JPS6059464B2 - Hydraulic transmission with oil filter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a hydraulic transmission equipped with an oil filter that centrifugally separates chips and other impurities mixed into hydraulic fluid.

Hydraulic transmission devices, particularly hydraulic pumps made up of a pump cylinder with a number of pump plungers arranged in an annular arrangement, and hydraulic motors made up of a motor cylinder surrounding the pump cylinder with a number of motor plungers arranged in an annular arrangement. Since devices that are connected to each other have many sliding parts, if the hydraulic fluid is mixed with manufacturing chips and other foreign substances that remain in each part of the device, the foreign substances will be mixed between the sliding members. This may cause inconveniences such as increasing the sliding resistance or damaging the sliding surface, causing oil leakage and reducing transmission efficiency.

SUMMARY OF THE INVENTION Therefore, the present invention provides a hydraulic transmission with a simple structure and an oil filter, which avoids the above-mentioned inconvenience by centrifuging foreign substances even if they are mixed into the hydraulic oil. The purpose is to

Hereinafter, an embodiment of the present invention will be described with reference to the drawings. 1 shows two case halves 1a divided in the longitudinal direction;
The transmission case equipped with the transmission case is composed of a hydraulic pump P and a hydraulic motor M.

The hydraulic pump P includes a pump cylinder 4 which is penetrated by an input shaft 2 and spline-coupled 3 thereto, and a large number of cylinder holes 5, 5, which are arranged in an annular arrangement surrounding the rotation center of the pump cylinder 4. A large number of pump plungers 6, 6...... are respectively slid together.
Power from an engine (not shown) is transmitted to the input shaft 2 via a flywheel 7.

On the other hand, the hydraulic motor M includes a motor cylinder 8 arranged to concentrically surround the pump cylinder 4 and rotate relative to it, and a motor cylinder 8 provided so as to surround the center of rotation of the motor cylinder 8. Numerous cylinder holes 9 in an annular arrangement
, 9, . . . and a large number of motor plungers 10, 10, . A pair of support shafts 11, 1" are provided on both axial end surfaces of the motor cylinder 8.
are protruded, one support shaft 11 is connected to the end wall of the right case half 1b via a ball bearing 12, and the other support shaft 1'' is connected to the end of the left case half 1a via a needle bearing 13. Each is supported by the wall.And one of the supporting shafts 1
A stop ring 14 that clamps the inner race 12a of the ball bearing 12 together with the motor cylinder 8 is fixed to the outer end of the outer race 12, and another stop ring 15 that is fixed to the outer end of the outer race 12b is fixed to the outer end of the outer race 12b. A retaining plate 17 that is engaged with an annular recess 16 on the outer surface of the end wall of the body 1b and further abuts the outer end of the outer race 12b is attached to the right case half 1 by a bolt 18.
b, and thus the ball bearing 1
2 and the support shaft 11 are prevented from moving in the axial direction relative to the right case half 1b. The other support shaft 1" is integrally formed with a gear 19 and serves as an output shaft, and the output of the hydraulic motor M is taken out from the gear 19 and transmitted to the differential gear device 21 via the intermediate gear 20. It's getting old.

A pump swash plate 22 inclined at a certain angle with respect to each pump plunger 6 is fixed inside the motor cylinder 8, and a sliding piece 6a that can smoothly slide on the surface of this pump swash plate 22 is attached to each pump plunger. The pump swash plate 22 is swingably attached to the spherical end of the pump cylinder 6, and thus the pump swash plate 22 can give reciprocating motion to each pump plunger 6 as the pump cylinder 4 rotates, thereby repeating the suction and discharge strokes. In addition, a motor swash plate 23 is pivotally supported in the mission case 1 so as to be tiltable via a pair of trunnion shafts 24 protruding from both outer sides of the motor swash plate 23, facing each motor plunger 10. Sliding piece 10 that can slide smoothly
a is swingably attached to the spherical end of each motor plunger 10, and thus the motor swash plate 23 is connected to the motor cylinder 8.
As the motor plungers 10 rotate, each motor plunger 10 is given reciprocating motion to repeat the expansion and contraction strokes.

At this time, the stroke of the motor plunger 10 can be adjusted steplessly from zero to the maximum by tilting the motor swash plate 23 from an upright position perpendicular to each motor plunger 101 to the maximum tilt position shown. can. A hydraulic closed circuit is formed between the hydraulic pump P and the hydraulic motor M via a distribution panel D and a distribution ring 25, which will be described later.

Therefore, when the pump cylinder 4 is rotated from the input shaft 2,
Cylinder hole 5 that accommodates the pump plunger 6 in the discharge stroke
The high-pressure hydraulic oil discharged from the cylinder hole 9 that accommodates the motor plunger 10 on the expansion stroke is fed to the cylinder hole 9 that accommodates the motor plunger 10 on the contraction stroke.
The hydraulic oil discharged from the pump plunger 6 in the suction stroke
During this period, the reaction torque that the pump plunger 6 in the discharge stroke applies to the motor cylinder 8 via the pump swash plate 22, and the reaction torque that the motor plunger 10 in the expansion stroke receives from the motor swash plate 23. The motor cylinder 8 is rotated by the sum of . in this case,
The gear ratio of the motor cylinder 8 to the pump cylinder 4 is given by the following equation.

As is clear from the above equation, by changing the capacity of the hydraulic motor M from zero to a certain value, the gear ratio can be changed from 1 to a certain required value. Incidentally, since the capacity of the hydraulic motor M is determined by the stroke of the motor plunger 10, the gear ratio can be changed from 1 to a certain value by tilting the motor swash plate 23 from the upright position to a certain inclination angle as described above. Can be adjusted in stages. A hydraulic servo motor S1 is provided in the transmission case 1 for tilting the motor swash plate 23. The motor cylinder 8 is composed of first to fourth parts 8a to 8d divided in the axial direction.

The first portion 8a has a cup shape, and the pump swash plate 22 is provided on the inner end surface of the first portion 8a.

The second portion 8b has a cylindrical shape, and a support hole 9 for supporting the motor plunger 10 among the cylinder holes 9 is provided in the peripheral wall of the second portion 8b.
a is provided over the entire length, and the pump cylinder 4 is housed in the hollow portion thereof. The third portion 8c has a disc shape,
The fourth portion 8d has an annular shape, and is provided with a series of motor hydraulic chambers 9b having a slightly larger diameter than the support hole 9a of the cylinder hole 9, and furthermore, the central disk-shaped portion of the third portion 8c forms a distribution plate D. is configured. The first part 8a is the second part 8
It has a connecting flange 26 integrally at the end opposite to b, and the flange 26 is tightly fitted into the positioning hole 27 on the end face of the second portion 8b opposite thereto, and the plurality of connecting bolts 2
8, it is fixed to the second portion 8b.

Further, the second, third and fourth portions 8b, 8c and 8d are positioned with respect to each other by inserting dowel pins 29 and 30 into their respective joint portions, and a plurality of connecting bolts 31 are used to connect the second and fourth portions. 8b and 8d are tightly connected, and the third portion 8c is firmly held between them, thus the first
-4 parts 8a-8d are joined together.

The input shaft 2 has its outer end fitted with a needle bearing 32.
is supported at the center of the support shaft 1' through a needle bearing 33, and its inner end is supported at the center of the distribution board D through a needle bearing 33, and between the input shaft 2 and the opposing circumferential surfaces of the pump cylinder 4. A compression spring 57 is housed in an annular spring chamber 56 formed adjacent to the spline joint 3.
7 elastically abuts its right end against a seat plate 58 that is engaged with the pump cylinder 4, and its left end against a seat plate 59 that is engaged with the input shaft 2, respectively.

On the other hand, a stopper plate 60 facing the inner end surface of the motor cylinder 8 is engaged with a portion of the input shaft 2 that protrudes from the left end surface of the pump cylinder 4, and a needle thrust bearing 61 is interposed between these opposing surfaces. Ru. Therefore, the elastic force of the spring 57 presses the pump cylinder 4 against the distribution board D via the seat plate 58 to prevent oil leakage from their rotating and sliding parts, and the reaction force of the elastic force is transmitted to and supported by the motor cylinder 8 via the seat plate 58, input shaft 2, stopper plate 60, and needle thrust bearing 61. A fixed shaft 35 passing through the support shaft 11 of the motor cylinder 8 is connected to the holding plate 17 via a pin 36, and a distribution ring 25 in contact with the distribution plate D is attached to the inner end of the fixed shaft 35 in an eccentric manner. The distribution ring 25 allows the hollow portion 37 of the fourth portion 8d of the motor cylinder 8 to be divided into an inner chamber 37a and an outer chamber 37.
It is divided into b.

On the other hand, discharge and suction boats 38 and 39 are bored in the distribution board D, and the discharge boats 38 connect the cylinder hole 5 of the pump plunger 6 in the discharge stroke and the inner chamber 37.
A is in communication with the cylinder hole 5 of the pump plunger 6 in the suction stroke by the suction boat 39 and the outer chamber 3.
7b are communicated with each other. Further, the distribution board D has a large number of communication boats 40, 40, . Holes are drilled from the inside, and these allow the motor hydraulic chambers 9b, 9b of the motor cylinder 8 to
... are communicated with the inner chamber 37a or the outer chamber 37b. Therefore, when the pump cylinder 4 rotates,
The high-pressure hydraulic oil generated by the discharge stroke of the pump plunger 6 is flowed from the discharge boat 38 into the inner chamber 37a, further via the communication boat 40 in communication with the inner chamber 37a, and into the motor hydraulic chamber 9b of the motor plunger 10 in the expansion stroke. A thrust is applied to the plunger 10, while the hydraulic oil discharged by the motor plunger 10 during the contraction stroke is supplied to the outer chamber 37b.
The hydraulic oil is returned to the cylinder hole 5 of the pump plunger 6 in the suction stroke through the connecting boat 40 and the suction boat 39, which communicate with It will be done.

An annular filter groove 46 is provided on the inner peripheral surface of the outer chamber 37b.
is formed, and the groove 46 has a large number of radial fins 47,
It is equipped with 47...

During transmission from the hydraulic pump P to the hydraulic motor M, the hydraulic oil passing through the outer chamber 37b is forcibly supplied with the fins 47, 47, which are integrated with the rotating motor cylinder 8. Rotation is applied, and by the action of the resulting centrifugal force, chips with a high specific gravity mixed into the hydraulic oil are separated and stored in the filter groove 46. The fixed shaft 35 has a center hole 41 and a plurality (two in the figure) of shorting boats 42 and 43 passing through the side wall thereof.
43 are connected to the inner chamber 37a through the center hole 41, and their outer ends are connected to the outer grooves 44, 4 of the fixed shaft 35.
These short-circuit boats 42 and 43 are connected to the outer chamber 37b through the outer chamber 37b, and these short-circuit boats 42 and 43 are opened and closed by rightward and leftward movement of a clutch valve 48 that slides into the center hole 41. That is, when the clutch valve 48 is in the rightward movement position, the shorting boats 42 and 43 are opened and the inner and outer chambers 37a and 37b are opened.
The hydraulic oil discharged from the discharge boat 38 of the distribution board D is immediately short-circuited to the suction boat 39, and the hydraulic oil is not supplied to the hydraulic motor M, so the hydraulic motor M is deactivated. When the clutch valve 48 is moved to the left to close both the short-circuit ports 42 and 43, the clutch is turned off because the hydraulic oil is circulated from the hydraulic pump P to the motor M. - Turns on.
A valve rod 50 is screwed onto the tip of the clutch valve 48, and an umbrella-shaped valve body 51 is swingably connected to the spherical end 50a of the valve rod 50.
This valve body 51 can be brought into close contact with the distribution board D so as to close the discharge boat 38 when the clutch valve 48 moves to the left beyond the clutch-on position.

The discharge boat 38 is blocked by the valve body 51 when the motor swash plate 23 is placed in an upright position and the gear ratio is set to 1:1. The motor cylinder 8 can be mechanically driven via the pump plunger group 8 and the pump swash plate 22, so that the motor plunger 10
The thrust applied to the motor swash plate 23 disappears, and the burden on each part due to the thrust can be reduced. For sliding operation of the clutch valve 48, a hydraulic servo motor S2 is provided on the fixed shaft 35.

A replenishment pump F is equipped on the outside of the left case half 1a,
The pump is driven by an input shaft 2 and draws oil from an oil reservoir (not shown) to generate hydraulic oil at a constant pressure. 53 and further via check valves 54 and 55 to the discharge boat 38 of the distribution board D and the outer chamber 37.
b, respectively. Therefore, when hydraulic oil leaks from the hydraulic closed circuit of the hydraulic pump P and the hydraulic motor M,
The amount can be automatically replenished from the replenishment pump F. As described above, according to the present invention, the annular filter groove provided with a plurality of radial fins is formed on the inner peripheral surface of the outer chamber defined by the distribution ring in the hollow part of the motor cylinder. Contaminants such as chips mixed in oil can be reliably separated and stored, eliminating inconveniences such as increased sliding resistance of sliding parts and damage to sliding surfaces due to contaminants, and improving transmission efficiency. can contribute to improvement.

In particular, since the relatively large-diameter outer chamber is used as the oil tank for the centrifugal filter, there is no need to provide a special oil tank for the filter, and the structure is simple, and it is possible to apply large centrifugal force to the hydraulic oil. This can enhance the filter effect.

[Brief explanation of the drawing]

Fig. 1 is a longitudinal sectional side view of the device of the present invention, and Fig. 2 is a side view of the device of the present invention.
It is a sectional view taken along the line -■. 4...Pump cylinder, 6...Pump plunger, 8...Motor cylinder, 10...
...Motor plunger, 25...Distribution ring, 3
7...Hollow part, 37a...Inner chamber, 37
b...Outer chamber, 38...Discharge boat,
39... Suction boat, 40... Communication boat, 46... Filter groove, 47... Fin, D... Distribution board, M...... Hydraulic motor, P...
····Hydraulic pump.

Claims (1)

[Claims] 1. A hydraulic pump comprising a pump cylinder having a plurality of pump plungers arranged in an annular manner fitted together, and a hydraulic motor having a motor cylinder surrounding the pump cylinder having a number of motor plungers arranged in an annular arrangement fitted together; The cylinder is provided with a distribution plate that makes rotational contact with the pump cylinder and a hollow part adjacent thereto, a distribution ring that partitions each into an inner chamber and an outer chamber is arranged in the hollow part, and the distribution plate is provided with a suction of the pump cylinder. A suction port that communicates between the side oil chamber and the outer chamber, a discharge port that communicates between the discharge side oil chamber and the inner chamber, and a communication port that communicates the hydraulic chamber of the motor cylinder with the inner chamber or the outer chamber are bored. In the hydraulic transmission device, the inner surface of the outer chamber includes:
A hydraulic transmission with an oil filter that has an annular filter groove with multiple radial fins.