JP2001065607A - Rotary fluid pressure device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To generate the braking force of different levels and to reduce the size in a rotary fluid pressure actuating device (a geroter motor) having a brake. SOLUTION: This rotary fluid pressure actuating device has an output shaft 39 rotatable with respect to a fluid displacing mechanism and a housing 41. The device has first and second brake disks 51, 53 for braking the output shaft 39. The brake disks 51, 53 are engaged by an actuating piston 59 energized to an engaged state by a coned disk spring 85. The actuating piston 59 partitions a first pressure chamber 73 from a second pressure chamber 75, and the coned disk spring 85 is disposed in the first pressure chamber 73. When both pressure chambers 73 and 75 are exhausted, the actuating piston 59 is energized only by the coned disk spring 85. However, when the first pressure chamber 73 is pressurized, the actuating piston 59 is energized by a substantially larger force, thus resulting in the generation of a larger braking torque.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION The present invention relates to rotary fluid pressure devices, and more particularly to such devices of the type including a fluid displacement mechanism.
More specifically, the present invention relates to an apparatus including a fluid displacement mechanism having a gerotor gear set.

[0002] The present invention may be included in a rotary fluid pressure device used as a pump, but is primarily suited for use in motors, especially low speed, high torque motors, and will be described in connection therewith. Also, the present invention may be utilized in axial piston motors, radial cam lobe motors, and other types of motors, but is particularly suited for use with gerotor motors and will be described in connection therewith.

[0003]

BACKGROUND OF THE INVENTION In many low speed, high torque gerotor motor vehicle applications, it is desirable to provide the motor with a parking brake or a parking lock, such that the parking lock is engaged only after the vehicle is stopped. Intentionally "locked" in certain situations
The term is preferred. In other words, such parking lock devices do not intend for dynamic breaks to be engaged to stop the moving vehicle. However, the term "brake"
It is widely used to include both brakes and locks. It is somewhat desirable to distinguish the term brake from a device that operates in either full engagement or full release. In fact, the device of the present invention provides at least two different engagement states.

For many years, those skilled in the art have attempted to incorporate a brake or locking device into a gerotor motor simply by adding a brake package on the output shaft of the motor. An example of such a device is described in U.S. Pat. No. 3,616,882.
No. 4,981,423. U.S. Patent 3,6
In the apparatus of U.S. Pat. No. 16,882, a brake element is located adjacent the front end of the gerotor and is biased by fluid pressure into frictional engagement therewith. In the device of U.S. Pat. No. 4,981,423, a "spring-biased pressure release" type multi-plate brake assembly is provided, making it difficult to utilize a spring-biased pressure release type brake assembly in a low speed, high torque motor. Minutes are commonly performed.

In the device of US Pat. No. 4,981,423, since the friction disk pack is splined to the output shaft, it is required that the entire output torque of the motor be braked or restrained, so that the disk, spring and actuation / release are required. All pistons need to be enlarged.

[0006] 1 related to a low-speed high-torque gerotor motor
One trend is that it be designed to operate at high pressures, and thus high torque. One particular construction of gerotor motors, particularly adapted to high pressures and torques, is the VIS series motor, which is commercially sold by the assignee of the present invention, and such motors are Nos. 4,741,681 and 5,211,551, both of which are assigned to the assignee of the present invention, the contents of which are incorporated herein by reference.

[0007]

Unfortunately, high motor output torque is transmitted to a friction disk pack that is generally coupled to the output shaft, and as a result, the brake assembly requires a large amount of torque, which is economical. Brake assemblies cannot be applied to many vehicles. In general, brake discs are provided in the class of friction materials, which increase the braking torque substantially adds to the cost of the brake disc.

[0008] A further disadvantage of conventional motor brake assemblies, especially of the spring-biased pressure-releasing type, is that they operate with only one specific level of braking torque. In practice, however, it is desirable for the brake assembly to be able to provide multiple levels of braking torque depending on operating conditions.

Accordingly, it is an object of the present invention to provide a brake assembly applied to a rotary hydraulic device which overcomes the above-mentioned disadvantages of the prior art.

A more specific object of the present invention is to reduce the total number and / or size of brake discs,
Accordingly, it is an object of the present invention to provide a brake assembly for use in a low-speed, high-torque motor having a brake assembly designed to be smaller and cheaper to manufacture.

It is another object of the present invention to provide a brake assembly that can achieve the above-mentioned objects and that can obtain at least two engagement states that generate different levels of braking torque. is there.

[0012]

SUMMARY OF THE INVENTION The above and other objects of the present invention are directed to a rotary fluid pressure of a type including a housing means, a rotary fluid displacement mechanism, and an output member for performing a motion corresponding to the output motion of the device. Achieved by the provision of equipment. No.
1 The brake disc (also referred to as `` stator '') is fixed to the housing means, the second brake disc is fixed so as to rotate with the output member, and the first and second brake discs are Thus, the output member is disposed in the operatively engaged state to brake the rotation of the output member with respect to the housing means. The working piston is movable between an engaged position and a released position, and a spring member biases the working piston toward the engaged position.

[0013] The improved rotary fluid pressure device is characterized in that the working piston cooperates with the housing means to form a first pressure chamber and a second pressure chamber located on both axial sides of the working piston. I do. The spring biasing means is disposed in the first pressure chamber. A first source of pressurized fluid is fluidly connected to the first pressure chamber and is selectively actuated, such that the spring biasing means attempts to move the working piston toward the engaged position, as well as to the working piston. An urging force can be applied. A second source of pressurized fluid may be fluidly connected to the second pressure chamber and selectively actuated to exert a biasing force on the actuation piston to move toward the release position.

[0014]

DETAILED DESCRIPTION OF THE INVENTION Referring to the drawings, which are not intended to limit the invention, FIG. 1 is an axial sectional view of a low-speed, high-torque gerotor motor of the type in which the brake assembly of the invention is particularly advantageously provided. . The motor shown in FIG. 1 can be of the general construction described and described in the aforementioned US Pat. No. 5,211,551.

The motor shown in FIG.
It comprises a modular motor assembly indicated at 1 and a front bearing package indicated generally at 13. The brake assembly of the present invention is located in the front bearing package 13.

Since the modular motor 11 is included in the above-mentioned reference patent and will be described only briefly here, the end cap 15, the fixed valve plate 17, and a gerotor gear set (rotational motor) generally indicated by reference numeral 19 are provided. A fluid displacement mechanism) and a flange member 21. Elements 15 to 21 are held in a sealing connection by a plurality of bolts 23, each of which includes a head 27 that engages a front surface 29 of the flange member 21.

The gerotor gear set 19 can be of a type known in the art, and includes an internally toothed ring member.
The ring member 31 includes a plurality of substantially semi-cylindrical openings, and a cylindrical roller member 33 provided as an internal tooth of the ring member 31 is disposed in each of the openings. As is known to those skilled in the art, an externally toothed star member 35 is eccentrically disposed within the ring member 31, and the star member 35 generally comprises internal teeth 33.
The number of outer teeth is one less than the number of teeth, so that the star member 35 can make a trajectory and a rotational movement with respect to the ring member 31. As known to those skilled in the art,
The orbit and rotation of the star member 35 in the ring member 31 are
Here, a plurality of expansion and contraction fluid volume chambers (not shown) are formed.

Various fluid ports and passages permit pressurized fluid to communicate with the expanded volume chamber of the gerotor gear set 19 and to retract, as not described in detail herein, as contained in the aforementioned US Pat. No. 5,211,551. The low-pressure fluid discharged from the volume chamber is conducted. It is sufficient that the orbit and the rotational movement of the star member 35 are transmitted by the drive shaft 37 (output member) as pure rotational movement of the output shaft 39 (output member) that forms a part of the front bearing package 13. Will be understood.

The front bearing package 13 in this embodiment includes a bearing housing assembly 41 consisting of two separate housing members joined together by suitable means not shown here. The bearing housing assembly 41 is provided with a pair of tapered roller bearing sets 43 and 45 that allow the output shaft 39 to pass therethrough and indicate rotation.

Referring principally to FIG. 2, reference numeral 47 is generally used.
A brake assembly of the present invention is described. The bearing housing 41 forms a disc chamber 49, in which a plurality of outer splined friction discs 51 (first brake discs) spline-coupled to the bearing housing 41 and the output shaft 39 are formed. A plurality of inner splined friction discs 53 (second brake discs) are spline-coupled to the pair of outer splines 55. Those skilled in the art, upon reading and understanding the present specification, will understand that the specific structural details of the friction disks 51 and 53 are not essential features of the present invention. The term "brake disc" as used in the description and in the claims, refers to the output shaft 39 by frictional engagement.
Will be understood to mean and include any member that generates a braking torque on a fixed portion of the motor, for example, the bearing housing assembly 41.

As is known to those skilled in the art of gerotor motors, the motor is typically a case drain region.
In this embodiment, the case drain region includes a substantially cylindrical space 57 surrounding the main drive shaft 37.
(See FIG. 1). The leakage fluid flowing into the case drain region 57 from the gerotor gear set 19 and the fluid in the case drain region 57 provide various lubrication functions such as lubrication of the spline connection of the shaft 37. Preferably, the disc chamber 49 is
In open fluid communication with the case drain area 57, these disk chambers 49 and case drain area 57 are generally maintained at a relatively low fluid pressure, e.g., in the range of about 0-200 psi (0-1379 kPa). .

Referring mainly to FIG. 2, the bearing housing 41 includes a radially outer seal member 61 (first seal member) and a radially inner seal member 63 (second seal member). An annular working piston 59 is arranged. The outer seal member 61 is in sealing engagement with the generally cylindrical inner surface 62 of the bearing housing 41, while the inner seal member 63 is formed on the cylindrical axial extension 65 of the bearing housing 41. It is in sealing engagement with the outer surface 64.

A partition member 67 is disposed adjacent to the working piston 59. The main function of the partition member 67 is to seal the low-pressure disk chamber 49 from the relatively high-pressure chamber in which the working piston 59 is disposed. It is to isolate. Partition member 67
Has an outer diameter and an associated sealing member 68, which sealingly engages the inner surface of the bearing housing 41. Further, the partition wall member 67 has an inner diameter 69 forming an opening.
Represented by 69. A sealing member 70 is provided in connection with the inner diameter 69, the sealing member 70 sealingly engaging the cylindrical outer surface of the substantially cylindrical axial extension engagement portion 71. Preferably, the engagement portion 71 is formed integrally with the working piston 59, and when the working piston 59 is in the release position shown in FIG.
The engagement portion 71 is dimensioned such that it can contact adjacent the friction disc 51 but does not substantially exert an urging force on the pack of friction discs 51 and 53.

The working piston 59 forms a first pressure chamber 73 and a second pressure chamber 75 in cooperation with the bearing housing 41 and the adjacent partition member 67. The bearing housing 41 has a fluid port 77
And a fluid port 79 is formed. The first pressure chamber 73 is connected by a fluid port 77 to a first pressurized fluid source 81, while the second pressure chamber 75 is connected by a fluid port 79 to a second pressurized fluid source 83. You. The pressurized fluid sources 81 and 83 are shown schematically here as consisting of fixed displacement pumps and simple solenoid valves, respectively. However, one of ordinary skill in the art will appreciate from the following description of the operation of the brake assembly 47 that, in general, that there is an appropriate connection between these valves and a vehicle microprocessor (not shown here) or other form of control logic. It will be appreciated that a class of intercommunication is provided. It is believed that the necessary valve construction and control will be well understood by those skilled in the art. For example, each valve shown in FIG. 2 includes a position where flow is "blocked", but in fact, when not energized, these valves are biased by springs to move their respective ports and chambers. Urged to the position to discharge. Also, the valves shown in FIG. 2 each have only two separate positions, but these valves are of a “stepless variable” type that adjusts the fluid pressure of each chamber 73 or 75. It will be clear to those skilled in the art that the brake can be gradually activated or released.

As mentioned in the Prior Art, the brake assembly 47 of the present invention is generally of the "spring biased pressure relief" type. Therefore, in the first pressure chamber 73, 1
A set of disc springs 85 (ie, springs) (spring biasing means) are disposed to bias the working piston from the release position shown in FIG. 2 to the engagement position. As will be appreciated by those having skill in the brake and clutch arts, the engaged and disengaged positions of a set of friction discs are often very slight. For example, in the release position of FIG.
And 53 are actually in contact with each other, but no sufficient actuating or biasing force is applied to the disk, and contact of the disk produces substantially no braking torque. The working piston 59 discharges the pressurized fluid from the first pressure chamber 73 and conducts the pressurized fluid to the second pressure chamber 75, thereby generating a sufficient urging force on the working piston 59, 2 is maintained in the release position of FIG. 2 by biasing the left side in FIG. 2 until it engages a shoulder surface 87 formed in the bearing housing 41.

To generate a "normal" braking torque, the first
And both the second pressure chambers 73 and 75 are discharged, so that only the biasing force of the disc spring 85 acts on the working piston 59,
As a result, the piston 59 is slightly moved rightward in FIG. 2, and the engaging portion 71 applies an engaging load to the friction disks 51 and 53. As a result of the sufficient frictional engagement of the discs 51 and 53,
When a predetermined normal level of braking torque is generated, the output shaft 39
Acted upon.

If it is necessary to generate a substantially greater level of braking torque, the pressurized fluid is conducted to the first pressure chamber 73 while simultaneously discharging the second pressure chamber 75 and the working piston 59 85 and the pressurized fluid in the first pressure chamber 73. As a result, the engaging portion 71
This causes a substantially greater engagement force to be applied to the friction disks 51 and 53, thereby increasing the braking torque capacity of the brake assembly 47.

The selection of the dimensions of the disc spring 85 and various other components of the brake assembly to produce the desired level of braking torque is considered to be within the ability of those skilled in the art. In general, a large level of braking torque will correspond approximately to the maximum continuous rated torque of the motor, but normal braking torque is only an example,
The torque required to prevent rolling down a 25 degree incline can be provided.

Referring mainly to FIG. 3, there is shown another embodiment of the present invention, wherein the same or similar elements as in the above main embodiment are given the same reference numerals, and are new or substantially different. Modified elements are numbered over 90. Therefore,
In the embodiment of FIG. 3, a working piston 91 is provided, and the working piston 91 is the piston 59 of the main embodiment.
Except that when the brake is activated, it moves backward (to the left in FIG. 3) and when the brake is released, it moves forward (to the right in FIG. 3). Further, in the main embodiment, the partition member 67 is provided, but in the embodiment of FIG. 3, the flange member 21 preferably includes an integral partition portion 93. The partition wall 93 is
The second pressure chamber 75 functions to support the seal members 68 and 70 and to separate the second pressure chamber 75 from the chamber that houses the friction disks 51 and 53 and opens to the case drain region 57 as described above.

In operation, the embodiment of FIG. 3 is substantially similar to the main embodiment, except that the direction of movement of the working piston 91 is reversed. Brake discs 51 and 53
In order to release the pressure, the pressure chamber 73 is discharged, and the pressure chamber 75 receives a high pressure. As a result, the piston 91 moves rightward in FIG. For normal braking, both pressure chambers 73 and 75 are evacuated and only disc spring 85 exerts a force on piston 91. To generate a larger braking torque, the pressure chamber 73 is pressurized, the pressure chamber 75 is discharged, and the disc spring 85 and the pressure chamber
The piston 91 is urged leftward in FIG. 3 by both of the pressures in 73, and the engagement state is established.

In connection with the development of the present invention, it has been found that the embodiment of FIG. 3 allows the entire front bearing package and brake assembly to be substantially smaller and more compact than the main embodiment. I have. Furthermore, the embodiment of FIG. 3 requires less parts, which has the potential to be manufactured at least somewhat cheaper.

While the invention has been described in detail in the foregoing specification, various alterations and modifications of the invention will become apparent to those skilled in the art upon reading and understanding the specification. All such changes and modifications are intended to be included in the present invention without departing from the scope of the claims.

[Brief description of the drawings]

FIG. 1 is an axial longitudinal sectional view of a gerotor motor including a brake assembly manufactured in accordance with the present invention.

FIG. 2 is an enlarged longitudinal sectional view of the brake assembly of the device of FIG. 1 including a control device.

FIG. 3 is an enlarged longitudinal sectional view of an essential part of a gerotor motor according to another embodiment of the present invention.

[Explanation of symbols]

 15 End cap 17 Fixed valve plate 19 Gerotor gear set 21 Flange member 37 Drive shaft 39 Output shaft 41 Bearing housing assembly 49 Disk chamber 59 Working piston 61,63 Seal member 73 First pressure chamber 75 Second pressure chamber 81 First pressurization Fluid source 83 Second pressurized fluid source 85 Disc spring

Continuation of front page (71) Applicant 390033020 Eaton Center, Cleveland and Ohio 44114, U.S.A. S. A. (72) Inventor Michael Jerome Gust Minnesota 55317, Chanhassen, Saddlebrook Curve 970, United States

Claims (9)

[Claims] The first brake includes a housing means (15, 21, 41), a rotary fluid displacement mechanism (19), and an output member (37, 39) performing a movement corresponding to an output movement of the apparatus. Disc (51)
Are fixed to the housing means (15, 21, 41), and
(2) A brake disc (53) is fixed so as to rotate with the output member (37, 39), and the first and second brake discs (5
(53) is engaged by an operating piston (59; 91),
The working piston is arranged to brake rotation of the output member (37, 39) with respect to the housing means, and the operating piston is movable between an engagement position and a release position, and the spring biasing means (8
5) is a rotary fluid pressure device of a type for urging the working piston (59; 91) toward the engagement position, (a) the working piston (59; 91) is provided with the housing means (4
(1) forming a first pressure chamber (73) and a second pressure chamber (75) disposed on both axial sides of the working piston (59; 91) in cooperation with (1), and (b) the spring biasing means. (85) is disposed in the first pressure chamber (73), (c) a first pressurized fluid source (77, 81) is fluidly connected to the first pressure chamber (73), and is selectively provided. Actuating, in addition to the spring biasing means (85) trying to move the working piston (59; 91) toward the engagement position, the working piston (59; 91)
(D) a second pressurized fluid source (79, 83) is fluidly connected to the second pressure chamber (75) and selectively operates to operate the operating piston (59; 9).
A rotary fluid pressure device, wherein a biasing force is applied to 1) to move the working piston (59; 91) toward the release position. 2. The working piston (59; 91) includes sealing means (61, 63) sealingly engaging with the housing means (41), whereby the first pressure chamber (73) and the second 2 pressure chamber
2. The rotary fluid pressure device according to claim 1, wherein (75) and (75) are isolated from each other. 3. The operating piston (59; 91) includes an annular member including a cylindrical outer peripheral surface and a cylindrical inner peripheral surface, and the sealing means includes a first seal member (61) engaged with the outer peripheral surface. 3. The rotary fluid pressure device according to claim 2, further comprising a second seal member 63 engaged with the inner peripheral surface. 4. The housing means (15, 21, 41) forms a disk chamber (49), and the first and second brake disks (51, 53) are disposed in the disk chamber (49). Wherein the rotary fluid pressure device forms a case drain region (57), and the disc chamber (49) is in open fluid communication with the case drain region (57). A rotary fluid pressure device as described. 5. The partition member (15, 21, 41), which is arranged so as to partition the disk chamber (49) and the second pressure chamber (75) to form an opening (69). 67; 93),
The working piston (59; 91) includes an engaging portion (71) extending in the axial direction through the opening (69), and the working piston (59; 91)
5. The rotary fluid pressure device according to claim 4, wherein when the lever (91) is in the engaging position, the rotary fluid pressure device operates to engage one of the first and second brake disks (51, 53). 6. The partition member (67; 93) includes a cylindrical outer peripheral surface sealingly engaging an adjacent surface of the housing means (41) and a cylindrical inner peripheral surface forming the opening (69). A substantially annular member, wherein the cylindrical inner peripheral surface is sealingly engaged with an engagement portion (71) of the working piston (59; 91), and
6. The rotary fluid pressure device according to claim 5, wherein the (71) moves in the axial direction with respect to the partition member (67; 93). 7. The housing means comprises a flange member 21.
The partition member (93) is formed integrally with the flange member (21), the flange portion (21) and the partition member
The rotary fluid pressure device according to claim 6, wherein the (93) cooperates with the first brake disc (51) to engage with the first brake disc (51). 8. The fluid displacement mechanism includes a gerotor gear set (19), the rotary fluid pressure device includes an output shaft (39), and the output member includes the output shaft (39). 2. The rotary fluid pressure device according to claim 1, wherein: 9. The gerotor gear set (19) comprises an internally toothed ring member (31), and a star member (e.g., externally toothed member) which is eccentrically arranged in the internally toothed ring member (31) and moves relative to each other and rotates.
The rotary fluid pressure device includes a drive shaft (37) operable to transmit the orbit and the rotational motion to the output shaft (39). Rotary fluid pressure device.