JP2018178935A - Hydraulic drive motor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydraulic drive motor which is improved in a resolution of output torque while suppressing the enlargement of a dimension in a rotation axial direction.SOLUTION: This hydraulic drive motor comprises: a plurality of pump motors having first cylinders connected to a hydraulic pressure source via an oil passage, and first pistons which are slidably inserted into the first cylinders, respectively; a plurality of second pump motors having second cylinders connected to the hydraulic pressure source via the oil passage, and second pistons which are slidably inserted into the second cylinders, respectively; and a rotating shaft having an eccentric cam part at which the first pistons and the second pistons slide on an external peripheral face. Center axes of the first cylinders and center axes of the second cylinders are arranged around the eccentric cam part in a radial shape on a first plane vertical to an axial direction of the rotating shaft, and capacities of a plurality of the first pump motors and capacities of a plurality of the second pump motors differ from each other.SELECTED DRAWING: Figure 1A

Description

  The present disclosure relates to a hydraulic drive motor.

Conventionally, a radial type hydraulic motor is known which generates rotational torque by reciprocating a piston radially arranged C with respect to a drive shaft in a cylinder using hydraulic oil supplied from a hydraulic pressure source. (Patent Document 1). In the hydraulic motor described in Patent Document 1, two rows of piston cylinder assemblies having different working capacities D ₁ and D ₂ are arranged in parallel in the drive shaft direction.

Japanese Examined Patent Publication No. 60-32043

  In the configuration described in Patent Document 1, two rows of piston and cylinder assemblies are arranged in parallel in the drive axis direction. Therefore, there is a problem that the dimension in the rotation axis direction is increased.

  An object of the present disclosure is to provide a hydraulic drive motor in which the resolution of output torque is improved while suppressing an increase in the dimension in the rotational axis direction.

  A hydraulic drive motor according to an aspect of the present disclosure includes a plurality of first cylinders connected via a hydraulic pressure source and an oil passage, and a plurality of first pistons slidably inserted in the first cylinders. A plurality of second pumps each comprising a first pump motor, a second cylinder connected to the hydraulic pressure source via an oil passage, and a second piston slidably inserted in the second cylinder. A hydraulic drive motor comprising: a motor; and a rotating shaft having an eccentric cam portion on the outer peripheral surface on which the first piston and the second piston slide, wherein a central axis of the first cylinder and the first driving shaft The central axes of the two cylinders are radially arranged around the eccentric cam portion in a first plane perpendicular to the axial direction of the rotation axis, and the displacements of the plurality of first pump motors are Second pump Take the capacity and different configurations of data.

  According to the present disclosure, it is possible to provide a hydraulic drive motor in which the resolution of the output torque is improved while suppressing the increase in the dimension in the rotational axis direction.

It is a side schematic diagram of a hydraulic drive motor concerning a 1st embodiment. It is a cross-sectional schematic diagram of the hydraulic drive motor which concerns on 1st Embodiment. It is an oil-path wiring diagram of the hydraulic drive motor which concerns on 1st Embodiment. It is an explanatory view of the 1st pump motor concerning this indication. It is explanatory drawing of the 2nd pump motor which concerns on this indication. It is a figure which shows the stroke which suck | inhales hydraulic oil from a low voltage | pressure side, and it discharges to a high pressure side. It is a figure which shows the stroke which suck | inhales hydraulic oil from a low voltage | pressure side, and it discharges to a high pressure side. It is a figure which shows the stroke which suck | inhales hydraulic oil from a low voltage | pressure side, and it discharges to a high pressure side. It is a figure which shows the stroke which suck | inhales hydraulic oil from a low voltage | pressure side, and it discharges to a high pressure side. It is a figure which shows the stroke which suck | inhales hydraulic oil from a low voltage | pressure side, and it discharges to a high pressure side. It is a figure which shows the stroke which suck | inhales hydraulic oil from a low voltage | pressure side, and it discharges to a high pressure side. It is a figure which shows the process in which hydraulic fluid flows in from a high voltage | pressure side, and flows out to a low voltage | pressure side. It is a figure which shows the process in which hydraulic fluid flows in from a high voltage | pressure side, and flows out to a low voltage | pressure side. It is a figure which shows the process in which hydraulic fluid flows in from a high voltage | pressure side, and flows out to a low voltage | pressure side. It is a figure which shows the process in which hydraulic fluid flows in from a high voltage | pressure side, and flows out to a low voltage | pressure side. It is a figure which shows the process in which hydraulic fluid flows in from a high voltage | pressure side, and flows out to a low voltage | pressure side. It is a figure which shows the process in which hydraulic fluid flows in from a high voltage | pressure side, and flows out to a low voltage | pressure side. It is a figure which shows the process in which hydraulic fluid flows in from a high voltage | pressure side, and flows out to a low voltage | pressure side. It is a cross-sectional schematic diagram of the hydraulic drive motor which concerns on 2nd Embodiment.

  Hereinafter, embodiments of the present disclosure will be described in detail with reference to the drawings.

First Embodiment
FIG. 1A is a schematic side view of a hydraulic drive motor 10A according to a first embodiment. FIG. 1B is a schematic cross-sectional view of a hydraulic drive motor 10A according to the first embodiment. FIG. 1C is an oil passage wiring diagram of the hydraulic drive motor 10A according to the first embodiment.

  The hydraulic drive motor 10A includes a support 11, a first cylinder 40A, a second cylinder 40B, a link mechanism L, a first piston 43A, a second piston 43B, and a rotating shaft 12.

  The support 11 is fixed to a housing (not shown) of the hydraulic drive motor 10A. In one example, the support 11 is a substantially annular body centered on the support central axis C1. In another example, the support 11 is a substantially disc centered on the support central axis C1.

  The first cylinder 40A has a capacity Q1 and is swingably connected to the support 11. In one example, three first cylinders 40A (40A-1, 40A-2, 40A-3) are connected to the support 11.

  The second cylinder 40B has a volume Q2 and is swingably connected to the support 11. In one example, three second cylinders 40B (40B-1, 40B-2, 40B-3) are connected to the support 11.

  The volume Q1 of the first cylinder 40A is different from the volume Q2 of the second cylinder 40B. In one example, the first cylinder 40A and the second cylinder 40B are equal in height and different in inner diameter.

  The central axis of the first cylinder 40A and the central axis of the second cylinder 40B extend on a first plane perpendicular to the axial direction of the support central axis C1 of the hydraulic drive motor 10A.

  The link mechanism L pivotally connects the first cylinder 40A (second cylinder 40B) to the support 11. The first cylinder 40A (second cylinder 40B) swings relative to the support 11 with the link mechanism L between the support 11 and the first cylinder 40A (second cylinder 40B) as a fulcrum. In one example, the link mechanism L includes a ball bearing. In one example, the link mechanisms L are equally spaced on a circumference centered on the support central axis C1 as shown in FIG. 1A.

  The first piston 43A is slidably inserted in the first cylinder 40A. In one example, the hydraulic drive motor 10A includes three first pistons 43A (43A-1, 43A-2, 43A-3), and each includes three first cylinders 40A (40A-1, 40A). -2, 40A-3), and the inside is filled with hydraulic fluid.

  The second piston 43B is slidably inserted in the second cylinder 40B. In one example, the hydraulic drive motor 10A includes three second pistons 43B (43B-1, 43B-2, and 43B-3), and each includes three second cylinders 40B (40B-1 and 40B). -2, 40B-3), and the inside is filled with hydraulic fluid.

  The rotating shaft 12 rotates around the support central axis C1. The rotating shaft 12 includes an eccentric cam portion 12a and a drive shaft 12b. The eccentric cam portion 12a is a cylinder. The first piston 43A and the second piston 43B contact the eccentric cam portion 12a in the direction of the eccentric cam portion central axis C2 and slide on the outer peripheral surface of the eccentric cam portion 12a. The drive shaft 12b is connected to a driven body (not shown) of the hydraulic drive motor 10A, and transmits the driving force to the driven body when the hydraulic drive motor 10A operates.

  As shown in FIG. 1A, in the hydraulic drive motor 10A, a plane (first plane) in which the central axis of the first cylinder 40A and the central axis of the second cylinder 40B are perpendicular to the axial direction of the rotation axis 12 The radial type hydraulic drive motor is disposed radially around the eccentric cam portion 12a. While the first piston 43A (second piston 43B) makes one reciprocation, the rotation shaft 12 makes one rotation.

  In one example, as shown in FIG. 1A, the first cylinder 40A and the second cylinder 40B are disposed to face each other across the eccentric cam portion 12a. Also, in one example, the first cylinder 40A and the second cylinder 40B are alternately arranged in the circumferential direction as shown in FIG. 1A. By arranging in this manner, it is possible to suppress the fluctuation of torque in one rotation of the hydraulic drive motor 10A.

  The hydraulic drive motor 10A further includes a first flow control unit 21A, a second flow control unit 21B, high pressure side oil passages 35A and 35B, low pressure side oil passages 36A and 36B, and a pump 37 (hydraulic source). , A crank angle detection sensor 13, and a valve body control unit 14.

  The first flow control unit 21A, the first cylinder 40A, and the first piston 43A constitute a first pump motor 20A. In one example, the hydraulic drive motor 10A includes three first pump motors 20A (20A-1, 20A-2, and 20A-3).

  The second flow control unit 21B, the second cylinder 40B, and the second piston 43B constitute a second pump motor 20B. In one example, the hydraulic drive motor 10A includes three second pump motors 20B (20B-1, 20B-2, and 20B-3).

  The first flow control unit 21A is connected to the high pressure side oil passage 35A, the low pressure side oil passage 36A, and the first cylinder 40A, and controls the flow of oil therebetween. Control of the flow of oil is described below with reference to FIGS. 3A-4G. In one example, the hydraulic drive motor 10A includes three first flow controllers 21A (21A-1, 21A-2, 21A-3).

  The second flow control unit 21B is connected to the high pressure side oil passage 35B, the low pressure side oil passage 36B, and the second cylinder 40B, and controls the flow of oil therebetween. Control of the flow of oil is described below with reference to FIGS. 3A-4G. In one example, the hydraulic drive motor 10A includes three second flow control units 21B (21B-1, 21B-2, 21B-3).

  The high pressure side oil passage 35A communicates with the first flow control unit 21A. In one example, the hydraulic drive motor 10A includes three high-pressure side oil passages 35A (35A-1, 35A-2, 35A-3).

  The high pressure side oil passage 35B communicates with the second flow control unit 21B. In one example, the hydraulic drive motor 10A includes three high pressure side oil passages 35B (35B-1, 35B-2, 35B-3).

  The high pressure side oil passages 35A, 35B deliver high-pressure hydraulic fluid to the first flow control unit 21A and the second flow control unit 21B, or the first flow control unit 21A and the second flow control unit 21B. Introduce high pressure hydraulic oil from

  The low pressure side oil passage 36A communicates with the first flow control unit 21A. In one example, the hydraulic drive motor 10A includes three low pressure side oil passages 36A (36A-1, 36A-2, and 36A-3).

  The low pressure side oil passage 36B communicates with the second flow control unit 21B. In one example, the hydraulic drive motor 10A includes three high pressure side oil passages 36B (36B-1, 36B-2, and 36B-3).

  The low pressure side oil passages 36A, 36B deliver low pressure hydraulic oil to the first flow control unit 21A and the second flow control unit 21B, or the first flow control unit 21A and the second flow control unit 21B. Introduce low pressure hydraulic oil from

  The pump 37 is in communication with the high pressure side oil passages 35A and 35B and the low pressure side oil passages 36A and 36B, and discharges the working oil sucked from the low pressure side oil passages 36A and 36B to the high pressure side oil passages 35A and 35B. Supply pressure oil. The configuration of the pump 37 is not particularly limited as long as the pressure oil flow rate can be maintained substantially constant, and a known pump can be used.

  In one example, as shown in FIG. 1C, three first flow control units 21A (21A-1, 21A-2, 21A) between the high pressure side oil passages 35A, 35B and the low pressure side oil passages 36A, 36B. 3), the three second flow control units 21B (21B-1, 21B-2, 21B-3), and the pump 37 are connected in parallel.

  Please refer to FIG. 1A. The crank angle detection sensor 13 detects the rotation angle θ of the eccentric cam portion 12a. In one example, the crank angle detection sensor 13 is an optical rotary encoder.

  The valve body control unit 14 performs a first solenoid 41 d (first actuator) provided in the first flow control unit 21A and the second flow control unit 21B according to the detected rotation angle θ of the eccentric cam unit 12 a. And the second solenoid 42d (second actuator). The first solenoid 41d and the second solenoid 42d will be described later with reference to FIGS. 2A and 2B. In one example, the valve body control unit 14 includes a CPU and a ROM, and the CPU includes a computer that reads and executes a program stored in the ROM.

  In FIG. 1B, for the sake of simplicity, the support 11 is arranged to be separated from the first cylinder 40A (the second cylinder 40B) by a plane perpendicular to the support central axis C1. It is shown. However, a configuration is also conceivable in which the support 11 is disposed on the outer diameter side of the first cylinder 40A (second cylinder 40B). Furthermore, as long as the crank angle sensor 13 can detect the rotation angle θ, the axial length of the rotating shaft 12 can be shortened. Such a configuration can further reduce the axial thickness of the hydraulic drive motor 10A.

  In this case, for example, the support 11 and the first cylinder 40A (the second cylinder 40B) are spaced apart to prevent the interference between the first cylinder 40A (the second cylinder 40B) and the support 11 Alternatively, a radial link mechanism may be employed.

  FIG. 2A is an explanatory view of a first pump motor 20A according to the present disclosure. FIG. 2B is an explanatory view of a second pump motor 20B according to the present disclosure.

  The first flow control unit 21 (21A, 21B) includes a low pressure side check valve 41 (first check valve) and a high pressure side check valve 42 (second check valve). The cylinder 40 (40A, 40B) is connected to the low pressure side oil passage 36 (36A, 36B) via the low pressure side check valve 41, and the high pressure side oil passage 35 (35A) via the high pressure side check valve 42. , 35 B).

  The low pressure side check valve 41 includes a first valve seat 41a, a first valve body 41b, a first spring 41c, and a first solenoid 41d. The low pressure side check valve 41 is, for example, a poppet valve.

  The low pressure side check valve 41 is configured to be able to close at a desired timing. Specifically, the low pressure side check valve 41 is provided with a first solenoid 41d for seating the first valve body 41b on the first valve seat 41a in accordance with a control signal from the valve body control unit 14. ing.

  The first spring 41 c presses the first valve body 41 b away from the first valve seat 41 a.

  The first solenoid 41 d causes the first valve body 41 b to be seated on the first valve seat 41 a only while power is supplied from the valve body control unit 14. The rotation angle θ of the eccentric cam portion 12 a detected by the crank angle detection sensor 45 a is input to the valve body control unit 14. The valve body control unit 14 controls the first solenoid 41 d to seat the first valve body 41 b on the first valve seat 41 a based on the input rotation angle θ of the eccentric cam portion 12 a.

  The high pressure side check valve 42 includes a second valve seat 42a, a second valve body 42b, a second spring 42c, and a second solenoid 42d. The high pressure side check valve 42 is, for example, a poppet valve.

  Further, the high pressure side check valve 42 opens at a predetermined timing. Further, the high pressure side check valve 42 is configured to be able to maintain the open state. Specifically, the high pressure side check valve 42 is provided with a second solenoid 42d that holds the separated state of the second valve body 42b separated from the second valve seat 42a. The second solenoid 42 d is controlled by a control signal from the valve control unit 14.

  The second spring 42c urges the second valve body 42b to be seated on the second valve seat 42a.

  The second solenoid 42d separates the second valve body 42b from the second valve seat 42a only while power is supplied from the valve body control unit 14. The valve body control unit 14 controls the second solenoid 42 d based on the rotation angle θ of the eccentric cam portion 12 a to separate the second valve body 42 b from the second valve seat 42 a.

  Next, a pumping process, a motoring process, and an idle process, which are the operation strokes of the pump motor 20 (20A, 20B), will be described. The valve control unit 14 controls the first pump motor 20A and the second pump motor 20B to operate in any of a pumping process, a motoring process, and an idle process described below.

<Pumping stroke>
FIGS. 3A to 3F are diagrams showing a stroke (pumping stroke) in which the hydraulic oil is sucked from the low pressure side oil passage 36 into the cylinder 40 and discharged to the high pressure side oil passage 35.

  In the suction stroke (FIGS. 3A to 3C) in which the piston 43 descends from the top dead center to the bottom dead center as the eccentric cam portion 12a rotates, power is supplied from the valve control portion 14 to the first solenoid 41d. Thus, the first valve body 41b is separated from the first valve seat 41a. Thus, in the suction stroke, the low pressure side check valve 41 is opened, and the hydraulic oil in the low pressure side oil passage 36 is introduced into the cylinder 40. Further, in the intake stroke, the high pressure side check valve 42 is closed.

  The valve body control unit 14 does not supply power to the first solenoid 41 d for a predetermined period of the discharge stroke in which the piston 43 rises from the bottom dead center to the top dead center. As a result, the first valve body 41b is kept apart from the first valve seat 41a.

  In a state where the first valve body 41b is separated from the first valve seat 41a and the low pressure side check valve 41 is opened, as shown in FIG. 3D, the high pressure side check valve 42 maintains the closed state. The hydraulic oil in the cylinder 40 does not flow to the high pressure side oil passage 35.

  During the discharge stroke, when power is supplied to the first solenoid 41d, the low pressure side check valve 41 is closed and the pressure of the cylinder 40 is increased, and the high pressure side check valve 42 is opened. Then, the hydraulic oil in the cylinder 40 is led out to the high pressure side oil passage 35 (FIGS. 3E to 3F). At this time, the thrust of the second solenoid 42d is not necessarily required to maintain the open state of the high-pressure side check valve 42, but the thrust of the second solenoid 42d causes the second valve body 42b to The load of the acting second spring 42c may be cancelled.

  Thus, by adjusting the timing at which the low pressure side check valve 41 is closed, the displacement of the first pump motor 20A (the second pump motor 20B) is adjusted from zero displacement to the maximum displacement Q1 (Q2). can do.

<Motoring stroke>
4A to 4G are diagrams showing a stroke (motoring stroke) in which the hydraulic oil flows from the high pressure side oil passage 35 into the cylinder 40 and flows out to the low pressure side oil passage 36.

  FIG. 4A shows a state in which the piston 43 is moving up and just before reaching the top dead center. At this time, no electric power is supplied from the valve control unit 14 to the first solenoid 41 d, and the low pressure side check valve 41 is opened by the first spring 41 c.

  In this state, the valve control unit 14 supplies power to the first solenoid 41 d. Thereby, the low pressure side non-return valve 41 is closed, and the high pressure side non-return valve 42 is opened as shown in FIG. 4B in the following upward stroke of the piston 43. Further, immediately after the supply of power to the first solenoid 41 d is started, the valve body control unit 14 also supplies power to the second solenoid 42 d.

  Thus, in the state where the piston 43 has reached the top dead center, the high pressure side check valve 42 maintains the open state (FIG. 4C). Subsequently, the hydraulic oil in the high pressure side oil passage 35 flows into the cylinder 40 and pushes down the piston 43 (FIG. 4D).

  Just before the piston 43 reaches the bottom dead center, the valve body control unit 14 stops the power supply to the first solenoid 41 d. As a result, the low pressure side check valve 41 is opened, and in the subsequent downward stroke of the piston 43, as shown in FIG. 4E, the high pressure side check valve 42 is closed. Further, immediately after the supply of power to the first solenoid 41 d is stopped, the control device 50 stops the supply of power to the second solenoid 42 d. As a result, in the state where the piston 43 reaches the bottom dead center, the low pressure side check valve 41 is opened, and the high pressure side check valve 42 is closed (FIG. 4F). From here, when the piston 43 ascends to the top dead center due to the rotational inertia of the eccentric cam portion 12a, the hydraulic oil in the cylinder 40 flows out to the low pressure side oil passage 36 (FIG. 4G).

  By supplying electric power to the first solenoid 41 d to advance the timing of opening the low pressure side check valve 41 in a stroke in which the piston 43 ascends from the bottom dead center to the top dead center, from the cylinder 40 thereafter. It is possible to prevent the hydraulic oil from flowing out to the low pressure side oil passage 36. Thus, by adjusting the timing at which the low pressure side check valve 41 is closed, the displacement of the first pump motor 20A (the second pump motor 20B) is adjusted from zero displacement to the maximum displacement Q1 (Q2). can do.

<Idle process>
The hydraulic drive motor 10A according to the first embodiment includes a plurality of first pump motors 20A and a plurality of second pump motors 20B. Assuming that the low pressure side check valve 41 is always in the valve opening state and the high pressure side check valve 42 is always in the valve closing state for some of the plurality of first pump motors 20A and the plurality of second pump motors 20B. It is possible to operate at an idle stroke that does not contribute in part to either pumping or motoring.

  In addition, as described above, the timing at which the low pressure side check valve 41 is closed is advanced to adjust the displacement of the first pump motor 20A (the second pump motor 20B) to zero displacement. Operating the pump motor 20A (the second pump motor 20B) in an idle stroke which does not contribute to either pumping or motoring in view of the total amount of oil moving during one rotation of the hydraulic drive motor 10A it can.

<Combination of capacity and operation stroke>
In the hydraulic drive motor 10A according to the first embodiment, the hydraulic drive motor 10A can realize various output torques by combining the capacity and the operation stroke of the pump motor 20 (20A, 20B).

  For example, when using six pump motors of the same capacity (capacity 1) and operating three motors at a time in the motoring stroke or idle stroke, the output torque of the hydraulic drive motor is three stages of 0, 3 and 6 Three-step torque corresponding to On the other hand, the first pump motor 20A having a capacity of 1.25 (Q1 = 1.25) and the second pump motor 20B having a capacity of 1 (Q2 = 1) each have three motoring strokes or Operate in the idle stage. Then, the output torque of the hydraulic drive motor 10A has four stages corresponding to four stages of 0, 3, 3.75, 5.75 (0, 3 x Q 2, 3 x Q 1, 3 x (Q1 + Q2)). It can be adjusted to torque.

  As described above, by using pump motors having different capacities and selecting a pump motor operated in the motoring stroke, even if the same number of pump motors are used, more stages of the hydraulic drive motor 10A (more Output torque can be realized.

  Further, a pumping process, a motoring stroke, three pumps each of the first pump motor 20A of capacity 1.25 (Q1 = 1.25) and the second pump motor 20B of capacity 1 (Q2 = 1), Or operate in the idle stroke. Then, the output torque of the hydraulic drive motor 10A is calculated by the following formula: 0, 0.75, 3, 3.75, 5.75 (0, 3 × (Q1-Q2), 3 × Q2, 3 × Q1, 3 × (Q1 + Q2) The torque can be adjusted to 5 levels corresponding to 5 levels of capacity.

  Thus, by using pump motors having different capacities and selecting a pump motor to be operated in the motoring stroke and the pumping stroke, torque corresponding to the difference in capacity can be utilized, and more hydraulic drive motors 10A can be used. An output torque of stages (higher resolution) can be realized.

  In one example, the following <Formula 1> holds between the displacement Q1 of the first pump motor 20A and the displacement Q2 of the second pump motor 20B.

  Q2 <Q1 <Q2 × 4/3 ... <Equation 1>

  By ensuring that Q1 and Q2 satisfy the relationship of <Expression 1>, the resolution of the output torque of the hydraulic drive motor 10A can be secured, while reducing the wasted space due to the difference in volume of the cylinder 40 in the hydraulic drive motor 10A. it can. The smaller the difference between Q1 and Q2, the less wasted space can be.

  In one example, Q1 is equal to Q2 × 5/4. In this case, the output torque of the hydraulic drive motor 10A is made substantially linear in the low output torque range of the hydraulic drive motor 10A by changing the capacity and the operating stroke of the first pump motor 20A (the second pump motor 20B). It can be changed.

  Thus, the hydraulic drive motor 10A according to the first embodiment is connected to the first cylinder 40A and the first cylinder 40A connected to the pump 37 via the high pressure side oil passage 35 and the low pressure side oil passage 36. First pump motors 20A-1, 20A-2, and 20A-3 each having a first piston 43A slidably inserted therein, a second cylinder 40B connected to the pump 37 via an oil passage, and Second pump motors 20B-1, 20B-2, and 20B-3 each having a second piston 43B slidably inserted in a second cylinder 40B, and a first piston 43A and a second on the outer peripheral surface And a rotary shaft having an eccentric cam portion 12a on which the piston 40B slides, and the central axis of the first cylinder 40A and the second cylinder 40B. The axes are radially disposed around the eccentric cam portion 12a in a first plane perpendicular to the axial direction of the rotation axis C1, and the capacities of the first pump motors 20A-1, 20A-2, 20A-3 are A configuration different from the capacity of the second pump motors 20B-1, 20B-2, and 20B-3 is adopted.

  According to the first embodiment, it is possible to improve the resolution of the output torque while suppressing an increase in the dimension in the rotational axis direction.

Second Embodiment
FIG. 5 is a schematic cross-sectional view of a hydraulic drive motor 10B according to a second embodiment.

  The hydraulic drive motor 10B includes a support 11, three first cylinders 40A, three second cylinders 40B, three third cylinders 40C, and three fourth cylinders 40D. .

  The first cylinder 40A and the second cylinder 40B are the same as those provided in the hydraulic drive motor 10A according to the first embodiment. The configurations of the third cylinder 40C and the fourth cylinder 40D are different in that their capacities Q3 and Q4 are different, and the capacities Q3 and Q4 may be different from the capacities Q1 and Q2 of the first cylinder 40A and the second cylinder 40B. Except for this, the configuration is the same as the configuration of the first cylinder 40A and the second cylinder 40B. In one example, the capacitances Q3 and Q4 are equal to the capacitances Q1 and Q2, respectively.

  The central axis of the third cylinder 40C and the central axis of the fourth cylinder 40D extend on a second plane perpendicular to the axial direction of the support central axis C1 of the hydraulic drive motor 10B. Here, the second plane is a plane different from the first plane in which the central axes of the first cylinder 40A and the second cylinder 40B extend.

  In the hydraulic drive motor 10A according to the first embodiment, while the first pump motor 20A and the second pump motor 20B constitute one bank, the hydraulic drive motor 10B according to the second embodiment Is composed of two banks. That is, in the hydraulic drive motor 10B, the first pump motor 20A and the second pump motor 20B constitute one bank, and the third pump motor 20C and the second pump motor 20D constitute one bank.

  The first pump motor 20A and the third pump motor 20C are provided in parallel in the direction of the support central axis C1. Further, the second pump motor 20B and the fourth pump motor 20D are also provided in parallel in the direction of the support center axis C1.

  The hydraulic drive motor 10B further includes a link mechanism L, an eccentric cam portion 12a, a second link mechanism S2, and a crank angle detection sensor 13. These components are the same as those of the hydraulic drive motor 10A according to the first embodiment.

  The hydraulic drive motor 10B further includes a valve control unit 14 '. In addition to the first pump motor 20A and the second pump motor 20B, the valve body control unit 14 'includes the third pump motor 20C and the fourth pump motor 20D in the pumping process, the motoring process, and the idle process. Control to operate either.

<Combination of capacity and operation stroke>
In the hydraulic drive motor 10B according to the second embodiment, the hydraulic drive motor 10B realizes various output torques by combining the displacements and operation strokes of the pump motors 20 (20A, 20B, 20C, 20D). Can.

  For example, when using 12 pump motors of the same capacity (capacity 1) and operating each with 3 motoring strokes or idle strokes, the output torque of the hydraulic drive motor is 0, 3, 6, 9, 12 There are 5 stages.

  On the other hand, the first pump motor 20A of six capacities of 1.25 (Q1 = 1.25, Q3 = 1.25) and the first of the six capacities of 1 (Q2 = 1, Q4 = 1) The two pump motors 20B are operated in a motoring stroke or an idle stroke, respectively. Then, the output torque of the hydraulic drive motor 10B can be adjusted to nine stages of 0, 3, 3.75, 6, 6.75, 7.5, 9.75, 10.5, and 13.5.

  Thus, by using pump motors having different capacities and selecting a pump motor to be operated in the motoring stroke, even if the same number of pump motors are used, more stages of the hydraulic drive motor 10B (more Output torque can be realized.

  Furthermore, the first pump motor 20A with six capacities of 1.25 (Q1 = 1.25) and the second pump motor 20B with six capacities of 1 (Q2 = 1) are pumped three each. Operate in process, motoring stroke, or idle stroke. Then, the output torque of the hydraulic drive motor 10 B is calculated as 0, 0.75, 1.5, 2.25, 3, 3.75, 4.5, 6, 6. 75, 7.5, 9.75, 10 It can be adjusted to 13 levels of 5 and 13.5.

  Thus, by using pump motors of different capacities and selecting the pump motors to operate in the motoring stroke and the pumping stroke, differential torque can be utilized, and more stages of hydraulic drive motor 10B (higher Output torque can be realized.

  In one example, only the pump motor in the same bank is used for the combination of the capacity and the operating stroke in which only the pump motor in the same bank can be used. As a result, it is possible to prevent the eccentric cam portion 12a from being twisted due to the forces from the pump motors in different banks acting on the eccentric cam portion 12a.

  Thus, the hydraulic drive motor 10B according to the second embodiment is slidably fitted in the third cylinder 40C and the third cylinder 40C connected to the pump 37 via the oil passage. Pump motors 20C-1, 20C-2, and 20C-3 each having a third piston 40C to be driven, and a fourth pump motor connected to the pump 37 via the high pressure side oil passage 35 and the low pressure side oil passage 36. And a fourth pump motor 20D-1, 20D-2, and 20D-3 each having a fourth piston 43D slidably inserted in the cylinder 40D and the fourth cylinder 40D. The third piston 43C and the fourth piston 43D slide on the outer peripheral surface, and the central axis of the third cylinder and the central axis of the fourth cylinder 40D are perpendicular to the axial direction of the rotary shaft 12, Of a plane different from a second plane disposed radially about the eccentric cam portion 12a, the capacitance 40C of the third cylinder is different from the fourth cylinder capacity 40D, a configuration.

  According to the second embodiment, compared to the hydraulic drive motor 10A according to the first embodiment, an output torque with higher resolution can be realized. Further, as compared with a hydraulic drive motor that realizes an output torque with the same resolution, it is possible to suppress an increase in the dimension in the rotational axis direction.

(Other embodiments)
In the first embodiment, six pump motors (20A, 20B) are used. In the second embodiment, twelve pump motors (20A, 20B, 20C, 20D) are used. Instead of this, an embodiment using three or more arbitrary number of pump motors is also conceivable. As the number of pump motors increases, the resolution of the output torque of the hydraulic drive motor can be further improved.

  In the first embodiment, two types of pump motors (20A, 20B) are used. In the second embodiment, four types of pump motors (20A, 20B, 20C, 20D) are used. Instead of this, an embodiment using three or more types or five or more types of pump motors is also conceivable. As the number of types of pump motors increases, the resolution of the output torque of the hydraulic drive motor can be further improved.

  In the first embodiment and the second embodiment, three of the pump motors of the same type are operated by the same operation stroke. Instead of this, an embodiment is also conceivable in which the operating strokes are different one by one between pump motors of the same type. Thereby, the resolution of the output torque of the hydraulic drive motor can be further improved.

  In the first embodiment, the first flow control unit 21A and the second flow control unit 21B are electrically controlled by the valve body control unit 14. Instead of this, a switching valve for mechanically switching the oil passage between the high pressure side oil passage 35, the low pressure side oil passage 36, and the first cylinder 40A (the second cylinder 40B) is provided. The form is also conceivable.

  In the first and second embodiments, the pump motor is operated at the maximum volume or zero volume, but the pump motor may be operated at an intermediate volume between them. Thereby, the resolution of the output torque can be further improved.

  The hydraulic drive motor according to the present disclosure is suitable for use in a hydraulic system that requires high resolution output torque.

10A, 10B Hydraulic drive motor 11 Support 12 Rotation shaft 12a Eccentric cam portion 12b Drive shaft 13 Crank angle detection sensor 14, 14 'Valve body control portion 20 Pump motor 20A 1st pump motor 20B 2nd pump motor 20C 3rd Pump motor 20D Fourth pump motor 21A First flow control unit 21B Second flow control unit 21C Third flow control unit 21D Fourth flow control unit 35 High pressure side oil passage 36 Low pressure side oil passage 37 Pump 40 Cylinder 41 low pressure side check valve 41a first valve seat 41b first valve body 41c first spring 41d first solenoid 42 high pressure side check valve 42a second valve seat 42b second valve body 42c second Spring 42d Second solenoid 43 Piston C1 Support center axis C2 Eccentric cam part center axis L Link mechanism θ rotation Degree

Claims (4)

A plurality of first pump motors each provided with a first cylinder connected via a hydraulic pressure source and an oil passage, and a first piston slidably inserted in the first cylinder;
A plurality of second pump motors each including a second cylinder connected to the hydraulic pressure source via an oil passage and a second piston slidably inserted in the second cylinder;
A rotary shaft having an eccentric cam portion on the outer peripheral surface on which the first and second pistons slide;
A hydraulic drive motor comprising
A central axis of the first cylinder and a central axis of the second cylinder are radially disposed around the eccentric cam portion in a first plane perpendicular to the axial direction of the rotation axis;
A hydraulic drive motor, wherein the displacements of the plurality of first pump motors are different from the displacements of the plurality of second pump motors.   The plurality of first pump motors and the plurality of second pump motors are alternately arranged in the circumferential direction, and the first pump motor faces the second pump motor with the crankshaft interposed therebetween. The hydraulic drive motor according to claim 1. A plurality of third pump motors each including a third cylinder connected to the hydraulic pressure source via an oil passage and a third piston slidably inserted in the third cylinder;
A plurality of fourth pump motors each provided with a fourth cylinder connected to the hydraulic pressure source via an oil passage and a fourth piston slidably inserted in the fourth cylinder;
And further
The third piston and the fourth piston slide on the outer circumferential surface,
The central axis of the third cylinder and the central axis of the fourth cylinder radiate around the eccentric cam portion in a second plane different from the first plane perpendicular to the axial direction of the rotation axis Placed in
The hydraulic drive motor according to claim 1, wherein a capacity of the third cylinder is different from a capacity of the fourth cylinder. The first pump motor is
A first check valve that opens when the pressure oil flows from the oil passage toward the first cylinder;
A first actuator capable of controlling opening and closing of the first check valve;
A second check valve that opens when the pressure oil flows from the first cylinder toward the oil passage;
A second actuator capable of controlling the opening and closing of the second check valve;
The hydraulic drive motor according to any one of claims 1 to 3, comprising:

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