31 has two intersection points C and D where the tooth tip circle 33A of the drive gear 21 and the tooth tip circle 33B of the driven gear 24 intersect as shown in the following formula 1. The distance L is set to a range of 40% or more at a distance L or less.

  Further, the groove length dimension B of the communication groove 31 is a distance between two intersections C and D where the tooth tip circle 33A of the drive gear 21 and the tooth tip circle 33B of the driven gear 24 intersect as shown in the following formula 2. It is preferable to set it to 40% or more and 80% or less of L.

  Here, the reason why the groove length dimension B of the communication groove 31 is set to 40% or more of the distance L between the two intersections C and D will be described.

  That is, when the groove length dimension B of the communication groove 31 is 40% (B = 0.4L) of the distance L between the two intersections C and D, the tooth 21A of the drive gear 21 is the tooth groove 24D of the driven gear 24. The groove length dimension B is substantially equal to the distance between the tooth tips of the two teeth 24A of the driven gear 24 sandwiching the teeth 21A of the drive gear 21 (see FIG. 6). Then, for example, when the groove length dimension B is less than 40% of the distance L between the intersections C and D, almost the entire area of the communication groove 31 is included in the meshing region 25C of the meshing portion 25, and the meshing This is because it is difficult to expect an effective reduction in input energy because there is less lubricant inflow / outflow (outflow and inflow) than the start point side region 25A and the end point side region 25B of the portion 25.

  On the other hand, the reason why the groove length dimension B of the communication groove 31 is set to 80% or less of the distance L between the two intersections C and D will be described.

  That is, when the groove length dimension B of the communication groove 31 is 80% (B = 0.8 L) of the distance L between the two intersections C and D, the tooth 21A of the drive gear 21 is the tooth groove 24D of the driven gear 24. The groove length dimension B is determined between the tooth tips of the two teeth 21A of the drive gear 21 positioned further outside the teeth 24A of the two driven gears 24 sandwiching the teeth 21A of the drive gear 21. (See FIG. 6). For this reason, for example, when the groove length dimension B exceeds 80% of the distance L between the intersections C and D, the communication groove 31 includes a region before reaching the start point side region 25A, and the end point side region. An area beyond 25B will be included. Then, for example, a part of the lubricating oil pushed out from the tooth groove 24E of the driven gear 24 by the engagement of the teeth 21A of the drive gear 21 and the teeth 24A of the driven gear 24 flows out to the outer peripheral side of the gears 21 and 24. In addition, in the tooth groove 24F of the driven gear 24 after the teeth 21A of the drive gear 21 and the teeth 24A of the driven gear 24 that are meshed with each other are separated, the lubricating oil filling the communication groove 31 is filled. In addition to flowing in, the lubricating oil also flows from the outer peripheral side of each gear 21, 24. For this reason, a large differential pressure between the start point side region 25A and the end point side region 25B cannot be secured, and the lubricating oil extruded from each tooth groove in the start point side region 25A using this differential pressure is the end point. This is because it is difficult to smoothly circulate to the side region 25B.

  Further, in the communication groove 31, the joint portion 31 </ b> E as both groove end portions orthogonal to the direction of the inter-axis distance between the axis of the drive gear 21 and the axis of the driven gear 24 is formed in an R shape. That is, the bottom surface 31A and each width direction side surface 31C are made to continue in a smooth circular arc shape by forming the joint portion 31E between the bottom surface 31A of the communication groove 31 and each width direction side surface 31C as an R shape.

  The hydraulic pump device 1 according to the first embodiment has the above-described configuration, and this hydraulic pump device 1 drives the drive pump 9 via the main rotating shaft 19 by power from an engine (not shown). By doing so, pressure oil can be discharged from the drive pump 9 toward a hydraulic actuator (not shown). Further, the rotation of the main rotary shaft 19 is transmitted to the driven rotary shaft 22 via the driven gear 24 meshed with the drive gear 21, whereby the driven pump 14 is driven, and the driven pump 14 also toward the hydraulic actuator. Pressure oil can be discharged.

  Next, the flow of the lubricating oil in the meshing portion 25 between the drive gear 21 and the driven gear 24 will be described.

  As described above, the lubricating oil for lubricating the drive gear 21 and the driven gear 24 is stored (filled) in the pump chamber 3B5 of the casing body 3. As shown in FIG. 6, when the drive gear 21 is rotating in the direction indicated by the arrow R, in the start point side region 25 </ b> A of the meshing portion 25 where the drive gear 21 and the driven gear 24 mesh, The teeth 24A of the driven gear 24 gradually enter the tooth groove 21D.

  At this time, the lubricating oil filled in the tooth groove 21D is caused by the tooth 24A of the driven gear 24 entering the tooth groove 21D, so that the tooth groove 21D mainly from one end face 21B, 24B side of each gear 21, 24. Will flow out (extrusion) rapidly. Also, in the end point side region 25B of the meshing portion 25 where the drive gear 21 and the driven gear 24 are engaged, the teeth 24A of the driven gear 24 are gradually separated from the tooth grooves 21E of the drive gear 21. At this time, the lubricating oil rapidly flows into the tooth groove 21E mainly from the one end face 21B, 24B side of each gear 21, 24 when the tooth 24A of the driven gear 24 is detached from the tooth groove 21E. become.

  As described above, when the drive gear 21 and the driven gear 24 are engaged with each other, the main flow is caused by the outflow of the lubricating oil from the tooth groove 21D in the start point side region 25A of the engaging portion 25 and the inflow of the lubricating oil into the tooth groove 21E. Input energy from the rotating shaft 19 is consumed as kinetic energy of the lubricating oil. As a result, the rotational torque of the drive gear 21 and the driven gear 24 is lost, and input energy is wasted.

  On the other hand, in the present embodiment, a block body 26 facing one end surface 21B of the drive gear 21 and one end surface 24B of the driven gear 24 is provided, and the partition portion 27 constituting the block body 26 is opposed to the gear. The surface 27A faces the meshing portion 25 where the drive gear 21 and the driven gear 24 mesh with each other with a slight gap, and a concave communication groove 31 that communicates the start point side region 25A and the end point side region 25B of the meshing portion 25 with each other. Is provided.

  Thereby, for example, when the drive gear 21 and the driven gear 24 mesh with each other, the lubricating oil filled in the tooth groove 21D flows out into the communication groove 31 in the starting point side region 25A of the meshing portion 25, and In the end point side region 25B of the meshing portion 25, the lubricating oil filled in the communication groove 31 flows into the tooth groove 21E.

  At this time, the start point side region 25A becomes high pressure when the lubricating oil flows out of the tooth groove 21D, and the end point side region 25B becomes low pressure when the lubricating oil flows into the tooth groove 21E. Since the communication groove 31 is substantially closed in the casing body 3 and communicates the high pressure start point side region 25A and the low pressure end point side region 25B, the start point side region 25A and the end point side region The differential pressure with respect to 25B can be increased as compared with the case where the flow of the lubricating oil is generated in the casing body 3 and the meshing portion 25. Thereby, in the communication groove 31, the flow of the lubricating oil can be generated from the start point side region 25A to the end point side region 25B. Therefore, the lubricating oil flows out from the meshing portion 25 and to the meshing portion 25. The resistance at the time of inflow can be reduced, and the loss of input energy can be reduced.

  Thus, according to the first embodiment, the block body 26 is formed in a U shape by the partition wall portion 27, the upper leg portion 28, and the lower leg portion 29, and the upper leg portion 28 and the lower leg portion 29 are formed in the casing body. The block body 26 is attached to the inside of the casing body 3 with bolts 30 in a state where the block body 26 is in contact with the partition portion 3 </ b> G as the inner wall 3. As a result, the gear facing surface 27A of the partition wall 27 can be opposed to one end face 21B, 24B of the drive gear 21 and the driven gear 24 with a slight gap.

  Therefore, the communication groove 31 provided on the gear facing surface 27A is isolated from the inside of the pump chamber 3B5 of the casing body 3, and the starting point side region where the driving gear 21 and the driven gear 24 mesh with each other has a high pressure. 25A can be communicated with the end point side region 25B having a low pressure. As a result, the lubricating oil extruded from the tooth groove 21D of the drive gear 21 is utilized by utilizing the differential pressure between the starting point side region 25A that becomes high pressure and the end point side region 25B that becomes low pressure across the meshing region 25C. The loss of input energy from the main rotating shaft 19 can be reduced by reducing the resistance of the inflow and outflow of the lubricating oil at the meshing portion 25, which can be supplied into the tooth groove 21E.

  Further, the block body 26 is attached to the inside of the casing body 3 with the bolt 30 in a state where the upper leg portion 28 and the lower leg portion 29 are in contact with the partition portion 3G as the inner wall of the casing body 3. Thus, the meshing portion 25 between the drive gear 21 and the driven gear 24 can be covered. Thereby, the periphery of the meshing portion 25 can be roughly separated from the inside of the casing body 3 by the block body 26, and the other end surface of the drive gear 21 and the driven gear 24 opposite to the one end surfaces 21 </ b> B and 24 </ b> B. 21C and 24C can face the partition portion 3G as the inner wall of the casing 2 with a slight gap, and the meshing portion 25 can be sandwiched between the leg portions 28 and 29 of the block body 26. As a result, the amount of lubricating oil filled between the drive gear 21 and the other end surfaces 21C and 24C of the driven gear 24, the partition portion 3G, and the leg portions 28 and 29 of the block body 26 is reduced, and driving is performed. The outflow and inflow of the lubricating oil on the other end surfaces 21C and 24C side of the gear 21 and the driven gear 24 can be reduced. As a result, most of the outflow and inflow of the lubricating oil between the start point side region 25A and the end point side region 25B of the meshing portion 25 can be performed through the communication groove 31, so that the loss of input energy is further effective. Can be reduced.

  Further, a joint 31E between the bottom surface 31A of the communication groove 31 and the width direction side surface 31C is formed in an R shape, and the bottom surface 31A and the width direction side surface 31C are smoothly joined. Thereby, the flow of the lubricating oil from the starting point side region 25 </ b> A having a high pressure to the end point side region 25 </ b> B having a low pressure in the meshing portion 25 can be made smooth.

  Next, FIG. 7 and FIG. 8 show a second embodiment of the present invention. A feature of the present embodiment is that a first block body is provided on one end face 21B, 24B side of the drive gear 21 and the driven gear 24, and a second block body is provided on the other end face 21C, 24C side. There is. In the second embodiment, the same components as those in the first embodiment described above are denoted by the same reference numerals, and description thereof is omitted.

  7 and 8, reference numeral 41 denotes a block body used in the second embodiment, and the block body 41 includes a first block body 42 and a second block body 47 which will be described later. Yes.

  Reference numeral 42 denotes a first block body located in the casing 2 and provided on one end face 21B, 24B side of the drive gear 21 and the driven gear 24. The first block body 42 is formed as a U-shaped frame similar to the block body 26 according to the first embodiment described above, and includes a first partition wall portion 43 to be described later and a pair of first legs. It consists of parts 44 and 45.

  Reference numeral 43 denotes a first partition portion facing the end surfaces 21B and 24B of the drive gear 21 and the driven gear 24 with a slight gap. The first partition wall 43 is formed in a rectangular parallelepiped shape extending in a direction orthogonal to the direction of the inter-axis distance between the axis of the drive gear 21 and the axis of the driven gear 24. A first communication groove 46 to be described later is provided on the first gear facing surface 43A of the first partition wall 43 facing the one end surfaces 21B and 24B of the drive gear 21 and the driven gear 24. ing.

  Reference numeral 44 denotes a first upper leg portion that extends from the upper end perpendicular to the direction of the distance between the axes of the first partition wall portion 43 to the middle in the axial direction between the drive gear 21 and the driven gear 24. The leg portion 44 covers the upper portion of the meshing portion 25 between the drive gear 21 and the driven gear 24. A bolt insertion hole 44 </ b> A that penetrates in the thickness direction is formed in a substantially central portion of the first upper leg portion 44.

  Reference numeral 45 denotes a first lower leg portion extending from a lower end perpendicular to the direction of the interaxial distance of the first partition wall portion 43 to the middle in the axial direction of the drive gear 21 and the driven gear 24. 45 covers the lower part of the meshing part 25 between the drive gear 21 and the driven gear 24. That is, the first lower leg portion 45 and the first upper leg portion 44 face each other with the meshing portion 25 between the drive gear 21 and the driven gear 24 interposed therebetween. A bolt insertion hole 45 </ b> A that penetrates in the thickness direction is formed in a substantially central portion of the first lower leg portion 45.

  Reference numeral 46 denotes a first communication groove provided on the first gear-opposing surface 43A constituting the first partition wall 43 of the first block body 42. The first communication groove 46 is the first communication groove 46 described above. Similarly to the communication groove 31 according to the embodiment, the groove is formed in a concave shape opened to the drive gear 21 and the driven gear 24 side, and faces the meshing portion 25 of the drive gear 21 and the driven gear 24 with a slight gap. .

  Reference numeral 47 denotes a second block body located in the casing 2 and provided on the other end faces 21C and 24C side of the drive gear 21 and the driven gear 24. The second block body 47 is also formed as a U-shaped frame similar to the block body 26 according to the first embodiment described above, and includes a second partition wall portion 48 to be described later and a pair of second legs. Part 49,50.

  Reference numeral 48 denotes a second partition portion facing the other end surfaces 21C and 24C of the drive gear 21 and the driven gear 24 with a slight gap. The second partition wall 48 is formed in a rectangular parallelepiped shape extending in a direction orthogonal to the direction of the inter-axis distance between the axis of the drive gear 21 and the axis of the driven gear 24. A second communication groove 51 described later is provided on the second gear facing surface 48A of the second partition wall portion 48 facing the other end surfaces 21C and 24C of the drive gear 21 and the driven gear 24. ing.

  Reference numeral 49 denotes a second upper leg portion extending from the upper end perpendicular to the direction of the distance between the axes of the second partition wall portion 48 toward the first block body 42. The second upper leg portion 49 is The upper portion of the meshing portion 25 between the drive gear 21 and the driven gear 24 is covered. A bolt insertion hole 49 </ b> A that penetrates in the thickness direction is formed in a substantially central portion of the second upper leg portion 49.

  Reference numeral 50 denotes a second lower leg portion extending from the lower end perpendicular to the direction of the interaxial distance of the second partition wall portion 48 toward the first block body 42, and the second lower leg portion 50 is driven. The lower part of the meshing part 25 of the gear 21 and the driven gear 24 is covered. That is, the second lower leg portion 50 and the second upper leg portion 49 face each other with the meshing portion 25 between the drive gear 21 and the driven gear 24 interposed therebetween. A bolt insertion hole 50 </ b> A that penetrates in the thickness direction is formed in a substantially central portion of the second lower leg portion 50.

  Reference numeral 51 denotes a second communication groove provided on the second gear facing surface 48A that constitutes the second partition wall portion 48 of the second block body 47, and the second communication groove 51 is the first communication groove 51 described above. Similarly to the communication groove 31 according to the embodiment, the groove is formed in a concave shape opened to the drive gear 21 and the driven gear 24 side, and faces the meshing portion 25 of the drive gear 21 and the driven gear 24 with a slight gap. .

  Then, the first upper leg portion 44 of the first block body 42 and the second upper leg portion 49 of the second block body 47 are brought into contact with each other, and the first lower leg portion of the first block body 42 is contacted. 45 and the second lower leg portion 50 of the second block body 47 are in contact with each other, the bolts are inserted into the bolt insertion holes 44A of the first block body 42 and the bolt insertion holes 49A of the second block body 47. 52, and the bolts 52 are inserted into the bolt insertion holes 45 </ b> A of the first block body 42 and the bolt insertion holes 50 </ b> A of the second block body 47, and these bolts 52 are inserted into the female screws of the partition portion 3 </ b> G of the casing body 3. Fastened to the hole 3G1. As a result, the first block body 42 and the second block body 47 can be mounted in the casing 2 with the meshing portion 25 between the drive gear 21 and the driven gear 24 sandwiched from both sides in the axial direction. Yes.

  Thus, according to the second embodiment, the first block body 42 and the second block body 47 cover the meshing portion 25 where the drive gear 21 and the driven gear 24 mesh. Then, the first block body 42 is opposed to the one end face 21B, 24B side of the drive gear 21 and the driven gear 24 with a slight gap, and the other end face 21C, 24C side of the drive gear 21 and the driven gear 24 is provided. In addition, the second block body 47 is faced with a slight gap.

  Thereby, the periphery of the meshing portion 25 between the drive gear 21 and the driven gear 24 can be roughly separated from the casing body 3 by the first block body 42 and the second block body 47, and the drive gear Outflow and inflow of the lubricating oil on one end face 21B, 24B side of the drive gear 21 and the driven gear 24 in the meshing portion 25 between the drive gear 21 and the driven gear 24 is a first communication groove of the first block body 42. 46, and the outflow and inflow of the lubricating oil on the other end surfaces 21 </ b> C and 24 </ b> C side of the drive gear 21 and the driven gear 24 can be performed via the second communication groove 51 of the second block body 47. It can be carried out. As a result, the outflow and inflow resistance of the lubricating oil at the meshing portion 25 can be further reduced, and the loss of input energy from the main rotating shaft 19 can be further effectively reduced.

  In the first embodiment, the case where the joint portion 31E between the bottom surface 31A of the communication groove 31 and the width direction side surface 31C is formed in a smooth R shape has been described as an example. However, the present invention is not limited to this. For example, as in the modification shown in FIG. 8, the communication groove 61 includes a bottom surface 61A, a length direction side surface 61B, and a width direction side surface 61C, and the bottom surface 61A and the width direction. The joint 61D with the side surface 61C may be formed as a chamfered shape. As described above, even when the joining portion 61D has a chamfered shape, the flow of the lubricating oil from the start point side region 25A in the engagement portion 25 to the low pressure end point region 25B can be made smooth. Therefore, loss of input energy can be effectively reduced. The same applies to the second embodiment.

  In the first embodiment, the flow of the lubricating oil in the meshing portion 25 is caused when the tooth 24A of the driven gear 24 enters the tooth groove 21D of the driving gear 21 and from the tooth groove 21E of the driving gear 21. As an example, the outflow and the inflow of the lubricating oil when the 24 teeth 24A are separated (separated) have been described. However, the present invention is not limited to this. For example, when the tooth 21A of the drive gear 21 enters the tooth groove of the driven gear 24, the tooth 21A of the drive gear 21 moves away from the tooth groove of the driven gear 24. The same applies to the outflow and inflow of lubricating oil at times. The same applies to the second embodiment and the modification.

  In the first embodiment, the case where the drive gear 21 and the driven gear 24 are configured as helical gears has been described as an example. However, the present invention is not limited to this. For example, the drive gear and the driven gear may be constituted by spur gears. The same applies to the second embodiment and the modification.

  Further, in the second embodiment, the case where the block body 41 is configured by two divided members of the first block body 42 and the second block body 47 has been described as an example. However, the present invention is not limited to this. For example, the first block body 42 and the second block body 47 may be configured as a single block body.

  In the first embodiment, a variable displacement oblique shaft hydraulic pump, which is one of axial piston hydraulic pumps, is illustrated. However, the present invention is not limited to this. For example, a swash plate type hydraulic pump may be used as another axial piston type hydraulic pump. That is, the present invention can be widely used in a parallel pump type hydraulic pump device in which power is transmitted by a gear. The same applies to the second embodiment and the modification.

DESCRIPTION OF SYMBOLS 1 Hydraulic pump apparatus 2 Casing 3 Casing main body 3G Partition part (inner wall)
DESCRIPTION OF SYMBOLS 9 Drive pump 14 Drive pump 19 Main rotating shaft 21 Drive gear 21B One end surface of the drive gear 21C The other end surface of the drive gear 22 Driven rotation shaft 24 Driven gear 24B One end surface of the driven gear 24C The other end surface 25 of the driven gear Part 26, 41 Block body 27 Partition part 27A Gear facing surface 28 Upper leg part 29 Lower leg part 31, 61 Communication groove 31E, 61D Joint part (groove end part)
32A Root circle of the driving gear 32B Root circle of the driven gear 33A Root circle of the driving gear 33B Root circle of the driven gear 42 First block body 43 First partition wall portion 43A First gear facing surface 44 First Upper leg portion 45 First lower leg portion 46 First communication groove 47 Second block body 48 Second partition wall portion 48A Second gear facing surface 49 Second upper leg portion 50 Second lower leg portion 51 First 2 communication grooves

Claims (5)

A casing, a drive pump housed in the casing, a driven pump housed in the casing in parallel with the drive pump, and the drive pump in series to transmit power from the outside to the drive pump A main rotating shaft supported by the casing; a driving gear provided on the driving pump side of the main rotating shaft and rotating integrally with the main rotating shaft and driving the driving pump; and in series with the driven pump A driven rotary shaft supported by the casing in parallel with the main rotary shaft, and provided on the driven pump side of the driven rotary shaft, and rotates integrally with the driven rotary shaft and meshes with the drive gear. In a hydraulic pump device comprising a driven gear, and a lubricating oil stored in the casing for lubricating the drive gear and the driven gear,
In the casing, a block body having a gear-facing surface facing at least one of the end faces in the axial direction of the drive gear and the driven gear is provided,
The gear-facing surface of the block body is provided with a concave communication groove corresponding to the meshing portion with which the drive gear and the driven gear mesh.
The communication groove has a groove width dimension (A) parallel to a direction of an inter-axis distance between the axis of the drive gear and the axis of the driven gear, and a root circle of the drive gear and a root circle of the driven gear. And the groove length dimension (B) perpendicular to the direction of the inter-axis distance intersects the tooth tip circle of the drive gear and the tooth tip circle of the driven gear. A hydraulic pump device characterized by being set to be equal to or less than a distance between two intersections.   The groove length dimension (B) of the communication groove is 40% or more of the distance between two intersections where the tooth tip circle of the drive gear and the tooth tip circle of the driven gear intersect with the tooth tip circle of the drive gear. 2. The hydraulic pump device according to claim 1, wherein the hydraulic pump device is set to a range equal to or less than a distance between two intersections where the toothed circle of the driven gear intersects.   The hydraulic pump device according to claim 1, wherein the communication groove is formed by forming both groove end portions orthogonal to the direction of the inter-axis distance as an R shape or a chamfered shape. In the casing, an inner wall that partitions the main rotating shaft and the driven rotating shaft is provided,
The block body includes a partition wall portion having the gear facing surface facing the one end surface of the drive gear and the driven gear with a slight clearance, and is orthogonal to the direction of the inter-axis distance of the partition wall portion. Formed as a U-shaped frame with a pair of legs extending from both ends to the inner wall of the casing,
By bringing the pair of leg portions of the block body into contact with the inner wall of the casing, the other end surface of the axial end surfaces of the drive gear and the driven gear is slightly smaller than the inner wall of the casing. The hydraulic pump device according to claim 1, 2 or 3, wherein the hydraulic pump device is configured to face each other with a gap. In the casing, an inner wall that partitions the main rotating shaft and the driven rotating shaft is provided,
The block body includes a first partition portion having a first gear-facing surface facing the end surface of the drive gear and the driven gear with a slight gap, and the shaft of the first partition portion. A first block body formed as a U-shaped frame body by a pair of first leg portions extending from both ends orthogonal to the distance direction toward the inner wall of the casing, and the first block A second partition wall having a second gear facing surface facing the body, the drive gear and the driven gear across the other end surface facing the other end surface of the drive gear and the driven gear; A second U-shaped frame is formed by a pair of second legs extending from both ends orthogonal to the direction of the inter-axis distance of the second partition wall portion toward the first block body. 2 block bodies,
The said block body becomes a structure attached to the inner wall of the said casing in the state which contact | abutted the 1st leg part of the said 1st block body, and the 2nd leg part of the said 2nd block body. The hydraulic pump device according to 1, 2 or 3.

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