JP2005325946A - Tripod type constant velocity universal joint - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To improve collapse strength of a deep groove ball bearing used in a tripod type constant velocity universal joint. <P>SOLUTION: This tripot type constant velocity universal joint is, as shown in Fig. (A), formed to satisfy the relationship expressed by:2.4<ä(D-d)/2}/dB, 2.5<(W/d<SB>B</SB>), and 1.2<äD/(PCD+d<SB>B</SB>)} where the outer ring outside diameter of the deep groove ball bearing is D, the inner ring inside diameter is (d), the bearing width is W, the ball diameter is d<SB>B</SB>, and the pitch circle diameter of the ball is PCD, whereby as compared with a standard bearing (a deep groove ball bearing used in the conventional tripod type constant velocity universal joint shown in Fig. (B)), the wall thicknesses of the outer ring 6a and the inner ring 6b are secured to improve the collapse strength. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a tripod type constant velocity universal joint.

  An example of a conventional tripod type constant velocity universal joint will be described with reference to FIG. In FIG. 1A, reference numeral 1 is an outer joint member, and three track grooves 2 are formed in the axial direction of the inner peripheral surface. Each track groove 2 is formed with a pair of guide surfaces 3 facing the circumferential direction of the outer joint member 1. The pair of guide surfaces 3 are concave curved surfaces (partial cylindrical surfaces) parallel to the axis of the outer joint member 1. Reference numeral 4 is a tripod member, and three leg shafts 5 project in the radial direction. A deep groove ball bearing 6 is fitted on each leg shaft 5.

  As shown in FIG. 1A, the deep groove ball bearing 6 has an outer peripheral surface formed in a convex curved surface (partial cylindrical surface) corresponding to the guide surface 3 of the outer joint member 1, and the track of the outer joint member 1. An outer ring 6a to be inserted into the groove 2, an inner ring 6b that is externally fitted to the leg shaft 5 of the tripod member 4 and rotatably supports the outer ring 6a, and a plurality of balls 6c interposed between the outer ring 6a and the inner ring 6b. Main components (see, for example, Patent Documents 1 to 4).

  The above-mentioned tripod type constant velocity universal joint is a deep groove ball bearing in which the tripod member 4 is inserted inside the outer joint member 1 and is externally fitted to the track shaft 2 of the outer joint member 1 on the leg shaft 5 of the tripod member 4. 6 is engaged, and torque can be transmitted with a relative axial displacement (operation angle) between the outer joint member 1 and the tripod member 4. As shown in FIG. 1 (B), when a torque is applied with a relative axial displacement (operating angle θ) between the outer joint member 1 and the tripod member 4, each deep groove ball bearing 6 has an outer ring 6a. Is reciprocated along the track groove 2 in the axial direction of the outer joint member 1. At this time, since torque is transmitted between the outer joint member 1 and the tripod member 4 via the deep groove ball bearing 6, a radial load is applied to the deep groove ball bearing 6. In particular, in the case of a tripod type constant velocity universal joint used for transmission of high torque in automobiles, industrial machines, etc., when an excessive radial load is applied to the deep groove ball bearing 6, the outer ring 6a and the inner ring 6b Has been confirmed by experiments. Therefore, it is necessary to use a deep groove ball bearing with increased strength against the radial load for a tripod type constant velocity universal joint for high torque transmission. According to the strength analysis by FEM, the maximum principal stress when the outer ring 6a and the inner ring 6b are broken is generated in the area indicated by the small pitch hatching in FIG.

  On the other hand, Patent Document 5 (Japanese Patent Laid-Open No. 11-132231) defines the dimensional relationship of bearing components in order to improve the outer ring crushing strength of the slide groove deep groove ball bearing. However, since the deep groove ball bearing 6 used for the tripod type constant velocity universal joint for high torque transmission is loaded with a larger radial load than the above-mentioned deep groove ball bearing for slide seat, the bearing defined in Patent Document 5 is used. The strength of the outer ring 6a and the inner ring 6b is insufficient with the dimensions of the constituent elements.

JP 2000-227124 A Japanese Patent Application Laid-Open No. 2000-257643 JP 2001-295855 A JP 2002-323060 A JP-A-11-132231

  The present invention was devised in view of such circumstances, and its object is to provide a deep groove ball bearing with improved radial load resistance in a tripod type constant velocity universal joint used in, for example, automobiles and industrial machines. Is to provide a tripod type constant velocity universal joint suitable for high torque transmission.

In order to achieve the above object, a tripod type constant velocity universal joint according to the present invention has an outer joint member in which three track grooves extending in the axial direction are formed on the inner peripheral surface, and three legs in the radial direction. A tripod member protruding from the shaft and inserted inside the outer joint member, and an outer ring inserted into the track groove of the outer joint member and an inner ring rotatably supporting the outer ring on the leg shaft of the tripod member. Fitted with a deep groove ball bearing with a plurality of balls interposed between the raceway surface of the outer ring and the raceway surface of the inner ring, and moves the deep groove ball bearing along the track groove of the outer joint member while rotating the outer ring. In the tripod type constant velocity universal joint configured so that the outer ring outer diameter (D), inner ring inner diameter (d) and ball diameter (d _B ) of the deep groove ball bearing are 2.4 <{(D−d) / 2} / are characterized by d is _B.

The outer ring outer diameter (D) of the deep groove ball bearing is determined so that the outer ring fits in the track groove of the outer joint member, and the inner ring inner diameter (d) is determined so that the inner ring can be fitted on the leg shaft of the tripod member. It is done. Therefore, the ball diameter (d _B ) of the deep groove ball bearing is a value less than 1/4 of {(D−d) / 2} (d _B <{(D−d) / 2} / 2). .4). Here, {(D−d) / 2} is the dimension of the bearing wall thickness from the inner periphery of the inner ring to the outer periphery of the outer ring. On the other hand, in the case of a general deep groove ball bearing (hereinafter referred to as a standard bearing) used in a conventional tripod type constant velocity universal joint, the outer ring outer diameter (D), inner ring inner diameter (d) and ball diameter (d _B The relationship of ') is 1.57 <({(D−d) / 2} / d _B ′) <2.1. That is, the ball diameter (d _B ′) of the standard bearing is ({(D−d) / 2} /2.1) <d _B ′ <({(D−d) / 2} /1.57). Within range. If the standard of the outer joint member and the tripod member of the tripod type constant velocity universal joint to be applied is the same for both the deep groove ball bearing and the standard bearing used in this tripod type constant velocity universal joint, the outer ring outer diameter (D ) And inner ring inner diameter (d) have the same dimensions. In other words, a deep groove ball bearing used in this tripod type constant velocity universal joint, if the same as the standard bearing bearing wall thickness {(D-d) / 2 }, the ball diameter than the standard bearing (d _B) is Therefore, the thickness of the outer ring and the inner ring is ensured, and the crushing strength of the outer ring and the inner ring is increased.

Further, the relation between the bearing width (W) and the ball diameter (d _B ) of the deep groove ball bearing is 2.5 <(W / d _B ). The bearing width (W) is determined so that the deep groove ball bearing fits in the track groove of the outer joint member. Therefore, the ball diameter (d _B ) is a dimension less than 1/2 of the bearing width (W) [d _B <(W / 2.5)]. On the other hand, in the case of a standard bearing, the relationship between the bearing width (W) and the ball diameter (d _B ′) is 1.26 <(W / d _B ′) <2.1. That is, the ball diameter (d _B ′) of the standard bearing is in the range of (W / 2.1) <d _B ′ <(W / 1.26). If both the deep groove ball bearing and standard bearing used in this tripod type constant velocity universal joint have the same specifications for the outer joint member and tripod member of the tripod type constant velocity universal joint, the bearing width (W) Have the same dimensions. In other words, a deep groove ball bearing used in this tripod type constant velocity universal joint as long as they have the same bearing width (W) is a standard bearing, since the ball diameter than the standard bearing (d _B) is small, the outer ring and the inner ring The wall thickness of the outer ring and the inner ring can be increased. If the upper limit of the ball diameter (d _B ) is set in relation to the bearing width (width), the maximum main stress generated in the region shown in FIG. 1C is relaxed, and the outer ring and the inner ring are less likely to be damaged. .

Further, the relationship between the outer ring outer diameter (D) of the deep groove ball bearing, the pitch circle diameter (PCD) of the ball, and the ball diameter (d _B ) is 1.2 <{D / (PCD + d _B )}. Here, (PCD + d _B ) is the inner diameter of the outer ring (hereinafter referred to as the groove bottom diameter) in the groove bottom portion of the annular ball groove formed in the circumferential direction on the raceway surface of the outer ring. That is, the groove bottom diameter (PCD + d _B ) of the outer ring is less than one-twelfth the outer ring outer diameter (D) [(PCD + d _B ) <(D / 1.2)]. On the other hand, in the case of a standard bearing, the relationship between the outer diameter of the outer ring (D), the pitch diameter of the ball (PCD ′) and the ball diameter (d _B ′) is 1.03 <D / (PCD ′ + d _B ′) <1. .19. That is, the groove bottom diameter (PCD ′ + d _B ′) of the outer ring of the standard bearing is within the range of (D / 1.19) <(PCD ′ + d _B ′) <(D / 1.03). If the standard of the outer joint member and the tripod member of the tripod type constant velocity universal joint to be applied is the same for both the deep groove ball bearing and the standard bearing used in this tripod type constant velocity universal joint, the outer ring outer diameter (D ) Have the same dimensions. That is, if the outer ring outer diameter (D) of the deep groove ball bearing used in the tripod type constant velocity universal joint is the same as that of the standard bearing, the groove bottom diameter (PCD + d _B ) of the outer ring is smaller than that of the standard bearing. The thickness of the outer ring at the groove bottom portion of the ball groove is ensured, and the crushing strength of the outer ring can be increased.

Each of the relational expressions 2.4 <{(D−d) / 2} / d _B , 2.5 <(W / d _B ), 1.2 <{D / (PCD + d _B )} Since it is obtained from the dimensional relationship when the maximum principal stress generated in the ball bearing is a predetermined value (threshold) or less, [{(D−d) / 2} / d _B ], (W / d _B ), respectively. ) And {D / (PCD + d _B )} are not shown. This upper limit value is limited by the fact that the deep groove ball bearing is interposed between the outer joint member and the tripod member and does not interfere with other parts (outer joint member, etc.). It is determined appropriately depending on the dimensional relationship with the member.

  According to the present invention, the dimensional relationship of the bearing components is determined so that the maximum principal stress generated in the outer ring and the inner ring of the deep groove ball bearing when torque is transmitted between the outer joint member and the tripod member is reduced. The crushing strength of the outer ring and the inner ring against a radial load is improved, and a tripod type constant velocity universal joint suitable for high torque transmission can be provided.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

The tripod type constant velocity universal joint according to the present invention includes an outer joint member 1, a tripod member 4, and a deep groove ball bearing 6, like the conventional tripod type constant velocity universal joint shown in FIG. The outer joint member 1 and the tripod member 4 are the same as those used for a conventional tripod type constant velocity universal joint. The deep groove ball bearing 6 includes an outer ring 6a, an inner ring 6b, and a plurality of balls 6c as main components, and the outer diameter (D) of the outer ring 6a, the inner diameter (d) of the inner ring 6b, the ball diameter (d _B ), and the bearing width. The relationship between (W) and the pitch circle diameter (PCD) of the ball is different from that of a standard bearing used in a conventional tripod constant velocity universal joint. Hereinafter, this difference will be mainly described.

  FIG. 2 (A) is a schematic sectional view in the axial direction showing an embodiment of a deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention, and FIG. 2 (B) is a conventional tripod type constant velocity universal. It is a schematic sectional drawing of the axial direction of the standard bearing applied to a coupling. 3A to 3C are diagrams illustrating a schematic cross section of the deep groove ball bearing shown in FIG. 2A in the direction perpendicular to the axis. In this embodiment, a deep groove ball bearing and a standard bearing in which eight balls 6c are arranged in a row in the circumferential direction will be described as an example.

As shown in FIG. 2A, the deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention includes an outer diameter (D) of the outer ring 6a, an inner diameter (d) of the inner ring 6b, and a diameter of the ball 6c ( d _B ), the bearing width (W), and the pitch circle diameter (PCD) of the balls 6c are configured to satisfy the following relational expressions (1) to (3).

・・・（１）

・・・（２）

・・・（３）

... (1)

... (2)

... (3)

As shown in FIG. 1A, the outer diameter (D) of the outer ring 6a, the inner diameter (d) of the inner ring 6b, and the bearing width (W) are such that the outer ring 6a is the guide surface 3 of the track groove 2 of the outer joint member 1. Since the inner ring 6b can be fitted onto the leg shaft 5 of the tripod member 4, the dimensions are determined by the standards of the outer joint member 1 and the tripod member 4. The leg shaft 5 of the tripod member 4 has, for example, an elliptical cross section as shown in FIG. 3A, and a collective cross sectional shape of two circles having different center positions O ₁ and O ₂ as shown in FIG. 3B. There are various cross-sectional shapes such as one having a cross-sectional shape of two ellipses having different center positions O ₁ and O ₂ as shown in FIG.

  Thus, since the values of the outer diameter (D) of the outer ring 6a, the inner diameter (d) of the inner ring 6b, and the bearing width (W) are determined by the standards of the outer joint member 1 and the tripod member 4, the above relational expression (1) to (3) can be regarded as constants. Accordingly, the above relational expressions (1) to (3) are transformed into the following expressions (1) 'to (3)'.

・・・（１）’

・・・（２）’

・・・（３）’

... (1) '

... (2) '

... (3) '

Here, {(D−d) / 2} in the expression (1) ′ is a dimension of the bearing wall thickness from the inner peripheral part of the inner ring 6b to the outer peripheral part of the outer ring 6a as shown in FIG. 2 (A). is there. Further, as shown in FIG. 2A, (PCD + d _B ) in the expression (3) ′ is the outer ring 6a at the groove bottom portion of the annular ball groove 6a2 formed in the circumferential direction on the raceway surface 6a1 of the outer ring 6a. The inner diameter (groove bottom diameter).

On the other hand, the standard bearing shown in FIG. 2B has an outer diameter (D) of the outer ring 6a, an inner diameter (d) of the inner ring 6b, a diameter (d _B ') of the ball 6c, a bearing width (W), and a pitch of the balls 6c. The circle diameter (PCD ′) is configured to satisfy the following relational expressions (4) to (6).

・・・（４）

・・・（５）

・・・（６）

... (4)

... (5)

... (6)

・・・（４）’

・・・（５）’

・・・（６）’ Similar to the deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention, the standard bearing has dimensions of the outer diameter (D) of the outer ring 6a, the inner diameter (d) of the inner ring 6b, and the bearing width (W). It is determined by the standards of the outer joint member 1 and the tripod member 4, and has the same dimensions as the deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention. Therefore, the above relational expressions (4) to (6) are transformed into the following expressions (4) ′ to (6) ′.

... (4) '

... (5) '

... (6) '

When the above relational expressions (1) ′ and (4) ′ and the above relational expressions (2) ′ and (5) ′ are compared, the deep groove ball bearing applied to the tripod constant velocity universal joint according to the present invention The diameter (d _B ) of the ball 6c is smaller than the diameter (d _B ′) of the ball 6c of the standard bearing. The above relational expressions (1) ′ and (4) ′ define the dimension range of the diameter (d _B ) (d _B ′) of the ball 6c in relation to the bearing thickness {(D−d) / 2}. Yes. Therefore, the deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention is equivalent to the standard bearing by which the diameter (d _B ) of the ball 6c is smaller than the diameter (d _B ′) of the ball 6c of the standard bearing. In addition, the thickness of the outer ring 6a and the inner ring 6b can be ensured. In addition, the above relational expressions (2) ′ and (5) ′ define the dimension range of the diameter (d _B ) (d _B ′) of the ball 6c in relation to the bearing width (W). Therefore, the deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention has a small pitch hatching region shown in FIG. 1C corresponding to the size of the ball 6c with respect to the bearing width (W). Can be relaxed more than the standard bearing. Thereby, the crushing strength of the outer ring 6a and the inner ring 6b can be increased.

Further, when the above relational expressions (3) ′ and (6) ′ are compared, the groove bottom diameter (PCD + d _B ) of the outer ring 6a of the deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention is standard. It becomes smaller than the groove bottom diameter (PCD ′ + d _B ′) of the outer ring 6a of the bearing. The above relational expressions (3) ′ and (6) ′ define the dimension range of the groove bottom diameter (PCD + d _B ) (PCD ′ + d _B ′) of the outer ring 6a in relation to the outer diameter (D) of the outer ring 6a. Yes. Therefore, the deep groove ball bearing applied to the tripod type constant velocity universal joint according to the present invention has the ball groove 6a2 corresponding to the size of the groove bottom diameter (PCD + d _B ) with respect to the outer diameter (D) of the outer ring 6a. The thickness of the outer ring 6a at the groove bottom portion can be ensured more than that of the standard bearing.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible. For example, in FIG. 2A, the tripod constant velocity universal joint according to the present invention. The outer diameter (D) of the outer ring 6a, the inner diameter (d) of the inner ring 6b, the diameter (d _B ) of the ball 6c, and the bearing width (W) satisfy the following relational expression (7). However, the following relational expression (8) may be satisfied.

・・・（７）

・・・（８）

... (7)

... (8)

  In the above embodiment, as shown in FIGS. 2A and 3A to 3C, eight balls 6c are arranged in a row between the outer ring 6a and the inner ring 6b. The number of 6c can be changed as appropriate.

(A) is a cross-sectional view in the direction perpendicular to the axis of a tripod type constant velocity universal joint, (B) is a cross sectional view in the axial direction of the tripod type constant velocity universal joint, and (C) is a tripod type constant velocity universal joint. It is a figure which shows the generation | occurrence | production area | region of the largest principal stress of a deep groove ball bearing with the fragmentary sectional view of the axial direction of a deep groove ball bearing for an application. (A) is an axial sectional view showing an embodiment of a deep groove ball bearing for a tripod type constant velocity universal joint according to the present invention, and (B) is a deep groove for a tripod type constant velocity universal joint of FIG. It is sectional drawing of the axial direction which shows an example of a standard bearing with the same application object as a ball bearing. (A) The figure thru | or (C) figure are sectional drawings of the axis orthogonal direction of the deep groove ball bearing for tripod type constant velocity universal joints.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Outer joint member 2 Track groove 3 Guide surface 4 Tripod member 5 Leg shaft 6 Deep groove ball bearing for tripod type constant velocity universal joint 6a Outer ring 6b Inner ring 6c Ball

Claims (3)

An outer joint member in which three track grooves extending in the axial direction are formed on the inner peripheral surface, and a tripod member projecting three leg shafts in the radial direction and inserted inside the outer joint member; The outer ring is inserted into the track groove of the outer joint member, and the inner ring that rotatably supports the outer ring is externally fitted to the leg shaft of the tripod member, and a plurality of balls are interposed between the raceway surface of the outer ring and the raceway surface of the inner ring. A tripod type constant velocity universal joint configured to move the deep groove ball bearing along the track groove of the outer joint member while rotating the outer ring.
The relationship between the outer ring outer diameter (D), inner ring inner diameter (d) and ball diameter (d _B ) of the deep groove ball bearing is 2.4 <{(D−d) / 2} / d _B. Tripod type constant velocity universal joint. The tripod constant velocity universal joint according to claim 1, wherein the relationship between the bearing width (W) and the ball diameter (d _B ) of the deep groove ball bearing is 2.5 <(W / d _B ). The relationship among the outer ring outer diameter (D), ball pitch circle diameter (PCD), and ball diameter (d _B ) of the deep groove ball bearing is 1.2 <{D / (PCD + d _B )}. Item 3. A tripod type constant velocity universal joint according to item 1 or 2.

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