KR100319371B1 - Swash plate type and variable displacement type parallel pump - Google Patents

Abstract

Taking advantage of the features of the swash plate type variable displacement pump, the casing is made of a plurality of control blocks by a large-scale control device or a complicated control device as in the prior art, and has a function equivalent to that of the prior art. By eliminating external piping required at the time and reducing the occupied area of the casing as a control block, a swash plate type variable displacement parallel pump can be provided, which can reduce oil leakage to the outside and improve space reduction. Two swash plate variable displacement pumps are disposed close to each other, drive shafts of each pump are arranged in parallel, one pump drive shaft is driven by a prime mover, and the driving force of the one drive shaft is driven to the other pump drive shaft through a gear mechanism. In the swash plate type variable displacement parallel pump configured to be delivered, the pumps have a configuration surrounded by a common housing 10 and a common cover 24 so as to integrate the pumps and adjust the discharge capacity of the pumps. The mechanisms 38a and 38b are provided respectively, and the discharge capacity adjusting mechanisms are arranged adjacent to each other in a single casing 46, and the adjustment rods 42a and 42b of the respective discharge capacity adjusting mechanisms and the drive shafts of the respective pumps ( The casings are detachably installed on the outer surface of the housing or cover surrounding each of the pumps such that 14a and 14b are substantially parallel.

Description

Swash plate type variable displacement parallel pump {SWASH PLATE TYPE AND VARIABLE DISPLACEMENT TYPE PARALLEL PUMP}

The present invention relates to a swash plate type variable displacement parallel pump, and particularly, when used in construction machinery, oil, such as mineral working oil, which adversely affects the global environment, is reduced in leakage from the mating surface of the casing or the like constituting the control block. The present invention relates to a swash plate type variable displacement parallel pump that can prevent oil from leaking in a pipe part when the pump is controlled by the entire horsepower, and can be easily assembled due to the reduction of assembly parts.

[0003] The control apparatus of a conventional bent axis variable displacement parallel pump is, for example, a pump controller configured to control the maximum discharge amount of the variable displacement pump and to control the constant horsepower (Japanese Patent Laid-Open No. 63-78175). ) And miniaturization of the entire structure without the complexity of the entire structure, even when a light quantity detection means is installed to control the minimum tilt position from the minimum tilt position to the maximum tilt position. Variable-capacity bent-type hydraulic rotator which can perform a long-term feedback control with high precision for the tilt angle by means of a tilt amount detection means (Japanese Patent Laid-Open No. 8-A). 232833) have been proposed.

That is, the former pump control device includes a pilot piston which acts on the force by the action of the pump discharge pressure, the force of the adjustment spring, and the force of the means for feeding back the pump angle of the variable displacement hydraulic pump. By moving the servovalve which controls the pilot piston to flow in the pump discharge pressure of the control piston which controls the inclination of the pump by the balance, the end of the pilot piston is larger than the pilot piston. A large diameter piston having a cap shape having an insertion hole formed at the end thereof is provided, and the maximum diameter of the variable displacement hydraulic pump is limited to the large diameter piston opposite to the insertion hole. At the same time, the action of the command pressure for controlling the horsepower constantly by the hydraulic force acting on the pilot piston when the pump discharge pressure exceeds the set value That is configured to be characterized.

Therefore, according to the pump control apparatus comprised in this way, a large diameter piston is provided in the pilot piston which controls a pump tilt angle, and a command pressure is made to act on this operating surface, The force due to the force and the command pressure can be calculated by the large diameter piston, and the pump can be controlled by automatically converting the maximum discharge amount control and the constant horsepower control, and the configuration is simple and can be manufactured at low cost.

The latter variable displacement bent axis hydraulic rotor has a cylindrical casing whose end face is closed by the head casing, a rotating shaft rotatably provided in the casing, and a plurality of casings provided in the casing in the axial direction so as to rotate together with the rotating shaft. A cylinder block in which a cylinder is formed; a plurality of pistons slidably installed in each cylinder of the cylinder block, the pistons being slidably supported on the rotating shaft via a connecting rod, and one end surface of the cylinder; A valve plate that is in sliding contact with the block and the other end surface is slidably in contact with the light sliding surface of the head casing; and a light mechanism that tilts the cylinder block together with the valve plate. A variable displacement bent axis hydraulic rotor, comprising: the valve for supplying hydraulic pressure for light control to the light mechanism. A control unit installed on the casing at least on the slit side of the casing; The link and the front end side are rotatably connected to the connecting portion of the feedback link, and the proximal end is a swing link provided rotatably to the valve plate, in a state in which the amount of tilt of the valve plate is proportionally reduced. An output pin installed in the middle of the detection part of the feedback link for feedback to the control part, and a detection rod provided outside the control part and following the rotational displacement of the feedback link, and detecting the displacement amount of the detection rod by A light quantity detection means for generating a light quantity of the valve plate is provided, and the feedback link is examined. Unit will, characterized in that a vibration suppressor for controlling that the small variation in the feedback link to a detection rod in contact with the detecting rod of the displacement angle detecting means travels.

Therefore, according to the variable displacement bent axis hydraulic rotor configured as described above, since the amount of light detecting means generates the rotational displacement amount of the feedback link at the front end of the detector, the vibration suppressor provided in the detector for the dimension from the support pin to the output pin. By the ratio of the dimensions up to the front end of, the amount of rotational displacement of the feedback link can be made proportionally large, and the amount of tilt of the valve plate can be detected more accurately. Therefore, by providing the light amount detecting means, the light amount of the valve plate can be always monitored, the capacity of the hydraulic rotor can be controlled with higher accuracy, and the whole structure is complicated by the light amount detecting means. Can be prevented, and the whole can be made compact to achieve miniaturization.

However, in the bent axis variable displacement parallel pump according to the prior art, a control cylinder of a control portion in which the pump control device performs movement control of the cylinder in order to change the discharge flow rate is provided in the cover and is controlled by a long stroke. This is problematic in that the size of the control device is increased or the weight is increased.

In the latter variable displacement bent axis hydraulic rotor, the position of the valve plate for varying the cylinder by varying the amount of light detection is provided by means of feedback, but it is controlled using a plurality of feedback links. As a result, the number of parts increases, and the control device of each pump uses the respective control casing, which causes problems such as an increase in the sealing portion and an increase in the oil leakage location.

Therefore, the inventors of the present invention have repeatedly arranged two swash plate variable displacement pumps in close proximity to each other, the drive shafts of the pumps are arranged in parallel, and the pump drive shaft of one side is driven by the prime mover. A swash plate type variable displacement parallel pump is configured to transmit the driving force of the drive shaft to the pump drive shaft on the other side by using a gear mechanism; Discharge capacity adjusting mechanisms for adjusting discharge capacities of the pumps are respectively provided, and the discharge capacity adjusting mechanisms are disposed adjacent to each other in a single casing, and the adjustment rod of each discharge capacity adjusting mechanism and the drive shaft of each pump The casing is detachably mounted to the outer surface of the housing and cover surrounding each pump so as to be substantially parallel. The discharge capacity adjusting mechanism for the pump of the pump can be compactly mounted in the casing as a single control block, and at the same time, all the external piping required for the control of the entire horsepower or the control of the variable horsepower is set as the inner passage in the casing. In addition, since it is configured as a single control block casing, when it is mounted on the housing or cover of the pump body, the sealing surface can be set to a minimum, thereby greatly reducing the flow rate leaking from the sealing surface. It has been found that advantages such as increased safety can be obtained in the pump.

Therefore, the object of the present invention is to utilize the features of a swash plate variable displacement pump, and does not have a casing composed of a plurality of control blocks by a large control device or a complicated control device as in the prior art, and has a function equivalent to that of the prior art. The swash plate type which can reduce the oil leakage to the outside and improve the space reduction by omitting the external piping required for controlling the whole horsepower or controlling the variable horsepower and reducing the occupied area of the casing as a control block. It is to provide a variable capacity parallel pump.

1 is a cross-sectional side view of a main portion showing an embodiment of a swash plate type variable displacement parallel pump according to the present invention.

FIG. 2 is a cross-sectional view of a main portion II-II of the swash plate type variable displacement parallel pump shown in FIG. 1.

Fig. 3 is a cross-sectional view of a main section III-III of the swash plate type variable displacement parallel pump shown in Fig. 1.

[Explanation of symbols on the main parts of the drawings]

10: housing

10a: inside

12a, 12b: swash plate

14a: drive shaft (input shaft)

14b: drive shaft (driven shaft)

16a, 16b: cylinder block

18: piston

19: spherical head

20: shoe

22: port plate

24: cover

26, 28: bearing

30a, 30b: gear mechanism

32: spring

34: bush

36a, 36b: power piston

38a, 38b: discharge capacity adjusting mechanism

40: control valve device

42a, 42b: adjustment rod

44a, 44b: feedback lever

46: casing

In order to achieve the above object, the swash plate type variable displacement parallel pump according to the present invention arranges two swash plate type variable displacement pumps in close proximity to each other, arranges drive shafts of each pump in parallel, and drives one pump drive shaft with a prime mover. In the swash plate type variable displacement parallel pump configured to simultaneously transmit the driving force of the one drive shaft via the gear mechanism to the other pump drive shaft,

Each pump is integrated with a common housing and a common cover, and a discharge capacity adjusting mechanism for adjusting the discharge capacity of each pump is provided, and each discharge capacity adjusting mechanism is adjacent in a single casing. And the casing is detachably installed on the outer surface of the housing or cover surrounding the respective pumps such that the adjustment rods of the respective discharge capacity adjusting mechanisms and the drive shafts of the respective pumps are substantially parallel to each other.

In this case, the gear mechanism which transmits a driving force from the said one pump to the other pump can be set so that it may be mutually engaged in the outer periphery of the cylinder block of each pump.

Further, the gear mechanism for transmitting the driving force from the one pump to the other pump can be configured to be engaged with the shaft end of the side to which the prime movers of the drive shafts arranged in parallel in each pump are connected.

In addition, the swash plate of each pump may be configured to drive the power piston, the power rod and the adjustment rod of the discharge capacity adjusting mechanism is linked to each other, and the position of the power piston may be configured to be fed back to the adjustment rod.

Embodiment of the Invention

EMBODIMENT OF THE INVENTION Hereinafter, the Example of the swash plate type variable displacement parallel pump which concerns on this invention is described in detail with reference to an accompanying drawing.

1 to 3 show one embodiment of a parallel swash plate piston pump in which two swash plate variable displacement parallel pumps according to the present invention are paired. That is, the swash plate type variable displacement parallel pump in this embodiment is basically provided with one swash plate 12a, 12b in sliding contact with the inner surface 10a of the housing 10 as the pump casing. 12a and 12b are inserted and mounted at right angles with the axial direction to the respective drive shafts 14a and 14b so as to be tiltable (i.e., tilted). In addition, one end of the drive shaft (14a) is configured to protrude to the outside of the housing 10 so that the input shaft is coupled to the appropriate rotation drive mechanism.

Further, cylinder blocks 16a and 16b are provided on the drive shafts 14a and 14b so as to be integrated with the drive shafts 14a and 14b, and a number of pistons 18 are respectively provided for the cylinder blocks 16a and 16b. It is possible to reciprocate in the directions of (14a, 14b), and it is formed so that fluid does not leak. Thus, each piston 18 couples the spherical heads 19 so as to rotate freely with respect to the shoe 20, and at the same time, these shoes 20 are arranged to be in contact with the swash plates 12a and 12b so as to slide. .

The port plates 22 are mounted on the suction and / or discharge port side end surfaces of the cylinder blocks 16a and 16b so as to be interviewed, and the port plates 22 are in contact with the opposite surfaces of the port plates 22, respectively. The cover 24, which is one component of the pump casing, is coupled with the housing 10 so as to surround the cylinder blocks 16a and 16b so as not to leak the fluid. This coupling of the cover 24 and the housing 10 can be made by means of common fastening means, for example screws, rivets or welding.

The drive shafts 14a and 14b are rotatably supported by bearings 26 and 28 fitted in the housing 10 and the cover 24, respectively. In addition, the bearing 26 mounted on the housing 10 is a type that can support the axial force on the cylinder block 16a, 16b side.

In addition, the cylinder blocks 16a, 16b integrally formed with the drive shafts 14a, 14b are provided with gear mechanisms 30a, 30b on their outer periphery, respectively, and the gear mechanisms 30a, 30b are engaged with each other to rotate integrally. It is configured to be. Accordingly, the surface where the port plate 22 and the cylinder blocks 16a and 16b come into contact with each other is slidable by the spring 32 installed on the opposite side of the port plate 22 and the bush 34 into which the high pressure oil flows. It is pressurized so that fluid may not leak, and it is comprised so that hydraulic pressure may flow.

The swash plate type variable displacement parallel pump configured as described above is a drive mechanism (not shown in the drawing), and when the driving shaft 14a on one side is rotated, the rotational force is transmitted to the cylinder block 16a on one side integrally formed with the driving shaft 14a and simultaneously. It is transmitted to the cylinder block 16b of the other side through the gear mechanism 30a, 30b provided in the outer peripheral surface of each cylinder block 16a, 16b.

In addition, each of the cylinder blocks 16a and 16b is integrally formed with the drive shafts 14a and 14b, and each of the drive shafts 14a and 14b, that is, the cylinder blocks 16a and 16b, is connected to the housing 10 and the cover 24. It is reliably supported by the mounted bearings 26 and 28. Therefore, the port plate 22 is pressurized to the sliding surface side of the cylinder blocks 16a and 16b, which are reliably supported, so that hydraulic pressure flows, so that the gear mechanism 30a is applied to the cylinder blocks 16a and 16b by the transmission of the rotational force. Of the respective light port plates 22 are pressed against the cylinder blocks 16a and 16b which are firmly positioned in the radial and axial directions even when the radial force or the frictional force of 30b is applied. Very high reliability can be obtained without any influence on function or performance.

Further, in the configuration of the gear mechanisms 30a and 30b for transmitting the driving force from the drive shaft 14a on one side to the drive shaft 14b on the other side, instead of the above embodiment, for example, a drive shaft disposed parallel to each pump ( It is also possible to provide the gear mechanisms 30a and 30b so as to engage with each other at the shaft end of the side to which the prime movers of 14a and 14b are connected.

Further, in the swash plate type variable displacement parallel pump of the above embodiment, the drive shafts 14a and 14b and the cylinder blocks 16a and 16b are integrally formed by different members, but the drive shaft 14a on one side as the input shaft is shown. Drive force in the cylinder block 16a, 16b can be configured to be smoothly transmitted to the other drive shaft 14b as the driven shaft through coupling with the spline drive shafts 14a, 14b provided in the inner diameter portion of each cylinder block 16a, 16b. have.

However, in the swash plate type variable displacement parallel pump of the present embodiment, in the swash plates 12a and 12b disposed on the housing 10 side, the swash plates 12a and 12b are centered on the axes of the drive shafts 14a and 14b. Power pistons 36a and 36b are arranged on the cover 24 so as to be operated at an inclined angle, and each power piston 36a is disposed on the outer surface of the cover 24 at the position where the power pistons 36a and 36b are installed. And control valve device 40 in which discharge capacity adjusting mechanisms 38a and 38b for 36b are respectively configured.

The discharge capacity adjusting mechanisms 38a and 38b are connected to the feedback levers 44a and 44b by power pistons 36a and 36b corresponding to the positions of the adjusting rods 42a and 42b mounted in the control valve device 40. It is configured to determine the position of. That is, one end of the feedback lever (44a, 44b) is rotatably fixed to the inner side of the control valve device, the other end is linked to the power piston (36a, 36b), the both The adjustment rods 42a and 42b of the discharge capacity adjusting mechanisms 38a and 38b are connected between the end portions thereof so that the feedback levers 44a and 44b are interlocked with each other as the adjustment rods 42a and 42b move. 36a and 36b are configured to move. In addition, the operation of the adjusting rods 42a and 42b may be performed by a device (for example, a solenoid or the like) added to the outside of the casing 46.

Therefore, the control valve device 40 has a feedback lever 44a, 44b respectively coupled to the power pistons 36a, 36b provided in the pump on the input shaft side and the pump on the driven shaft side, respectively, in the center of the cover 24. It can be compactly configured to include the entire configuration in the casing 46 as a single control block by arranging each adjacent in the vicinity. The power piston of reference numeral 36b is not shown, and has the same configuration as the power piston of reference numeral 36a.

According to the swash plate type variable displacement parallel pump of the present invention configured as described above, the discharge capacity adjusting mechanisms 38a and 38b for the two pumps are constituted by a control valve device 40 which is a casing 46 of a single control block. Therefore, all the external piping required for the control of the total horsepower or the control of the variable horsepower can be set to the inner passage of the casing 46 (see FIG. 3), and in this case a casing composed of a single control block compactly configured ( 46), the advantages of simplifying the processing of the inner passage are obtained.

In addition, since it is composed of a control valve device 40 consisting of a casing 46 of a single control block, when it is mounted on the housing 10 or the cover 24 of the pump body, the sealing surface may be minimized ( 2), this can greatly reduce the amount of oil leakage on the sealing surface, and can also obtain advantages such as increasing safety in this type of pump.

As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to the said embodiment, Many design changes are possible within the range which does not deviate from the technical idea of this invention.

As is clear from the above embodiment, the swash plate type variable displacement parallel pump according to the present invention has two swash plate type variable displacement pumps disposed close to each other, the drive shafts of the respective pumps are arranged in parallel, and the pump drive shaft of one side is disposed. In the swash plate type variable displacement parallel pump configured to drive the prime mover and transmit the driving force of the one driving shaft to the other pump driving shaft through the gear mechanism, each pump is surrounded by one housing and one cover. And discharging capacity adjusting mechanisms for adjusting discharge capacities of the pumps, respectively, and disposing each discharge capacity adjusting mechanism in a single casing, and adjusting rods of the discharge capacity adjusting mechanisms and driving shafts of the pumps. The casing outside the housing or cover surrounding each of the pumps such that the casing is substantially parallel. As it is detachably installed on the surface, it takes advantage of the features of the swash plate type variable displacement pump and does not have a casing composed of a plurality of control blocks by a large control device or a complicated control device as in the prior art, and has a function equivalent to that of the prior art. Many advantages can be obtained, such as eliminating external piping required for total horsepower control or variable horsepower control, reducing the oil occupied area by reducing the occupying area of the casing as a control block, and improving space reduction. Lose.

Claims (4)

Two swash plate variable displacement pumps disposed close to each other so that the drive shafts of each pump are parallel to each other, and a swash plate variable structure having a gear structure for transmitting the driving force of the drive shaft of one pump driven by the prime mover to the drive shaft of the other pump. In the capacitive parallel pump, A cover and a housing; An adjusting rod whose position is moved by the discharge amount adjusting input signal of each pump; A discharge capacity adjusting mechanism inserted into and mounted on each adjustment rod; A power piston for controlling the inclination angle of the swash plate in each pump; A feedback lever for linking each power piston to transfer the amount of movement of each power piston from said discharge capacity adjusting mechanism; And a single casing for accommodating each discharge amount adjusting mechanism, each adjusting rod, and each feedback lever, The respective pumps are mounted in a pump casing configured to fasten the cover and the housing by bolts, Each of the adjustment rods are arranged in close proximity to each other and at the same time the respective feedback levers are arranged in proximity to the respective adjustment rods and mounted in a single casing, The single casing is a swash plate type variable displacement parallel pump, characterized in that installed on the outer surface of the cover or the housing such that the adjusting rod is made parallel to the drive shaft of the pump. The method of claim 1, The gear mechanism for transmitting the driving force from one pump to the other pump is a swash plate type variable displacement parallel pump, characterized in that the gear is installed to engage with each other on the outer circumference of the cylinder block of each pump. The method of claim 1, A swash plate type variable displacement parallel pump comprising: a gear mechanism for transmitting a driving force from one pump to another pump, the gear mechanism being installed to engage each other at an end of a shaft to which the prime mover of the drive shaft arranged in parallel is connected. delete