1. Field of the Invention
The present invention relates to a wheel support bearing assembly having a sensor built therein, such as a rotation detector.
2. Description of the Prior Art
A wheel support bearing assembly having a sensor such as a rotation detector is well known in the art. An example of the prior art wheel support bearing assemblies of the type referred to above is shown in
The prior art wheel support bearing assembly shown in
In most cases, the pulsar ring 39 has a series of serrations formed on an outer peripheral surface thereof and has therefore a substantial thickness. Because of this, as shown in
In view of the foregoing, assemblage of the prior art wheel support bearing assembly of the structure discussed above is generally carried out, following the sequence of assembling steps shown in
(1) In the first place, as shown in
(2) A quantity of grease, that is a lubricant, is then applied to an outboard portion of the inner peripheral surface of the outer member 31, including the outboard rolling element 33, as shown in
(3) An annular outboard sealing member 37 is press-fitted into an outboard end of the outer member 31 from the outboard side as shown in
(4) The hub axle 32A is inserted into a bore of the outer member 31 from the outboard side as shown in
(5) The pulsar ring 39 is press-fitted onto an outer peripheral surface of the hub axle 32A from an inboard side, opposite to the outboard side, as shown in
(6) After the press-fitting of the pulsar ring 39, the inboard rolling elements 33 retained by an inboard roller retainer 36 are inserted into the other of the outer raceways 35, which is positioned on the inboard side, as shown in
(7) A quantity of grease is then applied to an inboard portion of the inner peripheral surface of the outer member 31, including the inboard rolling elements 33, as shown in
(8) The inner race 32B is subsequently press-fitted onto the inboard end of the hub axle 32A from the inboard side until the retained rolling elements 33 on the inboard side are seated on the inner raceway 35 defined in the inner race 32B, as shown in
(9) Finally, an annular inboard sealing member 38 is thereafter press-fitted into an inboard end of the outer member 31 from the inboard side as shown in
As discussed above, the prior art wheel support bearing assembly of the above structure requires a relatively large number of assembling steps, accompanied by increase of the assembling cost. Also, when the pulsar ring 39 is press-fitted onto the hub axle 32A as shown in
In view of the foregoing, an object of the present invention is to provide an improved wheel support bearing assembly which, even though a ring-shaped element to be detected is mounted on an inner member and positioned generally intermediate between inner raceways formed on the inner member, can be assembled with a minimized number of assembling steps and, hence, at a reduced cost, and in which not only can damage occurring during the press-fitting of the ring-shaped element be easily detected, but also dusts and dirt generated during the press-fitting of the ring-shaped element can also be removed.
In order to accomplish these objects of the present invention, there is provided a wheel support bearing assembly, which includes an outer member having an inner peripheral surface formed with a plurality of, for example, two, outer raceways, an inner member positioned inside the outer member, with an annular bearing space defined between it and the outer member, and having inner raceways formed therein in alignment with the respective outer raceways, and outboard and inboard rows of rolling elements rollingly accommodated within the annular bearing space and sandwiched between the outer raceways and the inner raceways, respectively. The inner member is made up of a hub axle, which has a radially outwardly extending hub flange formed therein for securement of a vehicle wheel thereto, and a raceway forming member mounted fixedly on an inboard end of the hub axle. The inner raceways are formed on an outer peripheral surface of the hub axle and an outer peripheral surface of the raceway forming member, respectively.
The wheel support bearing assembly also includes a ring-shaped element to be detected (or a ring-shaped to-be-detected element, as hereinafter used) mounted fixedly on a portion of the inner member between the inner raceways and a sensor, for detecting the to-be-detected element, fixedly mounted on a corresponding portion of the outer member between the outer raceways. The ring-shaped to-be-detected element has an outer diameter smaller than the diameter of the circle inscribed by the row of the rolling elements assembled into the outer raceway in the outer member.
According to the present invention, the outer diameter of the ring-shaped to-be-detected element is smaller than the diameter of the circle inscribed by the row of the rolling elements. Accordingly, the hub axle having the ring-shaped to-be-detected element mounted thereon can be inserted into a bore of the outer member having the rows of the rolling elements incorporated therein. Hence, as compared with the assemblage of the prior art wheel support bearing assembly discussed hereinbefore, the number of assembling steps can advantageously be reduced, which leads to reduction in number of assembling facilities and the man-hour, resulting in reduction of the manufacturing cost.
Also, since the ring-shaped to-be-detected element is press-fitted onto the hub axle prior to the incorporation of the hub axle into the bore of the outer member, any damage to the ring-shaped to-be-detected element such as cracking and/or deformation, which would otherwise occur during the press-fitting of the ring-shaped to-be-detected element, can easily be detected. Similarly, dusts and dirt generated during the press-fitting of the ring-shaped to-be-detected element can also be removed.
In a preferred embodiment of the present invention, the ring-shaped to-be-detected element may comprise a pulsar ring having a magnetic characteristic varying in a direction circumferentially thereof and the sensor referred to above may be a magnetic sensor. The pulsar ring and the magnetic sensor cooperate with each other to define a rotation detector.
According to this feature, the magnetic sensor detects change in magnetic characteristic of the pulsar ring then rotating together with the inner member to detect the rotation of a wheel.
In another preferred embodiment of the present invention, the ring-shaped to-be-detected element may be made of a magnetostrictive material, in which case the sensor may comprise a torque detecting element for detecting a torque, working on the inner member, by detecting change in magnetic characteristic of the ring-shaped to-be-detected element. This feature is effective to allow the torque acting on the inner member then supporting the vehicle wheel to be detected.
In a further preferred embodiment of the present invention, the raceway forming member may be an inner race which, for example, forms a dedicated member for defining the inner raceway.
Also, in the practice of the present invention, the raceway forming member may be an outer race of a constant velocity universal joint. In this case, the inner member may be of a structure, in which a shaft portion of the outer race of the constant speed universal joint is press-fitted into the bore of the hub axle, with the inner raceways defined in an outer peripheral surface of the hub axle and an outer peripheral surface of a base end of the shaft portion of the outer race of the constant speed universal joint, respectively.
Regardless of whether the raceway forming member is the inner race, or the outer race of the constant speed universal joint, the ring-shaped to-be-detected element can have its outer diameter that is smaller than the diameter of the circle inscribed by the row of the rolling elements incorporated in the outer member.
Other features of the present invention will become clear from the following detailed description.
In any event, the present invention will become more clearly understood from the following description of preferred embodiments thereof, when taken in conjunction with the accompanying drawings. However, the embodiments and the drawings are given only for the purpose of illustration and explanation, and are not to be taken as limiting the scope of the present invention in any way whatsoever, which scope is to be determined by the appended claims. In the accompanying drawings, like reference numerals are used to denote like parts throughout the several views, and:
A wheel support bearing assembly according to a first preferred embodiment of the present invention will be described in detail with particular reference to FIGS. 1 to 5C. The wheel support bearing assembly shown therein is of an inner race rotating type of a third generation and is shown as utilized to support a vehicle drive wheel.
As shown in
The annular bearing space delimited between the inner and outer members 1 and 2 has inboard and outboard open ends opposite to each other, which are sealed by respective contact type sealing members 7 and 8 in any suitable manner known to those skilled in the art.
The outer member 1 is a single unitary component, which is fitted to a vehicle body structure (not shown) and serves as a stationary member. On the other hand, the inner member 2 serves as a member rotatable relative to the outer member 1 and is made up of a hub axle 2A, which has a radially outwardly extending hub flange 2a formed therein for securement of a vehicle wheel thereto, and a raceway forming member 2B mounted fixedly on an inboard end of the hub axle 2A.
Because of the inner member 2 being of the two component construction, the first inner raceway 5 is formed on an outer peripheral surface of the hub axle 2A, whereas the second inner raceway 5 is formed on an outer peripheral surface of the raceway forming member 2B. The raceway forming member 2B is an inner race dedicated for defining the second inner raceway 5. The hub axle 2A has an axial bore defined therein, into which a shaft portion 12b of an outer race 12 of a constant velocity universal joint is inserted and splined to the hub axle 2A for rotation together therewith.
The joint outer race 12 is of one-piece construction including a cup 12a and the shaft portion 12b extending axially from a bottom of the cup 12. The shaft portion 12b is inserted into the axial bore of the hub axle 2A and is fixed thereto by means of a nut member 13 fastened to a free end of the shaft portion 12b. A large diameter base end 12ba of the outer race 12, continued to the cup 12a, is brought into tight contact with an annular inboard end face of the raceway forming member (inner race) 2B, to render the raceway forming member 2B to be axially immovable relative to the hub axle 2A. The hub flange 2a is formed on an outboard end of the hub axle 2a and the vehicle wheel is secured through a brake rotor (not shown) to the hub flange 2a by means of a plurality of bolts 20.
The wheel support bearing assembly also includes a ring-shaped to-be-detected element 9 mounted fixedly on a portion of the inner member 2 between the first and second inner raceways 5. In this first embodiment, the ring-shaped to-be-detected element 9 is mounted on a portion of the outer peripheral surface of the hub axle 2A, which is radially stepped down as at 2b from the outboard first raceway 5 adjacent the hub flange 2a. The portion 2b has an outer diameter smaller than that of the outboard first raceway 5. The inboard end of the hub axle 2A, where the raceway forming member 2B is fixedly mounted, is radially stepped down from the first mounting portion 2b to define a second mounting portion 2c of an outer diameter smaller than that of the first mounting portion 2b.
The ring-shaped to-be-detected element 9 is in the form of a pulsar ring having a magnetic characteristic varying in a direction circumferentially thereof as shown in
A sensor 10 is mounted on a portion of the inner peripheral surface of the outer member 1 between the first and second outer raceways 4 for detecting the ring-shaped to-be-detected element 9. This sensor 10 is employed in the form of a magnetic sensor such as a Hall element. A combination of the ring-shaped to-be-detected element 9 and the sensor 10 defines a rotation detector 11 for detecting the number of revolutions of the inner member 2 and, hence, that of the vehicle wheel. As shown in
The wheel support bearing assembly of the structure described hereinabove is assembled in the following sequence, which will be described with particular reference to
(1) In the first place, as shown in
(2) The rolling elements 3 retained by the respective roller retainers 6 are then inserted into the first and second outer raceways 4 of the outer member 1, respectively, as shown in
(3) A quantity of grease is applied to outboard and inboard end portions of the inner peripheral surface of the outer member, as shown in
(4) The outboard sealing member 7 is subsequently press-fitted into an outboard open end of the outer member 1 as shown in
(5) The hub axle 2A having the ring-shaped to-be-detected element 9 is inserted into the bore of the outer member 1 from the outboard side until the outboard first inner raceway 5 is held in position to receive the outboard row of the rolling element 3 as shown in
(6) Thereafter, the raceway forming member (inner race) 2B is press-fitted onto the second mounting portion 2c of the hub axle 2A as shown in
(7) Finally, the inboard sealing member 8 is press-fitted into an inboard open end of the outer member 1 to seal the inboard open end of the annular bearing space.
In the wheel support bearing assembly so assembled in the manner described above, since the outer diameter B of the ring-shaped to-be-detected element (the pulsar ring) 9 is, as shown in
Accordingly, as compared with the assemblage of the prior art wheel support bearing assembly, the number of assembling steps can be reduced by 2 steps. As a result, the number of assembling facilities and the man-hour can advantageously be reduced, resulting in reduction of the manufacturing cost. Also, since the ring-shaped to-be-detected element 9 is press-fitted on the hub axle 2A prior to the hub axle 2A being inserted into the bore of the outer member 1, any damage to the element 9 such as cracking and/or deformation, which would otherwise occur during the press-fitting of the element 9, can easily be detected. Similarly, dusts and dirt generated during the press-fitting of the element 9 can also be removed easily.
Other structural features of the wheel support bearing assembly of the second embodiment are substantially similar to those of the wheel support bearing assembly of the first embodiment and, therefore, the details thereof are not reiterated for the sake of brevity.
The wheel support bearing assembly according to a third preferred embodiment of the present invention is shown in
Other structural features of the wheel support bearing assembly of the third embodiment are substantially similar to those of the wheel support bearing assembly of the first embodiment and, therefore, the details thereof are not reiterated for the sake of brevity.
Referring now to
Other structural features of the wheel support bearing assembly of the fourth embodiment are substantially similar to those of the wheel support bearing assembly of the first embodiment and, therefore, the details thereof are not reiterated for the sake of brevity.
The wheel support bearing assembly according to a fifth preferred embodiment of the present invention is shown in
Other structural features of the wheel support bearing assembly of the fifth embodiment are substantially similar to those of the wheel support bearing assembly of the fourth embodiment and, therefore, the details thereof are not reiterated for the sake of brevity.
In a sixth preferred embodiment of the present invention shown in
Other structural features of the wheel support bearing assembly of the sixth embodiment are substantially similar to those of the wheel support bearing assembly of the fourth embodiment and, therefore, the details thereof are not reiterated for the sake of brevity.
In a seventh preferred embodiment of the present invention shown in
Other structural features of the wheel support bearing assembly of the seventh embodiment are substantially similar to those of the wheel support bearing assembly of the first embodiment and, therefore, the details thereof are not reiterated for the sake of brevity.
Even when the outer race 12 of the constant speed universal joint concurrently serves as a raceway forming member where the inboard raceway groove 5 is formed, as is the case with the first embodiment using the raceway forming member 2B, the assemblability can be increased by making the outer diameter of the ring-shaped to-be-detected element 9 smaller than the diameter of the circle inscribed by the outboard row of the rolling elements 3.
In any one of the foregoing embodiments of the present invention, the ring-shaped to-be-detected element 9 has been described as a pulsar ring utilized for the detection of the rotation, but it may be utilized for the detection of, for example, a load, torque or strain.
By way of example, as shown in
Also, in the first embodiment of the present invention shown in
Although the present invention has been fully described in connection with the preferred embodiments thereof with reference to the accompanying drawings which are used only for the purpose of illustration, those skilled in the art will readily conceive numerous changes and modifications within the framework of obviousness upon the reading of the specification herein presented of the present invention. Accordingly, such changes and modifications are, unless they depart from the scope of the present invention as delivered from the claims annexed hereto, to be construed as included therein.
Number | Date | Country | Kind |
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2003-395353 | Nov 2003 | JP | national |