KR20000022749A - Swash plate type and variable displacement type parallel pump - Google Patents

Abstract

PURPOSE: A variable capacity parallel pump is provided to reduce leakage of oil outside by reducing occupied area of a casing and to reduce space. CONSTITUTION: A parallel pump is acquired by installing swash plates(12a,12b) contacting to inner faces(10a) of a housing(10) as a pump casing, inserting the swash plates to be parallel with each driving shaft(14a,14b) to be able to inclined in vertical with the direction of shaft line, forming one driving shaft(14a) as an input shaft, protruding one end of the driving shaft(14a) outward to be combined to a rotary driving device, installing cylinder blocks(16a,16b) integrally with the driving shafts, forming many pistons(18) corresponding to the guide blocks to prevent the leak of fluid toward the deriving shaft line by combining using a slide member. The head(19) of each piston is combined by the slide member against shoes(20) arranged to slide on the sliding face of the electric swash plates.

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 variable displacement parallel pump, in particular, when used in construction machinery and the like to reduce the oil leakage of mineral working oil, such as mineral working oil adversely affects the global environment in the coupling surface of the casing, etc. constituting the control block, At the same time, the invention relates to a swash plate type variable displacement parallel pump capable of eliminating oil leakage in the piping portion during total horsepower control and facilitating assembly by reducing assembly parts.

As a control device of a conventional bent axis variable displacement parallel pump, for example, a pump control device configured to perform a maximum discharge amount control of a variable displacement pump and prioritize horsepower control (Japanese Patent Publication No. 63-78175). In addition, even when a light quantity detection means is provided to control the minimum light position from the maximum light position, the entire structure can be reduced without any complexity. And at the same time, a variable displacement bent axis hydraulic rotor for performing long-term feedback control with high accuracy for the warp angle by means of the warp amount detection means (Japanese Patent Laid-Open No. 8-232833). Publications).

That is, the former pump control device includes a pilot piston in which 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 are provided. The electric pilot piston moves the servovalve which controls the introduction of the pump discharge pressure of the control piston which controls the electric pump inclination by the balance of the force, and the diameter of the electric pilot piston is larger than the electric pilot piston at the end of the electric pilot piston. A cap-type large diameter piston having an insertion hole formed at the electrical end thereof is provided, and the large diameter piston is placed on the opposite side to the insertion hole to limit the maximum discharge amount of the electric variable displacement hydraulic pump. At the same time, when the pump discharge pressure exceeds the set value, the hydraulic pressure acting on the pilot piston is applied to the operating surface of the command pressure for the constant horsepower control. It is characterized in that that generated.

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 by the force and the command pressure can be calculated by the large diameter piston, the pump can be automatically converted to the maximum discharge amount control and the horsepower constant control, and the control is simple.

In addition, the latter variable displacement bent axis hydraulic rotor has a cylindrical casing whose cross section is occluded by the head casing, a rotating shaft rotatably provided in the casing, and an electric casing installed in the electric casing 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 swivelably supported on an electric rotating shaft via a connecting rod, and one end section of the electric 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 electric head casing; and a light mechanism that tilts the cylinder block together with the valve plate. A variable displacement bent axis hydraulic rotor, comprising: an electric valve for supplying hydraulic oil for light control to an electric light mechanism. A control unit disposed on the least sacred side of the electric casing, the detector being installed to be rotatable with a support pin interposed between the control unit and the casing, and the proximal side protruding into the electric control side, and the proximal end protruding into the electric casing. The feedback link and the distal end side are rotatably connected to the connecting portion of the electrical feedback link, and the proximal end is rotatably installed on the electric valve plate, and the amount of electric light of the electric valve plate is proportionally increased. An output pin provided in the middle of the detection section of the electrical feedback link to give feedback to the electrical control section in a reduced state, and a detection rod provided outside the electrical control section and following the rotational displacement of the electrical feedback link, Light-weighted amount detection means for deriving the light-weighted amount of the electric valve plate by detecting, and the electric feedback link Chulbu there will, characterized in that the electrical contact with the light-amount detecting means for detecting load, install the vibration suppressor to control that little vibration is transmitted on the feedback link to the detected load.

Therefore, according to the variable displacement bent axis hydraulic rotor configured as described above, since the amount of light detection means derives the rotational displacement of the feedback link from the tip 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 to the tip of, the amount of rotational displacement of the electrical feedback link can be increased proportionally, 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 monitored at all times, and the capacity of the hydraulic rotor can be controlled to a higher degree, and the whole structure is provided by the light amount detecting means. Can be prevented from being complicated, and the whole can be formed compactly, so that the size can be reduced.

However, in the conventional four-axis variable displacement parallel pump according to the prior art, in the former pump control apparatus, the control cylinder of the control portion that performs the movement control of the cylinder to change the discharge flow rate is inside the cover, and the control of the long stroke is performed. There are problems such as an increase in the size of the control device and an increase in weight.

In addition, in the latter variable displacement bent axis hydraulic rotor, the position of the valve plate for varying the cylinder is controlled by feedback by providing light amount detection means, but the control is performed by using a plurality of feedback links. As a result, the number of parts increases, and the control device of each pump uses a respective control casing, so that the sealing portion increases, and thus the oil leakage place increases.

Therefore, as a result of intensive studies, the present inventors have placed two swash plate variable displacement pumps in close proximity to each other, arranged the drive shafts of the respective pumps in parallel, and driven one pump drive shaft with a prime mover, thereby driving one electric drive shaft. The swash plate type variable displacement parallel pump is configured to transmit the driving force to the other pump drive shaft via the gear mechanism, and is integrated by configuring each electric pump in a common housing and a common cover. Each of the discharge capacity adjusting mechanisms for adjusting the discharge capacity is provided, and each of the electric discharge capacity adjusting mechanisms is disposed adjacent to each other in a single casing, so that the adjustment rod of each of the electric discharge capacity adjusting mechanisms and the drive shaft of each electric pump are substantially parallel. Two pumps by detachably installing the casing on the outer surface of the housing or cover surrounding each electric pump It is possible to compactly store all the discharge capacity adjusting mechanisms in the casing as a single control block, and at the same time, all the external pipes required in the case of total horsepower control or variable horsepower control can be set as internal passages in the electric casing, Furthermore, since it is constituted as a casing as a single control block, when it is mounted on the housing or cover of the pump main body, the sealing surface can be set to a minimum, thereby greatly reducing the amount of oil leakage on the sealing surface, It has been found that advantages such as increased safety in the pump can be obtained.

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-scale control device or a complicated control device as in the prior art, and has a function equivalent to that of the prior art. A swash plate type variable displacement type that reduces oil leakage to the outside and improves space reduction by omitting external piping required for total horsepower control or variable horsepower control, and by reducing the occupying area of the casing as a control block. It is to provide a 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: cross section

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

The swash plate variable displacement parallel pump according to the present invention for achieving the above object is to arrange two swash plate variable displacement pump in close proximity to each other, to arrange the drive shaft of each pump in parallel, and to drive one pump drive shaft to the prime mover In the swash plate type variable displacement parallel pump configured to transmit the driving force of one drive shaft to the other pump drive shaft via a gear mechanism.

Each electric pump is integrated with a common housing and a common cover, and a discharge capacity adjusting mechanism for adjusting the discharge capacity of each electric pump is provided, and each electric discharge capacity adjusting mechanism is adjacent in a single casing. And an electric casing is detachably installed on the outer surface of the housing or cover surrounding the electric pump so that the adjusting rod of the electric discharge capacity adjusting mechanism and the drive shaft of the electric pump are substantially parallel to each other.

In this case, the gear mechanism which transmits a driving force from the electric 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.

In addition, the gear mechanism which transmits a driving force from the electric one pump to the other pump can be set so that it may be mutually engaged in the shaft end of the side to which the prime mover of the drive shaft of each pump parallelly connected is connected.

In addition, the swash plate of each electric pump may be configured to be driven by a power piston, the electric rod and the adjustment rod of the discharge capacity adjusting mechanism are 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, referring an accompanying drawing.

1 to 3 show one embodiment of a parallel swash plate type two piston pump as a swash plate type variable displacement parallel pump according to the present invention. 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 so as to be tilted at right angles to the axial direction of the drive shafts 14a and 14b, respectively. In addition, one drive shaft 14a of the former is configured to be an input shaft, and one end thereof is protruded out of the housing 10 so as to be engaged with a suitable rotation driving mechanism.

Moreover, the cylinder block 16a, 16b is provided in the electric drive shaft 14a, 14b integrally with this, and the several piston 18 is sliding material with respect to the drive shaft direction with respect to these cylinder blocks 16a, 16b, respectively. And the fluid is formed so that it does not leak. Each piston 18 thus engages the spherical head 19 with the sliding material against the shoe 20, and at the same time these shoes 20 are arranged in sliding contact with the sliding surfaces of the electric swash plates 12a and 12b. It is.

Port plates 22 are placed in contact with the suction and / or discharge port side end surfaces of the cylinder blocks 16a and 16b, respectively, and the electric cylinder blocks 16a and 16b are held in contact with the rear surfaces of these pump plates 22, respectively. ) Is provided with a cover 24 as a pump casing which encloses < RTI ID = 0.0 >

The electric drive shafts 14a and 14b are rotatably supported by fitting bearings 26 and 28 to the housing 10 and the cover 24, respectively. Moreover, the bearing 26 supporting the electrical housing 10 is a type which can also 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 engage these gear mechanisms 30a, 30b to rotate integrally. It is configured to. Thus, the contact surface of the electric port plate 22 and the cylinder blocks 16a and 16b is formed by the spring 32 provided on the rear side of these port plates 22 and the bush 34 into which the high pressure oil is introduced. 16b), it is configured to be slidably pressed against the sliding surface with respect to the sliding surface with respect to the sliding surface with 16b), and the hydraulic pressure floats.

The swash plate type variable displacement parallel pump configured as described above rotates one drive shaft 14a by a drive mechanism (not shown), and this rotation driving force is applied to one cylinder block 16a integrally formed with the drive shaft 14a. At the same time, it is also transmitted to the other cylinder block 16b via the gear mechanisms 30a and 30b provided on the outer periphery of each cylinder block 16a and 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, since the port plate 22 is hydraulically floating while being pressed against the sliding surfaces of the cylinder blocks 16a and 16b which are reliably supported, the cylinder blocks 16a and 16b are transmitted by the transmission of the electric driving force. Light port plate 22 with respect to cylinder blocks 16a and 16b which are reliably positioned in the radial and axial directions even if a semi-directional force or frictional force from the gear mechanisms 30a and 30b acts on It is possible to obtain very high reliability without any influence on the pump function and its performance by setting the pressure contact.

In addition, instead of the electric embodiment, for example, the arrangement of the electric gear mechanisms 30a and 30b which transfers the driving force from one drive shaft 14a to the other drive shaft 14b is arranged in parallel, for example. It is also possible to provide the electric gear mechanisms 30a and 30b so as to mesh with each other at the shaft end on the side to which the prime movers of the drive shafts 14a and 14b are connected.

In addition, in the swash plate type variable displacement parallel pump of the above-described embodiment, the drive shafts 14a and 14b and the cylinder blocks 16a and 16b are integrally formed by different members, but one drive shaft as the input shaft ( The driving force in 14a) is smoothly transmitted to the other drive shaft 14b as the driven shaft through spline coupling with the drive shafts 14a and 14b by splines provided in the inner diameter portions of the cylinder blocks 16a and 16b, respectively. Can be configured.

However, the swash plate type variable displacement parallel pump of the present embodiment has a power piston for turning the swash plates 12a and 12b on the cover 24 side with respect to the swash plates 12a and 12b disposed on the housing 10 side, respectively. The discharge capacity adjusting mechanisms 38a and 38b for the respective power pistons 36a and 36b are arranged on the upper surface of the cover 24 on which the electric power pistons 36a and 36b are provided. The control valve device 40 which comprises each is provided.

The electric discharge capacity adjusting mechanisms 38a and 38b are coupled to the power pistons 36a and 36b through the feedback levers 44a and 44b corresponding to the positions of the adjusting rods 42a and 42b mounted in the control valve device 40. ) Is configured to determine the position.

Therefore, the control valve device 40 has feedback levers 44a and 44b respectively coupled to the power pistons 36a and 36b provided for the pump on the input shaft side and the pump on the driven shaft side, near the center of the cover 24. By arranging adjacent to each other in this case, it can be set as the compact structure which accommodated the whole in the casing 46 as a single control block.

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

Furthermore, since it is comprised as the control valve apparatus 40 which becomes the casing 46 as a single control block, when this is mounted in the housing 10 or the cover 24 of a pump body, a sealing surface can be set to the minimum ( 2), this can greatly reduce the amount of oil leakage on the sealing surface, and also provide advantages such as improving the safety of this type of pump.

As mentioned above, although preferred embodiment of this invention was described, this invention is not limited to an above-mentioned 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-described embodiment, 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 one pump drive shaft. In the swash plate type variable displacement parallel pump configured to drive the motor as a prime mover and transmit the driving force of one electric drive shaft to the other pump drive shaft via a gear mechanism, each electric pump is surrounded by a common housing and a common cover. Is integrated into the configuration, and each discharge capacity adjusting mechanism for adjusting the discharge capacity of each electric pump is provided, and each discharge capacity adjusting mechanism is disposed adjacent to each other in a single casing, and the adjustment rod of each electric discharge capacity adjusting mechanism is provided. And the casing surrounding the electric angular pump so that the driving shaft of the electric angular pump and the electric angular pump are substantially parallel. By detachably attaching to the outer side of the burr, it is possible to take advantage of the features of the swash plate type variable displacement pump and to avoid casing made of a plurality of control blocks by a large control device or a complicated control device as in the prior art. It has the same function as, and also reduces the oil leakage to the outside and reduces the space by omitting the external piping required for the control of the total horsepower and the variable horsepower, and reducing the occupied area of the casing as the control block. Many excellent advantages can be obtained.

Claims (4)

Two swash plate variable displacement pumps are arranged close to each other, the drive shafts of each pump are arranged in parallel, the one pump drive shaft is driven by the prime mover, and the driving force of one electric drive shaft is driven to the other pump drive shaft. In the swash plate type variable capacity parallel pump configured to be interposed to deliver, Integrating each of the pumps in a common housing and a common cover, and simultaneously disposing the discharge capacity adjusting mechanism for adjusting the discharge capacity of each electric pump, and installing each discharge capacity adjusting mechanism in a single casing. The swash plate is arranged adjacent to each other, and the casing is detachably installed on the outer surface of the housing or cover surrounding the electric pump so that the adjusting rod of the electric discharge capacity adjusting mechanism and the drive shaft of the electric pump are substantially parallel. Variable displacement parallel pumps. 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. The method according to any one of claims 1 to 3, The swash plate is configured to drive the swash plate of each electric pump with a power piston, and to link the electric power piston and the adjusting rod of the discharge capacity adjusting mechanism to each other, and to feed the position of the power piston back to the adjusting rod. Variable displacement parallel pumps.