CN100540891C - Pressure generation device - Google Patents

Abstract

The invention discloses a kind of pressure generation device (AP1), comprising: axle hub (20), it has via bearing (12 and 13) and rotatably is supported on rotary shaft (21A) in the non-rotatable cylinder supporting portion (11); Piston (30), it is with can integrally rotated mode and inhale the mode of action and be attached to rotary shaft (21A) can carry out pump, and collaborative with rotary shaft (21A), forms pump chamber (Ro) betwixt; Cam member (41) and cam follower (42), it is used for axle hub (20) is inhaled action with respect to the pump that rotatablely moving of cylinder supporting portion (11) is converted into piston (30); Suction path (21d), it is formed in the axle hub (20), and makes air can be introduced in the pump chamber (Ro); And vent pathway (21e), it is formed in the axle hub (20), and makes air to discharge from described pump chamber (Ro).

Description

pressure generating device

technical field

The present invention relates to a pressure generating device, such as a pressure (air pressure) generating device capable of supplying pressurized air to a tire air cavity of a wheel comprising a web-type wheel held on an axle hub of a vehicle and a tire Rotatable with the axle hub, the tire is mounted on a spoked wheel whereby a tire air cavity is formed therebetween.

Background technique

Such a pressure generating device is disclosed in, for example, Japanese Patent Application Laid-Open (kokai) No. 11-139118. In the pressure generating device (air pressure regulator for tires) described in this publication, the pump unit is arranged on a member that rotates together with the axle for rotationally driving the axle hub of the vehicle; the pump unit is arranged along the reciprocating movement in the axial direction; one end of the piston of the pump unit abuts against the ramp of the cam member, which is non-rotatable relative to the wheel. The piston of the pump unit reciprocates in association with the rotation of the wheel.

According to the structure of the pressure generating device described in the above publication, the axis of the piston of the pump unit is radially deviated from the axis of the axle by a predetermined distance. Therefore, the radius of the slope of the cam member that contacts the end of the piston must be equal to or greater than the radial offset of the axis of the piston, thereby making it difficult to downsize the pressure generating device and making vehicle mountability poor. Furthermore, in order to obtain good wheel balance (rotational balance), it is necessary to provide a counterweight (balance weight) for offsetting the weight of the pump unit. This also makes it difficult to reduce the size of the pressure generating device.

Contents of the invention

The present invention has been achieved to solve the above-mentioned problems. The pressure generating device of the present invention is characterized by comprising: a rotating member having a rotating shaft portion rotatably supported in a non-rotatable supporting member via a bearing; is attached to the rotating shaft portion of the rotating member in a suction manner, and cooperates with the rotating shaft portion to form a pump chamber therebetween; a motion conversion mechanism for moving the rotating member relative to the the rotational movement of the support member is converted into the pumping action of the pumping member; a suction passage is formed in the rotating member and enables fluid to be introduced into the pump chamber; and a discharge passage is formed in the rotating member and enables fluid to be expelled from the pump chamber.

In this case, the pressure generating device may be configured such that: the rotating member is an axle hub of a vehicle; the supporting member is a knuckle rotatably supporting the axle hub; and the fluid is air. Also, the pressure generating device may be configured such that the pumping member is a piston integrally rotatable and reciprocally fixed to the rotation shaft portion, and the motion converting mechanism The rotational motion of the rotary member relative to the support member is converted into reciprocating motion of the piston.

In this case, the pressure generating device may be configured such that the rotating shaft portion has a cylindrical bore formed coaxially so that the piston can move along the axial direction of the rotating shaft portion. accommodating the piston in a reciprocating manner; the piston has a load transmission member extending in such a manner that it is movable in the axial direction of the rotary shaft portion and immovable in the rotational direction of the rotary shaft portion passing through the rotation shaft portion; and, the motion converting mechanism includes a cam follower and a cam member, the cam follower being provided at an outer end of the load transmission element with respect to the radial direction of the piston , the cam member is attached to the inside of the support member.

Also, the pressure generating device may be configured such that: the piston is formed as a cylinder and is attached to the outer periphery of the rotation shaft portion in an integrally rotatable and axially reciprocable manner; a cylinder member interposed between the support member and the rotating shaft portion, provided integrally with the support member, and accommodates the piston in such a manner that the piston can axially reciprocate; and, the motion converting mechanism is provided at between the piston and the cylindrical member.

Also, the pressure generating device may be configured such that the rotating shaft portion has a cylindrical bore for accommodating the piston in such a manner that the piston can reciprocate in the radial direction of the rotating shaft portion. The piston, the motion conversion mechanism includes a cam follower and a cylinder cam, the cam follower is arranged at the outer end of the piston protruding outward from the cylinder bore, and the cylinder cam is attached fit inside the support member.

Also, the cam member may have a cam groove into which the cam follower is fitted. The cam groove may have a cam surface that receives an axial load and a radial load from the rotating shaft portion via the cam follower, and the cam groove may have a V-shaped cross section. The cam follower fitted into the cam groove may be a ball.

Also, the load transmitting member may be a shaft extending through the piston in the radial direction of the piston, and the axial movement of the shaft is controlled by an axial elongation formed in the rotating shaft portion. hole to guide. The pressure generating device may be configured such that the shaft is divided into two parts inside the piston, and a spring interposed between the two parts applies a radial direction to the two parts in a radial direction of the piston. external force. Also, the pressure generating means may be configured such that a roller is interposed between the axially elongated hole and the shaft, and as the shaft moves axially along the rotating shaft portion, the The rollers roll along the axially elongated holes. The roller may have a bearing that rollably supports the cam follower.

Also, the pressure generating device may be configured such that the cam member enables the cam follower to axially reciprocate at an even number of geometric periods in the circumferential direction of the rotating member, and the cam follower The pieces are set equal in number to the number of geometric periods. In this case, the pressure generating device may be configured such that the cam member includes a forward-moving cam and a backward-moving cam, and the forward-moving cam and the backward-moving cam are located at the ends of the rotating shaft portion. Axially spaced apart from each other by a predetermined distance; the cam followers include a forward-moving cam follower cooperating with the forward-moving cam and a rearward-moving cam follower cooperating with the backward-moving cam ; the number of said geometric periods being an even number is 4; said forward moving cam followers and said backward moving cam followers are arranged alternately with each other at equal intervals in the circumferential direction. Also, the pressure generating means may be configured such that: the forward moving cam and the backward moving cam are cam ring plates, respectively; the forward moving cam follower and the backward moving cam follower They are respectively rollers; and, the rollers are rotatably engaged with each cam ring plate.

In the above-mentioned pressure generating device according to the present invention, when the rotating member rotates relative to the supporting member, the motion converting mechanism converts the rotating motion of the rotating member into the pumping action of the pumping member, whereby the pumping member performs the pumping action . Accordingly, the volume of the pump chamber increases and decreases, whereby fluid is introduced into the pump chamber through the suction passage and is discharged from the pump chamber through the discharge passage.

In the pressure generating device according to the present invention, the rotating shaft portion of the rotating member is rotatably supported in the supporting member via the bearing, and the pumping member (piston) is attached integrally rotatably and in a manner capable of performing a pumping action. Fitted to the rotary shaft portion of the rotary member, and cooperates with the rotary shaft portion to form a pump chamber therebetween. Therefore, not only the rotating member does not require a balance weight for achieving rotational balance, but also the pressure generating device can be compactly constructed within the supporting member, whereby the pressure generating device can be downsized.

The present invention may also be realized in that the rotating shaft portion is rotatably supported by the support member via a first bearing and a second bearing, the first bearing and the second bearing being spaced apart from each other in the axial direction by a predetermined amount. distance. In this case, the first bearing and the second bearing can secure support rigidity when the rotation member is supported by the support member. The pressure generating device may also be configured such that the motion conversion mechanism is interposed between the first bearing and the second bearing. This enables the space between the first bearing and the second bearing to be effectively used as a space for accommodating the motion converting mechanism, so that the pressure generating device can be configured compactly.

The present invention can also be realized in such a way that the first sealing member and the second sealing member for sealing the first and second bearings sandwich the motion conversion mechanism and the first and second bearings , placed between the rotating shaft portion and the supporting member. In this case, the first and second sealing members can seal the first and second bearings and the motion conversion structure, ie, these sealing members can be commonly used, so that the pressure generating device can be reduced in size and cost.

Description of drawings

Fig. 1 is a sectional view schematically showing a first embodiment of a pressure generating device according to the present invention.

Fig. 2 is a sectional view schematically showing a second embodiment of the pressure generating device according to the present invention.

FIG. 3 is a partial sectional view schematically showing a modified embodiment of the second embodiment shown in FIG. 2 .

Fig. 4 is a sectional view schematically showing a third embodiment of the pressure generating device according to the present invention.

Fig. 5 is a cross-sectional view taken along line 5-5 of the third embodiment shown in Fig. 4 .

Fig. 6 is a sectional view schematically showing a fourth embodiment of the pressure generating device according to the present invention.

FIG. 7 is a sectional view showing an essential part of a modified embodiment in which the cam follower shown in FIG. 6 is rotatably supported by bearings attached to rollers.

Fig. 8 is a sectional view schematically showing a fifth embodiment of the pressure generating device according to the present invention.

Fig. 9 is a perspective view of the cam member (a pair of cam ring plates) shown in Fig. 8 .

Detailed ways

Embodiments of the present invention will be described below with reference to the drawings. Figure 1 shows a first embodiment of a pressure generating device according to the invention. The pressure generating device AP1 of the first embodiment can supply pressurized air to a tire cavity (not shown) of a wheel of a vehicle. The pressure generating device AP1 includes: a cylindrical support portion 11 serving as a supporting member and as a part of a steering knuckle; an axle hub 20 serving as a rotating member; a cylindrical piston 30 serving as a pumping member; a cam member 41 and two cam follower members. moving member 42, which cooperatively serves as a motion conversion mechanism for converting the rotational motion of the axle hub 20 relative to the cylinder support portion 11 into a reciprocating motion (vertical motion in FIG. 1 ) of the piston 30; and a rod 43, which The cam follower 42 is rotatably supported.

The cylindrical support portion 11 is formed in a cylindrical shape having an axis Lo, and is not rotatable about the axis Lo. The rotary shaft portion 21A of the axle hub 20 is rotatably and liquid-tightly supported inside the cylindrical support portion 11 via a pair of bearings 12 and 13 and a pair of annular seal members 14 and 15 about an axis Lo. The paired bearings 12 and 13 are spaced apart from each other by a predetermined distance in the axial direction of the rotary shaft portion 21A (along the axis Lo), and are interposed between the cylindrical support portion 11 and the rotary shaft portion 21A, while the paired bearings 12 and 13 sandwich the cam member 41 in the axial direction of the rotary shaft portion 21A, whereby rotation of the axle hub 20 relative to the cylindrical support portion 11 (ie, knuckle) can be permitted. The paired annular seal members 14 and 15 are spaced apart from each other by a predetermined distance in the axial direction of the rotary shaft portion 21A, and are interposed between the cylindrical support portion 11 and the rotary shaft portion 21A, while the paired seal members 14 and 15 The cam member 41 and the bearings 12 and 13 are sandwiched in the axial direction of the rotary shaft portion 21A, thereby providing a liquid-tight seal between the cylindrical support portion 11 and the rotary shaft portion 21A.

The axle hub 20 includes a hub main body 21 and a sleeve 22 which is screw-fitted fluid-tightly with the outer periphery of the lower end portion (as viewed in FIG. 1 ) of the hub main body 21 . The hub main body 21 includes a rotation shaft portion 21A and an annular flange portion 21B. The rotating shaft portion 21A has a pair of axially elongated holes 21a and a cylindrical bore 21b. The annular flange portion 21B has a mounting portion 21c (the detailed description of which is omitted) for a wheel (not shown). A suction passage 21d and a discharge passage 21e are formed in the rotation shaft portion 21A and in the annular rim portion 21B.

The paired axially elongated bores 21a collectively serve as guide means for guiding the piston 30, the cam follower 42, and the rod 43 so that these members can rotate integrally with the axle hub 20 and can rotate along the axis of rotation. Axial reciprocating motion of 21A. The paired axially elongated holes 21 a extend in the axial direction of the rotation shaft portion 21A and are spaced 180 degrees apart from each other in the circumferential direction of the rotation shaft portion 21A of the axle hub 20 . The cylindrical bore 21 b extends in the axial direction of the rotary shaft portion 21A, and accommodates the piston 30 . The cylindrical bore 21b cooperates with the piston 30 to form a pump chamber Ro in the rotary shaft portion 21A. The suction passage 21d is adapted to lead (introduce) air into the pump chamber Ro, and has a suction check valve Vi installed therein. The discharge passage 21e is adapted to lead out (exhaust) air from the pump chamber Ro, and has a discharge check valve Vo installed therein. The pressurized air discharged from the pump chamber Ro may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 20 .

The piston 30 is inserted into the cylindrical bore 21b of the rotary shaft portion 21A of the axle hub 20 via a pair of annular seal members 31 and 32, and is attached coaxially in a manner integrally rotatable and in a manner capable of reciprocating axially. to the rotating shaft portion 21A of the axle hub 20 . The piston 30 has an annular groove 30a and a through hole 30b extending radially therealong. A pair of annular seal members 31 and 32 are spaced apart from each other by a predetermined distance in the axial direction of the piston 30, and disposed between the piston 30 and the rotary shaft portion 21A at respective axial ends of the piston 30, thereby providing a piston 30 30 and the rotating shaft portion 21A is airtight and liquid-tight.

An annular groove 30 a is formed on the outer periphery of the piston 30 between the pair of annular seal members 31 and 32 , whereby an annular space R1 is formed between the piston 30 and the rotary shaft portion 21A. The annular space R1 communicates with an annular space R2 formed between the pair of annular seal members 14 and 15 through an axially elongated hole 21 a formed in the rotary shaft portion 21A. The annular spaces R1 and R2 maintain a constant volume during axial reciprocation of the piston 30 and are sealed by four sealing members 14 , 15 , 31 and 32 . The annular spaces R1, R2, etc. collectively serve as an oil chamber for containing a predetermined amount of lubricating oil. This oil chamber accommodates the bearings 12 and 13, the cam member 41, the cam follower 42, the rod 43, and the like.

The cam member 41 is a cylindrical cam integrally fixed (in an axially fixed manner and in a non-rotatable manner) to the cylindrical support portion 11, and is composed of a pair of cam sleeves 41A and 41B, which The sleeves 41A and 41B are arranged to contact each other in the axial direction. The cam member 41 is arranged coaxially with the rotation shaft portion 21A. The cam member 41 has an annular cam portion 41a whose axial position varies. The cam portion 41 a is a cam groove into which the cam follower 42 is fitted. The cam portion 41 a has a cam surface that receives an axial load (vertical load in FIG. 1 ) and a radial load (horizontal load in FIG. 1 ) from the rotary shaft portion 21A via the cam follower 42 . This cam surface has a V-shaped cross section, and has an even number of geometric periods (for example, two geometric periods) along the circumferential direction of the rotary shaft portion 21A.

The cam followers 42 are balls rotatably attached to each outer end of the rod 43 radially with respect to the piston 30 . The cam follower 42 is engaged with a cam portion (cam groove) 41 a at an end portion in the piston radial direction perpendicular to the axis Lo. By relative rotation with respect to the cam member 41 , the cam follower 42 can move in the axial direction (vertically in FIG. 1 ) of the rotation shaft portion 21A together with the rod 43 . The rod 43 serves as a load transmitting member, which is installed in the through hole 30b of the piston 30 in a manner movable in the radial direction of the piston 30 (the axial direction of the through hole 30b). The rod 43 extends through the axially elongated hole 21 a of the rotation shaft portion 21A in a manner that is movable in the axial direction of the rotation shaft portion 21A but not movable in the rotation direction of the rotation shaft portion 21A.

In the thus configured pressure generating device AP1 of the first embodiment, when the axle hub 20 rotates relative to the cylindrical support portion 11, the piston 30, the rod 43, and the cam follower 42 as a whole rotate along with the axle hub 20 and relatively Relative rotation is performed on the cam member 41 to thereby move axially. Therefore, the rotational motion of the axle hub 20 can be converted into the reciprocating motion of the piston 30 . The reciprocating motion of the piston 30 can increase and decrease the volume of the pump chamber Ro. Then, air can be introduced into the pump chamber Ro through the suction passage 21d in which the suction check valve Vi is installed, and air can be discharged from the pump chamber Ro through the discharge passage 21e in which the discharge check valve Vo is installed. The exhausted air (pressurized air) may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 20 .

In the pressure generating device AP1 of the first embodiment, the rotary shaft portion 21A of the axle hub 20 is rotatably supported in the cylindrical support portion 11 via the bearings 12 and 13, and the piston 30 is integrally rotatable and capable of Attached coaxially to the rotary shaft portion 21A of the axle hub 20 in such a manner as to reciprocate axially (to perform a pumping action), thereby forming a pump chamber Ro exposed to the rotary shaft portion 21A. Therefore, not only the axle hub 20 does not require a counterweight for rotational balance, but also the pressure generating device AP1 can be compactly constructed within the cylindrical support portion 11, whereby the pressure generating device AP1 can be downsized.

In the pressure generating device AP1 of the first embodiment, the rotary shaft portion 21A of the axle hub 20 is rotatably supported by the cylindrical support portion 11 via the pair of bearings 12 and 13 that rotate The shaft portions 21A are spaced apart from each other by a predetermined distance in the axial direction. Therefore, the paired bearings 12 and 13 can secure support rigidity when the axle hub 20 is supported by the cylindrical support portion 11 . Also, a cam member 41 and a cam follower 42 serving together as a motion conversion mechanism are interposed between the paired bearings 12 and 13 . This allows the space between the paired bearings 12 and 13 to be effectively utilized as a space for accommodating the motion converting mechanism, so that the pressure generating device AP1 can be compactly configured.

In the pressure generating device AP1 of the first embodiment, the paired annular seal members 14 and 15 for sealing the paired bearings 12 and 13 seal the cam member 41 and the two bearings in the axial direction of the rotary shaft portion 21A. 12 and 13 are sandwiched between the rotating shaft portion 21A of the axle hub 20 and the cylindrical support portion 11 . Therefore, the paired annular sealing members 14 and 15 can seal the paired bearings 12 and 13 and the cam member 41 and the cam follower 42 serving together as a motion conversion mechanism, that is, the sealing members can be shared so that the pressure can be reduced. Generate the size and cost of the device AP1.

In the pressure generating device AP1 of the first embodiment, the pair of annular seal members 31 and 32 for providing a liquid-tight seal between the piston 30 and the rotary shaft portion 21A of the axle hub 20 are spaced apart from each other in the axial direction by a predetermined amount. and the paired seal members 14 and 15 for providing a liquid-tight seal between the rotary shaft portion 21A of the axle hub 20 and the cylindrical support portion 11 are spaced apart from each other by a predetermined distance in the axial direction. The oil chambers (annular spaces R1 and R2) sealed by the four sealing members 14, 15, 31 and 32 and containing a predetermined amount of working oil accommodate the bearings 12 and 13, the cam member 41, the cam follower 42, the rod 43 wait. Therefore, lubrication of the sliding portion is ensured, so that the sliding resistance of the sliding portion can be reduced and durability can be improved.

Figure 2 shows a second embodiment of the pressure generating device according to the invention. The pressure generating device AP2 of the second embodiment can supply pressurized air to a tire cavity (not shown) of a wheel of a vehicle. The pressure generating device AP2 includes: a cylindrical support portion 111 serving as a supporting member and as a part of a steering knuckle; an axle hub 120 serving as a rotating member; a cylindrical piston 130 serving as a pumping member; a cylindrical cam member 141 and a cam follower. moving member 142, which cooperatively serves as a motion conversion mechanism for converting rotational motion of axle hub 120 relative to cylindrical support portion 111 into reciprocating motion of piston 130; and cylindrical member 150, which houses piston 130.

The cylindrical support portion 111 is formed in a cylindrical shape having an axis Lo, and is not rotatable about the axis Lo. The rotary shaft portion 121A of the axle hub 120 is rotatably and liquid-tightly supported inside the cylindrical support portion 111 about the axis Lo via a pair of bearings 112 and 113 and a pair of annular seal members 114 and 115 . The paired bearings 112 and 113 are spaced apart from each other by a predetermined distance in the axial direction of the rotating shaft portion 121A (along the axis Lo), and are interposed between the cylindrical support portion 111 and the rotating shaft portion 121A, while the paired bearings 112 and 113 sandwich the cylindrical member 150 in the axial direction of the rotation shaft portion 121A, whereby rotation of the axle hub 120 relative to the cylindrical support portion 111 (ie, knuckle) can be allowed. The paired annular seal members 114 and 115 are spaced apart from each other by a predetermined distance in the axial direction of the rotary shaft portion 121A, and are interposed between the cylindrical support portion 111 and the rotary shaft portion 121A, while the paired seal members 114 and 115 The cylindrical member 150 and the bearings 112 and 113 are sandwiched in the axial direction of the rotary shaft portion 121A, thereby providing a liquid-tight seal between the cylindrical support portion 111 and the rotary shaft portion 121A.

The axle hub 120 includes a hub main body 121 and a sleeve 122 which is screw-fitted with the outer periphery of the lower end portion of the hub main body 121 in a liquid-tight manner. The hub main body 121 includes a rotation shaft portion 121A and an annular flange portion 121B. The rotating shaft portion 121A has an axial groove 121a, a suction passage 121b and a discharge passage 121c. The annular flange portion 121B has a mounting portion 121d (the detailed description of which is omitted) for a wheel (not shown).

The axial groove 121 a is a guide for axially guiding the protrusion 130 a formed on the inner periphery of the piston 130 , and is formed on the outer periphery of the rotation shaft portion 121A of the axle hub 120 . The suction passage 121b is adapted to guide (introduce) air into a pump chamber Ro formed between the piston 130 and the cylindrical member 150, and has a suction check valve Vi installed therein. The discharge passage 121c is adapted to lead out (exhaust) air from the pump chamber Ro, and has a discharge check valve Vo installed therein. Pressurized air discharged from the pump chamber Ro may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 120 .

The piston 130 is accommodated in the cylindrical member 150 and arranged outside the rotation shaft portion 121A of the axle hub 120 . The piston 130 has the above-mentioned protrusion 130a and has a mounting hole 130b extending in a radial direction of the piston 130 and into which the cam follower 142, the spring 143 and the seat 144 are attached. The piston 130 is fitted into the axial groove 121a of the rotary shaft portion 121A via the protrusion 130a so as to be integrally rotatable with the rotary shaft portion 121A and capable of axial reciprocation. Coaxially attached to the rotary shaft portion 121A of the axle hub 120 in a manner of coaxial.

Piston 130 is fitted to rotary shaft portion 121A of axle hub 120 via a pair of annular seal members 131 and 132, and is fitted into cylindrical bore 150a of cylindrical member 150 via a pair of annular seal members 133 and 134, thereby being The outer circumference of the rotating shaft portion 121A and the inner circumference of the cylindrical member 150 cooperatively form the above-described pump chamber Ro and air chamber Ra. The atmospheric chamber Ra communicates with the atmosphere through a communication passage 121e formed in the rotary shaft portion 121A and a part of the suction passage 121b on the atmospheric side of the suction check valve Vi.

A pair of annular seal members 131 and 132 are spaced apart from each other by a predetermined distance in the axial direction of the rotary shaft portion 121A, and disposed between the piston 130 and the rotary shaft portion 121A at respective axial ends of the piston 130, thereby providing An air-tight and liquid-tight seal between the piston 130 and the rotary shaft portion 121A is achieved. A pair of annular seal members 133 and 134 are spaced apart from each other by a predetermined distance in the axial direction of the rotary shaft portion 121A, and disposed between the piston 130 and the cylindrical member 150 at respective axial ends of the piston 130, thereby providing An air-tight and liquid-tight seal between the piston 130 and the cylindrical member 150 is ensured.

The cylindrical member 150 is formed in a cylindrical shape; fitted to the rotation shaft portion 121A of the axle hub 120 via a pair of annular seal members 151 and 152 inside the cylindrical support portion 111 ; and placed on the cylindrical support portion 111 and the axle hub 120 Between the rotating shaft parts 121A. The cylindrical member 150 is arranged coaxially with the rotation shaft portion 121A, and is integrally attached to the cylindrical support portion 111 (in an axially non-movable manner and in a non-rotatable manner). The cylindrical member 150 has: a cylindrical bore 150 a accommodating the piston 130 in such a manner that the piston 130 can reciprocate in the axial direction of the rotary shaft portion 121A; and an annular groove 150 b formed on the outer periphery of the cylindrical member 150 .

The annular groove 150 b forms an annular space R11 between the cylindrical support portion 111 and the cylindrical member 150 . This annular space R11 communicates with the annular space R12 formed between the annular seal members 114 and 151 through the communication hole 150c formed in the cylindrical member 150, and communicates with the annular space R12 formed between the annular seal members 114 and 151 through the communication hole 150d formed in the cylindrical member 150. The annular space R13 between the sealing members 115 and 152 communicates. The annular spaces R11, R12 and R13 collectively function as oil chambers for containing a predetermined amount of lubricating oil. Lubricating oil contained in this oil chamber is supplied to the bearings 112 and 113 and the annular seal members 114, 115, 151 and 152, and to the cylindrical cam 141 and the cam follower through the communication hole 150e formed in the cylindrical member 150. The fitting part between the parts 142, the sliding part of the piston 130, etc.

The cylindrical cam 141 is integrally formed on the inner periphery of the cylindrical member 150 and arranged coaxially with the rotation shaft portion 121A. The cylindrical cam 141 has an annular cam groove 141a whose position varies in the axial direction of the rotary shaft portion 121A. The cam follower 142 is fitted into the cam groove 141a. The cam groove 141 a has a cam surface that receives an axial load (vertical load in FIG. 2 ) and a radial load (horizontal load in FIG. 2 ) from the cam follower 142 . This cam surface has a V-shaped cross section, and has an even number of geometric periods (for example, two geometric periods) along the circumferential direction of the rotary shaft portion 121A.

The cam follower 142 is a ball rotatably attached to a seat 144 inserted into the mounting hole 130 b of the piston 130 . The cam follower 142 is engaged with the cam groove 141 a when being urged by the spring 143 in the radially outward direction of the piston 130 . The spring 143 is interposed between the cam follower 142 and the seat 144 and urges the cam follower 142 in a radially outward direction of the piston 130 . The seat 144 is formed in a bottom-closed tubular shape, and is provided in the mounting hole 130 b of the piston 130 in a manner capable of moving in a radial direction of the piston 130 .

In the pressure generating device AP2 of the second embodiment thus configured, when the axle hub 120 rotates relative to the cylinder support portion 111, the piston 130 and the cam follower 142 integrally rotate with the axle hub 120 and relative to the cylinder. The cam 141 performs relative rotation, thereby moving axially. Accordingly, rotational motion of the axle hub 120 may be converted into reciprocating motion of the piston 130 . The reciprocating motion of the piston 130 can increase and decrease the volume of the pump chamber Ro. Then, air can be introduced into the pump chamber Ro through the suction passage 121b in which the suction check valve Vi is installed, and air can be discharged from the pump chamber Ro through the discharge passage 121c in which the discharge check valve Vo is installed. The exhausted air (pressurized air) may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 120 .

In the pressure generating device AP2 of the second embodiment, the rotary shaft portion 121A of the axle hub 120 is rotatably supported in the cylinder support portion 111 via the bearings 112 and 113, and the piston 130 is integrally rotatable and capable of Attached coaxially to the rotary shaft portion 121A of the axle hub 120 in such a manner as to reciprocate axially (to perform a pumping action), thereby forming a pump chamber Ro exposed to the rotary shaft portion 121A. Therefore, not only the axle hub 120 does not require a weight for rotational balance, but also the pressure generating device AP2 can be compactly configured in the cylindrical support portion 111, whereby the pressure generating device AP2 can be downsized.

In the pressure generating device AP2 of the second embodiment, the rotary shaft portion 121A of the axle hub 120 is rotatably supported by the cylindrical support portion 111 via the pair of bearings 112 and 113 that rotate The shaft portions 121A are spaced apart from each other by a predetermined distance in the axial direction. Therefore, the paired bearings 112 and 113 can ensure support rigidity when the axle hub 120 is supported by the cylindrical support portion 111 . Also, a cylindrical cam 141 and a cam follower 142 serving together as a motion conversion mechanism are interposed between the paired bearings 112 and 113 . This allows the space between the paired bearings 112 and 113 to be effectively used as a space for accommodating the motion converting mechanism, so that the pressure generating device AP2 can be compactly configured.

In the pressure generating device AP2 of the second embodiment, the pair of annular seal members 114 and 115 for sealing the pair of bearings 112 and 113 seal the cylindrical member 150 and the two The bearings 112 and 113 are interposed between the rotating shaft portion 121A of the axle hub 120 and the cylindrical support portion 111 in such a manner as to be in the middle. Therefore, the paired ring-shaped sealing members 114 and 115 can seal the paired bearings 112 and 113 and the cylinder cam 141 and the cam follower 142 serving as a motion conversion mechanism in common, that is, the sealing members can be shared, so that it is possible to reduce Dimensions and cost of the pressure generating device AP2.

In the pressure generating device AP2 of the second embodiment, oil chambers (annular spaces R12 and R13) that are sealed by annular seal members 114, 115, 131 to 134, 151, and 152 and accommodate a predetermined amount of working oil accommodate bearings 112 and 113. Also, lubricating oil can be supplied from the oil chamber (annular space R11 ) to the fitting portion between the cylindrical cam 141 and the cam follower 142 , the sliding portion of the piston 130 , etc. through the communication hole 150 e. Therefore, lubrication of the sliding portion is ensured, so that the sliding resistance of the sliding portion can be reduced and durability can be improved.

In the pressure generating device AP2 of the second embodiment, the cam follower 142 provided on the outer circumference of the piston 130 and the cylindrical cam 141 provided on the inner circumference of the cylindrical member 150 constitute a motion conversion mechanism (inscribed cam type motion conversion mechanism). mechanism) for converting the rotational motion of the axle hub 120 relative to the cylindrical support portion 111 into the reciprocating motion of the piston 130 . However, in the case of the modified embodiment shown in FIG. 3 , the cylindrical cam 141 provided on the outer periphery of the piston 130 and the cam follower 142 provided on the inner periphery of the cylindrical member 150 may constitute a motion conversion mechanism (circumscribed cam type motion conversion mechanism) for converting the rotational motion of the axle hub 120 relative to the cylindrical support portion 111 into the reciprocating motion of the piston 130 .

In the pressure generating device AP2 of the second embodiment, the protrusion 130a is formed on the inner circumference of the piston 130, the axial groove 121a is formed on the outer circumference of the rotation shaft portion 121A, and the protrusion 130a (piston 130) is integrally rotatable. And is fitted to the axial groove 121a (rotation shaft portion 121A) in a manner capable of reciprocating in the axial direction. However, in the modified embodiment shown in FIG. 3, the following configurations may be possible: the axial groove 130c is formed on the inner periphery of the piston 130; the protrusion 121f is formed on the outer periphery of the rotating shaft portion 121A; ) is fitted to the protrusion 121f (rotation shaft portion 121A) integrally rotatably and in a manner capable of reciprocating axially.

4 and 5 show a third embodiment of the pressure generating device according to the invention. The pressure generating device AP3 of the third embodiment may supply pressurized air to a tire cavity (not shown) of a wheel of a vehicle. The pressure generating device AP3 includes: a cylinder support 211 serving as a supporting member and as a part of a steering knuckle; an axle hub 220 serving as a rotating member; two pistons 230 serving together as a pumping member; a cam member 241 and two Cam followers 242 , which cooperatively serve as a motion conversion mechanism for converting the rotational motion of the axle hub 220 relative to the cylinder support 211 into reciprocating motion of the piston 230 .

The cylindrical support portion 211 is formed in a cylindrical shape having an axis Lo, and is not rotatable about the axis Lo. The rotary shaft portion 221A of the axle hub 220 is rotatably and liquid-tightly supported inside the cylindrical support portion 211 via a pair of bearings 212 and 213 and a pair of annular seal members 214 and 215 about the axis Lo. The paired bearings 212 and 213 are spaced apart from each other by a predetermined distance in the axial direction of the rotation shaft portion 221A (along the axis Lo), and are interposed between the cylindrical support portion 211 and the rotation shaft portion 221A, while the paired bearings 212 The sum 213 sandwiches the cam member 241 in the axial direction of the rotation shaft portion 221A, whereby the rotation of the axle hub 220 relative to the cylindrical support portion 211 (ie, the knuckle) can be allowed. The paired annular seal members 214 and 215 are spaced apart from each other by a predetermined distance in the axial direction of the rotation shaft portion 221A, and are interposed between the cylinder support portion 211 and the rotation shaft portion 221A, while the paired seal members 214 and 215 The cam member 241 and the bearings 212 and 213 are sandwiched in the axial direction of the rotation shaft portion 221A, thereby providing a liquid-tight seal between the cylindrical support portion 211 and the rotation shaft portion 221A.

The axle hub 220 includes a hub main body 221 and a sleeve 222 , and the sleeve 222 is screw-fitted with the outer periphery of the lower end portion of the hub main body 221 in a liquid-tight manner. The hub main body 221 includes a rotation shaft portion 221A and an annular flange portion 221B. The rotating shaft portion 221A has a pair of cylindrical bores 211a, that is, two cylindrical bores 211a. The annular flange portion 221B has a mounting portion 221d (the detailed description of which is omitted) for a wheel (not shown). A suction passage 221c and a discharge passage 221d are formed in the rotation shaft portion 221A and in the annular flange portion 221B.

Two cylindrical bores 221a are formed in the rotation shaft portion 221A of the axle hub 220 so as to extend in the radial direction of the rotation shaft portion 221A, and are spaced 180 degrees from each other in the circumferential direction of the rotation shaft portion 221A. The cylindrical bores 221a accommodate the respective pistons 230 in such a manner that the pistons 230 can reciprocate in the radial direction of the rotation shaft portion 221A. The cylindrical bores 221a cooperate with the respective pistons 30 to form respective pump chambers Ro in the rotary shaft portion 221A. The pump chambers Ro communicate with each other through a communication hole 221e provided in the rotation shaft portion 221A.

The suction passage 221c is adapted to lead (introduce) air into the pump chamber Ro, and has a suction check valve Vi installed therein. The discharge passage 221d is adapted to lead out (discharge) air from the pump chamber Ro, and has a discharge check valve Vo installed therein. Pressurized air discharged from the pump chamber Ro may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 220 .

Pistons 230 each have a columnar shape, and are inserted into respective cylindrical bores 221 a of rotational shaft portion 221A of axle hub 220 via respective annular seal members 231 . The piston 230 is rotatable integrally with the rotation shaft portion 221A of the axle hub 220 and is capable of reciprocating in the axial direction of the cylindrical bore 221a. The pistons 230 each have a recess 230 a for accommodating a portion of a compression coil spring 243 . Annular seal members 231 are fitted into respective annular grooves formed on the outer circumference of the piston 230 , thereby providing an air-tight and liquid-tight seal between the rotary shaft portion 221A and the piston 230 .

The cam member 241 is a cylindrical cam integrally attached to the cylindrical support portion 211 (in an axially non-movable manner and in a non-rotatable manner), and is arranged coaxially with the rotation shaft portion 221A. The cam member 241 has an elliptical cam surface 241a on its inner periphery. The cam follower 242 cooperates with the cam surface 241a. The cam surface 241 a can cause the cam follower 242 and the piston 230 to reciprocate twice in the axial direction of the piston 230 when the rotating shaft portion 221A rotates one turn relative to the cylinder support portion 211 .

The cam followers 242 are balls rotatably attached to each outer end 230b of the piston 230 protruding outwardly from the respective cylindrical bore 211a. The cam followers 242 are rotatably engaged with the cam surfaces 241a of the cam members 241 at respective outer ends 230b. The cam follower 242 may move in the axial direction of the piston 230 together with the piston 230 through relative rotation with respect to the cam member 241 . The annular space R21 accommodating the cam follower 242 and the like is sealed by the sealing members 214 , 215 , 231 and 231 . The annular space R21 accommodates a predetermined amount of lubricating oil for lubricating the bearings 212 and 213, the cam member 241, the cam follower 242, the piston 230, and the like.

The third embodiment has an air chamber R22 (see FIG. 5 ) that collectively serves as volume change reducing means for reducing the volume change of the annular space R21 associated with the reciprocating motion of the two pistons 230 . The volume of the air chamber R22 decreases as the volume of the annular space R21 decreases, and increases as the volume of the annular space R21 increases. The air chambers R22 are realized by respective air bags 250 integrally rotatably attached to the outer circumference of the rotation shaft portion 221A. The air bag 250 is formed of an elastic airtight material such as rubber, and accommodates compressed air therein. When the internal pressure of the annular space R21 increases as the volume of the annular space R21 decreases, the air bag 250 contracts, and when the internal pressure of the annular space R21 decreases as the volume of the annular space R21 increases, the air bag 250 expands . This reduces the magnitude of the rise and fall of the internal pressure of the annulus R21 during operation, thereby reducing pumping losses associated with the rise and fall of pressure.

In the pressure generating device AP3 of the third embodiment thus configured, when the axle hub 220 rotates relative to the cylinder support portion 211, the piston 230 and the cam follower 242 integrally rotate with the axle hub 220 and relative to the cam member. 241 undergoes relative rotation, thereby moving axially. Accordingly, the rotational motion of the axle hub 220 may be converted into a reciprocating motion of the piston 230 . The reciprocating motion of the piston 230 can increase and decrease the volume of the pump chamber Ro. Then, air can be introduced into the pump chamber Ro through the suction passage 221c in which the suction check valve Vi is installed and through the communication hole 221e, and air can be discharged through the communication hole 221e and through the discharge check valve Vo installed therein. The passage 221d is discharged from the pump chamber Ro. The exhausted air (pressurized air) may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 220 .

In the pressure generating device AP3 of the third embodiment, the rotary shaft portion 221A of the axle hub 220 is rotatably supported in the cylinder support portion 211 via the bearings 212 and 213, and the piston 230 is integrally rotatable and capable of Attached to the rotary shaft portion 221A of the axle hub 220 in such a manner as to reciprocate axially (to perform a pumping action), thereby forming a pump chamber Ro exposed to the rotary shaft portion 221A. Therefore, not only the axle hub 220 does not require a weight for achieving rotational balance, but also the pressure generating device AP3 can be compactly configured in the cylindrical support portion 211, whereby the pressure generating device AP3 can be downsized.

In the pressure generating device AP3 of the third embodiment, the rotational shaft portion 221A of the axle hub 220 is rotatably supported by the cylindrical support portion 211 via the pair of bearings 212 and 213 that rotate The shaft portions 221A are spaced apart from each other by a predetermined distance in the axial direction. Therefore, the paired bearings 212 and 213 can secure support rigidity when the axle hub 220 is supported by the cylindrical support portion 211 . Also, a cam member 241 and a cam follower 242 serving together as a motion converting mechanism are interposed between the paired bearings 212 and 213 . This allows the space between the paired bearings 212 and 213 to be effectively used as a space for accommodating the motion converting mechanism, so that the pressure generating device AP3 can be compactly configured.

In the pressure generating device AP3 of the third embodiment, the paired annular seal members 214 and 215 for sealing the paired bearings 212 and 213 seal the cam member 241 and the two bearings in the axial direction of the rotary shaft portion 221A. 212 and 213 are interposed between the rotating shaft portion 221A of the axle hub 220 and the cylindrical support portion 211 . Therefore, the paired ring-shaped sealing members 214 and 215 can seal the paired bearings 212 and 213 and the cam member 241 and the cam follower 242 serving together as a motion conversion mechanism, that is, the sealing members can be shared so that the pressure can be reduced. The size and cost of generating device AP3.

In the pressure generating device AP3 of the third embodiment, the annular sealing member 231 is provided for providing a liquid-tight seal between the piston 230 and the rotational shaft portion 221A of the axle hub 220 , and for providing the rotational shaft portion 221A of the axle hub 220 . The liquid-tight annular seal members 214 and 215 between 221A and the cylindrical support portion 211 are spaced apart from each other by a predetermined distance in the axial direction. An annular space R12 sealed by these sealing members 214, 215, 231 and 231 and containing a predetermined amount of working oil houses bearings 212 and 213, cam member 241, cam follower 242, piston 230 and the like. Therefore, lubrication of the sliding portion is ensured, so that the sliding resistance of the sliding portion can be reduced and durability can be improved.

Fig. 6 shows a fourth embodiment of the pressure generating device according to the invention. The pressure generating device AP4 of the fourth embodiment can supply pressurized air to a tire cavity (not shown) of a wheel of a vehicle. The pressure generating device AP4 includes: a cylindrical support portion 311 serving as a supporting member and as a part of a steering knuckle; an axle hub 320 serving as a rotating member; a cylindrical piston 330 serving as a pumping member; a cam member 341 and two cam follower members. moving member 342, which cooperatively serves as a motion conversion mechanism for converting rotational motion of axle hub 320 relative to cylinder support portion 311 into reciprocating motion of piston 330; and shaft 343, which rotatably supports cam follower 342 .

The cylindrical support portion 311 is formed in a cylindrical shape having an axis Lo, and is not rotatable about the axis Lo. The rotary shaft portion 321A of the axle hub 320 is rotatably and liquid-tightly supported inside the cylindrical support portion 311 about the axis Lo via a pair of bearings 312 and 313 and a pair of annular seal members 314 and 315 . The paired bearings 312 and 313 are spaced apart from each other by a predetermined distance in the axial direction of the rotation shaft portion 321A (along the axis Lo), and are interposed between the cylindrical support portion 311 and the rotation shaft portion 321A, while the paired bearings 312 and 313 sandwich the cam member 341 in the axial direction of the rotation shaft portion 321A, whereby rotation of the axle hub 320 relative to the cylindrical support portion 311 (ie, knuckle) can be allowed. The paired annular seal members 314 and 315 are spaced apart from each other by a predetermined distance in the axial direction of the rotation shaft portion 321A, and are interposed between the cylinder support portion 311 and the rotation shaft portion 321A, while the paired seal members 314 and 315 The cam member 341 and the bearings 312 and 313 are sandwiched in the axial direction of the rotation shaft portion 321A, thereby providing a liquid-tight seal between the cylindrical support portion 311 and the rotation shaft portion 321A.

The axle hub 320 includes a hub main body 321 and a sleeve 322 which is threadedly engaged with the outer periphery of the lower end portion (as shown in the figure) of the hub main body 321 in a liquid-tight manner. The hub main body 321 includes a rotation shaft portion 321A and an annular flange portion 321B. The rotating shaft portion 321A has a pair of axially elongated holes 321a and a cylindrical bore 321b. The annular rim portion 321B has a mounting portion 321c (the detailed description of which is omitted) for a wheel (not shown). A suction passage 321d and a discharge passage 321e are formed in the rotation shaft portion 321A and in the annular rim portion 321B.

The pair of axially elongated bores 321a collectively serve as guide means for guiding the piston 330, cam follower 342, and shaft 343 so that these members integrally rotate with the axle hub 320 and can reciprocate axially sports. The paired axially elongated holes 321 a extend in the axial direction of the rotation shaft portion 321A and are spaced 180 degrees apart from each other in the circumferential direction of the rotation shaft portion 321A of the axle hub 320 . The cylindrical bore 321 b extends in the axial direction of the rotation shaft portion 321A, and accommodates the piston 330 . The cylindrical bore 321b cooperates with the piston 330 to form a pump chamber Ro in the rotary shaft portion 321A. The suction passage 321d is adapted to guide (introduce) air into the pump chamber Ro, and has a suction check valve Vi installed therein. The discharge passage 321e is adapted to lead out (discharge) air from the pump chamber Ro, and has a discharge check valve Vo installed therein. The pressurized air discharged from the pump chamber Ro may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 320 .

The piston 330 is inserted into the cylindrical bore 321b of the rotary shaft portion 321A of the axle hub 320 via a pair of annular seal members 331 and 332, and is integrally rotatable and coaxially fixed to the The rotation shaft portion 321A of the axle hub 320 . The piston 330 has an annular groove 330a and a through hole 330b extending radially therealong. A pair of annular seal members 331 and 332 are spaced apart from each other by a predetermined distance in the axial direction of the piston 330, and disposed between the piston 330 and the rotation shaft portion 321A at respective axial ends of the piston 330, thereby providing the piston 330 The air-tight and liquid-tight seal with the rotating shaft portion 321A.

An annular groove 330a is formed on the outer periphery of the piston 330 between the pair of annular seal members 331 and 332, whereby an annular space R1 is formed between the piston 330 and the rotation shaft portion 321A. The annular space R1 communicates with an annular space R2 formed between the pair of annular seal members 314 and 315 through an axially elongated hole 321 a formed in the rotation shaft portion 321A. The annular spaces R1 and R2 maintain a constant volume during axial reciprocation of the piston 330 and are sealed by four sealing members 314 , 315 , 331 and 332 . The annular spaces R1, R2, etc. collectively serve as an oil chamber for containing a predetermined amount of lubricating oil. This oil chamber accommodates the bearings 312 and 313, the cam member 341, the cam follower 342, the shaft 343, and the like.

The cam member 341 is a cylindrical cam integrally attached to the cylindrical support portion 311 (in an axially non-movable manner and in a non-rotatable manner), and is composed of a pair of cam sleeves 341A and 341B, which The sleeves 341A and 341B are disposed in contact with each other in the axial direction. The cam member 341 is arranged coaxially with the rotation shaft portion 321A. The cam member 341 has an annular cam portion 341a whose axial position changes. The cam portion 341a is a cam groove into which the cam follower 342 is fitted. The cam portion 341 a has a cam surface that receives an axial load (vertical load in FIG. 6 ) and a radial load (horizontal load in FIG. 6 ) from the cam follower 342 . This cam surface has a V-shaped cross section, and has an even number of geometric periods (for example, two geometric periods) along the circumferential direction of the rotary shaft portion 321A.

The cam followers 342 are balls rotatably attached via respective rollers 344 to respective outer ends of a shaft 343 radially relative to the piston 330 within which the shaft 343 is divided into two parts. The cam follower 342 is engaged with a cam portion (cam groove) 341 a at an end portion in the piston radial direction perpendicular to the axis Lo. By relative rotation with respect to the cam member 341 , the cam follower 342 can move in the axial direction (vertically in FIG. 6 ) of the rotation shaft portion 321A together with the shaft 343 .

The shaft 343 serves as a load transmitting member, which is installed in the through hole 330b of the piston 330 in a manner movable in the radial direction of the piston 330 (the axial direction of the through hole 330b). Rollers 344 are attached to respective small-diameter ends of the shaft 343 . The shaft 343 extends through the axially elongated hole 321a of the rotation shaft portion 321A in a manner movable in the axial direction of the rotation shaft portion 321A by a roller 344 and in a manner immovable in the rotation direction of the rotation shaft portion 321A. The compression coil spring 345 is installed in the shaft 343 and urges the shaft 343 in a radially outward direction of the piston 330 .

When being rotatably fitted to the respective small-diameter end portions of the shaft 343, the rollers 344 are rollably fitted into the respective axially elongated holes 321a of the rotary shaft portion 321A. The rollers 344 can roll along the respective axially elongated holes 321 a of the rotation shaft portion 321A along with the axial movement of the cam follower 342 . Each roller 344 has a hemispherical concave bearing portion at its axially outer end. The bearing portion of the roller 344 rollably supports each cam follower (ball) 342 .

The compression coil spring 345 is pressing means for pressing the cam follower 342 toward the cam portion (cam groove) 341 a of the cam member 341 in the radial direction of the piston 330 via the shaft 343 and the roller 344 . A compression coil spring 345 is installed in a bottom-closed installation hole of the shaft 343 under a predetermined preload.

In the pressure generating device AP4 of the fourth embodiment thus configured, when the axle hub 320 rotates relative to the cylindrical support portion 311, the piston 330, the shaft 343, and the cam follower 342 as a whole rotate with the axle hub 320, and relatively Relative rotation is performed on the cam member 341, thereby moving axially. Therefore, the rotational motion of the axle hub 320 can be converted into the reciprocating motion of the piston 330 . The reciprocating motion of the piston 330 can increase and decrease the volume of the pump chamber Ro. Then, air can be introduced into the pump chamber Ro through the suction passage 321d in which the suction check valve Vi is installed, and air can be discharged from the pump chamber Ro through the discharge passage 321e in which the discharge check valve Vo is installed. The exhausted air (pressurized air) may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 320 .

In the pressure generating device AP4 of the fourth embodiment, the rotary shaft portion 321A of the axle hub 320 is rotatably supported in the cylindrical support portion 311 via the bearings 312 and 313, and the piston 330 is integrally rotatable and capable of pivoting. It is coaxially attached to the rotation shaft portion 321A of the axle hub 320 in such a manner as to reciprocate (to perform a pumping action), thereby forming a pump chamber Ro exposed to the rotation shaft portion 321A. Therefore, not only the axle hub 320 does not need a weight for rotational balance, but also the pressure generating device AP4 can be compactly configured in the cylindrical support portion 311, whereby the pressure generating device AP4 can be downsized.

In the fourth embodiment, since the compression coil spring 345 presses the cam follower 342 against the cam portion (cam groove) 341a of the cam member 341, the axial and radial play (play) of the piston 330 can be suppressed. Otherwise, the gap may occur between the cam follower 342 and the cam portion (cam groove) 341 a of the cam member 341 . Accordingly, motion conversion loss, which would otherwise be caused by the aforementioned gap, can be suppressed, whereby motion conversion efficiency can be improved.

In the fourth embodiment, the rotation shaft portion 321A has an axially elongated hole 321a for guiding the piston 330 and the cam follower 342 so that these members can rotate integrally with the rotation shaft portion 321A and can axially reciprocate movement, and the piston 330 is integrally rotatable and fixed to the rotation shaft portion 321A in an axially reciprocable manner. Therefore, no torque is applied to the annular seal members 331 and 332 interposed between the piston 330 and the rotary shaft portion 321A, and thus the durability of the annular seal members 331 and 332 can be improved.

In the fourth embodiment, the rollers 344 are rotatably supported by the shaft 343 provided in the piston 330, and the cam followers 342 are rotatably supported by the respective rollers 344 and are aligned with the cam portion (cam portion) of the cam member 341. Groove) 341a fit. Therefore, the roller 344 can reduce the sliding resistance between the axially elongated hole 321a and the cam follower 342, and the cam follower 342 can reduce the sliding resistance to the cam portion (cam groove) 341a of the cam member 341, As a result, the efficiency of the movement conversion can be increased.

In the fourth embodiment, the pair of annular seal members 331 and 332 for providing a liquid-tight seal between the piston 330 and the rotary shaft portion 321A of the axle hub 320 are spaced apart from each other by a predetermined distance in the axial direction, and are used The pair of seal members 314 and 315 that provide a liquid-tight seal between the rotary shaft portion 321A of the axle hub 320 and the cylindrical support portion 311 are spaced apart from each other by a predetermined distance in the axial direction. The oil chambers (annular spaces R1 and R2) sealed by the four sealing members 314, 315, 331 and 332 and containing a predetermined amount of working oil house the bearings 312 and 313, the cam member 341, the cam follower 342, the shaft 343, Roller 344, compression coil spring 345 etc. Therefore, lubrication of the sliding portion is ensured, so that the durability of the sliding portion can be improved.

In the fourth embodiment described above, the cam followers 342 are rotatably supported by the respective rollers 344 . However, as shown in FIG. 7, the fourth embodiment may be constructed as follows: a bearing 346 may be attached to each roller 344 so as to be interposed between the roller 344 and the corresponding cam follower 342, thereby rolling Respective cam followers 342 are supported. In this case, the bearing 346 can reduce the sliding resistance between the roller 344 and the corresponding cam follower 342, thereby improving the motion conversion efficiency. Also, a fourth embodiment may be that the shaft 343 extends through the rollers 344, ie the shaft (343) rollably supports the cam follower (342) without sandwiching the rollers (344) therebetween.

In the fourth embodiment described above, the cam portion (cam groove) 341a of the cam member 341 has two geometric periods along the circumferential direction of the rotating shaft portion 321A (when the rotating shaft portion 321A rotates once, the piston 330 reciprocates twice movement), and a pair of cam followers 342, that is, two cam followers 342 are engaged with the cam portion (cam groove) 341a. However, as in the case of the fifth embodiment shown in FIG. 8 , the fourth embodiment may be configured such that the cam portions (cam uneven surfaces) 441 a and 441 b of the respective cam ring plates 441A and 441B of the cam member 441 are along the The rotational circumferential portion 421A has four geometric periods in the circumferential direction, and is provided with a pair of cam followers 442A, that is, two cam followers 442A, which cooperate with the cam portion (cam concave-convex surface) 441a of the cam ring plate 441A; and A pair of cam followers 442B that cooperate with the cam portion (cam uneven surface) 441b of the cam ring plate 441B, that is, two cam followers 442B.

In the pressure generating device AP5 of the fifth embodiment shown in FIG. 8, the piston 430 has a pair of holes consisting of an upper through hole 430b1 and a lower through hole 430b2, which are slightly deviated from each other in the axial direction of the piston 430, and Its axis intersects the axis of the piston 430 . The cam member 441 is constituted by a pair of cam ring plates 441A and 441B which are spaced apart from each other by a predetermined distance in the axial direction. The cam member 441 is integrally attached to the cylinder support portion 411 (in an axially non-movable manner and in a non-rotatable manner), and is arranged coaxially with the rotation shaft portion 421A.

The upper cam follower 442A is a forward-moving cam follower (roller) for moving the piston 430 forward (downward), and the upper cam follower 442A is rotatably attached to each of the upper shaft 443A. Small-diameter end portion, the upper shaft 443A extends through the through hole 430b1 of the piston 430, and extends through the axially elongated hole 421a of the rotary shaft portion 421A, thereby allowing its axial movement to be guided. The upper cam follower 442A is rollably engaged with the cam portion (cam uneven surface) 441a of the upper cam ring plate 441A.

The lower cam follower 442B is a backward movement cam follower (roller) for moving the piston 430 backward (upward), and the lower cam follower 442B is rotatably attached to each small shaft of the lower shaft 443B. Diameter end portion, the lower shaft 443B extends through the through hole 430b2 of the piston 430, and extends through the axially elongated hole 421a of the rotary shaft portion 421A, thereby allowing its axial movement to be guided. The lower cam follower 442B is rollably engaged with the cam portion (cam uneven surface) 441b of the lower cam ring plate 441B.

In the fifth embodiment, an upper cam follower (forward movement cam follower) 442A and a lower cam follower (backward movement cam follower) 442B are divided at equal intervals in the circumferential direction of the rotation shaft portion 421A. The spaces are arranged alternately with each other. The upper shaft 443A and the lower shaft 443B abut against each other in a crossing manner at their intermediate regions, whereby the upper cam follower 442A is pressed against the cam portion (cam uneven surface) 441a of the upper cam ring plate 441A, and the lower cam The follower 442B is pressed against the cam portion (cam uneven surface) 441b of the lower cam ring plate 441B.

The structural features of the fifth embodiment other than the above (structural features other than those of the piston 430 and the cam ring plates 441A, 441B and cam followers 442A, 442B of the cam member 441 ) are the same as those of the fourth embodiment described above. are similar, and thus denoted by similar reference numerals beginning with 4, and descriptions thereof are omitted. In the fifth embodiment, the upper shaft 443A and the lower shaft 443B abut against each other at their intermediate regions, thereby pressing the cam followers 442A and 442B against the cam portions (cam uneven surfaces) 441a and 441b, respectively; therefore, omitting The equivalent of the compression coil spring 345 of the fourth embodiment is shown.

In the pressure generating device AP5 of the fifth embodiment thus configured, when the axle hub 420 rotates relative to the cylindrical support portion 411, the piston 430, the shafts 443A and 443B, and the cam followers 442A and 442B follow the axle hub 420 as a whole. Rotate, and perform relative rotation with respect to the cam member 441, thereby moving axially. Accordingly, the rotational motion of the axle hub 420 may be converted into a reciprocating motion of the piston 430 . The reciprocating motion of the piston 430 can increase and decrease the volume of the pump chamber Ro. Then, air can be introduced into the pump chamber Ro through the suction passage 421d in which the suction check valve Vi is installed, and air can be discharged from the pump chamber Ro through the discharge passage 421e in which the discharge check valve Vo is installed. The exhausted air (pressurized air) may be supplied into a tire air chamber (not shown) of a wheel attached to the axle hub 420 .

In the pressure generating device AP5 of the fifth embodiment, the rotary shaft portion 421A of the axle hub 420 is rotatably supported in the cylindrical support portion 411 via bearings 412 and 413, and the piston 430 is integrally rotatable and capable of pivoting. It is coaxially attached to the rotation shaft portion 421A of the axle hub 420 in such a manner as to reciprocate (to perform a pumping action), thereby forming a pump chamber Ro exposed to the rotation shaft portion 421A. Therefore, not only the axle hub 420 does not require a weight for rotational balance, but also the pressure generating device AP5 can be compactly configured in the cylindrical support part 411, whereby the pressure generating device AP5 can be downsized.

In the fifth embodiment, since the shaft 443A and the shaft 443B press the cam followers 442A and 442B against the cam portions (cam concave-convex surfaces) 441a and 441b, respectively, the backlash (playback) in the axial direction of the piston 430 can be suppressed. ), otherwise, the gap may appear between the cam followers 442A and 442B and the respective cam portions (cam uneven surfaces) 441a and 441b. Accordingly, motion conversion loss, which would otherwise be caused by the aforementioned gap, can be suppressed, whereby motion conversion efficiency can be improved.

In the fifth embodiment, the rotation shaft portion 421A has an axially elongated hole 421a for guiding the cam followers 442A and 442B so that these members can rotate integrally with the rotation shaft portion 421A and can axially reciprocate, And the piston 430 is attached to the rotation shaft portion 421A in an integrally rotatable manner and in an axially reciprocable manner. Therefore, no torque is applied to the annular seal members 431 and 432 interposed between the piston 430 and the rotary shaft portion 421A, and thus the durability of the annular seal members 431 and 432 can be improved.

In the fifth embodiment, the cam followers 442A and 442B are rollers that are rollably engaged with the respective cam portions (cam uneven surfaces) 441a and 441b. Therefore, the sliding resistance of the cam followers 442A and 442B against the respective cam portions (cam concave-convex surfaces) 441a and 441b can be reduced, whereby the efficiency of motion conversion can be improved.

In the fifth embodiment, the pair of annular seal members 431 and 432 for providing a liquid-tight seal between the piston 430 and the rotary shaft portion 421A of the axle hub 420 are spaced apart from each other by a predetermined distance in the axial direction, and are used The pair of annular seal members 414 and 415 that provide a liquid-tight seal between the rotation shaft portion 421A and the cylindrical support portion 411 are spaced apart from each other by a predetermined distance in the axial direction. The oil chambers (annular spaces R1 and R2) sealed by the four seal members 414, 415, 431 and 432 and containing a predetermined amount of working oil house the bearings 412 and 413, the cam member 441, the cam followers 442A and 442B, the shaft 443A and 443B etc. Therefore, lubrication of the sliding portion is ensured, so that the durability of the sliding portion can be improved.

Claims (20)

1. pressure generation device comprises: rotating member, and it has via bearing and rotatably is supported on rotary shaft in the non-rotatable supporting member; Pump is inhaled member, and it is with can integrally rotated mode and inhale the described rotary shaft that the mode of action is attached to described rotating member can carry out pump, and and described rotary shaft collaborative between it, to form pump chamber; Conversion of motion mechanism is used for described rotating member is converted into the described pump suction action that described pump is inhaled member with respect to rotatablely moving of described supporting member; Suction path, it is formed in the described rotating member, and makes fluid can be incorporated in the described pump chamber; And vent pathway, it is formed in the described rotating member, and makes fluid to discharge from described pump chamber.

2. pressure generation device according to claim 1, wherein, described rotating member is the axle hub of vehicle; Described supporting member is the knuckle that rotatably supports described axle hub; And described fluid is an air.

3. pressure generation device according to claim 1 and 2, wherein, it is piston that described pump is inhaled member, described piston is with can integrally rotated mode and can reciprocating mode being fixed to described rotary shaft, and described conversion of motion mechanism is converted into the to-and-fro motion of described piston with described rotating member with respect to described the rotatablely moving of described supporting member.

4. pressure generation device according to claim 3, wherein, described rotary shaft has the cylinder lumen pore of coaxial formation, and described cylinder lumen pore can hold described piston along the mode of the axially reciprocating of described rotary shaft with described piston; Described piston has load transmission element, and described load transmission element can and can not extend through described rotary shaft along the mode that the sense of rotation of described rotary shaft is moved along the axial motion of described rotary shaft with it; And described conversion of motion mechanism comprises cam follower and cam member, and described cam follower is arranged on the place, outer end radially with respect to described piston of described load transmission element, and described cam member is attached to the inside of described supporting member.

5. pressure generation device according to claim 3, wherein, described piston forms cylinder, and with can integrally rotated mode and be attached to the periphery of described rotary shaft in mode that can axially reciprocating; Cylinder element places between described supporting member and the described rotary shaft, integrally is provided with described supporting member, and holds described piston in the mode that described piston can axially reciprocating; And described conversion of motion mechanism is arranged between described piston and the described cylinder element.

6. pressure generation device according to claim 3, wherein, described rotary shaft has the cylinder lumen pore, described cylinder lumen pore can hold described piston along the radially reciprocating mode of described rotary shaft with described piston, described conversion of motion mechanism comprises cam follower and druum cam, described cam follower be arranged on described piston from the outwards outstanding outer end of described cylinder lumen pore, described druum cam is attached to the inside of described supporting member.

7. pressure generation device according to claim 4, wherein, described cam member has cam path, and described cam follower is assembled in the described cam path.

8. pressure generation device according to claim 7, wherein, described cam path has camming surface, and described camming surface bears via thrust load and the radial load of described cam follower from described rotary shaft.

9. pressure generation device according to claim 8, wherein, described cam path has the V-arrangement cross section.

10. pressure generation device according to claim 7, wherein, the described cam follower that is assembled in the described cam path is a ball.

11. pressure generation device according to claim 4, wherein, described load transmission element is an axle, and described axle radially extends through described piston along described piston, and the axial motion of described axle is guided by the hole that is formed on the axial elongation in the described rotary shaft.

12. pressure generation device according to claim 11, wherein, described axle is divided into two parts in described piston, and places spring between described two-part radially to apply radially outer power to described two-part along described piston.

13. pressure generation device according to claim 11, wherein, roller places between the hole and described axle of described axial elongation, and along with the axial motion of described axle along described rotary shaft, described roller rolls along the hole of described axial elongation.

14. pressure generation device according to claim 13, wherein, described roller has the bearing that rollably supports described cam follower.

15. pressure generation device according to claim 4, wherein, described cam member makes that described cam follower can be with the how much cycle axially reciprocatings of circumferential even number along described rotating member, and described cam follower quantitatively is configured to equate with the quantity in described how much cycles.

16. pressure generation device according to claim 15, wherein, described cam member comprises travel forward cam and motion cam backward, described travel forward cam and described motion cam backward described rotary shaft axially on the predetermined distance that is spaced apart from each other; Described cam follower comprises the follower of motion cam backward that travels forward cam follower and cooperate with described motion cam backward that cooperates with the described cam that travels forward; For the quantity in described how much cycles of even number is 4; Described cam follower and the described follower of motion cam backward of travelling forward alternately arranged each other with the interval that circumferentially equates.

17. pressure generation device according to claim 16, wherein, described cam and the described motion cam backward of travelling forward is respectively the cam ring flat-plate; Described cam follower and the described follower of motion cam backward of travelling forward is respectively roller; And described roller rollably cooperates with each cam ring flat-plate.

18. pressure generation device according to claim 1 and 2, wherein, described rotary shaft is rotatably supported by described supporting member via the clutch shaft bearing and second bearing, described clutch shaft bearing and the described second bearing predetermined distance that is spaced apart from each other in the axial direction.

19. pressure generation device according to claim 18, wherein, described conversion of motion mechanism places between described clutch shaft bearing and described second bearing.

20. pressure generation device according to claim 19, wherein, be used to seal first sealing component of described first and second bearings and second sealing component mode, place between described rotary shaft and the described supporting member in the axial direction described conversion of motion mechanism and described first and second bearings are clipped in the middle.

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