JPH0319412B2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention is applicable to large, especially ultra-large, construction machines that require an extremely large brake capacity and are often used in locations where detailed maintenance cannot be expected. The present invention relates to a wet brake that is useful for vehicles such as, for example, ultra-large wheel loaders used at coal mining sites.

(Prior art) Wet brakes attached to rotating parts of vehicles are
As shown in FIGS. 6 and 7, an annular fixed plate 2 is attached to the fixed body 4' side so as to be able to freely reciprocate in the axial direction and be restrained during rotational movement, and an annular fixed plate 2 is attached to the rotating shaft 5 side in the axial direction. An annular rotating plate 3 is attached to the plate so that it can freely reciprocate and be restrained during rotation, and one annular piston 1' (see Fig. 7) is arranged on the side of the plate surface 2a of the fixed plate. ) is projected in the axial direction (to the right in FIG. 6) and pressed into contact with each other, and the rotating plate 3, that is, the rotating shaft 5 is stopped by the frictional resistance between the rotating plate 3 and the fixed plate 2. There is.

However, in the case of a brake with the above configuration, the annular piston is integrally configured to correspond to the side shapes of the fixed plate and the rotating plate (see Figures 6 and 7), so the capacity of the brake is As the value increases, the weight of the piston increases, and accordingly, a large weight of the entire piston acts on the supporting portion of the piston 1'. On the other hand, the above supporting part,
That is, an elastic sealing material 7' for sealing hydraulic oil is installed between the sliding surfaces of the piston 1' and the cylinder portion 4a'. Therefore, the large pressure (gravity) from above acts on the sealing material 7'.

Further, the dimensions of the annular groove-shaped cylinder portion 4a',
In order to accurately identify the position, etc., all elements such as the center of the outer and inner circumferences, the roundness of each circumference, and the surface roughness of the circumferential surface must be satisfied, but due to the nature of the annular groove, The processing involves more steps than for a simple circular hole, and the processing machines, jigs, etc. that can be used are limited, making it more difficult to satisfy the above factors. In other words, it is extremely difficult to match the machining base points (lines) during many machining operations, and it is also difficult to satisfy the requirements for high surface roughness due to the inability to insert machining tools into narrow annular grooves. It is extremely difficult to form an accurate annular groove.

Therefore, as the capacity of brakes increases due to larger vehicles, the weight of moving parts increases, and dimensional errors due to reduced machining accuracy occur.
The pressure acting on the sealing material increases, and damage to the sealing material in a short period of time due to this pressure has become a problem.

In view of these problems, the present applicant has developed a system in which a plurality of small pistons that meet the desired braking capacity are moved in the axial direction to press the fixed body and the rotating body into contact with each other. By freely arranging the brakes, we are trying to propose a wet brake that does not have the above-mentioned problems.

The brake itself, which has a plurality of pistons that can protrude and move in the axial direction arranged on the sides of the rotating plate or fixed plate mentioned above, is disclosed in Japanese Patent Publication No. 44-26497,
No. 50-30790.

(Problems to be Solved by the Invention) However, in the case of the brakes disclosed in the above-mentioned Japanese Patent Publication No. 44-26497 and Japanese Patent Publication No. 50-30790, a plurality of pistons directly press the rotating plate or the fixed plate. Therefore, the pressure distribution of the pressing force on these parts is not exactly uniform, and as a result, problems such as deterioration of braking performance or uneven wear of the rotating plate or the fixed plate occur.

In addition, in general, in wet brakes, in order to effectively remove the frictional heat generated by friction between the fixed plate and the rotating plate, a discharge hole for supplying cooling oil is provided near the inner periphery of the fixed plate and the rotating plate. There are brakes that have a discharge hole for discharging cooling oil near the outer periphery of the plate and rotating plate (Special Publication No. 39-25912, Special Publication No. 8570 of 1972), and this type of wet brake is generally used for heavy-duty applications. has been done.

However, in a wet brake in which a plurality of small pistons are arranged instead of one large piston, a gap is formed between the fixed plate or rotating plate and the pistons. In other words, since the space in which the fixed plate and rotating plate are arranged cannot be partitioned by the pressure contact surface of the piston, cooling oil can flow smoothly.
The cooling oil cannot be passed between the fixed body and the rotary plate from the discharge hole near the inner periphery of the fixed body and the rotary plate, and can be smoothly discharged from the cooling oil discharge hole near the outer periphery of the fixed body and the rotary plate.

Therefore, in the wet brake with the above configuration,
The frictional heat generated by the friction between the fixed plate and the rotating plate will not be effectively removed. If the frictional heat is not removed in this way, the fixed plate or the rotating plate will be deformed by the heat, resulting in a decrease in braking performance. You end up doing it.

The present invention has been made in view of the above-mentioned current situation, and in the wet brake equipped with the above-mentioned plurality of small pistons, pressure is applied from each piston to the rotating plate or the fixed plate with an even pressure distribution, and An object of the present invention is to provide a wet brake configured to obtain high cooling efficiency inside a brake case.

(Means for solving the problem) A wet brake according to the present invention includes a fixed body and a rotary body arranged so as to form an annular space therebetween,
An annular fixed plate is movable reciprocally in the axial direction of the fixed body and is restrained when the rotary body rotates, and an annular rotary plate is movable reciprocally in the axial direction of the rotary body and restrained when the rotary body rotates. The fixed plate and the rotating plate are installed in the annular space alternately so as to be engaged with the fixed body and the rotating body, respectively, and a plate that can reciprocate in the axial direction is attached to the side of the fixed plate or the rotating plate. A plurality of pistons are disposed, and the protruding movement of the pistons presses the fixed plate and the rotating plate to stop the rotation of the rotating body, and the fixed plate and the rotating plate are A wet brake configured to cool the fixed plate and rotating plate in the annular space by providing a cooling oil discharge hole near the inner periphery and a cooling oil discharge hole near the outer periphery of the fixed plate and rotating plate, An integrally constructed pressure equalizing plate is disposed between the plurality of pistons and the adjacent fixed plate or rotating plate, with its inner circumferential end being close to the outer circumferential surface of the rotary body, and the pressure equalizing plate and the above-mentioned A blocking means for blocking the flow of cooling oil is provided between the fixed bodies, and the annular space in which the fixed plate and rotating plate are arranged is
It is characterized in that the partition wall is formed by using a pressure equalizing plate arranged so that the pressing force from each piston acts on the fixed plate and the rotating plate side with an even pressure distribution.

(Function) However, in the wet brake having the above-mentioned piston structure, since the integrally constructed pressure equalizing plate has a high structural composition, when the plurality of pistons respectively protrude due to the brake operation, the pressing force of the plurality of pistons can be applied to the stationary plate and the rotating plate with uniform pressure distribution in the strict sense.

In addition, when the brake is applied and frictional heat is generated between the fixed plate and the rotating plate, the integral pressure equalizing plate has its inner peripheral end close to the outer peripheral surface of the rotating body, as described above. Since the pressure equalizing plate and the fixed body are provided with a blocking means for blocking the flow of cooling oil, the annular space in which the fixed plate and the rotary plate are arranged can be connected to other spaces in the brake case. partition wall from
As a result, the cooling oil discharged from the discharge holes provided near the inner peripheries of the fixed plate and the rotating plate passes through the partitioned space between the fixed plate and the rotating plate and absorbs frictional heat from these surfaces. The coolant is absorbed and discharged to the outside of the brake case from cooling oil discharge holes provided near the outer peripheries of the fixed plate and rotating plate. That is, the cooling oil is exclusively
It effectively and smoothly passes through the annular space where the fixed plate and rotating plate are located, where frictional heat is generated, and cools the heat generation source extremely efficiently.

Therefore, in the wet brake according to the present invention, since frictional heat is effectively removed from inside the brake case, thermal deformation of the fixed plate, rotating plate, or pressure equalizing plate is minimized, and the wet brake is integrally constructed. The pressing force from multiple pistons acts on the stationary plate and rotating plate with equal pressure distribution through the pressure equalizing plate. Even if equipped, uneven wear of each component can be effectively prevented.

(Example) Hereinafter, based on an example according to the present invention, a more specific description will be given with reference to the drawings.

FIG. 1 is a partial sectional view in the axial direction taken along line X-X in FIG. 2, which shows the structure of a wet brake according to an embodiment of the present invention, and FIG. FIG. 3 is a detailed view taken along the Y--Y arrow in FIG. 2, showing the arrangement of the return spring mechanism for returning the piston to the retracted position.

In the figure, 1 is a piston, 2 is a steel plate that is a fixed plate, 3 is a disk plate that is a rotating plate, 4 is a piston housing that constitutes a part of the fixed plate, 5 is a rotating shaft that is a rotating body, and 6 is a structure Cooling oil that is physically (physically) integrated and transmits the pressing force of multiple pistons evenly to the fixed plate and rotating plate and bypasses it (cooling oil that does not flow between the fixed plate and rotating plate but flows into the discharge hole) 7 is a piston seal that is a sealing material that seals the sliding surface of the piston 1 and the cylinder portion 4a of the piston housing 4, and 8 is a pressure equalizing plate that prevents the cooling oil from flowing (the same applies hereinafter); The brake case cylindrical portion 9 forming the fixed body is a pressure equalizing plate seal serving as a blocking means for preventing cooling oil from bypassing between the outer periphery of the pressure equalizing plate 6 and the piton housing 4.

As shown in FIG. 2, six pistons 1 are arranged on the piston housing 4 at equal intervals (60 degree intervals) on the same radius centered on the axis O of the rotating shaft 5. In the figure, only the upper four are shown). Each of the pistons 1 is inserted into a recess, that is, a cylinder portion 4a, formed in the piston housing 4 so as to be able to reciprocate in the axial direction, and an annular groove 1a is formed on the outer periphery of the piston 1.
A piston seal 7 is installed in the annular groove 1a to seal the sliding surface between the piston 1 and the cylinder portion 4a. In addition, as shown in FIG. 1, the integrally constructed pressure equalizing plate 6 has a
In addition, in order to obtain a good contact state with each piston, six cylindrical convex portions 6b are provided so as to match the arrangement position of the piston 1 on the piston housing and the size of the contact surface with the piston 1. is formed, and the pressure equalizing plate 6 comes into contact with the six pistons 1 at the end face of the convex portion 6b. Each piston 1 is configured to equally press each circumferential portion of the side surface (plate surface) of the steel plate 2 and disk plate 3 via the pressure equalizing plate 6. Further, as shown in FIG. 1, the pressure equalizing plate 6 is arranged at its inner circumferential end so that the cooling oil is provided exclusively on the rotary shaft 5 and flows between the steel plate 2 and the disk plate 3 through the cooling oil conduit. is arranged close to the outer peripheral surface of the rotating body, and together with the arrangement of the pressure equalizing plate seal 9 described later, the annular space in which the steel plate 2 and disc plate 3 are arranged is isolated from other spaces of the brake. There are bulkheads.

Further, a steel plate 2, a disk plate 3, and a rotating shaft 5 are installed inside the brake case cylindrical portion 8, and the steel plate is locked against rotation on the inner cylinder surface of the brake case cylindrical portion 8. A spline 8a (corresponding to the outer periphery of the steel plate 2 and the spline) is formed on the outer periphery of the rotating shaft 5 to which the disk plate 3 is attached. A spline 5a (corresponding to the spline on the inner circumference) is formed. The rotating shaft 5 is disposed within the brake case cylindrical portion so as to substantially coincide with its axis, and as a result, an annular space is formed between them. In each of the splines 8a and 5a of the annular space, a plurality of annular steel plates 2 and disk plates 3 are arranged alternately in the axial direction, and are reciprocatingly movable in the axial direction. It is inserted to be restrained. Further, a brake case end plate portion having an abutment surface 10a at the left end and a shaft hole 10b for passing the rotating shaft 5 through the center of the cross section is attached to the right end surface portion of the brake case cylindrical portion 8, From the brake case cylinder part 8 and the rotating shaft 5, both plates 2 and 3
This prevents it from leaving to the right (see Figure 1). On the other hand, in FIG. 1, another brake case end plate part 11 corresponding to the brake case end plate part 10 is attached to the left end part of the brake case cylinder part 8 with the brake case cylinder part 8 etc. in between. It is screwed onto the piston housing 4 and the brake case cylindrical portion 8 in a state where it faces the end plate portion 10 . A cylindrical shaft-shaped projection 11a is formed in the center of the brake case end plate 11, and the projection 11a extends to the right in FIG. It supports the rotating shaft 5. Further, as shown in FIGS. 2 and 3, a return spring mechanism 13 is provided at an intermediate portion of the cylinder portion of the piston housing 4 (same position as the piston 1 in FIG. 2) and on approximately the same radius. (Second
(see figure), pressure equalizing plate 6 when no hydraulic oil is applied.
The steel plate 2 is configured to be spaced apart from the steel plate 2 (see FIGS. 1 and 3).

Incidentally, the brake case end plate portion 11 and the piston housing 4 are formed with hydraulic oil supply holes 11c and 4b for supplying pressure oil to the cylinder 4a. Moreover, it is configured to simultaneously supply pressure oil to each of the hydraulic oil supply holes from one hydraulic system. The brake case end plate portion 11 has a cooling oil supply hole 11d that supplies cooling oil to the contact surface between the steel plate 2 and the disc plate 3.
is formed. Further, the brake case cylindrical portion 8 and the brake case end plate portion 10 have a discharge hole 8b and a recess 10 for discharging the cooling oil.
c is formed.

Further, cooling pipes 16a and 16b are formed on the rotating shaft in the axial direction and at right angles thereto for supplying cooling oil from the side of the cooling oil supply hole 11d to the vicinity of the inner periphery of the steel plate 2 and the disk plate 3. ing. Furthermore, between the outer circumference of the pressure equalizing plate 6 and the inner circumference of the protrusion ring 4c of the piston housing 4,
A pressure equalizing plate seal 9 is fitted which prevents cooling oil from passing between them. Note that the blocking means, which is one means for blocking the flow of cooling oil bypassing the area other than between the steel plate 2 and the disk plate 3, is replaced with that shown in FIG.
As shown in FIG. 4, a protrusion ring 4d is provided on the inner circumferential side of each cylinder portion of the piston housing so as to circumscribe the inner circumferential surface 6c of the protrusion of the pressure equalizing plate, and the protrusion ring 4d and the inner circumference of the pressure equalizing plate 6 are provided. A pressure equalizing plate seal 9' may be attached to the pressure equalizing plate side of the surface (sliding surface).
Further, as shown in FIG. 5, a pressure equalizing plate seal 9'', which is freely expandable and retractable in the axial direction, is installed between the end surface 4e of the protruding ring 4c of the piston housing and the stepped portion formed on the piston side of the pressure equalizing plate. You may.

In addition, sealing materials 14 and 15 are installed between the rotating shaft 5 and the brake case end plate 10, and between the rotating shaft 5 and the brake case end plate 11, respectively, and liquid is removed at the contact parts of each member. Sealing material is attached to parts that require tightness. Then, in the space formed by each cylinder part 4a and piston 1,
The configuration is such that pressure oil is supplied from one hydraulic system.

Therefore, in the present wet brake having the above configuration, when the brake is applied, pressure oil is supplied from the hydraulic oil supply holes 11c and 4b into the space formed by each cylinder portion 4a and the piston 1. each piston 1 presses the pressure equalizing plate 6 to the right in FIG. As a result, the steel plate 2 fixed to the fixed body side and the disk plate 3 rotating together with the rotating shaft are sandwiched between the pressing surface 6d of the pressure equalizer 6 and the contact surface 10a of the brake case end plate 10. As a result, the two plates are pressed against each other, friction is generated between them, and the rotating disk plate 3, that is, the rotating shaft 5, is braked by the frictional resistance. At this time, since the pressure equalizing plate 6 has high rigidity, the pressing force of each piston 1 is evenly distributed and acts on each part of the steel plate 2 or the disc plate 3.

Furthermore, when the above-mentioned brake operation is released, the hydraulic oil in the space between the cylinder 4a and the piston 1 returns to normal pressure, and the spring force of the return spring mechanism 13 causes the piston 1 and the pressure equalizing plate 6 to move away from the pressed steel. Separated from plate 2.

When the brake is operated, cooling oil pipes 16a and 16b are provided inside the rotating shaft 5 near the inner periphery of the steel plate 2 and the disk plate 3, and a blocking means ( (See Figures 1, 4, and 5)
is provided in the pressure equalizing plate 6 and between the pressure equalizing plate 6 and the piston housing 4, and the inner circumferential end of the pressure equalizing plate 6 is disposed close to the outer circumferential surface of the rotating shaft 5, so that the cooling oil is exclusively The cooling oil passes through the cooling oil pipes 16a and 16b provided on the rotating shaft 5, passes between the steel plate 2 and the disc plate 3, and flows smoothly to the discharge hole 8a and the recess 10c, so that it flows extremely smoothly and efficiently. cooled down.

In addition, in this embodiment, since pressure oil is simultaneously supplied from one hydraulic system, each piston operates approximately synchronously, and each piston is operated via an integrally constructed highly rigid pressure equalizing plate. Since the steel plate and disk plate are pressed, pressure acts on each part of the pressed surface with an even pressure distribution in a strict sense.

Furthermore, in this embodiment, the required brake capacity is obtained by arranging six small pistons at equal distances according to the brake capacity. Since it is configured to abut against the cylindrical convex portion, it is possible to obtain the desired rigidity without increasing the thickness of the pressure equalizing plate itself, considering the overall brake capacity.

(Effects of the Invention) As described above, although the wet brake having the structure according to the present invention has a plurality of pistons, the cooling efficiency of the stationary plate and the rotary plate is extremely high, and the pressure from each piston is reduced. Since the pressure is applied in an evenly distributed state, the brake can sufficiently withstand severe use, and also exhibits the desired braking performance during use.

In addition, by utilizing the arrangement of the pressure equalizing plate and in conjunction with the other above configurations, it is possible to
Cooling oil is supplied effectively and extremely smoothly during this period, so these fixed plates or rotating plates do not reach abnormally high temperatures and do not seize, significantly reducing their durability (replacement time). This makes maintenance easier, and running costs can be significantly reduced.

Furthermore, due to the above configuration, the temperature of the cooling oil can be maintained at a much lower temperature than that of conventional ones, so deterioration of the cooling oil of wet brakes can be prevented and the replacement period of the cooling oil can be significantly extended. This also makes maintenance easier and contributes to lower running costs.

Therefore, it is possible to provide a wet brake that is extremely useful as a brake for vehicles used at construction sites, open pit coal mines, etc. where detailed maintenance cannot be expected.

[Brief explanation of the drawing]

FIG. 1 is a partial cross-sectional view in the axial direction taken along line X-X in FIG. 2, which shows the structure of the wet brake according to this embodiment, and FIG. A sectional view, and Fig. 3 is Fig. 2 Y showing the arrangement of the return spring of the piston.
4 and 5 are partial sectional views in the axial direction showing other embodiments of the blocking means according to the present invention, and FIG. 6 is an axial partial sectional view showing the structure of a conventional wet brake. FIG. 7 is a partial sectional view in the direction perpendicular to the axis taken along the Z--Z arrow in FIG. 6, showing the shape of the piston of the wet brake. 1... Piston, 2... Steel plate (fixed plate), 3... Disc plate (rotating plate), 4...
... Piston housing, 5 ... Rotating shaft (rotating body),
6... Pressure equalizing plate, 7... Piston seal, 8... Brake case cylinder, 9, 9', 9''... Pressure equalizing plate seal, 16a, 16b... Cooling oil pipe line.

Claims (1)

[Scope of Claims] 1. A fixed body and a rotating body are arranged to form an annular space therebetween, and an annular fixed plate is movable reciprocally in the axial direction of the fixed body and is restrained during rotational movement. The fixed plate and the rotating plate are alternately engaged with the fixed body and the rotating body, respectively, so that the annular rotating plate can freely reciprocate in the axial direction of the rotating body and be restrained during rotation. A plurality of pistons installed in the annular space and reciprocating in the axial direction are disposed on the sides of the fixed plate or the rotating plate, and the protruding movement of the pistons presses the fixed plate and the rotating plate. In this way, the rotation of the rotating body is stopped, and a cooling oil discharge hole is provided near the inner periphery of the fixed plate and the rotating plate, and a cooling oil discharge hole is provided near the outer periphery of the fixed plate and the rotating plate. In a wet brake configured to cool a fixed plate and a rotary plate in the annular space by providing a discharge hole, an integrally constructed equalizer is provided between the plurality of pistons and the adjacent fixed plate or rotary plate. A pressure plate is disposed with its inner circumferential end close to the outer circumferential surface of the rotating body, and a blocking means for blocking the flow of cooling oil is provided between the pressure equalizing plate and the fixed body, and the fixed plate and the rotating plate are The annular space where
A wet type brake characterized by a partition wall using a pressure equalizing plate arranged so that the pressing force from each piston acts on the fixed plate and rotating plate side with an even pressure distribution. 2. A part of the fixed body is a cylindrical body, and the rotating body is a shaft body disposed within the cylindrical body of the fixed body,
The pressure equalizing plate is inserted into a cylindrical body of the fixed body, and the blocking means is installed between an outer circumferential portion of the pressure equalizing plate and a circumferential portion of the cylindrical body or a circumferential portion of a cylindrical portion connected to the cylindrical body. 2. The wet brake according to claim 1, wherein the wet brake is a sheet material made of polyurethane. 3. A part of the fixed body forms a cylindrical body, and the rotary body forms a shaft body disposed within the cylindrical body of the fixed body,
The pressure equalizing plate is inserted into the cylindrical body of the fixed body, and the blocking means is arranged between the pressure equalizing plate and a protruding ring portion extending from a part of the fixed body so as to be in circumferential contact with the inner peripheral surface of the pressure equalizing plate. The wet brake according to claim 1, wherein the wet brake is a sealing material attached to the wet brake.