PUMP DEVICE

Abstract

A pump device according to one embodiment includes a pump and a symbol. The pump includes at least one pump structure and a suction port, wherein a displacement of the at least one pump structure, the displacement being a delivery amount per rotation, changes in accordance with a command current. The symbol is displayed on a surface of the pump, the surface facing in a direction different from a direction in which the suction port is open. The symbol stores actual measurement data or save location information on the actual measurement data, the actual measurement data indicating an actual relationship between the command current and the displacement of the at least one pump structure.

Description

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Japanese Patent Application No. 2022-181864, filed on Nov. 14, 2022, the entire disclosure of which is incorporated herein by reference.

BACKGROUND OF THE INVENTION

Field of the Invention

The present disclosure relates to a pump device including a pump that supplies hydraulic oil to a hydraulic actuator.

Description of the Related Art

In a machine such as a construction machine or an industrial machine, a pump that supplies hydraulic oil to hydraulic actuators is used. For example, Japanese Laid-Open Patent Application Publication No. 2019-210974 discloses a pump including two pump structures. Each pump structure is configured such that the displacement thereof, i.e., the delivery amount per rotation, changes in accordance with a command current. The pump is controlled by a controller such that the displacement of each pump structure increases in accordance with increase in the moving speed of a corresponding one of the hydraulic actuators.

Specifically, regarding each hydraulic actuator, an actuator operation signal corresponding to an operating amount of an operator to move the hydraulic actuator is inputted to the controller. The operator is a device to set the moving speed of the hydraulic actuator by an operating amount of the operator. The controller outputs a command current corresponding to the actuator operation signal to the pump.

SUMMARY OF THE INVENTION

Incidentally, each pump structure, due to their individual differences, has variation in I-q characteristics. The I-q characteristics are a relationship between the command current and the displacement of the pump structure. Japanese Laid-Open Patent Application Publication No. 2019-210974 describes the following: a code that stores actual measurement data indicating actual I-q characteristics of the pump structure (although Japanese Laid-Open Patent Application Publication No. 2019-210974 describes “a relationship between the command current and the delivery flow rate”, the displacement can be obtained by dividing the delivery flow rate by the number of rotations) is displayed on the surface of the pump, and by use of a code reader, the actual measurement data is inputted to the controller, which is a pump controller; and the variation in the I-q characteristics due to the individual differences is electronically calibrated by the controller. Specifically, the controller adjusts the command current outputted to the pump, such that a preset displacement corresponding to an operating amount of the operator is obtained.

For the pump device as disclosed in Japanese Laid-Open Patent Application Publication No. 2019-210974, in which the code is displayed on the pump surface, there is a desire to make it possible to easily read out a symbol, such as the code, even after the pump device is installed in a machine.

In view of the above, an object of the present disclosure is to provide a pump device that makes it possible to easily read out the symbol even after the pump device is installed in a machine.

The present disclosure provides a pump device including: a pump including at least one pump structure and a suction port, wherein a displacement of the at least one pump structure, the displacement being a delivery amount per rotation, changes in accordance with a command current; and at least one symbol that is displayed on a surface of the pump, the surface facing in a direction different from a direction in which the suction port is open, the at least one symbol stores actual measurement data or save location information on the actual measurement data, the actual measurement data indicating an actual relationship between the command current and the displacement of the at least one pump structure.

The present disclosure provides a pump device that makes it possible to easily read out the symbol even after the pump device is installed in a machine.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1A is a perspective view of a pump device according to Embodiment 1, and FIG. 1B is a perspective view of the pump device being in a reversed state.

FIG. 2A is a perspective view of a pump device according to a variation of Embodiment 1, and FIG. 2B is a perspective view of the pump device being in a reversed state.

FIG. 3A is a perspective view of a pump device according to Embodiment 2, and FIG. 3B is a perspective view of the pump device being in a reversed state,

FIG. 4A is a perspective view of a pump device according to a variation of Embodiment 2, and FIG. 4B is a perspective view of the pump device being in a reversed state.

FIG. 5A is a perspective view of a pump device according to Embodiment 3, and FIG. 5B is a perspective view of the pump device being in a reversed state,

FIG. 6A is a perspective view of a pump device according to Embodiment 4, and FIG. 6B is a perspective view of the pump device being in a reversed state.

DETAILED DESCRIPTION

Embodiment 1

FIG. 1A and FIG. 1B show a pump device 1A according to Embodiment 1. The pump device 1A includes: a pump 2 including at least one pump structure 3 of a variable displacement type; and at least one symbol 7 displayed on the pump 2.

In addition to the at least one pump structure 3, the pump 2 includes an input shaft 6, which protrudes from a front surface 21 of the pump 2. An output shaft of a prime mover, such as an engine or electric motor, is coupled to the input shaft 6. Generally speaking, the pump device 1A is installed in a machine in a state where the input shaft 6 extends horizontally. Hereinafter, this state is referred to as “the installed state”.

In the installed state, the front surface 21 of the pump 2 faces forward. The pump 2 includes, in addition to the front surface 21, the following components: a back surface 22, which faces backward in the installed state; a lower surface 23, which faces downward in the installed state; an upper surface 24, which faces upward in the installed state; a left side surface 25, which faces to the left in the installed state; and a right side surface 26, which faces to the right in the installed state. Hereinafter, for the sake of convenience, the description is given by using the directions in the installed state.

In the present embodiment, the pump 2 includes two pump structures 3. Also, in the present embodiment, the pump 2 is a tandem pump in which the two pump structures 3 are located in tandem. That is, the pump structures 3 are side by side in the front-back direction, i.e., the axial direction of the input shaft 6.

In the present embodiment, each pump structure 3 is of a swash plate type, which is one example of an axial piston type. Alternatively, each pump structure 3 may be of a tilted axis type, which is another example of an axial piston type. Further alternatively, each pump structure 3 may be of a different type, such as a vane-type pump structure.

Each of the front-side pump structure 3 and the back-side pump structure 3 includes a casing 30. The casing 30 of the front-side pump structure 3 is open backward, whereas the casing 30 of the back-side pump structure 3 is open forward. The pump 2 includes a valve cover 41. The valve cover 41 is located between the casings 30 of both the pump structures 3, and seals the openings of both the casings 30.

Each pump structure 3 includes, in addition to the casing 30, the following components: a rotating shaft extending in the same direction as the input shaft 6; and a valve plate, a cylinder block, and a swash plate that are accommodated in the casing 30. The rotating shaft of the front-side pump structure 3 is integrated with the input shaft 6. The valve cover 41 is a hollow cover. Inside the valve cover 41, the rotating shaft of the back-side pump structure 3 is coupled to the rotating shaft of the front-side pump structure 3.

The front surface of the casing 30 of the front-side pump structure 3 serves as the front surface 21 of the pump 2, and the back surface of the casing 30 of the back-side pump structure 3 serves as the back surface of the pump 2. The lower surfaces of both the casings 30 and the lower surface of the valve cover 41 collectively serve as the lower surface 23 of the pump 2. The upper surfaces of both the casings 30 and the upper surface of the valve cover 41 collectively serve as the upper surface 24 of the pump 2. The left side surfaces of both the casings 30 and the left side surface of the valve cover 41 collectively serve as the left side surface 25 of the pump 2. The right side surfaces of both the casings 30 and the right side surface of the valve cover 41 collectively serve as the right side surface 26 of the pump 2.

In the present embodiment, a suction port 11 is located on the lower surface of the valve cover 41, i.e., located on the lower surface 23 of the pump 2, and two delivery ports 12 are located on the left side surface of the valve cover 41, i.e., located on the left side surface 25 of the pump 2.

The valve plate of the front-side pump structure 3 is fixed to the front surface of the valve cover 41, whereas the valve plate of the back-side pump structure 3 is fixed to the back surface of the valve cover 41. Each valve plate includes an arc-shaped suction hole and an arc-shaped delivery hole. The valve cover 41 includes: suction passages that extend from the suction port 11 to the suction holes of the respective pump structures 3; and delivery passages that extend from the delivery holes of the respective pump structures 3 to the corresponding delivery ports 12.

In each pump structure 3, the cylinder block is fixed to the rotating shaft, and rotates together with the rotating shaft while sliding on the valve plate. The cylinder block includes cylinder bores that communicate with the suction hole or delivery hole of the valve plate.

The cylinder bores receive respective pistons therein. That is, the cylinder block holds the pistons in a slidable manner. A shoe that slides on the swash plate directly or via a shoe plate is mounted to the head of each piston.

In the present embodiment, two regulators 5 are located on the respective right side surfaces of the casings 30 of both the pump structures 3, i.e., located on the right side surface 26 of the pump 2. Each of the regulators 5 receives an input of a command current I intended for a corresponding one of the pump structures 3. Each regulator 5 changes the displacement q, i.e., the delivery amount per rotation, of the corresponding pump structure 3 in accordance with the command current I. For example, the regulator 5 may change the hydraulic pressure applied to a servo piston coupled to the swash plate of the pump structure 3 in accordance with the command current I, or may be an electric actuator coupled to the swash plate.

Further, in the present embodiment, a power take-off 13 is located on the upper surface of the valve cover 41, i.e., located on the upper surface 24 of the pump 2, The power take-off 13 enables motive power transmission to the rotating shafts of both the pump structures 3 as well as motive power transmission from the rotating shafts of both pump structures 3. The power take-off 13 may be eliminated.

In the present embodiment, one symbol 7 is displayed on the upper surface of the casing 30 of the back-side pump structure 3, i.e., displayed on the upper surface 24 of the pump 2. As described above, the suction port 11 is located on the lower surface 23 of the pump 2. Accordingly, the upper surface 24 faces in a direction different from the direction in which the suction port 11 is open.

For the display of the symbol 7 on the upper surface 24 of the pump 2, the symbol 7 may be printed on a plate, such as a nameplate or a display plate, and the plate may be mounted to the upper surface 24 of the pump 2. Alternatively, the symbol 7 may be directly printed on the upper surface 24 of the pump 2.

In the present embodiment, the symbol 7 stores actual measurement data that indicates actual I-q characteristics of the two pump structures 3. For example, the symbol 7 is a matrix two-dimensional code (QR code (registered trademark)). Alternatively, the symbol 7 may be a tag, such as an IC (Integrated Circuit) tag or an REM (Radio Frequency Identification) tag.

The number of symbols 7 need not be one. Alternatively, two symbols 7 corresponding to the two pump structures 3, respectively, may be displayed on the upper surface 24 of the pump 2, and each symbol 7 may store the actual measurement data of the corresponding pump structure 3.

Generally speaking, the pump device 1A is installed in a machine in such an orientation that the direction in which the suction port 11 is open is the downward direction. Accordingly, if the symbol 7 is displayed on the upper surface 24 of the pump 2, the upper surface 24 facing in a direction different from the direction in which the suction port 11 is open, as in the present embodiment, the symbol 7 can be easily read out even after the pump device 1A is installed in the machine. Then, by reading out the symbol 7, variation in the I-q characteristics due to individual differences can be electronically calibrated.

As in the case of a pump device 1B according to a variation shown in FIG. 2A and FIG. 2B, the delivery ports 12 may be located on the left side surface of the valve cover 41, i.e., located on the left side surface 25 of the pump 2. Alternatively, the delivery ports 12 may be located on the right side surface of the valve cover 41, i.e., located on the right side surface 26 of the pump 2.

In a case where the delivery ports 12 are located on the left side surface or the right side surface of the valve cover 41, the symbol 7 may be displayed on the upper surface of the valve cover 41. Alternatively, the surface on which the symbol 7 is displayed need not be the upper surface 24 of the pump 2, but may be the left side surface 25, the right side surface 26, or the back surface 22 of the pump 2. For example, as in the case of the pump device 1B according to the variation shown in FIG. 2A and FIG. 2B, the symbol 7 may be displayed on the right side surface 26 of the pump 2.

Embodiment 2

FIG. 3A and FIG. 3B show a pump device 1C according to Embodiment 2. In the present embodiment and the following Embodiments 3 and 4, the same components as those described in Embodiment 1 are denoted by the same reference signs as those used in Embodiment 1, and repeating the same descriptions is avoided.

In the present embodiment, the pump 2 is a parallel pump in which the two pump structures 3 are located in parallel. The pump structures 3 are side by side in the left-right direction orthogonal to the axial direction of the input shaft 6.

The two pump structures 3 share a container-shaped casing 30, which is open backward. The valve cover 41 of the pump 2 is positioned at the back of the casing 30, and seals the opening of the casing 30. Further, in the present embodiment, the pump 2 includes a gear cover 42 and a circular dish-shaped flange 43. The gear cover 42, together with the front wall of the casing 30, forms a gear chamber between the gear cover 42 and the front wall of the casing 30. The flange 43 is integrated with the gear cover 42, and the input shaft 6 is located at the center of the circular dish-shaped flange 43.

The front surface of the flange 43 serves as the front surface 21 of the pump 2, and the back surface of the valve cover 41 serves as the back surface 22 of the pump 2. The lower surfaces of the gear cover 42, the casing 30, and the valve cover 41 collectively serve as the lower surface 23 of the pump 2; the upper surfaces of the gear cover 42, the casing 30, and the valve cover 41 collectively serve as the upper surface 24 of the pump 2; the left side surfaces of the gear cover 42, the casing 30, and the valve cover 41 collectively serve as the left side surface 25 of the pump 2; and the right side surfaces of the gear cover 42, the casing 30, and the valve cover 41 collectively serve as the right side surface 26 of the pump 2.

Similar to Embodiment 1, the suction port 11 is located on the lower surface of the valve cover 41, i.e., located on the lower surface 23 of the pump 2. Meanwhile, in the present embodiment, the two delivery ports 12 are located on the upper surface of the valve cover 41, i.e., located on the upper surface 24 of the pump 2. Further, in the present embodiment, the two regulators 5 are located on the upper surface of the casing 30.

The rotating shaft of each pump structure 3 extends in the front-back direction to penetrate the front wall of the casing 30. In the present embodiment, the rotating shaft of the right-side pump structure 3 is integrated with the input shaft 6, and inside the aforementioned gear chamber, the rotating shaft of the left-side pump structure 3 is coupled to the rotating shaft of the right-side pump structure 3 via the gears.

In the present embodiment, the symbol 7 is displayed on the right side surface of the casing 30 of the pump structure 3, i.e., displayed on the right side surface 26 of the pump 2. Accordingly, the present embodiment provides the same advantageous effects as those provided by Embodiment 1.

Alternatively, the symbol 7 may be displayed on the right side surface of the valve cover 41. Further alternatively, the surface on which the symbol 7 is displayed need not be the right side surface 26 of the pump 2, but may be the left side surface 25, the upper surface 24, or the back surface 22 of the pump 2.

For example, as in the case of a pump device 1D according to a variation shown in FIG. 4A and FIG. 4B, the symbol 7 may be displayed on the upper surface of the valve cover 41, i.e., displayed on the upper surface 24 of the pump 2. In the pump device 1C shown in FIG. 3A and FIG. 3B, the two delivery ports 12 are adjacent to each other. On the other hand, in the pump device 1D shown in FIG. 4A and FIG. 4B, the two delivery ports 12 are spaced apart from each other in the left-right direction, and the symbol 7 is located between the two delivery ports 12.

Embodiment 3

FIG. 5A and FIG. 5B show a pump device 1E according to Embodiment 3. In the present embodiment, the pump 2 includes only one pump structure 3.

That is, the front surface of the casing 30 of the pump structure 3 serves as the front surface 21 of the pump 2, and the back surface of the valve cover 41 serves as the back surface of the pump 2. The lower surfaces of the casing 30 and the valve cover 41 collectively serve as the lower surface 23 of the pump 2. The upper surfaces of the casing 30 and the valve cover 41 collectively serve as the upper surface 24 of the pump 2. The left side surfaces of the casing 30 and the valve cover 41 collectively serve as the left side surface 25 of the pump 2. The right side surfaces of the casing 30 and the valve cover 41 collectively serve as the right side surface 26 of the pump 2.

Similar to Embodiment 1, the suction port 11 is located on the lower surface of the valve cover 41, i.e., located on the lower surface 23 of the pump 2. Meanwhile, in the present embodiment, one delivery port 12 is located on the right side surface of the valve cover 41, i.e., located on the right side surface 26 of the pump 2.

In the present embodiment, the symbol 7 is displayed on the left side surface of the casing 30 of the pump structure 3, i.e., displayed on the left side surface 25 of the pump 2. Accordingly, the present embodiment provides the same advantageous effects as those provided by Embodiment 1.

Alternatively, the symbol 7 may be displayed on the left side surface of the valve cover 41. Further alternatively, the surface on which the symbol 7 is displayed need not be the left side surface 25 of the pump 2, but may be the right side surface 26, the upper surface 24, or the back surface 22 of the pump 2.

Alternatively, the delivery port 12 may be located on the left side surface of the valve cover 41, i.e., located on the left side surface 25 of the pump 2. Further alternatively, the delivery port 12 may be located on the upper surface of the valve cover 41, i.e., located on the upper surface 24 of the pump 2.

Embodiment 4

FIG. 6A and FIG. 6B show a pump device 1F according to Embodiment 4. The pump device 1F of the present embodiment is different from the pump device 1E of Embodiment 3 only in the following points: in the pump device 1F, the suction port 11 is located on the back surface of the valve cover 41, i.e., located on the back surface 22 of the pump 2; and the delivery port 12 is located on the lower surface of the valve cover 41, i.e., located on the lower surface 23 of the pump 2. That is, also in the present embodiment, the symbol 7 is displayed on the left side surface of the casing 30 of the pump structure 3, i.e., displayed on the left side surface 25 of the pump 2.

The present embodiment provides the same advantageous effects as those provided by Embodiment 1. Alternatively, the symbol 7 may be displayed on the left side surface of the valve cover 41. Further alternatively, the surface on which the symbol 7 is displayed need not be the left side surface 25 of the pump 2, but may be the right side surface 26 or the upper surface 24 of the pump 2.

Other Embodiments

The present disclosure is not limited to the above-described embodiments. Various modifications can be made without departing from the scope of the present disclosure.

For example, instead of storing the actual measurement data of the pump structure(s) 3, the symbol 7 may store save location information on the actual measurement data. The save location information is, for example, the IP (Internet Protocol) address of a server that is the save location, or the URL (Uniform Resource Locator) of a particular hierarchy level of the server. In this case, the symbol 7 may be a character string.

SUMMARY

The present disclosure provides, as a first mode, a pump device including: a pump including at least one pump structure and a suction port, wherein a displacement of the at least one pump structure, the displacement being a delivery amount per rotation, changes in accordance with a command current; and at least one symbol that is displayed on a surface of the pump, the surface facing in a direction different from a direction in which the suction port is open, the at least one symbol storing actual measurement data or save location information on the actual measurement data, the actual measurement data indicating an actual relationship between the command current and the displacement of the at least one pump structure.

Generally speaking, the pump device is installed in a machine in such an orientation that the direction in which the suction port is open is the downward direction. Accordingly, if the symbol is displayed on the surface of the pump, the surface facing in a direction different from the direction in which the suction port is open, as in the above-described configuration, the symbol can be easily read out even after the pump device is installed in the machine. Then, by reading out the symbol, variation in characteristics due to individual differences can be electronically calibrated.

As a second mode, in the first mode, for example, the at least one pump structure may include two pump structures. The at least one symbol may include two symbols corresponding to the two pump structures, respectively. Each of the symbols may store it the actual measurement data, or the save location information on the actual measurement data, of a corresponding one of the pump structures.

As a third mode, in the second mode, for example, the at least one pump structure may include two pump structures, and the pump may be a tandem pump in which the two pump structures are located in tandem.

As a fourth mode, in the second mode, for example, the at least one pump structure may include two pump structures, and the pump may be a parallel pump in which the two pump structures are located in parallel.

As a fifth mode, in any of the first to fourth modes, for example, the at least one pump structure may be of an axial piston type.

As a sixth mode, in the fifth mode, for example, the at least one pump structure may include: a cylinder block that holds pistons in a slidable manner; and a container-shaped casing that accommodates the cylinder block. The pump may include a valve cover that seals an opening of the casing. The suction port may be located on the valve cover.

Claims

1. A pump device comprising:

a pump including at least one pump structure and a suction port, wherein a displacement of the at least one pump structure, the displacement being a delivery amount per rotation, changes in accordance with a command current; and

at least one symbol that is displayed on a surface of the pump, the surface facing in a direction different from a direction in which the suction port is open, the at least one symbol storing actual measurement data or save location information on the actual measurement data, the actual measurement data indicating an actual relationship between the command current and the displacement of the at least one pump structure.

2. The pump device according to claim 1, wherein

the at least one pump structure includes two pump structures,

the at least one symbol includes two symbols corresponding to the two pump structures, respectively, and

each of the symbols stores the actual measurement data, or the save location information on the actual measurement data, of a corresponding one of the pump structures.

3. The pump device according to claim 1, wherein

the at least one pump structure includes two pump structures, and

the pump is a tandem pump in which the two pump structures are located in tandem.

4. The pump device according to claim 1, wherein

the at least one pump structure includes two pump structures, and

the pump is a parallel pump in which the two pump structures are located in parallel.

5. The pump device according to claim 1, wherein

the at least one pump structure is of an axial piston type.

6. The pump device according to claim 5, wherein

the at least one pump structure includes: a cylinder block that holds pistons in a slidable manner; and a container-shaped casing that accommodates the cylinder block,

the pump includes a valve cover that seals an opening of the casing, and

the suction port is located on the valve cover.