Hydraulic piston pump motor
The use of rolling bearings with a drain channel and shielding member in hydraulic piston pumps/motors addresses lubrication and seizure issues, ensuring effective support and compactness.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- JTEKT FLUID POWER SYST CORP
- Filing Date
- 2022-07-21
- Publication Date
- 2026-06-29
Smart Images
Figure 0007881397000001 
Figure 0007881397000002 
Figure 0007881397000003
Abstract
Description
Technical Field
[0001] The present invention relates to a hydraulic piston pump / motor that uses a low-viscosity fluid such as water as a working fluid, sets the reciprocating momentum of a plurality of pistons arranged axially reciprocally in a cylinder block with an inclined plate, and inhales and discharges the working fluid.
Background Art
[0002] In this type of hydraulic piston pump / motor, a cylinder block is engaged with a rotating shaft (shaft) rotatably supported by a main body (casing). A plurality of pistons are arranged in the cylinder block so as to be reciprocally movable in the axial direction and equidistantly in the circumferential direction. A shoe pivotally attached to the tip of the piston is slidably contacted with an inclined plate fixed to the main body to set the reciprocating momentum of the piston. A pair of suction / discharge flow paths (supply passage, discharge passage) for sucking and discharging water as a working fluid are formed in the main body. In the pump operation, the cylinder block is rotationally driven by the rotating shaft, so that the piston reciprocates to suck water from one suction / discharge flow path and discharge water from the other suction / discharge flow path. In the motor operation, the piston reciprocates by the acting force based on the pressure of water supplied from one suction / discharge flow path, so that the rotating shaft rotates together with the cylinder block, and water is discharged from the other suction / discharge flow path.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] However, in such a conventional hydraulic piston pump / motor, since the rotating shaft is pivotally supported by a sliding bearing in the main body, although the pivotally supported portion is cooled with water, sufficient lubrication is still difficult to obtain, and there is a risk of seizure.
[0005] The object of the present invention is to provide a hydraulic piston pump motor that can properly support the rotating shaft to the main body and prevent seizure. [Means for solving the problem]
[0006] To achieve these objectives, the present invention employs the following means: low A hydraulic piston pump / motor that uses a viscous fluid as the working fluid, comprising: a rotating shaft rotatably supported on the main body; a cylinder block housed inside the main body and engaged with the rotating shaft in the rotational direction; a plurality of pistons arranged in the cylinder block so as to be reciprocating in the axial direction; a plurality of working chambers partitioned by each piston and the cylinder block for drawing in and discharging the working fluid; a swash plate that sets the reciprocating motion of each piston by sliding contact with the tips of each piston protruding from the cylinder block; and intake and exhaust passages formed in the main body for the flow of the working fluid drawn in and discharged to each working chamber, wherein the main body is provided with rolling bearings that rotatably support the rotating shaft, the rolling bearings are arranged on one end and the other end of the rotating shaft in the axial direction, a sealing member is provided axially inward of each rolling bearing to seal the inside of the main body, and each rolling bearing has a lubricant Furthermore, an opening for a drain channel that is vented to the atmosphere is formed between the rolling bearing and the sealing member, and a shielding member is provided to shield the side of the rolling bearing, with a recessed shielding drain channel forming the drain channel within the shielding member. This is a hydraulic piston pump motor characterized by the following features.
[0007] In this case, an opening for a drain channel that opens to the atmosphere may be formed between the rolling bearing and the sealing member, and a shielding member may be provided to shield the side of the rolling bearing. [Effects of the Invention]
[0008] As described in detail above, the invention described in claim 1 is provided with a rolling bearing in the main body that rotatably supports the rotating shaft, the rolling bearings are arranged on one end and the other end of the rotating shaft in the axial direction, a sealing member is provided axially inward of each rolling bearing to seal the inside of the main body, and each rolling bearing has a lubricant. For this reason, the inside of the main body is sealed by the sealing member by By making it less susceptible to the influence of dynamic fluids and by using rolling bearings that are well lubricated with a lubricant, the rotating shaft is supported by the main body at both the axial end and the other end, thus the rotating shaft can be well supported by the main body and seizure can be prevented.
[0009] Furthermore, claims 1 The invention described above provides a drain channel that opens to the atmosphere between the rolling bearing and the sealing member, and also includes a shielding member that shields the side of the rolling bearing. Therefore, inside the main body by Even if the dynamic fluid leaks from the sealing member, this leakage Made The dynamic fluid is discharged through the drain channel and further blocked by the shielding member, which is used in the rolling bearings. Made Rolling bearings prevent leakage because they prevent the dynamic fluid from coming into contact with them. Made This makes it less susceptible to the influence of dynamic fluids and allows for better pivotal support of the rotating shaft to the main body. Furthermore, a recessed drain channel is formed in the shielding member to constitute the drain channel. Therefore, since the drain channel is formed using the shielding member, the gap between the rolling bearing and the sealing member that provide the drain channel and shielding member can be narrowed, making the pump and motor more compact. [Brief explanation of the drawing]
[0010] [Figure 1] This is a longitudinal cross-sectional view of a hydraulic piston pump motor showing one embodiment of the present invention. [Figure 2] This is a cross-sectional view along line AA in Figure 1. [Figure 3] This is a cross-sectional view along line BB in Figure 1. [Figure 4] This is a cross-sectional view corresponding to Figure 1, which shows another embodiment. [Figure 5] This is a cross-sectional view showing a modified example of another embodiment. [Modes for carrying out the invention]
[0011] The following describes an embodiment of the present invention in which the hydraulic piston pump motor is replaced with a hydraulic piston pump, based on the drawings. In Figure 1, 1 is the main body, which consists of a cylindrical housing 2, a front cover member 3, and a rear cover member 4. The front cover member 3 closes one end opening of the storage hole 5, which is formed to penetrate the housing 2 axially, and the rear cover member 4 closes the other end opening of the storage hole 5. The two cover members 3 and 4, which sandwich the housing 2, are fastened together by a plurality of bolt members 6. The two cover members 3 and 4 are concentrically positioned by fitting them into the openings at both ends of the storage hole 5. 7 is the rotating shaft, which is inserted through the inside of the storage hole 5 and is rotatably supported by a radial ball bearing 8 as a rolling bearing located on the front cover member 3 and a radial ball bearing 9 as a rolling bearing located on the rear cover member 4. Its tip protrudes outside the front cover member 3 and is coupled to an electric motor (not shown), while its rear end is exposed to the outside. Each radial ball bearing 8 and 9 is filled with grease as a lubricant, and its axial outward side is exposed to the outside. Radial ball bearing 9 has a smaller diameter than radial ball bearing 8. 2A and 2B are drain holes formed in the housing, to which piping (not shown) is connected to discharge drain from inside the main body 1.
[0012] The front cover member 3 has a sealing member 10 positioned axially inward of the radial ball bearing 8. The sealing member 10 is annular in shape and is fitted onto the rotating shaft 7 to seal the inside of the main body 1. 11 is an annular shielding member provided on the front cover member 3, positioned between the radial ball bearing 8 and the sealing member 10, and loosely fitted onto the rotating shaft 7. The shielding member 11 shields the side of the radial ball bearing 8, preventing water leaking from the sealing member 10 from reaching the radial ball bearing 8. 12 is a first drain passage that opens to the atmosphere, consisting of a front cover drain passage 12A formed in the front cover member 3 and a shield drain passage 12B formed in the shielding member 11, and discharges water leaking from the sealing member 10. One end of the front cover drain passage 12A opens to the outer circumference of the shielding member 11 between the radial ball bearing 8 and the sealing member 10. As shown in Figure 2, the shielded drain channel 12B is formed as a radial recess on the side surface of the shielding member 11 facing the sealing member 10, and is connected to the front cover drain channel 12A.
[0013] A sealing member 13 is positioned axially inward of the radial ball bearing 9 on the rear cover member 4. The sealing member 13 is annular in shape with a smaller diameter than the sealing member 10 and is fitted onto the rotating shaft 7 to seal the inside of the main body 1. 14 is an annular shielding member provided on the rear cover member 4, with a smaller diameter than the shielding member 11, positioned between the radial ball bearing 9 and the sealing member 13, and loosely fitted onto the rotating shaft 7. The shielding member 14 shields the side of the radial ball bearing 9, preventing water leaking from the sealing member 13 from the inside of the main body 1 onto the radial ball bearing 9. 15 is a second drain passage that opens to the atmosphere and consists of a rear cover drain passage 15A formed in the rear cover member 4 and a shield drain passage 15B formed in the shielding member 14, which discharges water leaking from the sealing member 13. One end of the rear cover drain passage 15A opens to the outer circumference of the shielding member 14 between the radial ball bearing 9 and the sealing member 13. As shown in Figure 3, the shielded drain channel 15B is formed as a radial recess on the side surface of the shielding member 14 facing the sealing member 13, and is connected to the rear cover drain channel 15A.
[0014] 16 is a disc-shaped swash plate, fixed to the inclined surface of the front cover member 3 facing the inside of the main body 1. The rotating shaft 7 is loosely fitted to the axis of the swash plate 16. The swash plate 16 is inclined at a certain angle with respect to a line perpendicular to the axis of the rotating shaft 7. 17 is a cylinder block, which is housed in the housing hole 5 of the housing 2 that constitutes the main body 1, and engages with the rotating shaft 7 in the rotational direction by spline engagement at its own axis, and is rotationally driven by the rotating shaft 7. The cylinder block 17 has a plurality of piston holes 18 formed radially outward from the axis and at equal intervals in the circumferential direction. Each piston hole 18 opens to one end face of the cylinder block 17 facing the swash plate 16. 19 is a piston, which is fitted into each piston hole 18 of the cylinder block 17 so as to be able to reciprocate in the axial direction, and partitions the working chamber 20 in the cylinder block 17. Each piston 19 penetrates axially through its axis to form a flow hole 21, and its tip facing the swash plate 16 is formed into a spherical protrusion, allowing the shoe 22 to be pivotally attached.
[0015] The shoe 22 is formed to penetrate axially through a through-hole 23 communicating with the flow hole 21 of the piston 19, and includes a sliding contact member 24 that slidably contacts the inclined plate 16 at its tip. The sliding contact member 24 is formed in an annular shape from a resin material and is externally fitted to the shoe 22 by press-fitting. The inclined plate 16 sets the reciprocating momentum of each piston 19 based on the inclined angle. Each shoe 22 is provided with the spring force of a spring 25 housed in the axis of the cylinder block 17 being applied via a pin 26, a retainer 27, and a retainer plate 28, and is pressed against the inclined plate 16. The working chamber 20 increases in volume and sucks water during the forward movement of each piston 19 in the left direction in FIG. 1, and decreases in volume and discharges water during the return movement of each piston 19 in the right direction in FIG. 1. Connection holes 29 are connected to each working chamber 20, and each connection hole 29 opens at equal intervals in the circumferential direction on the other end surface facing one end surface of the cylinder block 17.
[0016] 30 is a disk-shaped valve plate that slidably contacts the other end surface of the cylinder block 17, and a pair of suction / discharge ports 31, 32 through which the water sucked and discharged through each connection hole 29 to each working chamber 20 flows are formed to penetrate therethrough. Both suction / discharge ports 31, 32 are in a semi-arc shape and are arranged at symmetric positions with respect to the axis of the valve plate 30. The valve plate 30 has its outer circumference in an inlay fit in a housing hole 5 into which the rear cover member 4 is inlay-fitted, and is arranged on the main body 1 concentrically with the rotating shaft 7. The valve plate 30 is provided with the spring force of the spring 25 being applied via the cylinder block 17 and is pressed against the rear cover member 4. The valve plate 30 is prevented from rotating by engaging a pin member (not shown) with the rear cover member 4.
[0017] One of the suction / discharge ports 31 communicates with the working chamber 20 whose volume decreases during the return movement of the piston 19, and functions as a discharge port through which the water discharged from the working chamber 20 flows. The other suction / discharge port 32 communicates with the working chamber 20 whose volume increases during the forward movement of the piston 19, and functions as a suction port through which the water sucked into the working chamber 20 flows. 33, 34 are a pair of suction / discharge channels formed in the rear cover member 4, one of the suction / discharge channels 33 is connected to one of the suction / discharge ports 31 that functions as a discharge port, and the other suction / discharge channel 34 is connected to the other suction / discharge port 32 that functions as a suction port.
[0018] Next, the operation of such a configuration will be described. In the state shown in Figure 1, when the rotating shaft 7 is driven to rotate, the cylinder block 17 rotates together with the rotating shaft 7. As the cylinder block 17 rotates, each piston 19 reciprocates with a reciprocating motion corresponding to the inclination angle of the swash plate 16, as the shoe 22 at the tip of each piston 19 slides along the swash plate 16, thereby increasing or decreasing the volume of each working chamber 20.
[0019] As the cylinder block 17 rotates, water is drawn into the working chamber 20, whose volume increases, through the intake / discharge passage 34 and the intake / discharge port 32. Conversely, as the cylinder block 17 rotates, the water in the working chamber 20, whose volume decreases, is discharged through the intake / discharge port 31 and the intake / discharge passage 33. In this way, the pump operates by continuously drawing in and discharging water in accordance with the rotation of the cylinder block 17. When the rotational drive of the rotating shaft 7 is stopped, the pump operation stops.
[0020] In this operation, the main body 1 is provided with radial ball bearings 8 and 9 that rotatably support the rotating shaft 7. The radial ball bearings 8 and 9 are positioned on one axial end and the other end of the rotating shaft 7. Sealing members 10 and 13 are provided axially inward of each radial ball bearing 8 and 9 to seal the inside of the main body 1, and each radial ball bearing 8 and 9 is filled with grease. As a result, the sealing members 10 and 13 make the main body 1 less susceptible to the effects of water, and the radial ball bearings 8 and 9, which are well lubricated with grease, support the rotating shaft 7 at both ends of the main body 1, so that the rotating shaft 7 can be well supported by the main body 1 and seizure can be prevented.
[0021] Furthermore, drain channels 12 and 15 that open to the atmosphere are formed between the radial ball bearings 8 and 9 and the sealing members 10 and 13, and shielding members 11 and 14 that shield the sides of the radial ball bearings 8 and 9 are provided. As a result, even if water leaks from inside the main body 1 through the sealing members 10 and 13, this leaked water is discharged through the drain channels 12 and 15, and the shielding members 11 and 14 prevent water from coming into contact with the radial ball bearings 8 and 9. Therefore, the radial ball bearings 8 and 9 are less affected by the leaked water, and the rotating shaft 7 can be supported on the main body 1 even more effectively.
[0022] Furthermore, the drain channels 12 and 15 are composed of shielded drain channels 12B and 15B formed in the shielding members 11 and 14. Therefore, since the drain channels 12 and 15 are formed using the shielding members 11 and 14, the gap between the radial ball bearings 8 and 9, which house the drain channels 12 and 15 and the shielding members 11 and 14, and the sealing members 10 and 13 can be narrowed, making the pump and motor more compact.
[0023] Figure 4 shows another embodiment of the present invention. Parts identical to those in one embodiment are denoted by the same reference numerals and their descriptions are omitted; only the different parts will be described. 35 is a shielding member that shields the side of the radial ball bearing 8 and is formed in the shape of a disc with a slightly smaller diameter than the sealing member 10. The shielding member 35 is fixed to the rotating shaft 7 between the radial ball bearing 8 and the sealing member 10 and rotates together with the rotating shaft 7. 36 is a shielding member that shields the side of the radial ball bearing 9 and is formed in the shape of a disc with a slightly smaller diameter than the sealing member 13. The shielding member 36 is fixed to the rotating shaft 7 between the radial ball bearing 9 and the sealing member 13 and rotates together with the rotating shaft 7.
[0024] 37 is an auxiliary shielding member fixed to the front cover member 3, formed in an annular shape with a larger diameter than the shielding member 35, and shields the outer diameter side of the radial ball bearing 8. 38 is an auxiliary shielding member fixed to the rear cover member 4, formed in an annular shape with a larger diameter than the shielding member 36, and shields the outer diameter side of the radial ball bearing 9.
[0025] As shown in Figure 5, the auxiliary shielding member 37 may be an auxiliary shielding member 37A integrally formed with the front cover member 3, and the auxiliary shielding member 38 may be an auxiliary shielding member 38A integrally formed with the rear cover member 4.
[0026] 12C is the second front cover drain channel, formed in the front cover member 3 on the side opposite to the radial ball bearing 8 of the auxiliary shielding member 37, and is connected to the front cover drain channel 12A to form the first drain channel 12. 15C is the second rear cover drain channel, formed in the rear cover member 4 on the side opposite to the radial ball bearing 9 of the auxiliary shielding member 38, and is connected to the rear cover drain channel 15A to form the second drain channel 15.
[0027] The pump operates by rotating the rotating shaft 7, causing each piston 19 to reciprocate and draw in and discharge water. When the rotation of the rotating shaft 7 is stopped, the pump operation stops. In this configuration, sealing members 10 and 13 are provided axially inward of each radial ball bearing 8 and 9 to seal the inside of the main body 1, and each radial ball bearing 8 and 9 is filled with grease. Therefore, similar to the first embodiment, the rotating shaft 7 can be properly supported by the main body 1, and seizure can be prevented.
[0028] Furthermore, drain passages 12 and 15 are formed between the radial ball bearings 8 and 9 and the sealing members 10 and 13, and shielding members 35 and 36 are provided to shield the sides of the radial ball bearings 8 and 9. As a result, similar to the embodiment, even if water leaks from inside the main body 1, it is discharged through the drain passages 12 and 15, and the shielding members 35 and 36 prevent water from coming into contact with the radial ball bearings 8 and 9. Therefore, the radial ball bearings 8 and 9 are less affected by leaked water, and the rotating shaft 7 can be supported on the main body 1 even more effectively.
[0029] Furthermore, the shielding members 35 and 36 are fixed to the rotating shaft 7 and rotate together with the rotating shaft 7. As a result, the centrifugal force of the rotating shielding members 35 and 36 can propel the leaked water radially outward, making the radial ball bearings 8 and 9 less susceptible to the effects of the leaked water, and allowing the rotating shaft 7 to be supported on the main body 1 even more effectively.
[0030] In the above-described embodiment, the rolling bearings were radial ball bearings 8 and 9, but radial roller bearings may also be used. Also, the lubricant in the radial ball bearings 8 and 9 was grease, but lubricating oil may also be used. Also, the working fluid was water, but a low-viscosity fluid that cannot be mixed with oil may also be used. Also, the swash plate type axial piston pump / motor was a swash plate type axial piston pump, but a swash plate type axial piston motor may also be used. In this case, the cylinder block 17 is rotationally driven by water supplied from the outside, and the cylinder block 17 rotates the rotating shaft 7. Also, although a constant-capacity type was used with a fixed inclination angle of the swash plate 16, it goes without saying that a variable-capacity type with a changeable inclination angle of the swash plate may also be used. [Explanation of Symbols]
[0031] 1: Main unit 7: Rotation axis 8, 9: Radial ball bearings (rolling bearings) 10, 13: Sealing member 11, 14, 35, 36: Shielding members 12, 15: Drain channel 16: Swash plate 17: Cylinder block 19: Piston 20: Working Room 33, 34: Intake and discharge channels
Claims
[Claim 1] A hydraulic piston pump motor for which a low viscosity fluid is used as the working fluid, comprising: a rotating shaft rotatably supported on a main body; a cylinder block housed inside the main body and engaged with the rotating shaft in the rotational direction; a plurality of pistons arranged in the cylinder block so as to be reciprocating in the axial direction; a plurality of working chambers partitioned by each piston and the cylinder block for drawing in and discharging the working fluid; a swash plate in which the tips of each piston protruding from the cylinder block slide against each other to set the reciprocating amount of each piston; and a working fluid formed in the main body for drawing in and discharging to each working chamber. A hydraulic piston pump motor characterized by comprising an intake and exhaust passage through which the body flows, a rolling bearing that rotatably supports a rotating shaft in the main body, the rolling bearings being positioned on one axial end and the other side of the rotating shaft, a sealing member that seals the inside of the main body being provided axially inward of each rolling bearing, each rolling bearing having a lubricant, an opening formed between the rolling bearing and the sealing member to open a drain passage to the atmosphere, and a shielding member being provided to shield the side of the rolling bearing, with a recess formed in the shielding member to constitute a shielding drain passage.