CN113847431A - Sealing device and piston assembly - Google Patents

Sealing device and piston assembly Download PDF

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Publication number
CN113847431A
CN113847431A CN202010595064.6A CN202010595064A CN113847431A CN 113847431 A CN113847431 A CN 113847431A CN 202010595064 A CN202010595064 A CN 202010595064A CN 113847431 A CN113847431 A CN 113847431A
Authority
CN
China
Prior art keywords
sealing
piston
skeleton
piston rod
sealing device
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Pending
Application number
CN202010595064.6A
Other languages
Chinese (zh)
Inventor
刘鑫
张岳林
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schaeffler Holding China Co Ltd
Original Assignee
Schaeffler Technologies AG and Co KG
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Schaeffler Technologies AG and Co KG filed Critical Schaeffler Technologies AG and Co KG
Priority to CN202010595064.6A priority Critical patent/CN113847431A/en
Publication of CN113847431A publication Critical patent/CN113847431A/en
Pending legal-status Critical Current

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Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
    • F16J15/3204—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip
    • F16J15/3208—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip provided with tension elements, e.g. elastic rings
    • F16J15/3212—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip provided with tension elements, e.g. elastic rings with metal springs
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D65/00—Parts or details
    • F16D65/14—Actuating mechanisms for brakes; Means for initiating operation at a predetermined position
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
    • F16J15/3204—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip
    • F16J15/3216—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip supported in a direction parallel to the surfaces
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
    • F16J15/3204—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip
    • F16J15/3232—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings with at least one lip having two or more lips
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16J—PISTONS; CYLINDERS; SEALINGS
    • F16J15/00—Sealings
    • F16J15/16—Sealings between relatively-moving surfaces
    • F16J15/32—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings
    • F16J15/3248—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings provided with casings or supports
    • F16J15/3252—Sealings between relatively-moving surfaces with elastic sealings, e.g. O-rings provided with casings or supports with rigid casings or supports
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2121/00—Type of actuator operation force
    • F16D2121/02—Fluid pressure
    • F16D2121/04—Fluid pressure acting on a piston-type actuator, e.g. for liquid pressure
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2125/00—Components of actuators
    • F16D2125/02—Fluid-pressure mechanisms
    • F16D2125/06—Pistons
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F16—ENGINEERING ELEMENTS AND UNITS; GENERAL MEASURES FOR PRODUCING AND MAINTAINING EFFECTIVE FUNCTIONING OF MACHINES OR INSTALLATIONS; THERMAL INSULATION IN GENERAL
    • F16D—COUPLINGS FOR TRANSMITTING ROTATION; CLUTCHES; BRAKES
    • F16D2125/00—Components of actuators
    • F16D2125/02—Fluid-pressure mechanisms
    • F16D2125/08—Seals, e.g. piston seals

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  • Engineering & Computer Science (AREA)
  • General Engineering & Computer Science (AREA)
  • Mechanical Engineering (AREA)
  • Sealing With Elastic Sealing Lips (AREA)
  • Sealing Devices (AREA)

Abstract

The invention relates to a sealing device and a piston assembly. The sealing device is used for dynamically sealing between the piston rod and the piston shell and comprises an annular elastic sealing body and an annular framework, wherein the framework and the elastic sealing body are coaxially fixed together, and the framework is a corrugated ring with elasticity. The sealing device and the piston assembly have reliable sealing performance.

Description

Sealing device and piston assembly
Technical Field
The invention relates to the technical field of sealing. In particular, the present invention relates to a sealing device for dynamic sealing and a piston assembly comprising such a sealing device.
Background
In parking brake systems for motor vehicle gearboxes, a piston mechanism is usually installed. The piston mechanism comprises a cylindrical piston shell and a cylindrical piston rod, wherein the piston rod is installed in an inner cavity of the piston shell and can slide along the axial direction of the inner cavity under the driving of hydraulic fluid, so that the parking brake mechanism is pushed.
In order to prevent the hydraulic fluid in the internal cavity from leaking from the gap between the piston rod and the piston housing, a sealing device needs to be installed between the piston rod and the piston housing. For example, CN 104470776B discloses a master cylinder for a pressure piston of a motor vehicle brake system, which has a sealing configuration typical in the prior art. Such a seal device is formed of an integrally formed annular elastic body including a main body portion and a plurality of sheet-like seal lips extending from the main body portion. In the assembled state, such a sealing device is mounted in a ring groove on the outside of the piston rod or on the inside of the piston housing.
Unlike the sealing device applied to the bearing, such a sealing device applied to the piston assembly needs to be installed at the axial middle portion of the cylindrical piston rod, not at the axial end portion. Therefore, during installation, the sealing device needs to be expanded in radius by elastic deformation so as to sleeve the sealing device on the piston rod. This means that a rigid skeleton similar to the bearing seal cannot be provided in the piston seal, otherwise the mounting would not be completed. However, in parking brake systems, for example, the annular grooves on the piston rod or piston housing are usually only about 4.5mm wide and 2.7mm high, for example, because of the limited space, which results in correspondingly very small dimensions of the sealing device. Therefore, the elastic sealing body of the sealing device has insufficient structural strength and stability, and is difficult to withstand a large operating pressure. When subjected to the hydraulic pressure generated by the hydraulic fluid, the sealing lip of the sealing device risks failure due to excessive deformation.
Disclosure of Invention
Therefore, the technical problem to be solved by the present invention is to provide a sealing device and a piston assembly with reliable sealing performance.
The above-mentioned object is achieved by a sealing arrangement according to the invention for dynamically sealing between a piston rod and a piston housing. The sealing device comprises an annular elastic sealing body and an annular framework, wherein the framework and the elastic sealing body are coaxially fixed together, and the framework is a wave-shaped ring with elasticity. The elastic sealing body is generally made of a relatively soft material such as rubber, and is small in size, and therefore insufficient in strength and stability. The framework of the sealing device formed by the wave-shaped ring (such as a wave-shaped spring) can be used as a supporting structure of the elastic sealing body, and the elastic sealing body is prevented from being excessively deformed and losing efficacy when the elastic sealing body bears the action of liquid pressure or sliding load in the piston assembly, so that the sealing reliability of the sealing device is improved; meanwhile, when the sealing device is installed on the piston assembly, the framework in the form of the elastic wave-shaped ring can deform along with the elastic sealing body under the action of external force, so that the radius of the framework and the radius of the whole sealing device are expanded, and the sealing device can be conveniently installed between the piston rod and the piston shell.
According to a preferred embodiment of the invention, the armature may have a greater stiffness than the elastomeric seal body, thereby providing stable support for the elastomeric seal body. Preferably, such a skeleton may be made of a metal material. For example, various wave springs of metal material are common elastomeric components, are low cost to manufacture, and are of high material strength, being much stiffer than the elastomeric seal, and thus sufficient to provide support for the elastomeric seal.
According to another preferred embodiment of the present invention, the elastic sealing body may have a main body portion and a sealing lip extending from the main body portion, and the skeleton may be fixedly connected to the main body portion, so that the skeleton may not affect the sealing lip to contact the piston rod or the piston housing to form a contact sealing surface while providing support for the elastic sealing body.
According to a further preferred embodiment of the invention, the skeleton may be at least partially embedded within the body portion, thereby ensuring that the skeleton and the body portion are stably connected together. Further preferably, the sealing lip extends from an axial first side of the main body portion, and the skeleton may be completely covered by the main body portion at least at a side portion facing the axial first side. For processing reasons, it is generally necessary to first place the frame in a mold and then inject a liquid rubber or the like into the mold to join the frame and the elastic sealing body together. Therefore, it is difficult to completely cover the portion of the skeleton that contacts the bottom of the mold with the elastic sealing body. Such a portion exposed by contact with the mold is located on the side of the main body portion away from the seal lip, thereby facilitating the injection molding process.
The above object is also achieved by a piston assembly according to the present invention, comprising a piston rod and a piston housing, the piston rod being axially slidably mounted radially inside the piston housing, wherein the piston assembly further comprises a sealing means having the above-mentioned features, the sealing means being mounted radially between the piston rod and the piston housing, thereby preventing hydraulic fluid in an inner cavity of the piston assembly from leaking through a gap between the piston rod and the piston housing. Preferably, the piston assembly may have an annular groove formed on a radially outer side of the piston rod or a radially inner side of the piston housing, the sealing means being mounted in the annular groove.
Drawings
The invention is further described below with reference to the accompanying drawings. Identical reference numbers in the figures denote functionally identical elements. Wherein:
FIG. 1 shows a cross-sectional view of a sealing device according to an embodiment of the invention as installed in a piston assembly; and
fig. 2 shows a perspective view of the skeleton of the sealing device in fig. 1.
Detailed Description
Embodiments of a sealing device and a piston assembly according to the present invention will be described below with reference to the accompanying drawings. The following detailed description and drawings are included to illustrate the principles of the invention, which is not to be limited to the preferred embodiments described, but is to be defined by the appended claims.
In accordance with an embodiment of the present invention, a seal for dynamically sealing a piston assembly is provided. Fig. 1 to 2 show a sealing device according to an embodiment of the present invention.
Figure 1 shows a cross-sectional view of the sealing device when installed in a piston assembly. The piston assembly comprises a cylindrical piston housing 10 and a cylindrical piston rod 20, the piston rod 20 being received in a form-fitting manner in a hollow interior of the piston housing 10 and being slidable in the axial direction along an inner surface of the piston housing 10. When the piston rod 20 slides axially in the piston housing 10, the outer surface of the piston rod 20 can abut the inner surface of the piston housing 10 with only a small radial clearance therebetween so as to allow axial relative movement therebetween. The sealing means is formed in an overall annular shape, and is coaxially installed between the piston housing 10 and the piston rod 20 in a radial direction.
Fig. 1 shows a cross section of the piston assembly only at the portion where the sealing device is mounted. As shown in fig. 1, a ring groove 21 recessed radially inward is formed on the radially outer side of the piston rod 20, and the seal device is fitted in the ring groove 21. In other embodiments, the ring grooves may be formed on the radially inner side of the piston housing 10 instead.
The seal assembly includes an annular elastomeric seal body 30 and an annular armature 40 coaxially secured together. The elastic sealing body 30 is made of an elastic material such as rubber, and includes a main body portion 31 and two seal lips 32. As shown in fig. 1, the main body portion 31 is substantially rectangular in shape as viewed in a cross section passing through the center axis of the seal device, and has axially opposite first and second sides. The second axial side may directly abut against a side wall of the ring groove 21, and the two sheet-shaped sealing lips 32 extend from the first axial side of the main body 31 in the direction of the other side wall of the ring groove 21. The seal lip 32 located radially outward is inclined toward the radially outward side with respect to the axial direction so that the end thereof can abut against the inner surface of the piston housing 10; the seal lip 32 located on the radially inner side is inclined toward the radially inner side with respect to the axial direction so that an end thereof can abut against the bottom of the ring groove 21.
Fig. 2 shows a perspective view of the skeleton 40. As shown in fig. 2, the frame 40 is a wave ring having elasticity, such as various types of wave springs commonly used in the industry. The annular metal sheets constituting the skeleton 40 alternately undulate toward both axial sides while extending in the circumferential direction, thereby forming a wavy structure. This shape provides the material of the armature 40 with the ability to elastically expand or contract in the circumferential direction.
As shown in fig. 1, the frame 40 is fixed to the main body 31 of the elastic sealing body 30, and is particularly embedded entirely or partially in the main body 31, thereby being stably connected to the elastic sealing body 30. In order to insert the bobbin 40 into the elastic sealing body 30 during processing, it is generally necessary to first place the bobbin 40 in a mold, and then inject a liquid rubber material and solidify it. Therefore, the contacting portion of the skeleton 40 in the form of the wavy ring with the bottom of the mold tends to be difficult to completely cover with the elastic sealing body 30. For this reason, it is preferable that the skeleton 40 is entirely covered by the main body portion 31 at least at a side portion facing an axial first side of the main body portion 31, and a side portion facing an axial second side may be used for contact with the mold, so that there may be a portion exposed outside the main body portion 31.
As shown in the left drawing in fig. 2, when the material of the bobbin 40 elastically contracts in the circumferential direction, the bobbin 40 as a whole contracts radially inward, thereby reducing its radius (including the inner diameter and the outer diameter); in contrast, as shown in the right drawing in fig. 2, when the material of the skeleton 40 elastically expands in the circumferential direction, the skeleton 40 as a whole expands radially outward, thereby enlarging its radius (including the inner diameter and the outer diameter). Therefore, when the sealing device is installed in the piston assembly, the bobbin 40 may be elastically deformed along with the elastic sealing body 30, thereby being conveniently installed between the piston housing 10 and the piston rod 20.
In this embodiment, the frame 40 is made of a metal material, which is elastically deformed by the special shape of the wave-shaped ring, but has a rigidity that is much higher than that of the elastic sealing body 30, and can provide support for the elastic sealing body 30, thereby improving the sealing reliability of the sealing device as a whole. In addition, due to the spatial constraints of the annular groove 21, the carcass 40 in a sealing device installed in place is difficult to undergo significant radial expansion or contraction, and therefore, no significant radial or axial deformation occurs. This makes the skeleton 40 in the form of a wave ring sufficient to increase the strength of the entire sealing device. It should be noted, however, that although the skeleton 40 is made of metal in the present embodiment, it may be a wave-shaped ring made of other material such as plastic, as long as it has a greater rigidity than the elastic sealing body 30 and can be elastically deformed at the time of installation. Further, the specific configuration of the elastomeric seal body 30, and in particular the shape and number of the seal lips 32, is merely exemplary and may be varied and modified depending upon the application, e.g., the elastomeric seal body 30 may have a greater or lesser number of seal lips 32.
According to another embodiment of the present invention, there is also provided a piston assembly comprising a sealing arrangement according to the previous embodiment. The piston assembly is particularly suitable for use in a parking brake system of a motor vehicle and may be used in other applications requiring a piston mechanism for actuation.
Although possible embodiments have been described by way of example in the above description, it should be understood that numerous embodiment variations exist, still by way of combination of all technical features and embodiments that are known and that are obvious to a person skilled in the art. It should also be appreciated that the exemplary embodiment or exemplary embodiments are only examples, and are not intended to limit the scope, applicability, or configuration of the invention in any way. From the foregoing description, one of ordinary skill in the art will more particularly provide a technical guide to convert at least one exemplary embodiment, wherein various changes may be made, particularly in matters of function and structure of the components described, without departing from the scope of the following claims.
List of reference numerals
10 piston housing
20 piston rod
21 ring groove
30 elastic sealing body
31 main body part
32 sealing lip
40 framework

Claims (8)

1. A sealing arrangement for dynamic sealing between a piston rod (20) and a piston housing (10), comprising an annular elastic sealing body (30),
it is characterized in that the preparation method is characterized in that,
the sealing device further comprises an annular skeleton (40), the skeleton (40) and the elastic sealing body (30) are coaxially fixed together, and the skeleton (40) is a waveform ring with elasticity.
2. The sealing arrangement according to claim 1, characterized in that the skeleton (40) has a greater rigidity than the elastomeric sealing body (30).
3. Sealing device according to claim 2, characterized in that the skeleton (40) is made of a metallic material.
4. A sealing arrangement according to any one of claims 1 to 3, characterised in that the resilient sealing body (30) has a main body portion (31) and a sealing lip (32) extending from the main body portion (31), the skeleton (40) being fixedly connected to the main body portion (31).
5. A sealing arrangement according to claim 4, characterized in that the skeleton (40) is at least partially embedded within the body portion (31).
6. A sealing arrangement according to claim 5, characterized in that the sealing lip (32) extends from an axial first side of the body portion (31), the skeleton (40) being completely enveloped by the body portion (31) at least at a side facing the axial first side.
7. A piston assembly comprising a piston rod (20) and a piston housing (10), the piston rod (20) being axially slidably mounted radially inside the piston housing (10),
it is characterized in that the preparation method is characterized in that,
the piston assembly further comprises a sealing arrangement according to any one of claims 1 to 6, which is mounted radially between the piston rod (20) and the piston housing (10).
8. Piston assembly according to claim 7, characterized in that it has an annular groove (21) formed on the radially outer side of the piston rod (20) or on the radially inner side of the piston housing (10), the sealing means being mounted in the annular groove (21).
CN202010595064.6A 2020-06-28 2020-06-28 Sealing device and piston assembly Pending CN113847431A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202010595064.6A CN113847431A (en) 2020-06-28 2020-06-28 Sealing device and piston assembly

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202010595064.6A CN113847431A (en) 2020-06-28 2020-06-28 Sealing device and piston assembly

Publications (1)

Publication Number Publication Date
CN113847431A true CN113847431A (en) 2021-12-28

Family

ID=78972267

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202010595064.6A Pending CN113847431A (en) 2020-06-28 2020-06-28 Sealing device and piston assembly

Country Status (1)

Country Link
CN (1) CN113847431A (en)

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Effective date of registration: 20240320

Address after: 1st Floor, Building 2, No. 1 Antuo Road, Anting Town, Jiading District, Shanghai

Applicant after: SCHAEFFLER HOLDING(CHINA) Co.,Ltd.

Country or region after: China

Address before: German Herzogenaurach

Applicant before: SCHAEFFLER TECHNOLOGIES AG & CO.KG

Country or region before: Germany